MadModder
Gallery, Projects and General => Project Logs => Topic started by: dbvandy on February 16, 2011, 12:36:17 AM
-
Now that I have put the Webster to rest, I am starting on the Otto from Jan Ridders plans. What a great guy! I have emailed back and forth with him and he has given me some good insight in his design process and reasoning. The plans arrived in my GMail box a few days ago, so off I go...
http://www.ridders.nu/Webpaginas/pagina_otto_viertactmotor/otto_frametekst_engels.htm
(http://farm6.static.flickr.com/5219/5464906199_efe193d112.jpg)
So far I have the cylinder, piston, and head cut and I am beginning to work on the valves... Afterword I will start on the uprights, shafts and 2 base plates. I have not decided on the fuel or ignition at this point, both can be determined after completion of the main engine. I have had very good success with the vapor carb, so I will probably go that route. For the ignition I am looking into the setup on the cheap little Chinese pocket bikes. It is a CDI system that you can get all the parts for for around $20 US.
Here is what I have so far: (I have altered Jans plans a bit by adding some cooling fins to the head and more fins to the cylinder)
(http://farm6.static.flickr.com/5292/5464905517_4b35ff822a.jpg)
The Cylinder is 2 inch x 2 inch 12L14 steel that I bored out (have not honed) and then I cut the fins with a 1/16 inch cut off tool skipping every thread on my lead screw. Worked really good until it snagged one time and stopped dead, thus breaking 3 teeth off the PLASTIC two speed transmission gears in the spindle (cheap Chinese lathe...) I have since replaced the gears with metal ones from LMS and do not plan on having to do that again. (one downside is that they are a bit noisy, but I hope that will wear in after running for a while...)
(http://farm6.static.flickr.com/5218/5465503676_85c84b1f22.jpg)
I tapped the head bolt holes to 6-32 for some stainless socket heads. I think they look better.
(http://farm6.static.flickr.com/5051/5465503840_31721d5364.jpg)
The head is 6061 T6 and is close to spec other than the fins and I am using an NGK CM-6 instead of making my own plug. I like to limit the points of failure as much as possible, these plugs should last 1000 times the life of the engine.
The underside of the head. The angle of the plug was changed to 20 degrees and could have been 25 for the shorter CM-6 NGK plug. Without a true mill, I had to use my poor mans mill and then clean it up with my dremel. The seat got a little wide and cut into the valve guide holes, but you will never see it when the guides are pressed in and the plug is capped.
(http://farm6.static.flickr.com/5098/5465503924_3db6727180.jpg)
The top of the head. I liked the cooling fins so much I decided to carry them up to the head. It will be functional and look good as well. I will have to cut the side back with my belt sander to clear the uprights.
(http://farm6.static.flickr.com/5293/5464905897_377a49aaf1.jpg)
Head and cylinder assembled.
(http://farm6.static.flickr.com/5091/5465503198_efbc30d1d5.jpg)
Head and cylinder assembled.
(http://farm6.static.flickr.com/5292/5465503298_4f4006628d.jpg)
Piston. I am going to use a viton o-ring to seal the piston. This worked VERY well in the Webster and I have a complete set from Harbor Freight.
(http://farm6.static.flickr.com/5292/5464905427_7a9c895b07.jpg)
more to come......
-
Hello Doug,
Wow! You have to be one of the fastest builders ever - the progress on the Otto is great. I liked your Webster build but am really looking forward to watching this one as that Ridders design was one I was thinking of doing.
Are you converting everything from metric to imperial or building to plan sizes? I really like the way you did the cooling fins on the cylinder. Can you provide more information on the ignition system - sounds like an ideal approach and good price.
Sorry for all the questions, but you are doing many things that I'd like to incorporate into my next engine.
Looking forward to watching this one.....
Best,
Mike
-
Those cylinder head cooling fins look quite large. Are you sure there is room for them ? They must come very close to the outer camshaft support pillar.
Dave
-
Wow, you do work fast Doug!
Never seen anybody build his otto so should be really interesting. I've not decided which I.c. to make as my first yet.
Do the cdi ignition systems need a battery. Guess the advantage is you can hide it all uunder the base and just have a little roller switch operated by the cam. You had good sucess with the magnet thing of the mini moto engine on the webster, any reason you're not going for that this time? What about Jan's piezo version? What puts you off that?
Thanks
Nick
-
Hi Doug, I'm truly impressed with the rapidity of your build. Can you put me in touch with Jan Ridder, as I would like to build one of these myself, and haven't figured out how to contact him. As to the CDI system, it is self contained, with a coil, and magnet on the flyweel to provide the drive current for the module, I have one on a weed eater engine. Great job so far, I'm looking forward to seeing it run. :nrocks: :poke: jack
-
I started the cylinder about 2 weeks ago... then broke the teeth on the transmission and had to order new bullet proof metal ones...
I am a private computer trainer and contractor, so I work on the engines when business is slow, which it always is in December and January... now that it is picking up, I will have to work at a more steady pace... (and still keep the little lady happy).
Jan is a SUPER nice guy! His email is jan.ridders@gmail.com, website http://heetgasmodelbouw.ridders.nu/index.htm. Just tell him what model of his you want to do and he will send off the plans to you. EVERYTHING is metric (great for most of you, but my American brain does not work that way) so I spend a lot of time switching back and forth... the model will be a mixture of both but will be just as shiny.
The fins will clear by about 1/8 of an inch on each side... I figure I can always put a flat on the sides if needed for clearance.
The CDI I am looking at will run on 6v, so a few AA's or a 6v power block should do it just fine. I might stay with the weedeater coil, but you have to have such high idle RPM (~1000) for a strong spark I think I might want to run the OTTO a bit slower. The CDI will do that and can all be hidden under the case. The really rewarding thing about designing on the fly is that if what you do does not work, you can try something else. Anyone can screw parts together from a kit of pre-machined parts and have a perfectly running engine, I prefer to re-purpose and adapt what I have laying around the shop.
Jan's piezo ignition uses a grill lighter that is not available in the states and I think the life span might be questionable. He sent me the pics of his design on the Atkinson engine and I think it would work but only at low RPM. Unlike Jan, I like to rev my engine until right before parts start flying off.
I have also been looking into using a hand held tazer for an ignition source... They put out a couple of million volts from a 9v battery and should be enough to drive a plug. Timing should be as easy as using a cherry switch to turn it on an off. I think I will order one off ebay tonight for 8 bucks and see if it is feasible.
Thanks for the kind words... more to come.
-
I worked a little on the engine on Tuesday and figured out how I am going to do the valves.
I'm using some 12L14 hex turned down to whatever drill I had that was close to 10mm for a press fit into the head.
(http://farm6.static.flickr.com/5291/5465504064_e140dc151f.jpg)
12L14 has very high lead content and should self lubricate as well as be very strong and wear well. It turns like butter as well...
(http://farm6.static.flickr.com/5253/5465504118_ce66681d34.jpg)
I have turned one and will work on the second and the two valves tomorrow. The key to getting a good seat is to set your compound up to 45 degrees and do not move it until all 4 parts are turned. You then have to center drill the guide and turn the seat in the same setup, then cut it off.
(http://farm6.static.flickr.com/5055/5464906065_8f9ec5e127.jpg)
More to come...
Doug
-
Didn't know you could buy tazers on ebay!
-
Hi Doug, thanks for putting in Jan Ridder's contact info, if you are looking for a CDI you can build, there's one available on http://www.siliconchip.com.au/cms/A_110499/article.html, which would give you the option of having a generator coil or battery, which ever you choose, and could be stand alone. I have one of those types on a small engine for a garden tiller, a very tiny tiller. Just a thought. I think I'm going to try Jan's use of the pietzo just because I've long wanted to. everything seems to be coming together there, and she ought to be running soon. Very nicely done. :nrocks: cheers, jack
-
Looking good. :D
-
Nice progress, dbvandy.
Unlike Jan, I like to rev my engine until right before parts start flying off.
Be warned, as that kind of engine isn't supposed to be fire-breathing beast. Even at 3000-4000 rpm, the engine may sound and look a lot more dangerous, than commercial, hi-tech engines at 10000 rpm.
Anyways, if you are going to rev it to the max, wear some bullet-proof jacket (http://emoticons4u.com/crazy/134.gif).
If I may suggest, try first some traditional solution for ignition. For example, motorcycle or automotive coil, and breaker points. Simpler the better. That way you can get reliable spark, and test the engine. When you get the engine to run smoothly, then you could test other ignition options.
-
Both valves are done now and ready to be pressed into the head... I'm quite pleased with how they turned out, great design, Jan.... (though I did alter them a bit just to make them mine and help it breath easier....)
I turned the valve between centers with a little extra nub on the head side that will be cut off. I have no idea what type of steel it is, it was shiny and came from some old printer. I turned the stem to be .0005 smaller than the bore in the guide. the second guide was a bit tighter after drilling, so I will turn the second valve down to match the second guide.
(http://farm6.static.flickr.com/5299/5472051777_e4e368dc35_z.jpg)
(http://farm6.static.flickr.com/5220/5465504504_f64963044e_z.jpg)
I precut the nub when it was still between centers, then chucked it up close very lightly and faced the head to size.
(http://farm6.static.flickr.com/5218/5465504576_1d2b1737a6_z.jpg)
Valve parts all turned are ready to be assembled. I used some e-clips I had in a kit. Springs are pre-made. I wound the ones for the Webster... done that... Ford does not wind their springs either... Notice that I cut a little relief into the stem where it will be out of the guide. This will give a little more room for the engine to breath without effecting strength.
(http://farm6.static.flickr.com/5053/5465504670_665b93f6a9_z.jpg)
Valve and guide assembled. I will seat the valves with valve grinding compound after they are mounted in the head and stable. There just enough play to allow the valve to seat after every cycle and the springs feel about right, not too stiff, not too soft.
(http://farm6.static.flickr.com/5092/5464906259_c8f65e9f25_z.jpg)
-
I have to admit, I have followed Jan's designs for a long time now and have come to the conclusion that not only are they very innovative, but by taking a little time over the quality of build, you usually end up with a nice running engine that looks really great when in operation.
He takes difficult designs and redesigns them so that almost anyone is able to get a running example.
I'm sure that by the care and attention you are paying to the build, you too will soon have one running.
Bogs
-
They look great Doug, the valves / seats seem to be a stumbling block for some people (or maybe that's just people that don't listen to advice of experienced people!)
Did you make the springs yourself or find some suitable ones?
Agree with Bogs, I've followed quite a few of Jan's builds and can always see where he's coming from. This one seems to be a steady runner, think he's only really having trouble with the last couple where he's trying to be really innovative. I must admit, I am tempted to do at least one of his engines as a starting point in i.c. - just not sure which one! Is the 2 stroke a cop out?!
Nick
-
Hello Doug,
You're really cooking on this build - looking great!
Two questions; you said you converted 'some' of the measurements to imperial from metric - any specific advise on doing this?
Assume you turned the valves between centers, hence the little extra pad that was subsequently parted off - is that correct?
I'm likely going to use this thread as an instruction manual if I build the Otto.
Thanks
Mike
-
Two questions; you said you converted 'some' of the measurements to imperial from metric - any specific advise on doing this?
Assume you turned the valves between centers, hence the little extra pad that was subsequently parted off - is that correct?
I only have fractional drills, so some of the measurements will be converted over... most are pretty close, but it will not effect the operation in the slightest. Also, all the bar stock and plate are in fractional measurements over here on the other side of the pond so it is tough to get a 10mm plate, but easy to get .375, etc... but I left the length of the valves 42mm and turned it using metric, but still do not have a good feel on the fly for close tolerances in metric (.002 clearance is what in metric, etc...) so I bump my digital DRO and calipers back and forth.
I did turn it between centers and then parted it with a hacksaw (I know, I know... I am very careful and go slow). The valves are MASSIVE in comparison to the Webster valves. One of the guide bores must have sucked through a chip when drilling it and was about .005 larger bore, so I just turned the valve stem to match (It's not like I could go down to Auto Zone to buy a replacement anyway...)
They look great Doug, the valves / seats seem to be a stumbling block for some people (or maybe that's just people that don't listen to advice of experienced people!)
Did you make the springs yourself or find some suitable ones?
Agree with Bogs, I've followed quite a few of Jan's builds and can always see where he's coming from. This one seems to be a steady runner, think he's only really having trouble with the last couple where he's trying to be really innovative. I must admit, I am tempted to do at least one of his engines as a starting point in i.c. - just not sure which one! Is the 2 stroke a cop out?!
Nick
I look at it like this: if it makes fumes and you learned along the way and you had some fun and maybe had to buy a new tool or two... then it is never a cop out. The valves are really easy to build, actually and only take a hour or so to knock out. The key is to keep the compound locked at 45 for all 4 surfaces, watch your tolerances and turn the guides and valve seats at the same time on the same setup. If you try to fix something later, you better just toss it and make another....
The springs are out of a kit of springs... I made them for the Webster from music wire... done that... and if I did not have the right ones I would have again... It was a bonus to have them pre-made...
Jan's designs are just like he describes them. Jewelery. The plans are well laid out and easy to follow and leave some room to personalize without sacrificing functionality. Some I just don't understand, like his split cylinder engine...I just don't get it... makes not logical sense to me... but still super cool and is in the queue to be built...
Thanks for the kind words... will be working on the base plates and uprights today... might just start looking like an engine soon...
Doug
-
Today was connecting rod and uprights day.... Wish I had a bigger band saw..... and a mill....
I blued up the connecting rod and cut it out with my band saw... the blade was a fine tooth and cut reeeaaalllyyyy slowly.
(http://farm6.static.flickr.com/5095/5464906729_7a0525c117_z.jpg)
I trued it up with my small belt sander and drilled out the holes. The bearing for the crank fits an old RC car drive line that I raced 15 years ago... nice to keep those old parts laying around, you never know.
(http://farm6.static.flickr.com/5299/5464906827_496f42e650_z.jpg)
I needed some cam shaft bearings... found some...
(http://farm6.static.flickr.com/5295/5465250705_942099fa82_z.jpg)
(http://farm6.static.flickr.com/5299/5464906631_0b6c453b04_z.jpg)
I blued and marked up the first upright. I will match the other two to this one so that they are uniform. I cut the upright out with an angle grinder and the roughed it to pretty damn close with the 4.5 inch hand grinder. The band saw was not up to it with the blade that was in it. Time for a trip to home depot for another...
(http://farm6.static.flickr.com/5259/5465505186_87f256fbac_z.jpg)
Then I got it really close with my 1x24 inch belt sander table. It is just cosmetics now, so I will wait until I start cleaning it up to get it perfect and polished.
(http://farm6.static.flickr.com/5100/5465505320_5161210d2f_z.jpg)
Two uprights cut...
(http://farm6.static.flickr.com/5294/5465505404_3c1834c1bc_z.jpg)
Starting to look like a motor... yea...
(http://farm6.static.flickr.com/5295/5465505502_f140d7953a_z.jpg)
Bearing holes to be drilled tomorrow...
More to come...
Doug
-
Looking fantastic. :bow: :bow: :bow:
-
Hi Doug, I'm following this one closely, just to watch what you do with conversions, as I will be doing very much the same very soon. It's looking good so far, moving right along and getting to the good parts. :nrocks: jack
-
Hi Doug, I'm following this one closely, just to watch what you do with conversions, as I will be doing very much the same very soon.
Jack, the only real conversions I am doing is when it come to drill sizes. The overall dimensions are super easy in metric so I am leaving them alone.
New band saw blade from Home Depot cuts like a hot knife... should go buy more...
(http://farm6.static.flickr.com/5297/5464908043_c19cf2f46a.jpg)
I received my 22mm drill bit in the mail so I was able to drill the bearing holes. I pre-drilled them with my unibit (love that thing) and then opened them up to 22 mm to match my high dollar skate bearings.
(http://farm6.static.flickr.com/5014/5464908265_33b5f934b9.jpg)
The 8mm shaft came from an ink jet old printer that I had laying around just waiting to become part of the Otto.
(http://farm6.static.flickr.com/5173/5465506168_fc394c3298_z.jpg)
After getting the bearings in, I pinned the uprights together with a part of the shaft and some tubing. Blacked them up and hit them with my belt sander to even them up to perfection.
(http://farm6.static.flickr.com/5297/5465506268_a612bc1c24.jpg)
(http://farm6.static.flickr.com/5095/5465505752_98cf18e2b8.jpg)
(http://farm6.static.flickr.com/5060/5465506330_43c80d1549_z.jpg)
Tomorrow (or later tonight maybe), I will start on laying out the base plates. Not quite sure how I am going to countersink the cylinder 5mm into the base plate (I do not have a rotary table... yet...) wish I had seen that earlier, I would have made the cylinder to mount flush and have a 5mm lip that is 2mm bigger than the bore to slide into a hole in the plate...
More to come...
Doug
-
Hi Doug :clap: :clap: :clap: :clap: :clap:
Your sure doing a fine job of building the engine :thumbup:
Rob
-
Hi Doug, nice job, coming right along, I guess I'd better get some skate bearings, they look cheaper than ordering them from a catalog. I will be doing a build soon, so you're getting me ready for it. I hope to follow you in using the metric numbers for most things, and converting only screws and such things as won't translate well in my shop to metric. Looking good :headbang: :poke: mad jack
-
yea, I like using 6-32 stainless socket heads. They are strong enough to hold things together and small enough to fit into most tight spaces.
I am at a cross roads now whether or not to move the center support over to give me more room for my massive head cooling fins and maybe a belt driven fan or to leave them "stock" and just grind off a few thou of the fins to fit the uprights.
I have already made the spacers between them and don't feel like making them again and moving the center support lessens my options for ignition.
It is a great engine to build and will look super when it is running and prettyfied....
Pics in the morning...
-
Hi Doug, just remember, if you leave the fins close enough to just touch, they will help bleed off heat into the structure, and be beneficial that way. I don't know if you've run across this or not, but those stainless allen bolts are not rated for strength, normally, unless they specifically state the standard, and generally have a grade two strength. I use them a lot because stainless is a poor heat conductor, but any bolt for strength ought to be a rated bolt or screw, black finished allens are generally grade eight or nine unless otherwise specified. I broke a #4-40 stainless head bolt on my oddball flame sucker, just unscrewing it, and had only used the short end of the wrench to tighten it, initially. I'm really looking forward to your success, as it will define my own direction to some degree. Glad to see a fine job going forward. :poke: jack
-
Hi Doug, just remember, if you leave the fins close enough to just touch, they will help bleed off heat into the structure, and be beneficial that way. I don't know if you've run across this or not, but those stainless allen bolts are not rated for strength, normally, unless they specifically state the standard, and generally have a grade two strength. I use them a lot because stainless is a poor heat conductor, but any bolt for strength ought to be a rated bolt or screw, black finished allens are generally grade eight or nine unless otherwise specified. I broke a #4-40 stainless head bolt on my oddball flame sucker, just unscrewing it, and had only used the short end of the wrench to tighten it, initially. I'm really looking forward to your success, as it will define my own direction to some degree. Glad to see a fine job going forward. :poke: jack
according to the mfg. these bolts are grade 3, so that should be far more than enough to hold these engines together. And most of the loads are not shear anyway, so they will be more than more enough... The Webster called for 4-40's and some 2-56's... I used the 4-40's on the intake block, but had enough meat to use the 6-32's everywhere else. I did use 1/4-20s in a few places like the flywheel and tank mount.
-
I got all three uprights made, bearings in and some 40mm plate spacers roughed out. Now it REALLY looks like and engine...
(http://farm6.static.flickr.com/5291/5465505816_b6658d6337.jpg)
(http://farm6.static.flickr.com/5056/5464907891_d1b990e95d.jpg)
(http://farm6.static.flickr.com/5100/5465505880_d7264dfc21.jpg)
More to come tonight... took Sunday off to go play...
Doug
-
Well, everything is mounted solid now and only a few things left to do. I might be making fumes this weekend...
I made a center line on all the uprights and one down the center line on the base plate, lined them up and transferred the holes in the uprights to the base plate. After the 3 back socket heads were in tight, I did the same for the front.
(http://farm6.static.flickr.com/5060/5467039051_cb078033e8_z.jpg)
(http://farm6.static.flickr.com/5012/5467636398_9b2c303633.jpg)
I had made the spacers for between the uprights last night and you can see them here. Also, the 4 corner post and tapped and mounted.
(http://farm6.static.flickr.com/5174/5467039141_b2f0776391.jpg)
The crank bearing mounts are marked with center lines as well and the hole locations are transferred from the base plates just like the uprights. I changed the design a bit here: the flywheel side is smaller so that I could mount the uprights from the bottom. This will not effect the operation in the slightest, but if I need to make alignment adjustments I can just oversize the holes in the base plate. The crank side is extra thick because that is what size stock I had in the drawer.
(http://farm6.static.flickr.com/5100/5467039201_6ec540e805_z.jpg)
I decided to drill and tap a hole into my drill press table as a pivot for the cylinder hole and a 3/8th 4 flute end mill to plunge the stock out. Worked pretty good. for those that are wondering... the chuck is heated and locktited on to the arbor. (I hope I never need to get it off.)
(http://farm6.static.flickr.com/5057/5467636546_7032fdab26.jpg)
The 1/4 -20 bolt was threaded through the table and then nylocked tight.
(http://farm6.static.flickr.com/5295/5467636574_0ece94b0d9.jpg)
Most of the stock was plunged out and then the base plate was spun to even the sides.
(http://farm6.static.flickr.com/5096/5467636628_a4c0bb4916_z.jpg)
Turned out pretty good... the hole was then drilled out with the unibit (still love that thing...)
(http://farm6.static.flickr.com/5292/5467039413_4c4682a613_z.jpg)
Here is where we are tonight.
(http://farm6.static.flickr.com/5300/5467636236_9645a5449a.jpg)
(http://farm6.static.flickr.com/5254/5467636288_50144cec39.jpg)
On the agenda for tomorrow: crank, cams, and intake/exhaust manifold...
more to come...
Doug
-
Absolutely flying along. Nice innovation cutting the large hole out.
It's a fair sized thing this one too ...
Nick
-
Well, finished the crank bearing blocks, crank, and cam blanks.
I cut the cams from 1 inch 4140. The OD is 24mm with a 17mm hub. I will cut the cam down to 20mm by removing the extra stock with the 4 inch belt sander down to the 20mm ledge I left on the hub side.
(http://farm6.static.flickr.com/5020/5473077136_c581a21c5d.jpg)
Both cams are 11.5mm which is the same distance as the valves are apart.
(http://farm6.static.flickr.com/5140/5473077238_4d2d3a3979.jpg)
The crank shaft is 8mm from an old Lexmark ink jet printer. I left it long so that I have options when it comes to the final flywheel design. I put 2 bearings on the crank side and one on the flywheel side with an aluminum spacer in between.
(http://farm6.static.flickr.com/5219/5473100572_2ae4d38708.jpg)
(http://farm6.static.flickr.com/5253/5473100606_20e67cd66c.jpg)
The holes have been drilled into the head for the intake and exhaust. The valve guides were high temp red loctited in (hope I never have to get them out). Tappets and guides to be made after cams are ground.
(http://farm6.static.flickr.com/5217/5473100644_117c6c5876.jpg)
As she sits tonight...
(http://farm6.static.flickr.com/5213/5472483757_089ce2bcfb.jpg)
left to do...
grind cams... Done
tappet holes and press in bronze bushings... Done
tappets... Done
Intake/exhaust manifold
muffler
flywheel (faceplate just arrived from LMS today)... 75% done
wrist pin in piston
mill slot in base plate for belt
design ignition system (got the tazer yesterday... don't think it will work, does not seem to recharge fast enough... bummer...)... 25% Done
design carb (have some really cool ideas....)
Belt and pulleys purchased from SDP/SI, should be here next week. I hated to spend the $$$$, but had to be done...
More to come....
-
It's looling amazing :bugeye:
-
left to do...
grind cams... Done
tappet holes and press in bronze bushings... Done
tappets... Done
Intake/exhaust manifold
muffler
flywheel (faceplate just arrived from LMS today)... 75% done
wrist pin in piston
mill slot in base plate for belt
design ignition system (got the tazer yesterday... don't think it will work, does not seem to recharge fast enough... bummer...)... 25% Done
design carb (have some really cool ideas....)
Good day today. Cams, tappets, flywheel, and part of the ignition done.
I blacked up the cam blanks and marked them as per the plans.
(http://farm6.static.flickr.com/5013/5475892648_9be63a32d2.jpg)
Then I used the 36x4 belt sander to sand off the extra stock down to the 20mm lip.
(http://farm6.static.flickr.com/5220/5475892718_e14cf209d9.jpg)
This is the finished intake cam. I will need to fine tune the timing once the belt is installed by grinding off more.
(http://farm6.static.flickr.com/5175/5475294989_ab51ea12fa.jpg)
I measured the actual distance from the upright to the valve stem. to my complete amazement, it was dead on... go figure... I then transferred those measurements to the cross brace so I could drill the 3/8 hole for the bushing.
(http://farm6.static.flickr.com/5097/5475892818_d4c07c2117.jpg)
(http://farm6.static.flickr.com/5298/5475295099_f0d5e9bf25.jpg)
The holes were drilled and then the bushings loctited in. I sanded them flat with the belt sander and counter sunk the bushings. The stock for the tappets is 1/4 inch stainless.
(http://farm6.static.flickr.com/5134/5475892920_4cd94f53e1.jpg)
(http://farm6.static.flickr.com/5052/5475892960_3a0306f612.jpg)
I then measured the distance between the cam and the top of the valve stem. Then made 2 tappets.
(http://farm6.static.flickr.com/5254/5475893016_6ac15b0d17.jpg)
Here is the finished cams and tappets.
(http://farm6.static.flickr.com/5092/5475295275_98fd5e2176_z.jpg)
(http://farm6.static.flickr.com/5213/5475893106_574e75950e.jpg)
(http://farm6.static.flickr.com/5220/5475893150_95e1cbbf8f_z.jpg)
Cams running:
I used the excel pie chart trick to divide the the flywheel into 6 parts for the lightning holes. AND I got to reuse my 1/4 hole in the drill press table as an axle to spin the flywheel on while drilling. I just took a piece of the 8mm shaft and threaded it 1/4-20. Worked well.
(http://farm6.static.flickr.com/5020/5475893178_eedeed40b9.jpg)
Here she sits tonight...
(http://farm6.static.flickr.com/5254/5475893212_c46bf1d8a2_z.jpg)
(http://farm6.static.flickr.com/5133/5475295491_21743b58f9_z.jpg)
(http://farm6.static.flickr.com/5015/5475892600_96dd8428f7_z.jpg)
Now off to bed... more to come...
Doug
-
dbvandy
You have got that baby looking pretty good. It won't be long now and it will be making some noise. :D :D
Cheers :beer:
Don
-
Very nice :bugeye:
-
Turns out very nicely :wave:.
Looking forward to see it run.
-
Belt an pulleys will be here Monday... still deciding on ignition... should make some fumes next week....
The roughness is bugging me more than anything, I want to start making it pretty!
Thanks for all the kind words.
Doug
-
Doug,
It looks brilliant that. I've never seen a close up of the valves moving up and down like that before. Was it just me or could you see the valves bouncing slightly? I'm not sure whether it'll have any bearing on how it runs? I was just sure I saw a gap sometimes between cam and follower. I know this problem sometimes occurs if revving an engine high, race prepared or high performance engines sometimes have dual springs. I'm going to use that great excel trick before I get some sort of dividing thingymbom. Also, it looks pretty already to me, not rough!
-
Nick,
You will find on most engines you have to have some sort of gap between the cam and what they are operating.
If you start a cold engine up with no gap, and by the time it has warmed up and expanded, the valves could in fact be held open or the valve timing all wrong. You usually set the 'tappets' up with a feeler gauge so that when the engine is up to running temp there is still a small gap to prevent the valves being held open and givng the correct valve timing.
John
-
Doug,
It looks brilliant that. I've never seen a close up of the valves moving up and down like that before. Was it just me or could you see the valves bouncing slightly? I'm not sure whether it'll have any bearing on how it runs? I was just sure I saw a gap sometimes between cam and follower. I know this problem sometimes occurs if revving an engine high, race prepared or high performance engines sometimes have dual springs. I'm going to use that great excel trick before I get some sort of dividing thingymbom. Also, it looks pretty already to me, not rough!
looking at the cam, it looks like at high revs the tappet is thrown up by the valve springs and rides along the cam relief for about 1/2 a rev, then settles down. The valves should not have enough mass to overcome the pressure of the springs as they are pretty stout.
I just bought one of these:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260731555933
I do not expect perfection, but it should work ok for what I am going to do with it.
Doug
-
Nick,
You will find on most engines you have to have some sort of gap between the cam and what they are operating.
If you start a cold engine up with no gap, and by the time it has warmed up and expanded, the valves could in fact be held open or the valve timing all wrong. You usually set the 'tappets' up with a feeler gauge so that when the engine is up to running temp there is still a small gap to prevent the valves being held open and givng the correct valve timing.
John
Correct. I guessed at .008 gap like every other car engine I have ever worked on (the plans said nothing about it). If it turns out to be too much, I can cut another tappet a bit longer. I toyed with the idea of an adjustable tappet, but they are so easy to make I decided against the extra effort.
Doug
-
Bogs,
Yeah good point, I know about the gaps - I remember setting them up on the older engines, turning the crank until each cam is at it's lowest lift then setting with the feeler gauge. Of course, most of the modern ones have these hydraulic tappets now which you just have to throw away when knackered instead of adjust!
I just thought it looked to me like the valves were bouncing at the bottom of their stroke with the inertia given to them by the cams. As you say though, this might change when warmed up. Not sure what speed you were spinning it at either. Should be ok, presume your springs are to the drawing Doug?
That rotary table looks like a good deal. I need to have a look at the Harrogate show, only trouble with going on the sat is, any bargains will probably have gone. At least I can go and have a play with them there though and get a feel for them
Nick
-
You don't get bargains any more Nick. If it is reduced, it is most probably cheap tat not worth looking at. All you are saving is the postage, and most of them are starting to do free anyway all the time.
At one time, you would get the VAT knocked off, but not any more. So I think you will be safe in the knowledge that what you want will be there.
John
-
You all must be living somewhere special, I don't remember giving up adjusting tappets, I still do on my bike, on my tractor and on my Mercedes too. It's good to see the progress, you're just about ready to fire it I expect. She's looking pretty good too. :beer: cheers, Jack
-
Great build Doug :clap:
-
Jack, I think the only cars that have solid followers here these days are stuff like BMW M3's etc, but you can't adjust those, you have to change 24 shims, hence why the servicing costs so much!!
John, that's good to know, will see what's on offer then. Can see me spending a lot of time around the machine DRO stand contemplating too!
Anyway sorry for going off topic Doug, can't wait for the next installment!
-
..Correct. I guessed at .008 gap like every other car engine I have ever worked on (the plans said nothing about it)...
In the notes for for the engine, referring to sheet six, Jan suggests 0.3 mm gap.
Dave.
-
..Correct. I guessed at .008 gap like every other car engine I have ever worked on (the plans said nothing about it)...
In the notes for for the engine, referring to sheet six, Jan suggests 0.3 mm gap.
Dave.
Guess I should read the notes at some point during the build.....
Doug
-
Well... its been a few days since I have uploaded some pics, so, here you go...
Let me first start off with a video of how you should listen to that little voice in your head when it says.. "be ready to grab it if something happens"
All is well... camera fine, engine fine... clamp not fine, extra tight now....
Anyway, I got the piston and connecting rod cut and assembled. I am going to use a Viton o-ring for a good seal, but I might not need it... it seems to have decent compression now... we will see...
I had to make something shiny...
(http://farm6.static.flickr.com/5176/5482084175_f82e634417.jpg)
I used a hard brass rod for the wrist pin. Jan suggest steel, but that might grove the side of the cylinder, so brass works good. Not enough compression to worry about sheer... The bushings are brass as well. The oil blow by from the fuel mix will keep them good and lubed.
(http://farm6.static.flickr.com/5293/5482680940_7ce482b48b.jpg)
Piston installed. What a pain... I see now why Jan has only three bolts in the bottom of the cylinder, you can then take the cylinder off to remove the piston. I have four and one is under the main bearing support, so to remove the piston I have to take the engine just about completely apart. I think on next assembly I will forget to put in the hidden bolt... oops...
(http://farm6.static.flickr.com/5258/5482083625_ff2ab5b125.jpg)
I added some footsies. The center spacers were removed and drilled and tapped 1/4-20 on the bottom for some threaded rod jam locked into the 1 1/8 38mm long feet. I will get some rubber to glue onto the bottom.
(http://farm6.static.flickr.com/5136/5482680062_3326d16d3c.jpg)
The flywheel supports took forever. If I had it to do over again, I would line drill them out when fully assembled and trued on the lathe. I oversized the hole on the flywheel so that it is only supported by the two aluminum end pieces. It is within .0005 eccentricity and .001 wobble. I could probably get that out with bolt tightening, but its pretty close...
(http://farm6.static.flickr.com/5256/5482680300_9e4399181c.jpg)
Now for something that I have been dreading... the manifold. I would like to say it came to me in a dream, but really it dawned on me what to do while watching Survivor on Wednesday. The engine usually lives on the coffee table when we are not in the shop, so I have time to stare at it and design.
I decided to have the intake and exhaust come out the top for symmetry and then I don't have to cut into the side of a curved surface for the intake.
The stock was just a piece of 1/2 x 3/4 6061 rough cut on the band saw, drilled for mounting holes (I used two, plan only one) then indicated on the lathe.
(http://farm6.static.flickr.com/5133/5482680414_bdb17d5b5f.jpg)
(http://farm6.static.flickr.com/5051/5482680522_d471f29070_z.jpg)
Then I turned and grooved. Turned out pretty good... I was worried that it might grab and get thrown because there was VERY little on the inside lip to chuck onto.
(http://farm6.static.flickr.com/5099/5482084001_54b512123d_z.jpg)
I then cut out the extra on the top sides and drilled the holes for the muffler and intake (to be made today)
(http://farm6.static.flickr.com/5051/5482680712_5ecf9ffb56_z.jpg)
And now some videos for your viewing pleasure...
Piston and crank. Nothing hits, but it is reeeaaalllyyy close.. about .5mm gap between the connecting rod and the base. Might have to modify if it starts rubbing when at full speed...
Clamp REAL tight and plug removed so there is no compression.
Exhaust valve held open with cam, plug in.
More to come... thanks for your constructive comments and suggestions...
Doug
-
Your'e engine comes up very nisley now :clap:
-
In the notes for for the engine, referring to sheet six, Jan suggests 0.3 mm gap.
Dave.
Dave, you must have a different set of drawings than me. Mine are dated Jul 25 -09 and I have read it cover to cover now and do not see that info...
Could you send your copy to dbvandy@gmail.com so I can compare?
Thanks!
Doug.
-
I'm running out of things to do without belts and ignition parts. Belt and cogs will be here tomorrow... I hope I got the right size...
I redesigned the muffler. It looked like it might be a bit fragile and exposed and easily damaged or knocked off. Not that I am going to be tossing the motor around, but things happen, so I made it with a mount that bolts to the tappet cross member.
(http://farm6.static.flickr.com/5016/5484806952_fc312c6fbf_z.jpg)
It is high temp loctited together.
(http://farm6.static.flickr.com/5218/5484807014_9667828109_z.jpg)
The intake was the same idea. I will connect the nipple to the vapor tank with some silicone hose or some aluminum tubing.
(http://farm6.static.flickr.com/5011/5484807114_6500c39ece_z.jpg)
(http://farm6.static.flickr.com/5259/5484807210_62472f613e_z.jpg)
And a view of it on the motor. Starting to look pretty complete now.
(http://farm6.static.flickr.com/5060/5484212055_ab8464a614_z.jpg)
More to come... not much more, but more just the same...
-
I'm running out of things to do without belts and ignition parts. Belt and cogs will be here tomorrow... I hope I got the right size...
I redesigned the muffler. It looked like it might be a bit fragile and exposed and easily damaged or knocked off. Not that I am going to be tossing the motor around, but things happen, so I made it with a mount that bolts to the tappet cross member.
(http://farm6.static.flickr.com/5016/5484806952_fc312c6fbf_z.jpg)
It is high temp loctited together.
(http://farm6.static.flickr.com/5218/5484807014_9667828109_z.jpg)
The intake was the same idea. I will connect the nipple to the vapor tank with some silicone hose or some aluminum tubing.
(http://farm6.static.flickr.com/5011/5484807114_6500c39ece_z.jpg)
(http://farm6.static.flickr.com/5259/5484807210_62472f613e_z.jpg)
And a view of it on the motor. Starting to look pretty complete now.
(http://farm6.static.flickr.com/5060/5484212055_ab8464a614_z.jpg)
More to come... not much more, but more just the same...
Doug, it takes a lot of gall to say you're not going to toss it around or anything, when you just posted a video of you tossing it around and everything :poke: :lol: I guess my thoughts on using four bolts for the bottom of the cylinder would be another problem too. That is a very nice connecting rod, and you are definitely making it "your own", by the unique modifications from the design, I'm really looking forward to seeing and hearing it run. :beer: cheers, Jack
-
Doug,
You should have an email with a copy of my pdf. If not let me know and I'll do a screen dump of the relevant section.
I note that my version is dated October 2007. You may have an updated set.
I echo the 'nice build' comments of the others. I made a cylinder barrel and roughed out the head months ago before I retired from work, whilst I still had access to big machines. Haven't done anything else on it yet.
The only thing that does raise an eyebrow is that you have a brass piston pin running in a brass small end bush. Don't know if that will last very long. One way to get around the problem of the steel pin scoring the bore is to shorten the pin a bit and fit some small brass 'end pieces' that will prevent the pin touching the bore.
Just an idea.
Dave.
-
Doug,
You should have an email with a copy of my pdf. If not let me know and I'll do a screen dump of the relevant section.
I note that my version is dated October 2007. You may have an updated set.
I echo the 'nice build' comments of the others. I made a cylinder barrel and roughed out the head months ago before I retired from work, whilst I still had access to big machines. Haven't done anything else on it yet.
The only thing that does raise an eyebrow is that you have a brass piston pin running in a brass small end bush. Don't know if that will last very long. One way to get around the problem of the steel pin scoring the bore is to shorten the pin a bit and fit some small brass 'end pieces' that will prevent the pin touching the bore.
Just an idea.
Dave.
Wow! these plans are great! There is just something about hand drawn plans that feel right. He also includes the info about the piezo igniter, I am still on the fence on where to go there. The CDI is looking better and better, but the piezo is really clean looking.
On the brass wrist pin: I had a stainless wrist pin in the webster and it was starting to mar the cylinder, so I did some research and the jury is about 50/50 on the use of brass on brass. Being as this is not a high HP or RPM engine, it will probably be fine. The new one in the webster (brass on brass) has about 20 hours on it and it looks about brand new.
I have some old school IC engine books that talk about that same thing: using steel rod with brass buttons on the end. Being as it looks like I have some time before it runs (not that I am on any deadline anyway...) I think I might go ahead and make one up and use it.
You should pull that cylinder off the shelf and see if it speaks to you....
Doug
-
Brass is good, and some small commercial 2-stroke glow engines, like Thunder Tiger, used to have ptfe wrist pins. Maybe they still do.
That piezo ignition is a very interesting, and compact alternative. But as Jan has stated, it works reliably only on his 4-stroke engines, but not on 2-strokes.
I guess, that the speed limitation isn't in the piezo itself, but in the mechanism, that drives that piezo.
All of the local market/grocery store barbique grill/gas stove igniters, that I've had, have exactly same size piezo unit in them. Could make them easy to replace.
-
Doug,
...You should pull that cylinder off the shelf and see if it speaks to you....
I did; it said 'sod off, can't you see I'm asleep?'
Dave.
-
A good one :lol: :lol: :lol:
-
Doug,
...You should pull that cylinder off the shelf and see if it speaks to you....
I did; it said 'sod off, can't you see I'm asleep?'
Dave.
Googling " 'sod off "....... :zap:
-
cogs and belt arrived today... yea... the belt calculator online was dead on! I bought one smaller and one bigger just in case. Tomorrow I strip the engine and cut some slots...
(http://farm6.static.flickr.com/5297/5487826864_c6b2f548ed_z.jpg)
Here is a link to the calculator: http://www.sdp-si.com/Cd/default.htm
(http://farm6.static.flickr.com/5092/5489656910_c638e9d443_z.jpg)
Vapor tank will be a glass tube with socket heads to adjust the mixture and throttle... we will see how well it works...
(http://farm6.static.flickr.com/5255/5487826950_fc92a05612_z.jpg)
More to come...
Doug
-
Really interesting to watch Doug with your own take on things. Thanks for the videos - that will be of great benefit to prospective builders. I think some people make their fits way too tight, but a video is worth 1000000 words and that shows the sort of friction people should be aiming for. It does many many revolutions when spun over. :thumbup:
On the wrist pin, I usually make it a tight fit in the rod so the pin always stays central with enough clearance so that it never touches the bore - not sure whether it's good practice or not but seems to work.
Nick
-
I cut the slot today and mounted the 192 tooth belt, though I think a 191 would have been PREFECT, it was not offered. I had to bore the holes larger in the cogs to 8mm drill, still do not have an 8mm drill. I drove all over today looking for one. I used a 5/16th and then made a reamer with my chop saw and some 8mm rod. It worked ok. Might make one perfect then harden it for future use.
To cut the slot, I had to mount the plate square to a piece of 3/8 x 2 inch aluminum bar so I had something the clamp to with the vise.
(http://farm6.static.flickr.com/5220/5490961950_3943c99623_z.jpg)
I plunged the holes to start with, then ran the XY compound vise along the sides to clean them up. Not a perfect setup, but it is what I have and works good for cuts that do not have to be super precise.
(http://farm6.static.flickr.com/5259/5490367857_fa6b61cbea_z.jpg)
The finished slot. A bit wider than I wanted to clean it up good, the table moved just a bit between the first and second plunge, but unless you have the plans in front of you and a caliper, you would never know.
(http://farm6.static.flickr.com/5216/5490962160_2110866213_z.jpg)
This is a wide shot of my "mill" setup. I purchased the $89 XY compound vise from Harbor Freight for $13 (had a good coupon) and I have had the 8 in drill press for 15 years. Bounces around a bit, but plunges well, and then side cuts to clean up the edges. I made a locking bolt for the spindle so that I could set depth and lock it in place.
(http://farm6.static.flickr.com/5056/5490962268_4c24a4555a_z.jpg)
The small cog with the spacers to keep the bearings apart.
(http://farm6.static.flickr.com/5137/5490421255_7677994d1e_z.jpg)
The top cog and belt. I will make the tension idler pulley, top spacers, and cut a slot in the middle support tomorrow.
(http://farm6.static.flickr.com/5053/5491014842_dae549e73e_z.jpg)
Ordered some lighters last night... we will see...
A little video of the progress... still have to set timing, I think I will have the motor run toward me, front of cam going down... I think it looks better.
More to come...
Doug
-
On the wrist pin, I usually make it a tight fit in the rod so the pin always stays central with enough clearance so that it never touches the bore - not sure whether it's good practice or not but seems to work.
Nick
I think that approach is probably fine. The webster plans even call for some 4-40 set screws to lock the pin in place. 4-40 and smaller are too hard to tap IMHO... all that work to pop off a tap in the piece right before installing... ouch... I will let my brass pin float.
(http://farm6.static.flickr.com/5056/5490504351_9b4bf014bc.jpg)
Doug
-
Just thinking about that piston pin (Gudgeon pin as we used to call them), I suppose that if one was very careful then one could machine a groove at each end in the pin hole (like the circlip groove in the full size pistons) and fit a tiny spring clip, say, a turn off a coil spring. That would solve the problem.
Could be fun holding the piston whilst you do it though.
Dave.
-
Just thinking about that piston pin (Gudgeon pin as we used to call them), I suppose that if one was very careful then one could machine a groove at each end in the pin hole (like the circlip groove in the full size pistons) and fit a tiny spring clip, say, a turn off a coil spring. That would solve the problem.
Could be fun holding the piston whilst you do it though.
Dave.
Seems like you would be able the hold it in the 4 jaw. On the webster I spent about an hour pondering just that for some tiny tiny internal cir clips I have around. A coil of a spring would work better.
Doug
-
Well, I am officially out of things to do until the lighters arrive. I will probably work on the vapor tank tomorrow, but I plan to use the one off the webster in the beginning.
I plan to put a belt powered fan on the engine after she starts running. Might not do much, but will look cool. The round groove will have an o-ring the will be connected to a small shaft, thus giving about a 1 to 10 ratio, driving the fan fast.
(http://farm6.static.flickr.com/5256/5493071136_c7394e168b_z.jpg)
The pulley is adjustable along a slot to tighten the belt. You can see the o-ring waiting to drive the fan....
(http://farm6.static.flickr.com/5257/5493071028_27f2ebceac_z.jpg)
(http://farm6.static.flickr.com/5171/5492478023_a745fb1cbe_z.jpg)
Engine as she sits tonight...
(http://farm6.static.flickr.com/5291/5492477831_5c449a82ac_z.jpg)
(http://farm6.static.flickr.com/5056/5492477721_56fcb0a2c7_z.jpg)
And a little video showing the compression and valve action. I have just eyeballed the timing for now, will get it right later...
More to come...
Doug
-
Looks great Doug, can't wait to see the fan, like the pulley idea it will add more visual appeal.
Nick
-
Probably a little late in the day, but on short duration between rebuild bike engines (say under 300 hours), its a preferred option to use a tool steel gudgeon (wrist) pin narrower than the outside diameter of the piston, with teflon buttons either end to make up the pack spacing to the width of the piston. It does eventually polish the bore, but at that point its long past rebuild time anyway and it is a lot less painful than having a circlip pop out mid pass and causing mayhem inside.
I think for a model engine it would be just fine wear wise.
-
Got Gas...
Got Spark...
Got To Go!!!!!!!!!!!!!!!!!!!!!!!!!!!!
THE OTTO LIVES!!!!
I had another coil from junk weed eater and I got tired of waiting for the lighters to get here, so I epoxied some neo magnets to the flywheel and used one of the original coil mounting brackets from the Webster to mount the coil to the Otto. I also used the working vapor carb from the Webster, but will make one just for this engine soon. Not looking for pretty right now, just want to hear some pop...
After some eyeball timing, I pulled the cord and it popped popped... but, it kept jumping ignition time, retarding about 45 degrees, I would reset, it would fire 4-5 times, then jump time 45 degrees again.
Turns out the three tiny 8-32 set screws did not have enough bite to hold the flywheel on the 8mm shaft, so I tapped them out for 1/4-20 set screws and all is well. will probably thread the end of the crank shaft and put on a locking nut and star washer.
Then she came to life after some fine tuning of the intake and exhaust timing. But, the camera battery died so this is all for now...
Got too late to run it more because everyone was in bed, so I will fine tune it more tomorrow...
More to come...
Yeah.....
Doug
-
Very well done indeed Doug.
A good informative post and a runner at the end, what more could we ask for?
Bogs
-
Great Job Doug
Excelent thread with a running engine completed.
:clap: :clap: :clap: :clap: :clap: :clap: :clap:
Stew
-
Nice gratilations :clap:
-
Wonderful :clap: !
I can't get my head round the fact that in mid February you showed the cylinder and one or two bits and pieces, and only three weeks later the engine is up and running :bugeye:
Andy
-
Good job and fast build too.
Ron
-
Inspirational . :clap: :clap:
Now you need to get it running on hydroxy .which is why I wanted to build the engine; as a test bed.
Dave :nrocks:
-
Nick,
...not sure whether it's good practice or not but seems to work....
That used to be the standard way of holding the old single cylinder motor bike engine pins. You had to warm up the rod end before fitting the pin; same to remove it.
Dave.
First bike, 1948 Royal Enfield Model G. 350cc
-
Hello Doug,
Amazing work as well as speed! Compared to you I'm moving a bit slower than a glacier - Oh well!
Congratulations on another successful build - love the sharp crack of the exhaust.
Best,
Mike
-
Dave, I think that was the way it was done on my Escort RS Turbo. Apparently you could freeze the pin to reassemble too but when I rebuilt the engine I just got someone to press them in!
Doug, that is fantastic, another good example of the ignition I've been wondering about for so long. Well done :bow: Can't wait to see more
You certainly don't mess around either!
Nick
-
Thanks for all the kind words, guys, I really love doing this, so the time spent pays big dividends in my sanity column.
The motor is running really good and smooth now, I will have some good vids and pic tonight. Hopefully the lighters will be in today's mail and I can get started on that this weekend.
More to come...
Doug
-
Well, I spent a few minutes tweaking the motor today. No new parts, just a timing wheel made from a 360 deg protractor.
Here are some videos:
The Engine running about 2500 RPM. Being as there is no real throttle to control RPM, you control it through mixture. Richer runs cooler and slower, lean runs hotter and faster. One issue with the vapor carb is that this is a moving target as the powerful hydrocarbons vaporize first and so you have to add a ton of air, then what is left is less volatile and you have to adjust it with less air bypass to enrich the mixture.
I used a smaller and lighter flywheel (5 inches) than the plans called for because this is about all my 7x12 can turn. Maybe when the cam timing is better and the ignition more reliable, I can get it slower, but this is about it for now.
The old timing light I have pops ghost images, but the timing is pretty close to 10 degrees BTDC. I did not have the timing wheel when I shot this, so I will use it when I fine tune the ignition timing.
After 20 minutes and 2 tanks of Coleman fuel with a few drops of Marvel Mystery Oil, the cylinder only got up to 190 degrees and the head only up to 145. I do not see it being run much harder than this, so that is about my benchmark for temp. Then she ran out of gas....
The coil was mounted with the old bracket from when I had the coil mounted fixed to the Webster base. If it becomes a permanent part, I will make a more elegant mounting system. Timing is changed by rotating the position of the flywheel and the new 1/4-20 setscrews hold it very well. Right now it HAS to be clamped tight to the table because the flywheel is way out of balance from the addition of the magnets. I might epoxy some washers 180 degrees to balance it.
(http://farm6.static.flickr.com/5098/5498840082_9728ea8fe1_z.jpg)
The Vapor tank is a transplant from the Webster. It ran good, so I just wanted as few variables as possible to get it running smooth. The tank for this engine will be made when my rotary table arrives.
(http://farm6.static.flickr.com/5136/5498840130_e40d7a3520_z.jpg)
The intake valve seem to be floating a bit causing it to stay open and blow fuel out of the tank. I later deduced was exhaust timing closing too early and creating pressure in the cylinder, then the intake opened and the pressure went into the tank, spewing fuel. But, I had some stronger springs, so I put them on just to make sure. The other ones seemed a bit week.
(http://farm6.static.flickr.com/5093/5498840316_497883f675_z.jpg)
The Marvel mystery oil does not burn so it just collects in the cylinder. This is a good thing. Once it is broken in I will reduce the mixture as even now it does not smoke when running. The smoke you see in the videos is from 3and1 oil used to lube the valves and cams.
(http://farm6.static.flickr.com/5293/5498245301_f151846130_z.jpg)
There is a little burnt oil and carbon on the exhaust side as to be expected when it is so oil rich. This is after about an hour of running and 10 tanks.
(http://farm6.static.flickr.com/5091/5498245357_bb813e98a5_z.jpg)
Still on the fence when it comes to the piezo ignition. I might see if I can tuck this coil in under the cam in a tasteful way. I do not know if it will deliver a reliable spark at cam RPM, so it might have to stay on the flywheel. Maybe if I paint the lamination silver or something...
More to come...
-
Great analysis Doug, love it. It runs so well now, sounds like much larger stationary engines.
Nick
-
From the way it runs, Doug, I'd think about making an actual carburetor with fixed jets and actual fuel control, so as to get the full range of rpms. You might inset the magnets into the flywheel, rather than leave them outside, and thus need less work to balance it out. The key is the magnets switching the flux precisely at the same time each time, and that is controlled by their placement, which being fixed, means it should be possible to put a key in the flywheel once the timing is perfected. You definitely need to have valve overlap if you're going to run it at any significant speed, to avoid the pressure build up you speak of. I've got a copy of Jerry Howell's carburetor he designed for small engines, as part of my radial engine plans, and his carburetor will give good control and has an idle jet and all, basically a real and complete carburetor, and not too complicated. :bugeye: you've definitely got her down to just working out the last little bugs, fine job, all the way. :headbang: cheers, Jack
-
From the way it runs, Doug, I'd think about making an actual carburetor with fixed jets and actual fuel control, so as to get the full range of rpms. You might inset the magnets into the flywheel, rather than leave them outside, and thus need less work to balance it out. The key is the magnets switching the flux precisely at the same time each time, and that is controlled by their placement, which being fixed, means it should be possible to put a key in the flywheel once the timing is perfected. You definitely need to have valve overlap if you're going to run it at any significant speed, to avoid the pressure build up you speak of. I've got a copy of Jerry Howell's carburetor he designed for small engines, as part of my radial engine plans, and his carburetor will give good control and has an idle jet and all, basically a real and complete carburetor, and not too complicated. :bugeye: you've definitely got her down to just working out the last little bugs, fine job, all the way. :headbang: cheers, Jack
Thanks for the suggestions.... I have some smaller magnets that will fit into the flywheel by just drilling some holes, so if I go that route with the ignition coil. I do not have a method for broaching the keyway right now, though I could do a piece of round stock and drill a hole between the shaft and the flywheel just like a square key would be cut.
I would love to take a look at those carb drawings to see if it would be a good fit. Can you send a copy to dbvandy@gmail.com?
I will keep updating the build as changes are made.
More to come...
Doug
-
Dbvandy, grats for getting the engine to run :beer:.
What comes to carburetor, as a shortcut, why not to try commercial one, as Webster's designer suggested on his engine.
But anyways, it would be worth to make a homebrewn test carburetor, to see, what the engine likes. Even if it is a shot in the dark.
-
I have two OS carbs from my old RC days. I had them on the webster, but they seemed finicky and hard to adjust. maybe they will work better on the Otto... I will try tonight...
-
FYI... 1/4inch clear vinyl tubing melts at exactly 222 degrees F....
That is all....
(http://farm6.static.flickr.com/5300/5501576240_ae3410fcbf_z.jpg)
-
Well... I had her up to 5600 RPM today running really smooth... Idles about 800...
I tried to use a carb off an RC car with about the same results as the webster... bad...
I whipped up a quick adapter for the 10mm carb
(http://farm6.static.flickr.com/5215/5501575830_25e1d2eaab_z.jpg)
The carb installed... it ran, but either idled or sputtered to 2000 RPM then died. after about throwing it across the room in frustration, I put the vapor carb back on. I love that thing...
(http://farm6.static.flickr.com/5258/5501575932_e93a0b44e5.jpg)
I did play around a bit and ran the engine on propane and some other stuff... maybe I will make a demand valve and run it off a bottle...
This week I plan to finalize some things... glass vapor tank, and ignition (coil or piezo)
More to come...
Doug
-
Hi Doug
Just read the thread from the start :bugeye: ,,,, great stuff :bow: :bow: :bow: :bow: :bow: ,, the engine runs well on gas :med:
Rob
-
Hi Doug
Just read the thread from the start :bugeye: ,,,, great stuff :bow: :bow: :bow: :bow: :bow: ,, the engine runs well on gas :med:
Rob
Thanks, Rob... now comes the fun part where I get to play with it until it is exactly the way I want it. I will start work on my glass vapor tank on Monday, should work pretty good now that I understand the physics behind it...
AND... I am starting to dream up my own design now... a V4, all open... I like to see the parts spinning around.
Doug
-
Well, I was able to spend a little time on the Otto this afternoon and nailed down the vapor tank. It works excellent and looks good to boot!
I roughed out the sides and then turned the top portion on the lathe. It serves no real purpose to be round, I just thought it would look better.
(http://farm6.static.flickr.com/5218/5510926727_f5d090781f_z.jpg)
The insets were milled with my new rotary table. There is an o-ring that goes between the sides and the 1.75 od glass.
(http://farm6.static.flickr.com/5015/5510927297_3ee0b5d589.jpg)
The throttle/air mixture is controlled with a socket head that screws down and covers the air bypass hole. The other side is the filler.
(http://farm6.static.flickr.com/5258/5511525846_16da50f634_z.jpg)
The Vapor tank finished. The glass was a bud vase and has a blue tint.
(http://farm6.static.flickr.com/5136/5511526076_609fb07386_z.jpg)
(http://farm6.static.flickr.com/5258/5511526252_c34d3f7aac_z.jpg)
(http://farm6.static.flickr.com/5219/5511526542_693bce6ef1_z.jpg)
The engine running with the new tank and magnets set into the flywheel for balance. The motor now has full control of the idle with the mixture and it will rev from 800 RPM to 3500 pretty quickly.
You can control the Revs with your finger covering the air bypass hole. With it open, it is too lean so it slows to an idle. With your finger over it, the mixture enriches and she speeds up.
Now to make a permanent mount of the coil and then pull it all apart and polish it all pretty.
More to come...
Doug
-
Really nice Doug, a pretty tank / carb. That vapour carb is a cracking innovation by Jan considering so many people struggle with carburettors he has thought of an easy way to get around the problem that appears reliable.
Nick
-
the springs look like the are not square at the bottom end , just clipped off , that may be the cause of the deformation
BTW very good build post, well documented , its something I do not seem to be able to do , I build OK ( with plenty of tip from this site ) but I am poor at documenting it ( dyslexia does not help ) takes me 15 min to type this line
-
Yeah, Doug, this looks really great!
Question about the springs that were to weak... Did they permanently compress / deform after running, or was this their state all along?
(http://farm6.static.flickr.com/5093/5498840316_497883f675_z.jpg)
These were some stock springs out of a kit. The first ones were probably fine, it turned out to be timing between the exhaust and intake cams, I did not have enough overlap. The second set was a bit long, so I had to lop off a 1/4 inch (I will fix the bottom seat of the spring when I do the polish). The only issue with the weaker springs is that they might float at about 3000 RPM, but I don't plan on having the engine running that fast very often.
Nick, The vapor carb if definitely the way to go. It is super simple to make and very forgiving with dimensions. This new one I just guessed at the hole sizes and what felt good, worked good. I like the fact that you can see the fuel through the glass as it makes it easier to explain what is going on to gear head friends that have never seen one (like me until 2 months ago).
I will post some more pics when I get her all polished and rounded.
More to come...
Doug
-
well... I think I am now done with the Otto and will start spending some time designing the V4.
Here is a pic of all the pieces that make up the engine... I did not realize how many bolts were in this thing... that's a lot of 6-32 tapping! The uprights are cut out and lightened. You can see the bearing in the middle upright, that is where the fan goes. The right upright has two holes to mount the coil. I also added some extra holes in the bottom plate to make it easier to get to the cap screws in the top plate from underneath the engine with the allen wrench.
(http://farm6.static.flickr.com/5097/5518610495_a08ebd38aa_b.jpg)
It is all back together now and the final touches have been done to the legs and spacers. I built the fan today but it kinda bugs me... it makes some whinny noise (like a fan will I guess...) but it is functional and I will upload some vids tomorrow.
More to come...
Doug
-
Well.... I am officially done with the Otto, now it will be a discussion piece on my mantle. The number one question I get it is: "What do you do with it?". To which I respond: "Show it to you..."
She runs really well; idles at about 900 steady and revs to 3500 with the softer springs installed.
The vapor tank performs wonderfully and the engine will run for 45 minutes on one tank at 1500 RPM.
Maximum temperature is 222 F at full throttle for about 2 minutes, but does not seem to rise much after that.
The Vitron o-ring seals well and with a little squirt of 3-in-1 oil in the intake valve every 5-10 minutes, stays lubed.
Ignition coil with strong neodymium magnets installed on the flywheel produces a strong spark down to about 600 RPM.
Fan does circulate air well, but probably is not needed for this motor.
(http://farm6.static.flickr.com/5294/5520192628_eb0d12327d_b.jpg)
(http://farm6.static.flickr.com/5294/5519603589_3c207e0fb1_b.jpg)
(http://farm6.static.flickr.com/5251/5519603299_a640c7acf5_b.jpg)
Here is a little video of the cooling fan. It is powered by an o-ring on the idler pulley.
Thanks for all the kind words and advice during this build, it has been very rewarding to construct and complete.
That is all....
Doug
-
Nicely done engine you got there, Doug :ddb:.
What comes to that "What do you do with it?" question, answer could be: "I use it to ride for shopping"(http://emoticons4u.com/crazy/134.gif).
-
I will only say :bow: :bow: :bow:
-
Very nice build Doug. :thumbup:
Sure is shiny. :clap:
Bernd
-
I like shiny...
Thanks for the comments!
Here's a little video of the Otto finished and running:
That is all....
Doug
-
Greate thanks for showing :clap: :clap: :clap:
-
Great job :bow:
I'm looking forward to your V4 :nrocks:
-
Man, I had to put on my sun glasses to watch that. Great job. :thumbup:
Bernd
-
Great job on that engine, it looks beautiful, sounds very smooth, and runs great, and I think the visible vapor carb is a great addition. A very fine job, very well done. :bugeye: Jack
-
Thanks for the kind words, guys... I love the visible vapor tank! It is the number one conversation piece when I am explaining the engine to people. All the gear heads wonder how it can run without a "proper carburetor", however, after I tell them the physics of what is going on, it makes perfect sense to them.
I think I will make one that I can use for my new engines just as a "test bed" vapor tank so that I can fine tune other aspects of the engine like valve and ignition timing without having to worry about the fuel system. The tank is VERY forgiving on settings and looks cool as well...
Just in case you have not seen it, I have started a thread on the V4 at:
http://madmodder.net/index.php?topic=4577
Thanks again, I loved making this engine.
Doug
-
Nice build, Doug. The finished engine looks stunning. I'm curious about the weed eater coil. Does it have points or electronic circuitry built in? Or is it just a coil activated by the magnets on the flywheel? If the latter, I'm surprised the will generate enough voltage for a spark.
Chuck
-
Nice build, Doug. The finished engine looks stunning. I'm curious about the weed eater coil. Does it have points or electronic circuitry built in? Or is it just a coil activated by the magnets on the flywheel? If the latter, I'm surprised the will generate enough voltage for a spark.
Chuck
Thanks for the kind words...
What you see is all that is there, just the coil and lead wire. I used two neodymium magnets on the flywheel, maybe overkill, but I had them from a previous project. The coil produces a BRIGHT blue spark all the way down to about 500 RPM, then it fades away. This is not an issue, because the smaller and lighter flywheel I used can't really get the engine around to another compression stroke at that RPM anyway (tons of compression with the Viton o-ring). It is the same coil arraignment used on my Webster and it works beautifully.
It is strong enough that I have been zapped a few times pretty hard by accidentally touching the kill pin on the coil while holding the engine. Not quite a tazer, but I did let go of it very quickly!
Doug