MadModder
Gallery, Projects and General => Project Logs => Topic started by: cfellows on July 01, 2011, 07:07:19 PM
-
I started this engine back in the fall of 2007 and finally got it running. The past couple of days, I installed some points, a condenser and a dual wire coil I got from Jerry Howell. Hooked it up to a vapor carb and finally got it started. Clearly got lots of tuning to do to get it to run the way I want, but it's a start!
There is a build article over on HMEM for those of you that are interested.
http://www.youtube.com/watch?v=jZTSmiSO-oE (http://www.youtube.com/watch?v=jZTSmiSO-oE)
Chuck
-
Very nice Chuck
I struggle to understand how the vapor carb gets to make the vapor is their some sort of feed from the engine to make bubbles in the fuel.
Thanks for showing.
Stew
-
Nice Chuck. :thumbup:
Sounds like it's got a slight gas problem. :lol: :lol: :lol: :lol:
Bernd
-
Very nice Chuck
I struggle to understand how the vapor carb gets to make the vapor is their some sort of feed from the engine to make bubbles in the fuel.
Thanks for showing.
Stew
Thanks Stew. The engine provides suction through the clear tube that goes to the vapor fuel tank. This causes air to be sucked into the tank through the small brass fixture on the left side of the tank lid. The suction is pretty aggressive and causes a strong stream of incoming air to be directed against the surface of the fuel. As you can see in the video, the fuel is splashing all over the place. That is not from vibration, but rather from the incoming stream of air.
In other engines I've built, there really doesn't need to be any splashing. Apparently the fuel is constantly evaporating into the space above the fuel and the engine just keeps sucking this layer away as it's generated.
This engine performance is so eratic because the fuel regularly splashes up into the tube and gets sucked into the engine which causes flooding. I think a carburetor is going to provide much steadier performance.
Chuck
-
Very nice indeed Chuck, like all your designs.
I am looking at a slightly enlarged vapour generator for when I start on my R&B engine build.
The engine is designed to run on both petrol and propane, but the carbs for each type are different. I am looking at maybe one carb that can run from either gas or petrol vapour, to save having to make both.
John
-
Very nice i like the open crank :thumbup: :thumbup:
John
-
Very nice indeed Chuck, like all your designs.
I am looking at a slightly enlarged vapour generator for when I start on my R&B engine build.
The engine is designed to run on both petrol and propane, but the carbs for each type are different. I am looking at maybe one carb that can run from either gas or petrol vapour, to save having to make both.
John
Thanks for the kind words, John. It's always a compliment to have you weigh in on my builds. If you get that dual carburetor working, I'd be interested in seeing the plans. Heck, I'd be interested in seeing whatever you come up, dual or not!
Chuck
-
Very nice i like the open crank :thumbup: :thumbup:
John
Thanks, John. I always appreciate folks' comments.
Chuck
-
I added a half inch thick steel ring to each of the flywheels today. I figure I probably more than doubled the weight. They are now 6" diameter. Turned the rings to an interference fit then heated them as hot as I could get them with my mapp gas torch. I left a small shoulder in the bottom of each ring as a stop for the flywheel to rest on. The first one went real nice and dropped right in with only a little nudging to get it straight. Unfortunately the second went in about half way and stuck. Luckily I was able to use my 20 ton press to coax it into place. I had to work my way around the rim a little at a time and it took me a full 15 minutes to drive it home. But it is now in and straight. This picture was taken before I started cleaning them up. I'm doing some tapering and rounding to make it look like one integrated piece.
(http://s192.photobucket.com/albums/z195/cffellows/01af91e2.jpg)
Chuck
-
I got the new flywheels remounted and changed over to a carburetor that I had originally built for the engine. The carb is pretty basic, but it was readily available. The engine ran a little better, but still mostly on one cylinder. And, I couldn't get it to idle very slow.
So, I abandoned the carburetor and decided to go back to a vapor carb. I happened to have a glass jar that was 2 - 3 times taller than the pimento jar I had been using. And, it turns out, the pimento lid was the same screw size as the new bottle, so I just switched bottoms. This eliminated the splashing up into the intake tube and the engine smoothed out and ran pretty well, again, on one cylinder with the other cylinder firing intermittently. I increased the rocker arm clearance on both intake valves by quite a bit and this allowed me to slow the engine down to a pretty reasonable idle. The good cylinder was now firing ever time and the missing cylinder still fired intermittently. I removed the push rod from the intake valve on the good cylinder to see if I could get the engine to run on the missing cylinder. My thought was that maybe it wanted a leaner (or richer) mixture or maybe the other cylinder firing was interfering with the bad cylinder. However, I could barely get it to run on just the bad cylinder. I put it all back together and fired it up again. This time, I discovered when opened up the throttle a little, then I put a load on the engine by holding a rag against the flywheel, I could get it to fire on both cylinders pretty consistently at a pretty slow speed. I don't get it! But if all I have to do is put a load on the engine to make it run the way I want, so be it.
So here is what I've checked so far. Compression on both cylinders is excellent. Both intake valves are opening and closing at about the same position. Same with the exhaust valves. Ignition timing is identical for both cylinders. I'm beginning to think I might have a small air leak in the intake side of the bad cylinder. This is making run real lean and only firing ocassionally. Could be the manifold or it might be the valve stem on the intake valve. I might try putting a couple of drops of heavy gear oil on the valve stem and see if that seals it up temporarily. The other thing I haven't checked is the gap on the spark plugs.
By the way. Since this is a two cylinder, 4 stroke with the crank throws 180 degrees apart, the engine fires twice in one revolution, then goes a complete revolution without firing. This means one cylinder fires, then the second one fires 90 degrees later. The cylinder that is missfiring is the first in that firing order.
Chuck
-
I'm happy to report that the misfiring cylinder has been corrected. I pulled the plug and there was virtually no gap. So I widened the gap to about .035", reinstalled the plug, and the problem was fixed. Why don't I ever check the easy (and obvious) things first??? :doh:
It's still not running as consistently as I'd like, so I have some more work to do. But it does idle pretty slow and will keep running slow for quite a while. One problem with the vapor carburetor is that the mixure keeps getting leaner as the fuel level drops. So, you have to keep adjusting the fuel mixture.
The other issue I have is way too much lift on the cams, about 0.125". I can compensate for that by adjusting the valve clearance extremely loose, but it makes the rocker arms look sloppy and I really only need a lift of about .060". I may remove the cams and take them down a bit.
And, of course, I still have to put everything in a more permanent and attractive package. That means building a base, a mount for the gas tank and a nice enclosure for the electrics along with safer and more attractive routing for the wiring. Stay tuned...
Chuck
-
Here's another short video showing the state of the engine as of this morning. You can see the taller vapor fuel tank, the larger flywheels, and the better, slower idle. Still not running very smooth, but at least it's missfiring equally on both cylinders. The sound is kind of a cross between a John Deere and a Harley!
http://www.youtube.com/watch?v=nfe9sE1RdZ0 (http://www.youtube.com/watch?v=nfe9sE1RdZ0)
Chuck
-
OK, sorry to keep flooding you with videos, but this is the final one until I get the engine prettied up with a base and proper placement and connection of all the odd bits.
This video sounds pretty much the way I had originally hoped for. All I did was basically open up the throttle some then use friction drag on the flywheel to slow it down. Seems to do the trick.
http://www.youtube.com/watch?v=jAE9En2xsZg (http://www.youtube.com/watch?v=jAE9En2xsZg)
No more videos for awhile... ::)
-
Video is always welcome to me :thumbup: :thumbup:
That engine has a nice sound to it
You must have similar wear resistant skin on your hands as me :bugeye: :bugeye:
John
-
Video is always welcome to me :thumbup: :thumbup:
That engine has a nice sound to it
You must have similar wear resistant skin on your hands as me :bugeye: :bugeye:
John
Thanks John! Not sure if the hands are wear resistant or just numb from all the abuse over the years.
Chuck
-
I'm thinking about a base for the engine and I want to incorporate some kind of a load for the engine since it sounds better and runs better when it's pulling. The only real requirement so far is that it needs to be adjustable. I've thought of the following possibilities:
1. A blower or fan. This would also help cool the engine, but isn't easily adjustable.
2. Generator. This could double as a starter but would require a pretty beefy rheostat for adjustment.
3. Friction brake. This would be the simplest, but seems kind of boring, maybe even crass!
Anybody got any other ideas?
Chuck
-
What about a simple hydraulic pump? You could restrict the output with a simple needle valve. Just be sure you put in a relief valve so you don't blow anything apart if you restrict the output too much.
Don
Long time lurker
-
What about a simple hydraulic pump? You could restrict the output with a simple needle valve. Just be sure you put in a relief valve so you don't blow anything apart if you restrict the output too much.
Don
Long time lurker
Good Idea, Don. I could probably make a simple, double gear pump. Wouldn't have to be very large, simple to adjust. I'll have to think about that.
Chuck
-
Sounding wonderful. Reminds me a bit of my Harley.
-
I know this is kind of old, and you've probably figured something out by now, but why not run a small generator with a good old incandescent bulb. It could be a very entertaining way of adding a little light to the shop.
-
Wow :bugeye:
This was something... :clap: :clap:
Very nice build :thumbup:
-
A very nice looking and sounding engine, now that you've ironed out the bits, putting a piece of wire mesh in the jar will stop splashes from being sucked up, and a broad, shallow jar makes for more even mixtures as the fuel is used. Very nice and fun to watch. :bugeye: :bow: :beer: Cheers, mad jack
-
Hi Chuck,
I might have missed it, but how are you lubricating the cylinders on the IC twin when using the vapor carb?
I have a multi-cylinder I recently completed that had similar running issues using propane. They have all been worked out, but load does play a small part. Nice engine. Generators seem the only practical variable load for models engines. I have done a few and they work well. What are you thinking for load on this one?
Jeff
-
Hi Chuck,
I might have missed it, but how are you lubricating the cylinders on the IC twin when using the vapor carb?
I have a multi-cylinder I recently completed that had similar running issues using propane. They have all been worked out, but load does play a small part. Nice engine. Generators seem the only practical variable load for models engines. I have done a few and they work well. What are you thinking for load on this one?
Jeff
Hi Jeff, sorry I didn't notice this until just now.
I mix WD40 with the fuel in the vapor fuel tank and it seems to get sucked up with the fuel. I've lubricated several engines this way and when I disassemble them, there is plenty of lubricant in the cylinder.
Chuck
-
Chuck
You want to put it under a load. :bang: Make a Dynamometer and hook it to it. Adjust just how much load you would like to have. :beer:
Nelson Collar
-
I started building this engine a number of years ago and kind of got it running the middle of last year. I've messed around with the fuel system some, trying a vapor carburetor, a model airplane carburetor, and a home built carburetor. A couple of weeks ago I decided it was time to buckle down, get it running right and finish it. I rebuilt my home made carburetor, taking a lot of care to shape the venturi and replace my 2-56 tapered needle valve with a largish sewing needle. I built a new base for it, installed proper spark plug wiring and boots and hid the battery and wiring in the base under a small, removable trap door. I added a 90 volt DC motor as a generator powering a 60 watt light bulb and now feel like I've got it running and looking pretty good.
http://www.youtube.com/watch?v=eXF6i00pE3c (http://www.youtube.com/watch?v=eXF6i00pE3c)
Chuck
-
Super engine, Chuck. :clap: I'm impressed by how quiet it is. Most of the noise seemed to be the tappets.
Andy
-
Lovely smooth running engine Chuck extreamy quite
:clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap: :clap:
Stew
-
Super bit of engineering, very professional :bow: