Webster IC Engine build log.

[raynerd]

Doug
Thanks for then info!! You have ben very helpful!! I`m sorry, I have been meaning to say that I have been intending to use the vapour carb for months now so yes, I will be taking your advice here. I just keep talking about the "carb" because it is what the plans state. OK, thanks again.
I`m struggling like hell to cut the valves. Must have wasted about 5 hours now on unsuccessful attempts. 1" is just causing chatter and a terrible unusable finish on the shaft.

[dbvandy]

Doug
Thanks for then info!! You have ben very helpful!! I`m sorry, I have been meaning to say that I have been intending to use the vapour carb for months now so yes, I will be taking your advice here. I just keep talking about the "carb" because it is what the plans state. OK, thanks again.
I`m struggling like hell to cut the valves. Must have wasted about 5 hours now on unsuccessful attempts. 1" is just causing chatter and a terrible unusable finish on the shaft.

I did mine with the head part on the tail stock side with a live center in it, then cut off the extra little stub... Here is a pic the valve from the otto, but done the same way:



Doug

 

[Bogstandard]

Chris,

If you still have trouble making them from solid, the other way is to silver solder the valve head onto a precision shaft, and machine it to shape afterwards.

Just another recognised way to do it.


Bogs

[dbvandy]

Chris,

If you still have trouble making them from solid, the other way is to silver solder the valve head onto a precision shaft, and machine it to shape afterwards.

Just another recognised way to do it.


Bogs

I thought about doing that for the V4 quad cam, but I don't trust it.  It seems like a solid piece of metal is more sound than two pieces soldered together....

Doug

[NickG]

Bogs, I've seen the soldered method used before too to good effect, guess you could use a piece of silver steel then and chuck it in a collet.

Nick

[Bogstandard]

Nick,

I have used that method a few times in the past, where the valve stems required were rather thin.

As long as your silver soldering is in the capable category, then it saves a lot of wasted material, plus the stems fit the guides perfectly.


John

[raynerd]

Hi John

I must admit, I`ve just done one of the valves using the method that Doug described. I didn`t want to do it with the head at the tailstock, ideally I wanted to do it the other way around so I could keep testing the shaft in the valve guide but I think that has something to do with my lacking in confidence in my machining. However, with some careful measuring and using my mircona parting tool with a live centre in the tail stock, it took me about 45 minutes and countless measurements, but I`ve managed one. I then went for a second one, spent another 30 minutes and bent the damn shaft parting it off!!  

I`m in two minds as to carry on and try another. The one I`ve made is a very good fit, but I do believe that it is a fraction narrower than the 3/32 drill rod I have tried in it.

I don`t want to waste too much of your time because I must admit I might go first try and machine another one piece valve but could you briefly explain how you would go about making a 2 piece valve? I think I`ll go tomorrow and see if I can get a few 3/32" drill rod sections and then make some two piece valves and see which are best. I`m guessing you would cut your drill rod section to size and then on the end of a steel bar stock, centre drill, turn the OD and the cut the valve head angle, insert the drill rod and silver solder up?   I think I`d have two concerns, holding the shaft absolutely square to the head (will the hole in the head square it automatically?) and secondly, I`d end up getting solder on the shaft and where the shaft and head meet, probably stopping it mating correctly with the valve. Could you loctite the shaft into a head?

Chris  

[Bogstandard]

I think a little common sense and more thought is required with your last statement.

In such a hot environment, Loctite would definitely not work.

With regards to fitting the seperate valve head. What I do is to make the valve head slightly larger than what is required, drill the hole for the stem then part it off slightly overlength. Just remember, the hole requires to be a couple of thou larger than the stem, to allow the solder to penetrate and make the strong joint required.

That is then silver soldered to the stem, and then a brass or aluminium split collet is made to fit the stem for holding in your chuck, unless you have a very true running collet set. By holding the head as close as possible to the chuck, the head is very finely and gently turned to size, perfectly concentric to the valve stem. When silver soldering, carry out from the opposite side of the head to the stem, just to stop solder flowing up the stem, and on no account, if using silver steel (drill rod) cool it down by artificial means (dropping into water) otherwise you might find that you won't be able to machine the head as it will get hardened too much, let things cool down naturally. I always used stainless steel for the heads.

I have made valves by both methods, and I found that this method caused less anal sphincter twitching when valves with such small stems were required.


Bogs

[raynerd]

The plans on page 10 state that the valve guides are "pressed and loctited into place" in the valve block. I was presuming that the valves would therefore be at a very similar temperature as the loctite supporting the guides in the blocks. I`m going to have to get some high temp loctite anyway so I was just thinking it might work for both... clearly your advice is that it will not, but that is where my thoughts had come from.

 I`ve just come back from my local K-supplies with a few lengths of 3/32" silver steel however, I expect I`ll try and machine another valve for the time being as I don`t expect my silver soldering skills are good enough. I didn`t appreciate that the hole needed to be a fraction bigger to allow the silver solder to flow into the joint. It seems obvious but my last failed attempt at silver soldering I expect I made the two parts too tightly fitting. I also didn`t consider that the head would be turned after being attached to the shaft. I stupidly was thinking that the head would be turned to shape and size and then soldered concentric with the shaft, which would be extremely difficult. So using the correct method, your basically using the silver steel as a perfect shaft diameter and then silver soldering a wide head blank which you then turn to size once fitted to the shaft so that it is machined concentric with it. Thank you, that makes sense. I may very well give it a go (or even have to give it a go if these one piece valves don`t work out)!

Cheers
Chris

[dbvandy]

The plans on page 10 state that the valve guides are "pressed and loctited into place" in the valve block. I was presuming that the valves would therefore be at a very similar temperature as the loctite supporting the guides in the blocks.

The valve guides do not take the beating that the valves will take and the amount of surface area that the valve guides and valve block have will keep it from moving.

My valve blocks never got above 220 degrees F when running full out, so the high temp loctite hold them just fine.  The problem I think results from the two piece design is keeping the head and stem concentric without having a perfect collet in my lathe. 

I bent one up when I was doing it the first time as well, so don't let that get you down... those things are tiny...  I did make a little collet to hold the valve as I faced the head and stem to length.  I cut mine off with a hacksaw and then faced it to size.

Doug

[madjackghengis]

Just to chime in a bit, when the valve is open, the head gets much hotter than the cylinder or valve seat, as the stem is the only heat drain.  Silver solder works because it's high temp, but locktite was never meant to be in a combustion chamber.  In making small valves, I've found using a free cutting steel, whether it be something like 12L14 or one of the easier to machine stainlesses is the key, and machining them with the head towards the headstock, the stem with an extra bit for a center hole, supported in the tailstock until it is to size and the retaining groove cut, (if that is how it is retained) in the stem, then the head contoured with the 45 angle, and a very thin cut off tool made, something about as thick as the valve stem, so cutting off at the head, can be a final finish on the face of the head.  Once cut off, a split pair of rounds to clamp the stem in, and then cut off the stub from the tailstock end, has given me good service and heads and stems accurately aligned.  Two piece valves can also be riveted together and hold well too.  The head needs a shoulder to butt up to, and a taper for the riveted end of the stem to obdurate into to seal it, but it takes great care to keep from bending the stem while riveting it in place.  Glad to see everything going along well, and getting closer to firing it up.   Cheers, Jack

[raynerd]

Guys, I did reply to these messages but my battery went on the laptop and I lost it, then I lost the will to repeat it! Sorry. Basically I was appreciating that I was being a moron considering loctite!

Finally, I have made a successful valve after many failed attempts at one piece valves. My pal Rodger kindly offered to silver solder some .25" heads onto 3/32" drill rod shafts with me, so that the valves could be machined from these blanks. I haven`t done any silver soldering so although I did consider this method, I couldn`t attempt it. Once I had these blanks at home, it took me 10 minutes to complete the valve, including cross drilling the 3/32" shaft 1mm, which surprisingly went just fine!
I`ll show pictures of the valves once complete and polished, but here is a quick photo of the first valve I made with the 3 other blanks behind it (I only need 2 valves, so we made 2 spares!!)

[dbvandy]

Guys, I did reply to these messages but my battery went on the laptop and I lost it, then I lost the will to repeat it! Sorry. Basically I was appreciating that I was being a moron considering loctite!

Finally, I have made a successful valve after many failed attempts at one piece valves. My pal Rodger kindly offered to silver solder some .25" heads onto 3/32" drill rod shafts with me, so that the valves could be machined from these blanks. I haven`t done any silver soldering so although I did consider this method, I couldn`t attempt it. Once I had these blanks at home, it took me 10 minutes to complete the valve, including cross drilling the 3/32" shaft 1mm, which surprisingly went just fine!
I`ll show pictures of the valves once complete and polished, but here is a quick photo of the first valve I made with the 3 other blanks behind it (I only need 2 valves, so we made 2 spares!!)

That looks great...

My mini lathe has a repeatability in the chuck of +/- .0015, so I wonder if that would be too much for the stem to head concentricity.  Probably not...  A collet would make it zero, so maybe I need to buy more tooling...   

looks good...  bout time to make some fumes.. I can't wait to see the ignition work, as I will be ordering one next week....

Doug

[NickG]

Looking good Chris, another string to your bow that I am yet to try!

[madjackghengis]

Hi Chris, we only say we're making extras because we don't trust ourselves, when we really make "the extra couple" with the hopes the first two will turn out perfect, and we can use the second two for the next engine, right?  Your mate did you well with that set of silver soldered blanks, and the valve looks good, I expect you'll be up and running before you know it.  Looking very good, and very nice detailing in the build log, can't wait to hear her run.   I was thinking, maybe the cam gear ought to be faced out, so you can look at the cam and gear while it's running.  I was just going over some of the earlier posts, just to remember details, and I thought that gear and cam looked good sitting there out in the open.    Cheers, Jack

[raynerd]

Well really feel for the first time like I`m getting somewhere now!

I have finished the valve except the springs - need to sort those out as currently they are just 2 random springs I found just to hold it all together.



And I managed to get an M10 tap with a fine pitch for the spark plug and so far, assembled it looks like this:



So now I need to decide where to go next! I`m going to go with a vapour carb but I don`t know if I should go with the ignition system next - there are no instructions with this one from China so I haven`t a clue what to do with it!! What power supply do I need?

Chris

[j45on]

Looking good Chris 
That will be a runner soon

[Rob.Wilson]

  now that looks like an engine Chris 



Rob

[raynerd]

Cheers guys.

Rob, you told me to get my finger out so thought I better have a few hours on it
Chris

[saw]

Nice 

[raynerd]

Thanks again for your comments chaps. Time for a few more questions. I think I spoke a little early in my last post regarding the electronic ignition. I`ve just got it all out and taken some pictures and now I definately have a few questions.

So this is what is in the packet - no instructions!



You can see a much bigger image here: http://raynerd.co.uk/wp-content/upLoads/copysensor1.JPG although to be honest, the quality is still poor!

So for a start the unit says working voltage 4.8 - 6V so I presume I could use a 4 AA battery holder for a 6V output? This will obviously connect to the red and black lead from the ignition unit.

So the other thing I can see is of course the little sensor. There is also a little black plastic holder. Now I`m going to look an idiot here but is this a holder for the sensor?  I don`t know if I`d want to use this, I think I`d quite like just a little brass tube which the sensor sticks out of the top, but for now is this at least what the black plastic holder is for?



So the ignition module comes with some things for the alternative spark plug shown in the first image. Removing these, I`m left with the following components of which I haven`t a clue what any are for!



Any idea what any of these are for?



So far I can`t see a magnet to trigger the sensor - do I just need a standard neobidium magnet? 

0.5mm or a bit small: http://cgi.ebay.co.uk/50-tiny-neodymium-disk-magnets-2-x-0-5-mm-magic-craft-/130471479669?pt=UK_Collectables_MagicTricks_RL&hash=item1e60b4c975
or perhaps 1mm http://cgi.ebay.co.uk/100-Neodymium-round-disc-magnets-1-x-1-mm-magic-craft-/130471479278?pt=UK_Collectables_MagicTricks_RL&hash=item1e60b4c7ee 

As far as I understand, when a magnet is flashed past the sensor the plug will spark. I can guess how to test the system, but could someone clarify this for me? Is it as simple as hooking it all up, getting a good earth on the plug and literally holding and magnet and moving it past the sensor ? 

Also how near does the magnet need to run past the sensor?

Sorry, lots of questions... I didn`t actually think I read instructions but without them, on this one I`m lost!

[raynerd]

Well I got no replies and I was in the mood to have  a bash this evening and I`m chuffed. The ignition system sparks the plug 

I did just what I had outlined above, moved a magnet (the base of a DTI stand!) over the senser and   

Next job is to get it mounted.

[madjackghengis]

Hi Chris, I don't know anything about that particular ignition, but most hall effect sensors want one or the other end of the magnet to trigger it.  You might want to check since your magnetic indicator holder has both poles.  Good to hear you got sparks already   Looking good   Cheers, Jack

[raynerd]

Hi Madjack, as always, thanks for your reply. I`ve got a little further with the engine, infact I have made the magnet holder which connects to the crank. I also ordered some 3mm magnets yesterday which arrived today so I put it all together for a quick test. The video isn`t great, but I`m pleased that it is sparking!!   The sensor is just strapped to that steel bar for a temporary fix, it is going to be held through a brass tube or similar.

I also started work on Jan Ridders vapour carb. I couldn`t find any brass tube at a decent price and when I went to my local scrappy yesterday, I picked up the solid bar end for less than I would have paid for a length of tube.



Since I don`t have any silver solder (will pick some up at the Harrogate Show), I wanted to keep any soldering to a minimum. Rather than bore a tube and then cap it, I figured I may as well leave one end solid.  Here it is part way through machining.


Jan suggests 45mm inside diameter, the only glass disc I could get my hands on was 50mm!


And then finally machined down some more and also the recess made for the glass disk - the glass disk which is the fuel tank viewing window is actually in position in the photo, so looks good and a nice fit! I`m a bit worried about sticking it in place and getting a good seal!




I have left it in the state of the last picture. I need to sleep on the next step and would appreciate any advice. I would quite like to machine a larger diameter at the ends, a bit like if I had capped it and had an overhang on the cap. The only way I can see I can do this is if I use some sort of stub mandrel and taper it to go into the bore, then machine the outer diameter all from that. It just seems a large bore to attempt this with.

The other thought is with holding it, i.e a base or stand for the tank. Does anyone know if there is any sort of height restriction, I guess the fuel level should be lower than the cylinder bottom or does it really not matter? I could make two little stands to sit it on like Jan or I was thinking about soldering a bar into the bottom of the tank, tapping the bottom of the bar and then screwing it down from under the base.

The third option was with so much material, to mill a flat on the bottom of the tank and just sit it on the base!! Seems a shame removing so much brass (£££££  ) but then I think it looks a bit large when sat next to my model, especially with my small ally base.

Hummm, any thoughts?

EDIT:
and I`ve been thinking about fuel for a while now and was going to get some colemans but after the discussion today by John-som I ended up trying to find some Aspen 2T alkylate petrol ready-mixed (2%)
http://madmodder.net/index.php?topic=4838.msg53742#new
 
My dad actually said he has some colemans so I can try both without spending any more. Only problem is, I couldnt get a small bottle!!!



So if anyone is at Harrogate on the Saturday and fancies trying a few litres for a couple of quid let me know as I expect I`ll not go through this bottle dispite its apparent 25 year shelf life.

[NickG]

Well done Chris, it's looking great and sparking! What's the compression like with the valves in place? Sounds like it's nearly ready!   

Did you go with 4 AA's in the end? The only thing you might find is that they don't last that long, but you could just use some C batteries instead in that case.

Not heard of that fuel before. All looking promising, glad you went for the vapour carb, they seem so fuss free from every build log I've read. Are you doing the latest version? I think the valve was simplified, I think Chuck discovered a simpler way on his Henry Ford engine.

Nick