Author Topic: Webster IC Engine build log. (Read 223626 times)

raynerd · « **Reply #275 on:** May 09, 2011, 06:51:07 PM »

Yes, cheers guys. Albeit a short quick burst, it did run!

I have a few further thoughts. The fact that it runs does suggest the the timing of exhaust and ignition is OK for now. I know I`ve just been speaking to Kwackers and I think fuel could be the problem. The engine seems to behave differently and some of my best results not caught on camera (but not massively better !!) were when I was leaning the petrol tank back and the inlet was below the fuel line like in a bubble vapour carb.

Just to add that I`ve not had any luck with the lighter gas - a squirt doesn`t seem to let the engine fire, it is just dead!

I`m wondering if the inlet valve isn`t opening as it should and especially at low revs. I think it is a bit sticky. I opened it by hand on a few attempts and that kicked it up but didn`t keep the cycle going. I also felt like in those videos you have seen that I wanted to give it a pull on the throttle to kick up the revs as it seemed to run out of steam and fall dead!

Quote from: NickG on May 09, 2011, 07:58:19 AM

What was your piston made from again? If it's aluminium and it's too close, it could be binding in the cylinder. It expands a lot faster than cast iron.

Quote from: Anzaniste on May 09, 2011, 05:51:03 PM

The abrupt stop suggests tp me a tightening up probably as a result of piston expansion due to ignition temperatures.

I forgot to answer this earlier on - piston and cylinder are both cast iron so I`m guessing thermal expansion shouldn`t be a problem as they will expand at the same rate?

There is a little air leak from the edge of the valve block and head, I noticed just now when I saw some spare oil bubbling slowly. It isn`t a big leak and certainly not enough to considerably reduce compression but it may be worth putting another paper gasket on.

I`m also using this http://madmodder.net/index.php?topic=4838.0 Aspen's Fuel rather than colemans suggested by Jan Ridders. I`m almost naturally insulting John-Som when asking this question as he has clearly stated it is good with his Webster but could this be perhaps more difficult to combust than Coleman's especially on a young engine? Or is a fuel a fuel and either work just as well.

All the best
Chris

dbvandy · « **Reply #276 on:** May 09, 2011, 10:01:16 PM »

YEEEAAAAAA!

I have watched the video about 10 times and do not see anything mechanically wrong.

Have you tried it without the check valve? The vapor tank should be should be sloshing WAY more than that which explains why it runs for a bit, burns off the rich vapors, then nothing...

Try some real gas... way more aromatic, so should provide more bang... don't know what that Aspen stuff is that you are burning now... don't mix any oil with it, just squirt some WD-40 directly into the cylinder when it is running.

Put some more advance in the timing. My webster loves 20 degrees advance (spark before top dead center) and runs up to 5600 rpm with a lean mixture, so yours could do this as well.

After watching the video, I now think it is a fuel issue. Raising it will not make any difference with a vapor carb. You should see the fuel indented a great deal each stroke, yours is barely moving which leads me to think the intake stroke is not pulling a vacuum.

1. Make sure the exhaust valve has some clearance (.010 in) between the valve and the rocker tappet when not on the exhaust stroke.
2. try some gas (petrol 87)
3. remove check valve to help with intake vacuum
4. seal ANY leaks
5. put a little piece of fuel line on the end of the tank tube so that it is below the fill level (will help agitate it)

EXCELLENT JOB!!!!!!!!!!!! It will run smooth VERY SOON!!!!!!!!

Doug

lordedmond · « **Reply #277 on:** May 10, 2011, 03:01:41 AM »

good progress there Chris keep at it

Stuart

Stilldrillin · « **Reply #278 on:** May 10, 2011, 03:37:31 AM »

Well done Chris!

Yer in the right street......

I'm sitting here with a big silly grin..... Very pleased for you!

David D

NickG · « **Reply #279 on:** May 10, 2011, 06:02:06 AM »

I can't see the vids at work - got to wait 6h to see it!

Well done Chris, on the home straight now.

Your posts have inspired me to get back in the workshop. I had no motivation but I went in, all be it only for an hour, last night and got a little done on poppin no. 2. Trying to clear project back log before starting something else!

Nick

raynerd · « **Reply #280 on:** May 10, 2011, 07:11:21 AM »

Nick - glad you felt like some time in the shop after seeing the build. I wouldn`t get too excited about the video`s, it only runs for a few seconds and then stops

I also think that the problem with the engine is the fuel intake. It doesn`t seem to be getting a constant supply of fuel and is only running on a shot of a good rich mixture. The spring is very very light so I really can`t see this is the issue. I`m wondering if the valve seat is a little wide and is causing a larger pressure than ideal to open it? That being said, (very very technical) I can put my tongue on the air intake tube and the suction will pull and lock my tongue to the air intake tube - so it is sucking!

I have made sure the exhaust valve has some clearance but I`ll make a concious effort to make about 0.01" clearance rather than just guessing like I have been doing.

I did remove the check valve some time ago based on one of your earlier post. There is no ball bearing in there so although you see the "check valve" case, there actually is not valve action, it is just a way of attaching the tube to the valve block.

I`ll attempt your other advice as well.

Can you please clarify, what do you mean by:

Quote from: dbvandy on May 09, 2011, 10:01:16 PM

Try some real gas... way more aromatic, so should provide more bang...

and

Quote

2. try some gas (petrol 87)

Petrol 87 ?? "Real Gas" ?? Are we talking about unleaded petrol here? I`m sorry, just don`t want to explode anything attempting to run it on what I would consider "gas" ...methane!

metalmad · « **Reply #281 on:** May 10, 2011, 08:47:14 AM »

Well done Mate
she's alive

Pete

dbvandy · « **Reply #282 on:** May 10, 2011, 09:25:36 AM »

Quote from: craynerd on May 10, 2011, 07:11:21 AM

I did remove the check valve some time ago based on one of your earlier post. There is no ball bearing in there so although you see the "check valve" case, there actually is not valve action, it is just a way of attaching the tube to the valve block.

Petrol 87 ?? "Real Gas" ?? Are we talking about unleaded petrol here? I`m sorry, just don`t want to explode anything attempting to run it on what I would consider "gas" ...methane!

excellent! glad to hear that you have some good suction!

Yes, just some gasoline like you put in the car. Exhaust will stink a bit, but it should run pretty strong, I did that early on until I had it broken in and dialed in. That is where you are now.

remember... this is the fun part albeit frustrating sometimes, just listen to the machine and it will tell you all it needs...

Doug

NickG · « **Reply #283 on:** May 10, 2011, 01:21:54 PM »

Nice work Chris, it's so close. Yeah your fuel doesn't seem to be sloshing around like it does on Jan ridders' engines!

klank · « **Reply #284 on:** May 11, 2011, 01:12:57 PM »

Very well done - I am sure you will get it purring away.
Thanks for such an interesting build.

Peter

dbvandy · « **Reply #285 on:** May 11, 2011, 10:32:12 PM »

is it swimming with the fishes???? did you throw it through a window? did your wife toss it in the recycle bin??????

whats going on with it????????????????????????

raynerd · « **Reply #286 on:** May 12, 2011, 01:04:25 PM »

Well after several tormenting hours of trying to love a seemingly dead engine, I had a visit to fellow madmodder, Kwackers, today and brought it with me. Last night I`d had enough. It was popping and spluttering but wouldn`t start and then just before I called it a day there was a terrible binding and bumping on the crank shaft.

So this morning I got there and looking a right t1t, within 30 seconds he identified one of my bearings in the frame had died. OK OK I packed up quickly last night and so I promised him that wasn`t the issue. Then we looked at the valve block and it wasn`t holding a seal - I assured him it had been, we took the valve off and stripped it down and a piece of sh1t in the valve was holding it open - looked like a t1t for the second time - I assured him that wasn`t the issue. Anyway, we had a look at the rest of the engine and it was good just to have another set of eyes spotting any potential problems. He thought the compression was good enough without the O-ring and had concerns about the weight of the intake spring. He also went through the process of setting it all up.

So when I got home I setup as he described. Replaced the bearings that had broke and set the timing up as he said. Hurray it ran

but for only 10 seconds or so again. It did this more concistently. So I then guessed that it wasn`t getting fuel correctly and trimmed down a bit off the spring. Put it all back together and first kick we were flying!!

It ran for about 1 minute and then I accidently killed it by opening the air intake and making the mix too lean.

I kicked it up again and thankfully it started (I`ve been having a problem with concistency!) and I let it run for a good 5 minutes then stopped it and let it cool down for 5 minutes.

I then fired it up again and watched it more closely, after 3 minutes I stopped it to adjust the ignition timing and go get my camera for the proof of running shot

I started the engine up...

and then all of a sudden it just kept reving higher and higher, within the space of a few seconds I was so flustered that with the camera stuck in one hand I couldn`t shut it off and then crack!!!

The con-rod wall of the big end cracked! Not to worry at all. I think the photo clearly shows that it did run and it did run well !! (either that or I`m lieing and I cobbed it through the window and it broke!!)

So now I`m going to make another con-rod but to be honest, I`m confident it runs so I`m going to polish some parts, make a base and go for a more final assembly! So I promise.... it runs, it runs, it runs!

I just need to learn how to control it! I guess the mixture needs to be more lean? Why did it just take off?

Chris

NickG · « **Reply #287 on:** May 12, 2011, 02:05:43 PM »

Wow! Chris, a video would have been sufficient .. .you didn't need to show us it has the power to break con-rods for us to believe you

klank · « **Reply #288 on:** May 12, 2011, 02:18:17 PM »

Sounds like the cyl. and piston are getting used to each other, hence the more reliable running but why did the revs climbed so rapidly??
So very sorry to see the demise of the con rod, but very pleased you got it pretty well sorted otherwise.
Maybe you are on the last lap now.

Best wishes

Peter

saw · « **Reply #289 on:** May 12, 2011, 02:41:00 PM »

It seams to me as you don't need to think about what to do tomorow

dbvandy · « **Reply #290 on:** May 12, 2011, 03:59:54 PM »

CONGRATS!!!!!!!!!!!!!!!!

things break... make sure you don't have any sharp corners and it should not break the second time.

With the vapor carb, once it is a perfect mixture it revs wide open, you can either lean it out or enrichen it to slow it back down. The lean option is a little less sensitive but makes the motor run hotter.

now you know what you are looking for and can start to feel what the motor is asking you for. You have done something very few people would or could do, you have created life!

Make some parts and get some video... a long one so we can see the fruits of your labor, and oh, take your wife out to dinner... it will help!

Doug

raynerd · « **Reply #291 on:** May 12, 2011, 04:36:05 PM »

Haha! Thanks guys, yes, it is interesting as to why the revs climbed so high and so quickly!

To be honest, I'm not surprised the con rod broke, the wall of the big end was far too thin once I'd opened it out so that the bearing could be inserted. Hopefully I'll make a new one tomorrow and get it running again! I was quite shocked how hot it got!!

NickG · « **Reply #292 on:** May 12, 2011, 04:46:35 PM »

Yeah, when you think about it, the throttle is wide open because there isn't one! I think I've seen somebody successfully added a throttle with a vapour carb to control the speed.

Nick

metalmad · « **Reply #293 on:** May 12, 2011, 05:08:35 PM »

Hi mate
Shame about the con rod but if there was no other damage then its sweet, cos u needed a better one anyway

Pete

dbvandy · « **Reply #294 on:** May 12, 2011, 08:55:08 PM »

I just checked out your wordpress site... well done....

Doug

Stilldrillin · « **Reply #295 on:** May 13, 2011, 03:57:30 AM »

Chris.
Regard the new engine as a little kid. Just bursting with enthusiasm!

Really nice saga, still unfolding.......

David D

srm_92000 · « **Reply #296 on:** May 13, 2011, 05:16:01 AM »

Nice one Chris

I bet your next con-rod will be a bit thicker !!!

I'm just starting a Webster build, made the first chips yesterday. I was planning on putting a butterfly valve of some sort beetween the vapour mixture control and inlet so that the mixture can be left right but the flow controlled, maybe something like that would help yours.
(And it'd help me if it works.... or doesn't

)
I'm goint to start my log tomorrow (as it's Friday 13th today

).
I'll be calling it a Webster-S cause I just can't help changing stuff.

Steve.

raynerd · « **Reply #297 on:** May 13, 2011, 06:09:47 AM »

Thanks for your replies guys. I know I came up buzzing with excitement last week when it run for a few seconds but yesterday I really felt I understood what the engines needs to look like to run, if that makes any sense. I started the new Con rod last night and was very impressed with the bush I made for the big side rather than running in bearings like before. I just need to profile the round ends and then it`ll be done!

I obviously dismantled some of it last night so I could replace the con rod and I have to say that I`m really thrilled with the cylinder and piston and how good it just is without an o-ring. It was a little stiff when I put it in at first but it seems much smoother now and with a light skim of oil there is so little friction yet an amazing seal. Whether it wears over time is a possibility but I can always put the o-ring on in future if I feel I need to.

I started the wooden base last night. It`ll sit quite high because the electronics will be in a hollow below it but that way it`ll be nice and compact.

Doug, thanks for checking out my wordpress site. I get quite a few hits on it and am in contact with a few interesting people! It isn`t an example showcase work, just a little diary of the stuff I do.

Steve, I look forward to your build! I`m not really familiar with engines and so I really wouldn`t know how a butterfly valve would work. Could you give me any more details about how this would be made to fit the vapour carb / intake? How exactly does it work, is the air hole on the vapour carb getting a good mix and then is a butterfly valve just another valve further down the line which can add even more air to the mix? I do have the one way valve which I`m not using. The top screws out of there and I`m wondering if I could some how adapt the top piece to incorperate this valve if that is how it works.

Chris

srm_92000 · « **Reply #298 on:** May 13, 2011, 08:45:31 AM »

Chris,
I was thinking of something like Stew has just made (page 14 of his crank wall engine log).
It would be mounted after the mixture valve and before the inlet. It doesn't let in more air, just restricts the flow into the cylinder so the mixture stays about right but the engine is literally throttled and draws in less mix.
IN THEORY

I have no idea if it would work in practice, it would be best to try something rough to start, say clamping the flexible pipe to the inlet to restrict flow?

Steve.

dbvandy · « **Reply #299 on:** May 13, 2011, 09:25:27 AM »

Quote from: srm_92000 on May 13, 2011, 05:16:01 AM

I'm just starting a Webster build, made the first chips yesterday. I was planning on putting a butterfly valve of some sort between the vapour mixture control and inlet so that the mixture can be left right but the flow controlled, maybe something like that would help yours.
(And it'd help me if it works.... or doesn't )

Steve.

Steve, I think you will find that having a butterfly valve between the engine and the tank will keep the tank from pulling an adequate vacuum and thus not pull in fumes. The mixture adjustment is more than satisfactory for throttle control, just not what we have been taught about how an engine should be controlled. The vapor carb is very forgiving, but needs to be adjusted as the volatile hydrocarbons burn off. My first incarnation on the Webster (http://madmodder.net/index.php?topic=4413.0) vapor carb works flawlessly and you can adjust the "throttle" from 500 rpm all the way to 5400 RPM (though I don't recommend it due to what you saw on Chris's engine...) just by adjusting the mixture. These engines are not designed to be and cannot be run for more than 20-30 minutes straight without a cool down period, so the vapor tank is perfect.

I believe my design of the vapor tank that I used on the Otto (http://madmodder.net/index.php?topic=4425.0) is about as good and easy as it gets. The Otto starts on the first pull every time even after the fuel has been sitting in the tank for weeks.

But, all that being said, the nice thing about building your own engine is that you can do whatever you want, and it it works... great... and if it does not... you can try something else.

I look forward to seeing your take on the Webster. Take tons of pics and videos and post frequently......

Doug

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Author Topic: Webster IC Engine build log. (Read 223626 times)

lordedmond