Yet Another Webster Begins

[awake]

Aha - the discussion about the #10 bolt has made me aware of a key difference between the type of points you are using and the tractor points I used. If I am understanding correctly - and based on the pictures in the eBay ad - the points you are using have one of the screws that secure it in place passing through the "hinge" of the points. Is that correct? On the tractor points, the securing screws do not pass through that hinge, so no binding occurs. That was not a matter of planning or wisdom on my part - I just lucked out on the points I happened to use!

 

[CFLBob]

Exactly right, Andy. The #10 screw goes through the part that the spring wraps around - the hinge.

This support piece for the crankshaft was the second or third piece of the engine I built. I built the cylinder head first, and then did the two sides. If I had really understood the drawing and that I was making the mounting location for the points, I might have gone to my auto parts store, found the cheapest points they stocked that looked good, and laid out the holes for those. The points that Webster specifies are available, it's just that no shop in town has them, and they all required I make two trips to the store.

Since the post office says the points will be here Monday, I may as well dissect these.

 

[CFLBob]

OK, the new points came in on Monday (they were promised tomorrow), but due to some veterinary problems, I just got to put them on the engine today.

They didn't work. I couldn't measure continuity with an ohmmeter between the contacts with them off the engine and closed. I looked at the points under magnification and saw some sort of film on them. Scraped. Ran brown paper over them, finally 400 sandpaper before they worked.

Then I convinced it to run for another minute and change.

 

[werowance]

that was a pretty consistent run id have to say. the stabalizing bracket seems to have worked very well. with your permission i might copy that idea over to mine. i couldnt see any rocking happeing on the head block. hope all is well with the animal. and the webby is looking good.

 

[CFLBob]

The cylinder is much more solid this way. The last time I tried to start it, the vibration would shake the carb's throttle out of whatever place I set it. Now it's really steady.

Feel free to try it. I don't think anyone needs my permission. I probably need Joe Webster's permission for modifying his engine!

 

[awake]

Very nice - but what a puzzle that you keep having problems with the points. A basic engine component that has been in existence for what, 100 years? Having to fight with them almost makes the effort seem ...

... wait for it ...

... pointless!

 

[wburnett2922]

points have always been a problem. I just installed set on model I am building same problem rub with old fashion point file problem solved why do you suppose the auto co. went electronic remember back in good days always carried point file. I am 92 started with 23 chevy superior Bill

 

[CFLBob]

This is my third set of points. The first set didn't ever try to run. I just ordered the wrong part number. It met the description from Webster's sheet 21, but didn't have the connection to the other end of the spring steel on the moving contact.
https://www.homemodelenginemachinist.com/threads/yet-another-webster-begins.31310/post-349880
My next set, the ones that just quit working, were used the longest but I noticed the problem with them not closing not long after I got them. I actually took them off the engine, squeezed them open and they wouldn't close. After poking and prodding for a few minutes, I put a drop of oil in the right side around where the sheet steel spring goes around the screw boss, and they started working. And worked until they didn't anymore. Did I kill them by tightening the 10-32 SHCS too tight? I don't know.

This third set is a set of CH14VT from eBay. I'm starting over on the counter of how long they'll last. As Brian suggested, I put the SHCS in without putting any pressure on the points, and hold the screw with a little LocTite 680 (green) on the screw.

I noticed that in yesterday's video, I can see the intake valve moving a little. That's first time I've seen that.

 

[Vietti]

I have been using 1974 MG points in my magnetos as they about the smallest I can find. Anyway they are well made and seem to work well with modifications to fit the mag. I get them from the auto parts store.

Anyone aware of a smaller set of ignition points??

Thanks, John

 

[CFLBob]

I have been using 1974 MG points in my magnetos as they about the smallest I can find. Anyway they are well made and seem to work well with modifications to fit the mag. I get them from the auto parts store.

Anyone aware of a smaller set of ignition points??

Thanks, John

That would be a useful thread on its own! Imagine a list of points and sizes. These have two holes spaced 1-1/16" apart, one is supposed to be #10 and other #8. Is that some sort of standard? If I knew points other than the one Webster calls out, I might have found a set I could just walk into my local stores and buy. As it is, all three chains in town had to order from out of town, and required me to drive there to order and to pick up.

 

[Brian Rupnow]

Bob--I use Chrysler points part # 018-4126-8 A110P on all of my engines. I have never had a problem with them on over 20 engines. If you do like I say and run a 3/16" drill thru the main attachment hole, then they do accept a #10 cap screw. Don't run the screw down and tighten it, because the points do have to rotate there a bit. A bit of Loctite on the bolt threads keep it from unscrewing. The other bolt which lets you adjust the opening of the points should be a #6 pan head bolt. You must also use a condenser, or the points rapidly burn out. I use a condenser # 018-1555-4 G120P. ---Brian My Partsource automotive store knows that I build these engines, so they always keep a set of points and condenser and an NGK sparkplug CM10 in stock.

 

[wburnett2922]

Auto parts stores generally have 72 any model Chrysler points in stock as far as I know most or all are made in Mexico they seem to work 3/16 drill thru #10 hole is very good idea and you certainly need condenser auto parts store need car model and year to look up parts try 72 Chrysler shough work.

 

[wburnett2922]

Also if you place paper bill$ between points pull through will generally clean so they will work
Of course if you paid 10$for points you would have to use larger money amount . bill

 

[CFLBob]

No video, and nothing about points. (Yes, a pointless post)

I'm just wondering what to do next. I can ordinarily get it to run after a few tries, and it will run for maybe a full minute. I've gotten it to run a bit for several days. If I keep trying to restart it, I can get it to run for maybe two full minutes. The carb throttle lever is EXTREMELY sensitive. There's no such thing as using the lever to goose the engine and have it speed up and then slow it down.

The lever is open around 1/4. It's almost straight out over the air port.

The engine seems to run fast. I'm bad at judging this, but maybe a thousand RPM? It seems to stop running because the cylinder gets too hot. (I keep telling myself to get one of those "laser tachometers")

So I'm here to ask questions of you guys who are way ahead of me in this world.

First off, is this pretty much what it's going to do? Am I likely to get it to run much better? Since the throttle is barely open, which way would I try to adjust the screw, more open or more closed?

Is it time to clean it up, mount it on a plaque, and try to do better on the next engine?

 

[Brian Rupnow]

1000 rpm is about what you can expect for idle speed with these engines unless you go to a really heavy flywheel like I did on mine, then you MIGHT get down to around 800 but that's pretty questionable. My Webster will run all day without stopping from being to hot, but thats more a matter of what ring you used and how closely the piston fits in the cylinder. Some people have changed the cylinder so that it has a water-jacket for cooling water around it to get around the overheating, and some people have fitted a small fan driven by an o-ring belt to blow cooling air over the cylinder.

 

[CFLBob]

That's interesting. Can you change the throttle position and change speeds, or is it touchy and shuts down easily? I'm guessing you can adjust it.

I used cast iron piston rings from Dave Reed, and all I honestly know is all the compression tests seemed OK before I got it running. I've run it with an electric drill turning the flywheel for most of an hour, and might have another 10 minutes total time running itself, spread out over days.

I've watched a few videos on YouTube of various Websters and they seem to run the minute or two of the video, so I thought maybe that was all I could expect.

What I've been thinking is that the engine runs with the throttle close to minimum, that closes off the air input as if it was choked and makes the fuel/air mixture more fuel-rich, right? Maybe it needs a richer fuel air mixture. I guess that means I should open the idle speed screw? Or the low-speed mixture screw on the right?

 

[Brian Rupnow]

If the engine dies out when you increase the throttle, it is because the carb is running too lean. You need to adjust the mixture needle to richen up the amount of fuel being admitted to the carburetor as much as you can at idle. That will help a lot when you open the throttle. Ignition timing plays a role in this as well. You have to advance your ignition timing as much as possible when the engine is idling, because these Webster engines have no automatic spark advance on them, and higher revs require more advanced timing.

 

[werowance]

Bob, this is a bad way to describe it but if using regular straight coleman fuel, my carb which is the same model as yours, when adjusted to what i call the best response but hardest to start is rich. it will spray oil / fuel out the exhaust sort of like an rc car runnign on nitro (just not as bad). it starts better on lean (i dont mean extremely lean) but if its spraying fuel / oil out then it responds better when its running. now that said its hard to "goose" it but you can rev it up and it hold a good rev when very rich. you can slow goose it if that makes sense. or at least thats what i found on mine before i put it on the shelf

 

[CFLBob]

it will spray oil / fuel out the exhaust sort of like an rc car runnign on nitro (just not as bad). it starts better on lean (i dont mean extremely lean) but if its spraying fuel / oil out then it responds better when its running.

I think mine is close to what you describe, but I can't seem to advance the throttle at all. It seems to spray a lot of oil, and I don't even have any oilers on it. I put a drop of oil in the piston oiler hole and a little in the intake valve guide, that's about it. Look at the engine in my last video of it running. It's covered in oil.

Better yet, I did a screen capture of it. There's oil you can't see on the cylinder head, too. It seems to ooze out of everywhere.

Been wrapped up in other things to do, but something occurred to me. I've messed with the high-speed mixture and idle speed screw by that diagram. I never touched the low speed mixture screw. The instructions don't say much about it.

I ran across a YouTube video that runs really sweet. This is how I'd like mine to run.


I think I'm going to make something to put on the crankshaft so I can start it with the drill there, rather than with the pinstripe eraser. The one I got covers everything in eraser dust. You can see it on the base under the edge of the flywheel.

 

[awake]

That's a beautiful example of a Webster!

My experience echoes Brian's and Weworance's but maybe is not quite identical. On first start, it works best if it is a little rich, throttle maybe half-open. After warming up for 30 seconds, it starts to labor a bit until I lean it out some. As Brian said, lean it out too much, and it won't throttle up very far, so it is a balancing act.

Keep in mind, my experience is using a Chuck Fellows style carburetor; it has only a mixture needle and a throttle screw. The mixture needle setting is very sensitive - only very small movements make a significant difference.

You will definitely benefit from a different mechanism to transmit rotation from the drill to the engine. It really helps if you can run the drill continuously (turning over the engine continuously) while adjusting the carburetor settings until it begins to fire. I would think it would be hard to accomplish that with a friction transfer.

One last thought - go easy on the oil. I find that it doesn't take much, and doesn't have to be applied all that often, at least not for the 1-2 minute runs that I do.

Hang in there - it has run before, so you know a living engine is in there somewhere!