startin' on a Webster

[dgjessing]

Chuck, nails for valves sounds terrible, but they really do seem to be pretty good ;D

I lapped them to their seats, cut them to length, and drilled those impossibly tiny holes in the shafts for the keepers:

I tried making springs, got frustrated, and went and got Harbor Freight's spring assortment, just to see if I'd get lucky. I did - those are both from the assortment. They are larger in diameter then the plans call for but I just made the spring caps to fit them, and I think it will work fine. (Also picked up their Viton O ring assortment; hopefully there will be one to replace the current Nitrile piston ring.)

So here's the valve block installed on the head:

I'll cut those screws to length later.

It's got what seems like OK compression , and you can see the intake valve operating on the down stroke. I need to make a head gasket - that will undoubtedly help compression-wise.

On to the exhaust valve rocker arm! ;D

 

[dgjessing]

Decided to make the rocker arm out of aluminum instead of steel. Beefed up the pivot point to 1/4" dia instead of 1/8" the plans called for, and added a steel insert where it rides on the cam.

Racing mods... :

 

[ShedBoy]

Nice
Brock

 

[dgjessing]

OK, I think I'm just about ready to try to run it:

I'm going to run out and get some coleman fuel and a lantern battery.

What's the danger potential with these things? Any last bits of advice? I think I've got the valve and ignition timing right, and as you can see I'm going to try a rudimentary vapor carb setup.

 

[dgjessing]

I can get it to fire on straight ether (starting fluid) squirted into the intake whilst turning it with an electric drill. Thm:

Unfortunately the flywheel has come loose from it's hub, so I need to take things apart and glue that together. I'm going to mill a square on the end of the crank too so I can pull the drill away if and when it actually starts.

 

[Longboy]

OK, I think I'm just about ready to try to run it:

I'm going to run out and get some coleman fuel and a lantern battery.

What's the danger potential with these things? Any last bits of advice? as you can see I'm going to try a rudimentary vapor carb setup.

Danger? Well Dave.....you may end up with "internal combustion disease". Some of its manifistations are: Can't believe you got it to run. Lying awake at nite waiting to get back to it the next day. The television and computor are no longer primary in your life. The only "material things" in life important to you are brass, iron, aluminum and steel......so just be aware as you finish the build. The vapor carb works fine on these single cyl. engines.

 

[Brian Rupnow]

This is when you get to find out if your valves are really sealing okay or not!!! I got really lucky when I built my Webster. It started right up and ran like a champion. Then I darn near went crazy trying to get the valves to seal on my Kerzel hit and miss engine.----Brian

 

[dgjessing]

I think the valves are working OK - I got good compression, and it's sucking lots of bubbles in the vapor carb's intake.

The new Viton ring seems to seal better than the old one.

When does the spark take place - when the points close, or when they open? I should know this, but have managed to confuse myself...

I've epoxied the flywheel to the hub, and have made a hex nut into a starter drive collar thingie.

We'll try it again tomorrow

 

[Brian Rupnow]

It sparks when the points open. This collapses the primary field and induces a high voltage in the secondary coil windings.

 

[dgjessing]

It sparks when the points open.

Thanks! That confirms what all my past experience was telling me

So with this engine we want the spark like 10 degrees BTDC, thereabouts?...

 

[Catminer]

TDC is fine for a little engine, especially hit and miss.
Even a little past TDC will help soften the blow when it fires.

Peter

 

[dgjessing]

This is when you get to find out if your valves are really sealing okay or not!!!

They aren't :'(

Compression is far better with the valve block off and my finger over the transfer port. Need to do some tweaking...

 

[Brian Rupnow]

You have no idea of the fun that lays ahead of you now!!! I can clearly remember, on my hit and miss engine build running clear vinyl tubing from exhaust port into a pail of water and spinning the engine by hand to see if it blew bubbles, thus proving that the exhaust valve really wasn't sealing. (It wasn't) I can remember making a screw in adapter that fitted in the spark plug hole and blowing my guts out with both valves closed and the same vinyl tubing leading from the intake port to the pail of water to see if it bubbled, thus proving that the intake valve was leaking. (it was). And so on, and so on. Eventually I got it, but not untill after remaking the valves and seats/cages a few times and finally building a valve seat cutting tool.

 

[dgjessing]

You have no idea of the fun that lays ahead of you now!!!

Fun fun fun! :

 

[rhitee93]

Whatever you do, please keep posing about it. I am learning a lot that I hope to be using soon. :bow:

 

[dgjessing]

Well here's a weird problem - I'm getting a nice plump spark when I turn it over by hand (slowly), but no spark at all when turning it fast with a drill! Is my junk yard coil bad maybe?

 

[dgjessing]

Well here's a weird problem - I'm getting a nice plump spark when I turn it over by hand (slowly), but no spark at all when turning it fast with a drill! Is my junk yard coil bad maybe?

Figured this one out - I had the anchor screw holding the points too tight. As near as I can tell this resulted in the moving point being a bit sluggish in it's movement. Apparently when turning slow the thing would creak and groan and return to the closed position, but when spinning fast it never closed.

Damn... thought I had an ignition problem (instead of a leaky valve issue).

 

[dgjessing]

... so I just wrapped a couple of turns of thin aluminum foil strip in the ring groove to shim the Viton rings and get an equivalent seal.

Thanks for the tip! I just did the same to mine & the compression is much better. It's almost there - putt-putt-putts when turning with the drill, even a couple times after it's pulled away. And it outright runs for a second or two on ether ;D

The intake valve is still leaking though - turning it by hand slowly makes fuel come up out of the vapor carb's vent line.

I feel like it's almost there!

 

[dgjessing]

It lives!

http://www.youtube.com/watch?v=L7Da8laaJaY&feature=youtu.be

I widened the ring groove in the piston slightly so the o-ring was free to move about (had been a light press-fit in the groove). This made the piston / ring slide a lot more freely in the cylinder, and apparently that's what was needed.

I've made a rudimentary mixture control - it seems to be quite sensitive to this adjustment.

Now I need to make a proper vapor carb with this adjustment mounted on the engines's frame (instead of the current jar w/tubes).

I had switched to real gasoline as one of many things to try to get it running (that's what it's running on in in the video). Will try the coleman fuel again this afternoon (gas stinks!).

Thm: ;D

 

[thayer]

Very cool Dave, well done!

Thayer