Horizontal Air Cooled Engine

[olf20]

Great job Brian! It's almost always the little things. A elder mechanic once told me that mechanics are their worst
enemy. They pre determine the problem before they examine the it. I have done that many times. LOL
olf20 / Bob

[BobH]

Great job Brian. I enjoy the way you work your way through solving your problems. Going forward, would you use o-ring head gaskets again or stick with flat gaskets? Bob

[brian Rupnow]

BobH--Yes, going foreword I will use Viton o-rings for head gaskets from now on.---Brian

[brian Rupnow]

Today, after some minor tweaking and tuning and the addition of a Casey Jones style throttle lever, the engine is running much more sedately. The folks who I generally buy Belleville washers from are temporarily out of stock, so even with the addition of my throttle lever the engine wants to "creep" to a higher rpm.--That gets scary as heck when the engine pulls the throttle wide open. My next trick will be to add the piston with cast iron rings and see how well it runs.---Brian
https://www.youtube.com/watch?v=M47bVIBb6tw

[Willy]

One other thing you could do to dampen the movement of the throttle instead of a Belleville washer is to use a small O-ring at the bottom pivot of your Casey Jones throttle arm.
It's sounding good though!
Will be interesting to see how she runs with the cast iron rings.

[aostling]

. . . I seem to recall that the crankshaft did not have counterweights, so perhaps they could be added to make it run more smoothly at higher speed. It looked like that engine was ready to jump out of its idle to a full gallop!

Adding counterweights to the flywheels would achieve that goal, since the flywheels are essentially just an extension of the crankshaft. If the flywheels were made from iron or non-stainless steel it would be simple to add (neodymium) fridge magnets, one at a time, until vibrations are minimized.

Once the optimum mass of a counterweight is determined there is a clever alternative: instead of adding a counterweight, add a hole which subtracts the same mass. if placed at 180° with its center at the same radius, a hole can have the same dynamic effect as a counterweight,

Probably not going to happen with this engine, but food for thought!

[Tundra Twin Track]

Nice job Brian,really like the sound of this one and enjoyed Video. Happy New Year as well!

[fjk]

Looks great!

[Cuttings]

Looks and sounds good Brian. It reminds me of the old Fairbanks we had on the farm. Best wishes to you and your family for a happy and healthy new year.

[brian Rupnow]

Today I removed the piston with the Viton ring on it and installed the piston with the two cast iron rings. The engine tried it's best to run, but never quite made it. The engine would fire and start, but after I removed the drill/starter the engine would gradually slow down and quit. I thought that perhaps if the flywheels were a bit heavier it would let the engine "carry thru" from one power stroke to the next and help the engine to keep running. I dug around in my "shorts" bin and found a piece of round cast iron that I set up in the lathe and bored it to fit over the drive pulley on the back side of the engine, held in place by a 1/4" set screw. It didn't help. Tomorrow I will investigate why the cast iron rings aren't holding compression properly and see what can do about that.

[Sparky_NY]

Did you remove the piston/rod out the bottom of the cylinder? If you did its pretty unlikely anything else on the engine was disturbed.

[PStechPaul]

The cast iron rings may have too much friction. You could compare the torque needed to spin the crankshaft with iron and Viton rings.

[brian Rupnow]

Paul--the cast iron rings always have less friction with the cylinder walls than Viton does. Viton friction is comparable to trying to slide on dry concrete with rubber running shoes on. Yes Sparky, the rod cap comes off by removing the two bolts that hold it in place and then the rod and the piston slide out the bottom of the cylinder. I have a lead in taper at the bottom of the cylinder that allows a piston with rings or Viton to be slid in fairly easily. I can change pistons in ten minutes. I did notice that the cast iron rings didn't seem to have as much gap between the ends as they did when they came out of the heat treat oven. It's possible that the rings were binding in the piston ring grooves and not expanding in the cylinder the way they should. I still have two unused rings that were part of the batch of springs that I made for this piston. I'll know better tomorrow when I pull the piston out.

[mattthemuppet]

I don't have much to say about troubleshooting the engine, but I think that fan housing and set up is the slickest one you've done yet. Looks really good and very functional.

[brian Rupnow]

Thanks Matt--I agree, that fan and housing are the coolest of the cool.----Brian