A new attempt at making piston rings

[Dan Dubeau]

Congrats Brian. Perseverance pays off.

[tlfamm]

Congrats, Brian - is there an award for undaunted persistence in the home machine shop?

There oughta be ...

[brian Rupnow]

This post is not so much about rings, but it does show something very important. I am always amazed at how much a difference in gas tank height affects an engine. When I built this engine a few years ago, I had made a gas tank to fit underneath the cylinder, with a 3/32" diameter check valve in the discharge. This year when I went to start it, I couldn't get it to draw fuel up from the tank. Okay, when these engines set around on the shelf for years, check valves have a tendency to freeze up. That wasn't a big deal, I just grabbed a spare gas tank I had and mounted it on a block of wood. This allowed me to start the engine and see that it actually did run. After putting the cast iron rings in, the engine would run good for four or five minutes and then die, as if it were running out of fuel. When everything else is set at "optimum" and the engine dies for no good reason, I always suspect the gas tank height. In this picture you see a 1.6" tall aluminum spacer under the tank. That fixed it!! Now the engine will run until I turn it off with the switch in the electrical system.

[Sparky_NY]

You should experiment with the method the RC airplane folks use. They have a fitting on the muffler and a tube to the gas tank that slightly pressurizes the tank. RC airplanes operate nose up, nose down, upside down, you name it, the engine has to keep running reliably. That would make your tank position far less critical and ensure a good constant flow of fuel. Might not even need the check valve, RC airplanes don't use one. There is no vent on the tank, the pressure line connects to what would be the vent line in the tank.

In extreme cases the RC guys use a fuel pump that operates only by the vibration of the engine. http://perrypumps.com/prod02.htm

[Robg]

Wow! Talk about perseverance! I really couldn’t see why the rings weren’t working as I’ve seen so many engines running that were highly worn out. The fact that they were multi cylinder made the reason they did run. I felt that going to a narrower ring would do the trick which it did. Whether that was the deciding factor or not is somewhat debatable but not that much. Many high performance engines do go to a thinner ring and stand up quite well in the longevity aspect. Highly informative & successful - congratulations!

[brian Rupnow]

-Every once in a while, I run into something that I don't think I'm going to be able to do.---and that worries the Hell out of me. I've always been the man who can do anything, and I hate to think that there is something that has defeated me. I'm happy that I was able to finally get some workable rings and a "process". Not bad for a "geezer". I'll be 75 this Wednesday.

[Sparky_NY]

-Every once in a while, I run into something that I don't think I'm going to be able to do.---and that worries the Hell out of me. I've always been the man who can do anything, and I hate to think that there is something that has defeated me. I'm happy that I was able to finally get some workable rings and a "process". Not bad for a "geezer". I'll be 75 this Wednesday.

Nice work ! I know you are taking the summer off from engine building. How about revisiting that propane fuel setup that you shelved a while back? Maybe the second time will be the charm there too !

[brian Rupnow]

Robg--A multi cylinder engine will run with worn out rings. A good point in case is the old v8 ford flatheads. I've seen them so worn out that they hardly had enough power to move the car, but they would idle just fine. That's because a cylinder fired every 90 degrees of rotation and kept the crankshaft turning with no load. Single cylinder engines only get a power stroke every 720 degrees of rotation, so they have a greater dependency on getting a good "kick" on the power stroke to keep them running. Sparky---I have it in mind to build a T head engine because that is a configuration that I have no experience with. I will try and coast thru July and August, but a lot depends on how bored I get. If I end up with "nothing to do, nowhere to go" syndrome, I can always come down to my computer and design a new engine.

[EthanConor707]

Well tried Wish you best of luck for this effort Sir.

[brian Rupnow]

And today we get to see how slow the engine will run. I've got about an hours continuous run time on it now, and as those cast iron rings "bed in" the compression gets higher and higher, and consequently the idle speed can become less and less. I'm pretty impressed with this.
https://www.youtube.com/watch?v=4Q1RYoAJbFo

[Willy]

If the compression keeps going up you're going to have to switch to premium gas, or hmm, diesel!

And I think I can speak for all of us when I say we're pretty impressed with you not throwing in the towel and seeing this to fruition. Congratulations Brian!

[brian Rupnow]

Willy---I spent my birthday doing two of the things I like best.---Designing a new engine and running an old one (with new rings).

[PStechPaul]

Happy birthday! So, did you determine that the heat treating process was the "magic wand"? Can you repeat the success for other engines?

[olf20]

Happy Birthday Brian. Take the time to enjoy your day.

[brian Rupnow]

PS Techpaul---I think I have it all sussed out, but I won't know until I build another engine.---Brian