Cylinder Material/Piston Combo

BronxFigs · Jul 15, 2013

I have intentions to build a full scale, single-cylinder, air-cooled, 4-stroke motorcycle engine based on a 1906 design. I will be using weldments, scrap steel, and bar-stock. to construct the various parts. The engine is based on the 1906 design outlined in the Hasluck book. Bore: 2-1/2" - 3" & Stroke: 3" - 4" approx. Commercially available timing gears, and intake and exhaust valves, tool-steel cams, alloy steel push-rods, lifters, rocker-arms.

The book calls for castings made from cast-iron for the cylinder, piston, head, etc. I will be using steel tube for the cylinder, maybe Aluminum for the cooling fins, and scrap steel for the head, and some other not too critical parts..

Can I use a steel cylinder, with a 6061 Aluminum piston/cast iron rings, or would a cast iron piston/ring combo be more durable running against the steel cylinder?

While this engine will be approx. a full-scale recreation, it will be only used for demonstration at shows, etc. It will not be a "working" engine. Recommended fuel is low octane Coleman's

Please suggest material(s) for fabricating these parts. Include options, alloy names, etc.

Con-rod
Piston
Crank-pin
Rocker-arms
Cam and lifters

I ask because what works for small model engines may not work well for a full-scale engine. I would rather over-build the engine for extra strength. Weight is not a factor.

Thanks for any help you can offer.

Frank

kf2qd · Jul 15, 2013

Personally I would use a cast iron sleeve and an aluminum piston. You might consider using a piston from some commersial product like a small gas engine, or check out WISECO to see what the have close in size. You will get lighter weight and more strength that way.

A cast iron sleeve helps with lubrication - a part from the oil and part from the graphite in the cast iron. A cast iron sleeve inside an aluminum cylinder would work real well - and is rather common in aircooled construction. The sleeve handles the pressure and the aluminum conducts heat well.

robcas631 · Jul 15, 2013

My moped has an aluminum head and steel sleeved piston. The piston is aluminum held in place with a stainless steel rod and "circ" clips. The rings are made of steel. I've put 2,700 miles on it and I have had no problems. Regarding lubrication woul it hurt to add a liitle oil to the fuel? Incorporate an oil pan? I hope this helps.

Give this a look [ame]http://www.youtube.com/watch?v=B9zt3SF_Flc[/ame]

BronxFigs · Jul 15, 2013

Thank-you for the suggestions about selecting materials for this engine.

Wish I new more about the theory behind the engine construction. The engine resembles a very large, single-cylinder "Hoglett"... with a crankcase. Having a crankcase, I would guess that it must hold some amount of oil, and that this oil slings around to keep the lower end nice and slick. I also know that the crankcase gets ventilated.

The 1906 engine/bike build can be seen on the MadModder Forum in the Project Log section, and, on page 4, you can see a video of the engine running. Amazing talent, and machining. The bike ain't too shabby either.

If I can find commercially available pistons, con-rods, etc. I will try to use them. I going to search for a CI cylinder liner.

Frank

robcas631 · Jul 15, 2013

Post a picture of the engine.

BronxFigs · Jul 16, 2013

Forgive my computer ignorance, but I don't know how to post photos, etc. I have included, in my last posting, the site where this engine can be seen in photos and also a video. MadModder....Project Log section. Sorry I can't give you the direct link.

Frank

PS... I recently found out that my local library will be conducting computer skills-type classes for those like me who have trouble with computers. Eventually I will learn how to post more information.....maybe...I hope.