Corvair Engine Two Stroke Conversion

[California Racer]

Talked to my machinist Vair buddy and he checked off on it earlier this afternoon.

He said the cylinders and heads are lathe work.I guess that means the major portion of it.

Either some kind of steel or aluminum with steel sleeves.

Also said the head could be made to screw into the cylinder with threads.

My questions are this:

What compression to two stroke engines run at?

Could this new engine get rid of the heat?

Would the Vair bottom end hold up to any new requirements building the engine as a two stroke?

Thanks!

[bbodie52]

Disadvantages of the Two-stroke

...Two-stroke engines have two important advantages over four-stroke engines: They are simpler and lighter, and they produce about twice as much power. So why do cars and trucks use four-stroke engines? There are four main reasons:

• Two-stroke engines don't last nearly as long as four-stroke engines. The lack of a dedicated lubrication system means that the parts of a two-stroke engine wear a lot faster.
• Two-stroke oil is expensive, and you need about 4 ounces of it per gallon of gas. You would burn about a gallon of oil every 1,000 miles if you used a two-stroke engine in a car.
• Two-stroke engines do not use fuel efficiently, so you would get fewer miles per gallon.
• Two-stroke engines produce a lot of pollution -- so much, in fact, that it is likely that you won't see them around too much longer. The pollution comes from two sources. The first is the combustion of the oil. The oil makes all two-stroke engines smoky to some extent, and a badly worn two-stroke engine can emit huge clouds of oily smoke. The second reason is less obvious but can be seen in the following figure:
  Each time a new charge of air/fuel is loaded into the combustion chamber, part of it leaks out through the exhaust port. That's why you see a sheen of oil around any two-stroke boat motor. The leaking hydrocarbons from the fresh fuel combined with the leaking oil is a real mess for the environment.

These disadvantages mean that two-stroke engines are used only in applications where the motor is not used very often and a fantastic power-to-weight ratio is important.

In the meantime, manufacturers have been working to shrink and lighten four-stroke engines, and you can see that research coming to market in a variety of new marine and lawn-care products.

With a power pulse every crankshaft rotation, I would think that there would be MORE — perhaps double — the heat to dissipate via the air-cooled system — not less.

Why would such a conversion be considered or desirable?

Two-stroke engine
https://en.wikipedia.org/wiki/Two-stroke_engine

[California Racer]

Thanks Brad

'Why would such a conversion be considered or desirable?'

' they produce about twice as much power'

That is the first I've heard that! Wikipedia two stroke article did not say a word about that.Because they did not cover two stroke

vs. four stroke I suppose.

'They are simpler and lighter'

There are two other good reasons.

Keep in mind this is racing.Engines go in very light cars.

So keeping engine weight down is important too.

Simple does not hurt either.

Seems like an interesting hop up for Vair engine.