"Dave Rolley" skrev i melding
...
You didn't indicate a displacement size.
about 60-70cc
Assuming you are interested in
something up to about 10cc displacement, but most likely in the 1cc -
2.5 cc displacement range:

4032 AL for the cylinder with chrome plating on the bore

A high silicon (20%) AL sintered piston (not quite, but almost
unobtainium)

2024 AL for the rod with the lower end bushed or perhaps 7068 AL without
a bushing

2024 AL T3 or T4 for the case if you machine it from a block

390 AL aged to T6 if you cast it

Stay away from 6061 and 7075 for model airplane engines. 6061 moves too
much under pressure and heat. 7075 loses a lot of its desirable
properties when heated much over 125 to 150 degrees C

Titanium has a lot of nice properties except it has a tendency to gall
when there is a moving interface. It's temperature expansion ratio is
very different that the normal bushing materials, AL, and steels used in
model engines which bring a whole new set of problems.

Ed is right, the SAE has some very good materials. Send them lots of
money and brush up on your math. Those reports have a wealth of
information but are not written for the non-engineering type.

Dave Rolley

Ed Huntress wrote:
"Haaken Hveem" wrote in message
...

Does anyone know some good materials too use in making of racing
cylinders
for two strokes?

The problem is that alcohol and nitro mixes create unusual high
temperatures.
It must altso tolerate punishing high revs' (20,000 rpm )

And the piston?

Titanium perhaps?


If you want information from professional engineers who research this
subject with the aid of serious money and well-equipped labs, it's a
subject
that has come up from time to time in SAE white papers. You have to pay
for
them, but it's cheap if you're serious about building something.

Go to the SAE site and you'll find the publications.

--
Ed Huntress