For a real competition engine, any of the OE cast pistons are totally
unacceptable. Decking the block with flat tops doesn't help much,
if you run at the piston at zero deck height that only allows
about .050 (gasket) of clearance which you must have. To get
11.5 or more you must have a dome. The R16 piston is way to wimpy
for sustained revs over 7k.
Probably the best choices for custom pistons are Venolia or JE.
Even after you get a set from them, consider that a starting point
since you will usually have to machine various portions for optimal
performance and clearance.
If you want to get really serious about it, I have a set of Cosworths
around here some where I'll sell at a good price. They came out
of Studdards program. They are the lightest/strongest.
They can't be used for street since the under side of the dome is
relieved (meaning you can't cut some of it off to lower the
compression. They are all out racing pistons.
Jim
Mike Poorboy wrote:
>
> List,
> After Stephan's use of 1600 domed pistons in his U20 it
> had me wondering what the race car engines that are running
> 11.5 to 1 or higher compression ratio's are using for pistons.
>
> NISMO catalog shows an Arias .40 over piston, but it doesn't
> mention if it is domed or not. The standard U20 piston is a flat
> top cast piston. I am thinking there are at least two ways to increase
> compression in the U20 one is use the flat top style piston and deck
> the block. the other is using dome top or pop up type pistons.
> I realize that the engine would have to be run on racing fuel.
>
> I am just trying to get an idea what has been done out there to
> accomplish
> this on the U20 race cars.
>
> Thanks,
> Mike
> 2 69 SRL's part cars.
|