Does anyone know how to tell what size the an HPD dome is? On the inside one set of letters is "RG" and the other is "EX" Also, I hve a 416 Big Bore, can it be bored out even more if the cylinder walls are scored?

 

Call Rick at Ritter Cycle 618-644-3211, he'll have the answers for you.

 

*RG* stands for race gas .

The area marked *EX* goes above the exhaust port .

Your jug can be bored , but hurry . There are only two 87 mm pistons left in the world for your cylinder and there are no more to be made .

Back in 1995 or 1996 there was another piston that one could use to get to big bore sizes , I am going to have to look up my old notes and make a few of those pistons up . There are going to be a lot of useless cylinders out there if no one has pistons to fit them . I am planning on checking into that .

Rick Ritter

 

Why are the 87mm pistons not being made anymore?

 

The pistons must be made in a large batches , which requires a large outlay of cash. Since this engine is currently not being built the benefit doesn't cover the risk.

I purchased the remaing pistons this morning , so at least I have a couple spares at this point.


Rick Ritter

 

Will any of the big bore pistons be made? At one time there was also a 87.5mm piston?

 

What about .20 .40 .60 and .80 over, is there gonna be a stop to them also?

 

I have in my barn a Wiseco piston from a Aaen Big bore from 1998 it is 88.3 or 88.5 mm
It is no good, might call Aaen and see if they have any more.

good luck....................

 

The STD through 80 over are not going to be a problem .

It is the bigbore sizes that we won't see . True though - Aaen does have the sizes mentioned in a previous post, I was refering to the 86.5 - 87.5 sizes .


Back in the early days of Polaris 400 there was an existing piston from another machine that was used to make big bore kits . I need to reread some OLD notes .


On another note ----- Does anyone remeber the great Wiseco Piston Famine ?? What year was that ? 1997 ?? Wiseco was out of 400 Pistons for a long time . The mold got broke at Wiseco I thought I heard .

 

I can't remember what year Wiseco had their problem.
But Rick! you might want to corner the market now on Aluminum billet Polaris pistons.
Because when we ran the 88+mm pistons from Aaen the harmonic vibration is so bad due to the cylinder wall is so thin that we had to run .005 to .008 piston to clyinder clearance. So piston life is shorter but the engine ran a lot cooler. So cool that we wired the fan on all the time for a while until we got a water temp. gage hooked up. Found out the fan didn't need to be on. Only came on in very hot weather or very cold when it was running lean.

Billet Pistons for Polaris 400 2-stroke......................