Now is this something like FRM? Is that how you say it? I think S2000 had FRP or FRM blocks so if you run forged pistons you have to sleeve them yah? Help me out with this Racerx?
J. R.
J.R., Most of the aftermarket piston manufacturers offer a variety of ring choices. If you don’t ask, you will get their most common rings. Only a few of the manufacturers make their own rings, and buy from a ring manufacturer anyway.
I use Ross pistons on most of my engines, purely because the quality of material and the tolerances are equal to or better then their competition. This fact coupled with the shortest lead time in the industry, has made them my choice… as I’m always in a rush to get a build done, and have never been able to get by with an off the shelf piston.
If I had more time and more money for lets say a pro team, I would most defiantly use Mahale pistons like RTR used. I have since been to the PRI show where all the HP piston manufacturers display their products and strengths. Mahale started as a piston company that only sold to auto manufacturers but has recently opened their services to the HP public. They truly set the bar for piston technology in many ways; Ring design, material, machining, coatings, etc. You will notice how many pro teams use this more expensive brand when expense is not the limiting factor. Champion, RTR, Pratt & Miller, etc. all rely on this brand because it’s without a doubt better then the rest. A few of the other manufactures use Mahale rings on their own brand top end pistons, but the pistons weren’t made specifically for the shape of the ring.
An example of superiority is the unique material used in the design for less expansion so the piston to wall clearence can be tighter without having problems with sticking or seizing. The rings are shaped differently for less tension, and the pistons are shaped to receive this ring. The coating is patented and not used on any other brand; the pin bore is obround to be round when heated, etc. I was under the impression that Mahale makes the cast piston for the NSX and that is why RTR went to them for a forged variation… this was before they did custom work as regular business. If I remember correctly RTR was out of piston sets when I was buying parts from them, and Mahale wanted a minimum order of like 10 or 20 sets at a high price. RTR was willing to split the order with me but that was out of my budget.
To make a long story short: The aluminum cylinder design has multiple benefits; one of them is that they expand at the same rate as the aluminum pistons. This allows you to have a much tighter tolerance between the two. Many of the piston manufacturers and all the ring manufacturers have experience with motorcycle engines (Like Weisco) and they will understand your needs for a lower tension ring.
Cool stuff-
Pratt & Miller had a display at the show with a custom Mahale piston that came out of the winning engine from the 24 hr Le Mans. The piston looked nearly new.