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I'm not a FF driver or owner, but I do own a X-flow powered Caterham which I race. I'm restricted as to the cc class I run in, gasoline octane permitted and piston material which the rules say must be cast. So basically it translates to a FF engine with twin 40 DCOE Webers. I've checked most of the FF rule books and most of them do not permit Mahle pistons. Why? Thanks in advance.
FF rules restricted engine parts to stock parts as much as possible to control costs. The original pistons were supplied by Hepolite to Ford and the rules specified them by part #. This prevented engine builders from supplying more costly pistons with shallower bowls to raise compression and increase power. Mahle pistons are excellent but SCCA specifically excluded them.Quote:
Originally Posted by Ktrum
Hepolite supply started to become a problem about 10 years ago. Jay Ivey worked with CP Pistons and the SCCA and produced an excellent forged piston with identical weight, dimensions and performance to the Hepolite. They last about twice as long and supplied at a reasonable cost. Jay can work with you and supply the pistons you want.
The Mahle pistons do not meet the FF rulebook dimensions (power advantage), thus not allowed.
Class rules say I must run a cast piston. So, Mahle pistons provide a shallower bowl thus increasing compression ratio. Sounds like the perfect piston for my application.Quote:
Originally Posted by Roland V. Johnson
Quote:
Originally Posted by Ktrum
FYI: JE makes a forged piston identical to the CP piston, but approximately half the cost.
And illegal, for FF
Quote:
Originally Posted by Norm Marshall
No, they're not identical to the only legal FF pistons.Quote:
Originally Posted by Norm Marshall
9.1.1. Formula Car (FC/FF) Category SpecificationsGCR - 226
e. Pistons
1. Standard or 0.005 inch oversize pistons shall be used.
2. Standard size AE pistons P/N 18649, casting P/N 18634, standard size CP piston, part #81-2 FF1600, or CP oversize piston, part # 81-2- FF1600+5 may be used. CP pistons bearing part #81-2-ff1600 or #81-2-FF1600+5 must bear the Ivey logo.
3. Alternate piston identified as follows is allowed: P/N AE-M717D, casting number 711 M 6110. AE Hepolite P/N 20552, Casting # 20548A. Note: Mahle pistons are not allowed.
There were some counterfeit forged pistons produced and sold with Ivey the part number and Ivey logo. This led to legal action against the counterfeit producer. Buyer beware.
I think I still have some used .060” oversized high compression cast pistons that came with my car.. they didn’t look like they were used long before the camshaft broke (came to me with a dead engine). I can dig them out if interested. I may still have a set of new Hepolites as well (stock bore)
Quote:
Originally Posted by Ktrum
Many years ago already, Tom Andresen told me Mahle pistons resulted in more horsepower. I believe he knew that from an engine he took delivery of, which had them installed. He refused to build a cheater.
There are no international FF rules. Each country has evolved its own. USA have allowed a forged piston. UK, Australia cast. Some countries specify the brand and part number. Others just state cast pattern copy.
If your rules state cast but do not list any makes then you are open to any brand of cast piston. There is nothing wrong with Mahle. You may need to check your rules for a minimum weight. Your rules may dictate where the weight can be removed. Some allow under the crown, others don't. Original Ford pistons were very good but hard to find now. Rings are important - low tension are best for reducing ring drag. What cam profile are you allowed? I am sure cam timing will be critical. Lastly check valve lift. Rocker profile affects actual cam lift. Each valve needs to be checked. Are you allowed to modify valves? Are your rules open regarding heads? if they do not specify a 1600 head find an 1100. The 1100 when ported has better port shape and will flow better than a 1600 head.
Quote:
Originally Posted by Ktrum
The Ivey forged pistons are miles better in reliability and longevity than the original pistons. They are also FF legal in the U.S. and I believe in New Zealand also.
I have 4 new left that I do not use