Gudgeon pin Q, ideas, opinions...

[Porschekid962]

There are engines floating around all over Porschedom using aftermarket goodies for one reason or another. There are many different valves, Stainless, Ti, sodium filled, smaller stem diameters, custom valve seats, custom pistons, rods, cylinder, aftermarket heads, bearings, intakes, exhausts, the list is endless.

There is performance, price, durability, personal opinion on what you want so on and so forth.

While putting a motor together in my mind the other day I came to the rods and pistons. Even though some aftermarket pistons are lighter they are still quite heavy. Where to save weight then? What about a smaller diameter pin and while your at it make it shorter in length, go with an X style forged piston with short skirts but maintain 3 rings for durability and longevity. I should dig up the specs on the JE pistons I have in the motor now but I am certain they weigh more than 400grams a piece. I know you can get a 100mm piston under 400grams. Plus now you move the gudgeon pin upwards in the piston allowing for a longer rod and better angularity. How about cutting the crank at this point for slightly smaller rod bearings and reduced friction?

Just thinking aloud at this point. There are only a few manufacturers that I would trust to make custom pistons and rods and JE really isnt one of them, off the shelf I would use them but big money goes to Cosworth, Pankl/CP, Accralite and perhaps Arrow. I like the idea of Cosworth and Pankl/CP because they make pistons and rods and therefore could design the two as a package to ensure the parts work together properly.

Has anyone out there got some slick lightweight pistons 95mm or greater in an engine? I would love to know where you got them. Also how about custom rods in longer lengths and turning down the bearings on the crank?

I am sure it has been done but isnt documented that well.

Cheers all

[911pcars]

Can't help you with real-world specific products, but I think significant weight can be removed from the piston pin via thinner wall and tougher pin material to compensate.

If budget is not a problem, there are always custom-made forged pistons available from sources. However, Mahle pistons, for example, are already pretty pricey in the standard items available.

Custom pins would be easier to fabricate compared to an equivalent weight reduction from a piston.

Sherwood