[RS Barn]

This is a picture of the fancy pistons from one of my race motors. They are made by J&E for me. There are several design features that vary from stock. They are much lighter due to less mass. The valve pockets are larger for big cams and valves.The squish area is 16% less OE. The skirt is coated with a different material that Mahle uses.

This motor runs at 11.8 to 1 compression. It is very docile and quiet. With more modern fuel injection they could be used in a street car. But they won't last 200k like originals. These were actually run a few hours using 944 Turbo rods which are heavy. Motor is going back together with Woosner lightweight rods. Rotating assembly going to be re-balanced again. Piston rod combination down 139 grams per cylinder.

So race only.

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[flash]

j&e has been around for a very long time.  they were practically in my back yard when i was in socal.  over the years, i've used them a few times to make custom pistons.

 

we had to do much the same thing on the MG motors, when we went to higher compression, bigger valves, and higher lift cams.  we found that we really had to focus on getting rid of all the hard edges , and smooth things out, or we got hot spots.  we melted a few pistons, and burned a few valves, before we figured out the right design.

 

good luck

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[RS Barn]

No problem with hot spots. The 968 is a modern engine style with 4 valve per cylinder and pentroof combustion chamber. We get excellent cylinder filling and burn. The combustion chamber shape doesn't require much spark timing advance. Multipoint fuel injection eliminates fuel pooling which can cause hot spots.

New production engines can run 12.0:1 compression with a combination of direct and intake manifold injectors.

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[RS Barn]

Assembled Block. So pretty

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[Rap]

Shiny!

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[gtolou]

Sweet! - Nice eye candy.

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[unknown4u]

Great to see such a beauty!!
Original bores?

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[RS Barn]

Original bores. They were polished using the Sunnen hone paste required by Porsche. This brings the silicon crystles to the surface. The rings have a special coating for Alusil.

One of the benefits of Alusil is virtually no break in required.

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[RS Barn]

Side view showing Calico CT-3 coating of .0005"    

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[Rap]

So I will ask the question I suspect some are wondering. How much extra does it produce?

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[flash]

you say it doesn't require much timing advance.  does that mean you get to pull back from the insane 30 degrees that some areas have?  when i first started tuning this motor, i was astounded at how much advance they used.  i was used to 10 degrees.  30 blew my mind.

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[RS Barn]

I don't think it produces more ponys. Just a lighter rotating mass for quicker acceleration and ability to run higher compression and more aggressive camshafts.

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[unknown4u]

Good job?

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