Visual and Spec Differences for Pistons - 67/68S, 69S, 906

Hi,
From what I see there is very small difference between 906 pistons and the 911S 80P26E:
- 906 pistons have 2 holes on both sides of the wrist pin hole
- 911S pistons have 2 lateral notches on the wrist pin hole
Appart from these differences, do you know if:
- the cylinder are exactly the same?
- if we can mount 906 pistons + cylinder sets in a MFI 2.0S without any issues?
- Where can we find real MFI 2.0S pistons/cylinders (second hands or new)?

I was able to find 906 pistons here:
http://www.aasesales.com/collections...0-4102p-109560
But could not find new 80P26E!
Thanks a lot for your answer.

Quote:

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Originally Posted by Renaudtwingo

Apart from these differences, do you know if:
- the cylinder are exactly the same?

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Original 906 cylinders were Chromal, while original 2.0 S cylinders were Biral. Later replacement 2.0 S cylinders have been Nikasil.

Jon B.
Vista, CA

Thanks Jon
Any idea concerning the compatibility between 906 piston/cylinder set and a MFI 2.0S set?

Quote:

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Originally Posted by Renaudtwingo

Any idea concerning the compatibility between 906 piston/cylinder set and a MFI 2.0S set?

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The set in your link are described as "906" that "fits racing models" of 911 and 914/6. No manufacturer name or specs are given.
The piston shown is marked 79,940, and the cylinder appears to be made for a 2-liter head gasket.

You didn't mention the intended use for the engine you're building.
If the compression ratio is too high for street use, it might be possible to detune these with careful machining, but I would look for a set with stock S specs first.

Jon B.
Vista, CA

Quote:

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Originally Posted by blue72s

Here is a picture of later Mahle 67/68S set (Nikasil). 9.8 to 1 CR, 160 hp.
But the valve pockets look squarer than the originals. Is there a reason for this?

Attachment 255111

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Attachment 578989

For the records:
These later 67/68 911S Nikasil P/C are Mahle 80P2E marked.
Claudius

What are these? 80?25 E(?) is a 67/68S number, but 69S pockets?
Bought several years ago from a racing dude.

Looks ok but I have to clean and measure for wear.

The old R pistons for my 69’ sports purpose car are marked simply E and Nothing else.

Those look great! Rare pistons!

My pistons are also narrow where the wrist pin sit, and lighter than 67/68S pistons?