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Discussion Starter · #1 ·
Hi guys,

I've been debating whether to continue using these pistons or go with different ones.
On the right are stock C20LET pistons which are too worn out to be used in my bore.
On the left are pistons I acquired some time ago. They are machined down.

I'm currently putting the engine back together and I'm measuring the compression ratio.
Bore: 86mm (stock)
Stroke: 86mm
Head gasket thickness: 1.2mm (Z20LET)
Gasket bore: 88mm
Deck clearance: -0.5mm (they extrude above the deck)
Combustion chamber volume: 43cc (I don't have a head yet this is of the internet).

With the old worn C20LET pistons I measure 14cc dish.
With the new machined pistons I measure 20cc.

This results with OEM pistons to 9.137:1 compression (why isn't this 9.0:1?).
With the machined pistons I get 8.412:1.

Question 1:
Would you guys run with these pistons? Compression seems a bit low. Will be planning on running around 300hp with the K16 turbo for now. Will upgrade later.

Question 2:
1.2 - 0.5 gives 0.7mm squish (piston to head clearance). Isn't this a bit low?

Thanks in advance:)
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