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Piston compression heights?


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Posted

Hi there!

I'm trying to find some suitable (preferably forged) pistons for my turbo project, but I've had no luck finding information on compression heights for the pistons that match my criteria.

Has anyone come across a catalog or a web page where they would give actual dimensions of the pistons, not just the diameter?

My pistons would be between 67-72mm in diameter with maybe an 18mm pin (or smaller, I can always sleeve my con rods), but it would be really nice to know the compression height before ordering a set.

Posted
2 hours ago, vizman said:

what engine are you using and what compression are you aiming for?

Not the biggest i'll guess as asking about 67-72mm pistons

  • Like 1
Posted
2 hours ago, vizman said:

what engine are you using and what compression are you aiming for?

GR72A (GSX750ES), and aiming for 9-10:1. So stock size is 67mm.

If I can find pistons with a diameter of 67-69mm, I can bore the existing cylinders. If not, there is the option of fitting bigger liners and going for 70-72mm in diameter.

CBR600F 1990-98 has a 17mm pin, and those can be had in 67mm size. 2003-06 has a 16mm pin, and 2007-16 a 15mm one. No idea on compression height.

ZX6R has both 15 and 16mm pins, and those too are offered in 67mm, the same goes for GSXR600 2001-03 with a 14mm pin, and 2008-12 with a 15mm pin.

As long as the pistons would be a close match, that would help. Milling the piston tops or shaving a bit from the block is doable, boosting the engine with original pistons beyond the pressure generated by the average fart is not...

I'm putting the engine back together with stock internals, but I know I will be tempted to turn up the boost so I'm trying to find stronger pistons and a spare block to match.

 

  • 2 months later...
Posted

I guess compression height you mean the pin to top measurement ?

Could you measure the standard piston.  Ask parts sellers to measure that on the new pistons.  Then get a rough idea and some data to do maths with?

id like to know this to !

Posted

Mtc do a turbo flat top piston for the gs1100 4v 18mm pin but it’s 73mm. Can’t see many other pistons from different manufacturers giving you the comp ratio you would be looking for in a turbo application. Put some gsxr750 liners in and bore it to 73mm. 

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