Using pistons with the wrong pin height

[Phyxius]

Is this possible assuming the pin height makes the piston farther from the head?

 

I can't think of why it wouldn't. The swept volume would be the same, so shouldn't the compression ratio be the same?

 

I have to be way off base or something...i know i'm not the first to think of this.

[BlackBeaut]

Is this possible assuming the pin height makes the piston farther from the head?

 

I can't think of why it wouldn't. The swept volume would be the same' date=' so shouldn't the compression ratio be the same?

 

I have to be way off base or something...i know i'm not the first to think of this.[/quote']

 

By moving the piston further down the bore, you will in effect be adding to the CCs of the cylinder head which will drop compression noticably. You'll also effect the squish of the fuel/air mix at TDC because the cylinder walls will be exposed slighty rather than say having a nicely smoothed dish on the top of the piston.

 

If you haven't got the lengine.exe already go find it as you can plug in pretty much all the variables you want and it will show you your compression ratio.

 

For example a standard L28 flat top with 38.1mm pin height has a 9.82:1 CR, if the pin height is dropped to 37.1mm the CR drops to 8.93:1. Pretty much the same drop in CD can be acheived with a 6cc dish in the pistons.

 

I naturally bow to anyone who knows what they're talking about though!

 

Cheers.

Rob