swapdohc

I have a built B18C with high comression rollerwave pistons (13.?/1, 305 psi), I am going turbo and need to lower my compression. The b16 rods are 140/1000's shorter which, if they fit, would lower my compression by around 2 points.

I think that if there is a problem it would be crank to piston clearence. Has anyone actually tried this?

Thanks.

Flamenco-T

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by swapdohc &raquo;</TD></TR><TR><TD CLASS="quote">I have a built B18C with high comression rollerwave pistons (13.?/1, 305 psi), I am going turbo and need to lower my compression. The b16 rods are 140/1000's shorter which, if they fit, would lower my compression by around 2 points.

I think that if there is a problem it would be crank to piston clearence. Has anyone actually tried this?

Thanks.</TD></TR></TABLE>

are you keeping the GS-R Crank ?

tony1

How about a thicker headgasket?

Flamenco-T

Tony's right, if you're .014 too tall, you can get a .044 or higher and it should clear

swapdohc

Yes I will be keeping the b18c crank, but I had not considered a b16 crank. Hmmmm.

As far as the thicker head gasket it would be VERY thick which messes with cam timimg (Not really a big deal) but I am intend on putting at least 350ish to the wheels before the N2O at 11/1 CR = high cylinder pressure = not good for thick gaskets.

Also the high dome on the pistons helps to minimize detonation, that is why I am trying to keep them.

swapdohc

140/1000 = .140 not .014

tony1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by swapdohc &raquo;</TD></TR><TR><TD CLASS="quote">Also the high dome on the pistons helps to minimize detonation, that is why I am trying to keep them.</TD></TR></TABLE>

How do you figure? It's like trying to burn a whole building down with a conrete wall in the middle. A dished piston is the most efficient. What you're trying to do is a band aid way of lowering the compression any way you look at it. Either put a thick head gasket on it and lower it the band aid way (use cam gears to line the cams back up) or put lower comp. pistons in it...

swapdohc

I understand that the dome piston is more efficent, but it is my understanding (I may be wrong, I am more than I like to admit) that the high dome provides more surface area giving the flame front a longer distance to travel = longer burn cycle.

This is not just me trying to get away cheap. I own a mobile dyno and tune mainly Hondas. There are many high cr hondas here that want to convert to boost but are discouraged by the expense, I am basicly guinny pigging myself.

Thank you for your input BTW.