I REALLY would love to sleeve at 90 but obviously reliability goes south. Anyone having any luck on a 90mm block with boost? what engine builder did you use?

 

1. Past 89mm you can not o-ring the head and you will run into major issues with gaskets because of the big bore size. Sealing area becomes very small. This is not a big problem with N/A engines but being FI we have very little room to work. I am using a OEM gasket @ 89.5mm. The thickness is .030". Given your deck height after your new setup is install and how much comes off the head if you have it reworked ect ect ect may require you to modify the piston spec before installation do to having a limited amount of gaskets to use. I personally did not want to use cometic in any way esp @ that bore size. I see nothing wrong with a 88mm bore.

 

start with a small bore, that way if something gets f'ed up, you don't need new sleeves because you were already at the bore limit.

And it's not like the 1mm makes a big difference, if any at all, in power.

 

x2

87mm FTW.

upp the boost for more power

 

How come when one person advises correctly, some people have to ask 500 others to get the same answer?

 

factory bore 9:1 compression.

 

^^^ I would listen to Mase

 

9 to 1? why so low? Not with vtec, maybe in an engine with a fixed cam profile. Mase' thoughts on dynamic compression.

 

If you need any more info just PM me again. Good luck.

 

How many run 90mm on a boosted application? Any recommendations/pitfalls that could be shared? (except for comments relating to NOT using 90mm...)