Hi All

Can a six bolt block be bored out to 2.1 or does this apply to 8 bolts only

Cheers David

Hello,

Yes, you can bore any of the B20s to 2100 and more.

And if you want, you can use an 8 bolt crankshaft and rods in a 6 bolt block in case you want to use IPD's 2130 big bore kit.

We sell a true 2100 kit that works with 6 bolt crankshaft and rods, but it costs more. And that's because our 2100 kit has custom made forged pistons with performance rings and lighter tool steel wrist pins. Although IPDs big bore kit has high quality Mahle pistons, those pistons are cast aluminum not forged.
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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

Forged Pistons? Do you have any quality hypereutectic cast pistons for NON-Supercharged builds?

You are right about the B21 Mahle pistons, they are tough but way too HEAVY.

I've come across a few B20s - not many, maybe 4 or 5 - that didn't have thick enough walls to allow for a 2.1 - both 6 and 8 bolt. I'd get the block sonic tested just to be sure.

Cameron
Portland

What you said. For a performance build, definitely a Sonic test is a must. I'd be inclined to offset bore towards the inlets to the limit of a 93mm gasket these days.