To shave or not to shave the block ?

[ADEN]

I am doing a rebuild to my poor m20b20 and getting new pistons and rings and head refresh , will i benefit from shaving the block to raise cr or just leave it stock?

[E30SPDFRK]

If you're getting new pistons then just get them in whatever cr you want.

[digger]

You’d benefit from a b25/27 84mm bore block if you’re spending money. Some also bore the b20 block out to 84mm

[jbontke]

The 2.7 eta engines are cheap (saw a complete pulled runner for $100 on the r3v FB page). I would fine one that was running prior and use that. If you have the 731 head, that will be a nice compliment. Increasing the compression ratio will help power some, but it wont be anything compares to larger volume.

[ADEN]

Thank you all but where i live no eta no nothing the e30 is facing extention lol.
about boring to 84mm i heard that the b20 block will face a huge reduction in its life if done and i couldn't find someone did it to confirm this info.

[digger]

On E30zone forums it is fairly common there might be something on e30 zone wiki . The wall thickness ends up about the same as the factory 84mm