Will leaving the head stock while boring out the block to 84 or 85 do anything bad? It would probably be like that for about a year or so.

 

higher compression thats all, just make sure its not too high.

 

There's alot of debate about this. Traditional thinking is that you open up the combustion chambers to match the block, and in so doing decrease the possibility of detonation. You're also enlarging the cc and dropping compression by doing this. I questioned Joe Alaniz(Alaniz Tech) about this and he said no way never, don't touch the head. The local Honda head wiz said precisely the same thing when I dropped mine off to be matched to the 85mm bore, so mine is only getting a minor cleanup.

 

yeah may wanna grind off teh sharp engines just to make sure. just keep the shavings out. but still, not necessary

 

Yes. The JE 12.3:1 pistons I got were very nicely finished, I still did a tiny bit of sanding though. I've seen some forged pistons with lotsa edges though. My head was realy smooth after the port and polish job, but I'd recommend going over the CCs and removing any carbon buildups or sharp edges, particularly if you're going over 12:1 compression.

 

So I shouldn't have the head matched to 85mm?

 

Nope. Course if you get detonation you may well have to make adjustments later, but I'd let it ride for now. Just make sure you have no glaring sharp edges on the pistons or CCs. Also run high octane w/ high compression and make sure your timing isn't advanced too far when you first break the engine in. You can find the timing threshold later, and run a colder plug if need be.

 

Cool thanks

 

Not a problem. Good luck bro.

 

is it bad not to run 12.1+ compression when ur boring ur engine between 84-85mm..i'm asking cuz i'm afraid of running such a high compression and something happening (its gonna be a daily driver) i don't want to go over 12.1 compression..is that bad?!?

 

Not at all. This decision should be based on your cam choice as much as anything though since a high ABDC cam will cost you compression.