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Main Area => General GS500 Discussion => Topic started by: V8Pinto on October 30, 2004, 11:02:04 AM

Title: Raising Compression
Post by: V8Pinto on October 30, 2004, 11:02:04 AM
I'm going to bump the compression up on my 89' by milling the head.  I don't want to lose combustion chamber volume though.  Is it better to mill the top of the cylinder block instead of the base of the head?

How much material can I remove on a stock motor before piston-to-valve clearance becomes an issue?  (I will clay it up before I start cutting but I'm just looking for a ballpark figure).  Also, do I need to slot the cam sprockets to degree in the cam or will it be *ok*?
Title: Re: Raising Compression
Post by: D-Day on October 30, 2004, 11:14:04 AM
Quote from: V8PintoI'm going to bump the compression up on my 89' by milling the head.  I don't want to lose combustion chamber volume though.  Is it better to mill the top of the cylinder block instead of the base of the head?

How much material can I remove on a stock motor before piston-to-valve clearance becomes an issue?  (I will clay it up before I start cutting but I'm just looking for a ballpark figure).  Also, do I need to slot the cam sprockets to degree in the cam or will it be *ok*?

Well.............by definition, you will lose combustion chamber volume, that is why you get higher compression.  Generally, you would mill the head, as then you don't have to remove the barrels.  

I believe you can remove 50 thousandths of an inch with stock pistons.  Somebody back me up on that.  You can leave the cam alone, and it will run fine.

Paul
Title: Re: Raising Compression
Post by: V8Pinto on October 30, 2004, 11:21:36 AM
Quote from: D-Day
Well.............by definition, you will lose combustion chamber volume, that is why you get higher compression.  
Paul

(chuckle) duhhh.  I just re-read my post and yeah.... hahahaha.  I'm going to go wrench on something now and stop trying to be smart hahahaha.