6.0 heads on a 4.8

Reply Subscribe

Thread Tools

Search this Thread

08-27-2004 | 10:58 AM

#11

Andy1

TECH Enthusiast

Joined: May 2004

Posts: 713

Likes: 0

From: SoCal

Quote:

Originally Posted by vanillagorilla

There's 3 types of 6.0L heads:
1.Cast iron pieces of ****
2. LQ4 12562317
3. LQ9 12572035

2 and 3 both have 71.06cc comb. chambers and 210cc intake runners, I'm pretty sure they're close to identical, and the cr diff in the LQ9 and LQ4 came from the pistons.

Your 4.8L heads have a 61.15cc comb. chamber, so in order to get back to stock 9.5:1 cr you need to lose about 10cc! Without milling them you would get about a 8.48:1cr, and if you took off about .050" that would get you back to 9.5:1cr.

I used Performance Trend's compression calc program......hope that helps!

What about piston to valve clearance issues? I depends on the cam lift/duration....is there any reference point to the stock cam for example?

Thanks,

Andy

Reply Like

08-27-2004 | 08:30 PM

#12

vanillagorilla

TECH Veteran

iTrader: (1)

Joined: Apr 2004

Posts: 4,038

Likes: 0

From: Arizona Bay

I'm not sure about piston to valve clearance issuse, or pr length. With milled heads, both of those do become an issue. My suggestion about the pr length would be to buy an adjustable pr length tool. And use it when you have the heads on, that way you can get the exact or almost exact size you need. As for the piston to valve clearance, the only way I know to check that, is with the head/gasket on, and with clay. If it's too close, a thicker gasket might cure it. But I don't know, since that's a pretty unique combo.

Reply Like

08-27-2004 | 10:56 PM

#13

Dark Halo

Thread Starter

TECH Fanatic

iTrader: (14)

Joined: Aug 2004

Posts: 1,505

Likes: 1

From: Texas

may be I will sell my 6.0 heads if they will not do anything for me. I do want to get a 6.0 motor, but it might take a little while. If I can some how make them work with out problems that would be great.

Reply Like