INTERNAL ENGINE MODIFICATIONS Valvetrain |Heads | Strokers | Design | Assembly

6.0L with 862 heads and compression???

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Old 09-26-2008 | 03:06 PM
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Your starting point is off. The LQ9 is 10.1:1
Old 09-26-2008 | 03:11 PM
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I'll entertain that idea to prove a point. Even IF I was off by that .1 compression point, that still leaves 10.9:1 instead of 10.8:1 with 243 heads.

And for the record, GM says 10.0:1

http://media.gm.com/us/powertrain/en...TEC60LGENIIIV8
Old 09-26-2008 | 05:13 PM
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Hey poopie pants, my LQ4 with 243 heads and stock 6L gaskets and the pistons being .014" out of the hole comes out to 10.6:1 comp. You need to know your piston to deck height as well
Old 09-26-2008 | 05:14 PM
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Originally Posted by GMCtrk
one of the guys who help me put in the LQ9 asked me if I wanted to stick my 4.8L heads on it LOL
I wouldn't LOL too much, I entertained the same idea building my 6L. It was more cost effective however to buy NEW 243's and have a guy port them locally than it would have been to buy heavily ported 862's from patriot.
Old 09-26-2008 | 06:00 PM
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Originally Posted by hirdlej
Hey poopie pants, my LQ4 with 243 heads and stock 6L gaskets and the pistons being .014" out of the hole comes out to 10.6:1 comp. You need to know your piston to deck height as well
that's what i'm planing to do except i would like to try to get close to 11:1.
Old 09-26-2008 | 09:00 PM
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If time permits I'm going to check piston to deck clearance. I'd also like to cc the heads after I get them done to be accurate. I have too many other jobs going on at the same time so I'm trying to fit this one in.
Old 10-06-2008 | 04:38 PM
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I picked up the heads today. BEI did them and they look very nice. I'll post pictures when I get home and start assembly.
Old 10-07-2008 | 09:56 AM
  #18  
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Checked piston to valve clearance last night. Exhaust side is .250" and intake is .133". This is with no head gasket in place and piston at TDC. Heads are now assembled with LS6 springs.
Old 10-08-2008 | 11:33 AM
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TI-89 yea baby! nothing like the Caddy of calculators

nt to hyjack but keeping the mathematicans working
what compression for LQ9, L92 heads, GM MLS gaskets?
I read 10.8:1 but felt like a double check
Old 10-13-2008 | 07:47 AM
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There is hardly any difference in the two Joe. I think you gained a tenth or two. You'd have to be down around 65cc or so to get the compression up that high.

The Tahoe now runs. Fired the 6.0L last night. Trans goes in tonight.



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