</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by ls1290:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by ls1290:
<strong>Thanks Bret, it does help a lot. Would say a dome of +4cc with 58cc chamber heads be excessive? TIA.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Bret, I would still like to get your $0.02 on this.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">The flame problem is due too the fact that that the dome gets in the way. Not alowing perfect burn. There's cars on here that have small domes that makes over 440 HP heads and cam.

Bret is 100% correct.. but it dose not seem like a 4cc dome is not larg enough too be a problem.. plus domes for the LS1 is pritty flat.

<img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by buschman:
<strong>Great post Bret, wonderfully informative. Not to hijack this thread but I got a question for you, or anyone else who can answer this. What happens if you thrwo FI into the mix? Keeping in mind I'm a novice and some of the stuff you guys are talking about is over my head at the time. but I'm trying to plan out my car logically. Rear is next then Heads/Cam and then FI(Not sure if it is super or Turbo yet). Do domed heads work better when there is boost in the chamber? Would that speed up the flash burn? Would 6.0L heads be a better investment for someone considering FI since they lower your compression ratio .7? I want to run over 10PSI of boost, is the LS1s compression ratio my enemy or is it the weak cast internals? I realize that I would not see as much rwhp gain as a set of heads that kept the same compression and increased flow, but how much would I be sacrificing?

Again excellent posts guys, I'm learning a ton <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Mike B.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">In a FI case run the heads but don't have them mill that will give you almost -1 extra cc after milled Chamber work is done. a dome hurts all motors. it's just the only way too get big compression. Engine builder have too test the trade off of losing and gaining. when building our motors too get the needed Compression we always start at the head. But there are times when you are going too have too get that dome. it just works out that way.

<img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

 

Okay.. now too answer your original post..

The LS6 and 6.0 heads Intake port is diffrent.

However The max flow our head porters got out of The LS6 is 345CFM, This head feeds a 418 too 7800RPM making over 650hp(flywheel)

The Max flow our head porters got out of a 6.0 head on the same bench is 330CFM but the reaseach is still going on, and it seem that the 6,0 head in our shop will soon get up too it's big brother (LS6).

The 6.0 is on a 408 car that makes over 500 RWHP

And there is a similar set on heads cam cars that made over 440RWHP.

If you are building a High lift motor the LS6 is still the way too go. As the 6.0 heads our guy have makes 330@550 lift and level off. The LS6 heads pulls too 700 alot easer.

<img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> Hope this helps.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Phil:
[QB]Okay.. now too answer your original post..

The LS6 and 6.0 heads Intake port is diffrent.</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Are you sure you are referring to the LQ9 6.0 head? According to the LSx engine chief at GM, it is identical in every way to the LS6 head except for combustion chamber size.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by kewlbrz:
<strong>Are you sure you are referring to the LQ9 6.0 head? According to the LSx engine chief at GM, it is identical in every way to the LS6 head except for combustion chamber size.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Is the LQ9 chamber wider or deeper? If wider, would not milling the head 0.040" produce the same chamber as the LS6 head( LQ9 69cc : LS6 65cc ). So if this is true, for about $500( LQ9 heads $400 + $100 milling ) one could have LS6 heads. Of course, unported.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">If wider, would not milling the head 0.040" produce the same chamber as the LS6 head( LQ9 69cc : LS6 65cc ). So if this is true, for about $500( LQ9 heads $400 + $100 milling ) one could have LS6 heads. Of course, unported.[/QB]</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Not sure if they are wider or deeper, nor how much one would have to mill to get to LS6 heads chamber size. There is the problem of valve train geometry and intake port alignment issues to consider if milled to far.

 

The 6.0 and the LS6 have a very diffrent Intake port

Speedaholic
Engines & Cylinder heads

<small>[ September 19, 2002, 06:36 AM: Message edited by: One Monkey ]</small>

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by One Monkey:
<strong>The 6.0 and the LS6 have a very diffrent Intake port

Speedaholic
Engines & Cylinder heads</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Could you elaborate how they are different? Size, shape, pics?

thanks

 

I posted this last night. You might want to take a look at it (flow numbers from both heads stock):
https://ls1tech.com/ubb/ultimatebb.p...c;f=1;t=007587

 

Tring too explain too a none head porter is a bit hard... but the intake port on bouth heads is very diffrent. The short side, the Cylinder wall, the valve guide.. there are all diffrent..

I had this converstion here before. If your GM guy did say that. he's ether lieing too you, or don't know him self. There can't even be mistaken for each other. And I am talking just the intake port..
Brent

<small>[ September 19, 2002, 05:45 PM: Message edited by: One Monkey ]</small>

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">If your GM guy did say that. he's ether lieing too you, or don't know him self. [/QB]</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">He's not "my" GM guy. He is the Cheif Powertrain engineer for the LSx program. I beleive you if you say the LQ9 intake port among other things (besides the chamber size) is different than the LS6 head. I just find it baffeling that the Chief LSx Engine man at GM would say they are the same heads in print media.

 

The Powertrain engine guy is wrong. You can't say the new 6L truck heads are exactly the same as the LS6 heads because they are not.

Thats like half the people who say their car is bone stock except for lid, cat-back and gears.

Bone stock is bone stock, exactly is exactly.

Look at the flow comparisons that were posted earlier. The LS6 outflows the 6L truck on the exhaust side throughout the lift range, and beats it on the intake side over .4 lift.

Plus iron vs. aluminum. I doubt the printed media really cares or can tell the difference anyway. They just want the story and GM just wants people with 6L truck engines to think they have Z06 heads.

p.s. I work for GM

<small>[ September 20, 2002, 04:15 PM: Message edited by: soslo ]</small>

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by soslo:
<strong>Plus iron vs. aluminum.

p.s. I work for GM</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Now im really confused since you say you work for GM, because I am certain the LQ9 6.0 heads, that that powertrain cheif refers to as being identical with the exception of the combustion chamber size being larger for the 4.0 bore are in fact aluminum heads.