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Wooohooo
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Im sure there is a post on this but I have not been able to locate. What exactly is different from head to head. Would it be better to swap out to the LS6 and why? Or would it be just as beneficial to have our heads massaged a little?
 

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The LS6 head has a revised port design, both intake and exhaust. The exhaust is immediately recognized by its "D" shape vs. the oval shape of an LS1 head. The LS6 heads are equipped with very light weight sodium filled exhaust valves. The LS6 chamber side is slightly smaller, providing a touch higher compression.
 

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I like boobs.
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I'm willing to bet no, but with the light weight valves and such it would be capable of revving higher if their was to be power had that high depending on the cam and other mods.

Now porting a pair of LS6 heads on the other hand... ;)
 
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Head Clinic?

Brains said:
The LS6 head has a revised port design, both intake and exhaust. The exhaust is immediately recognized by its "D" shape vs. the oval shape of an LS1 head. The LS6 heads are equipped with very light weight sodium filled exhaust valves. The LS6 chamber side is slightly smaller, providing a touch higher compression.

All of that is true, but focus on the casting, not the valves. After you have sent them to us to be ported, the stock valves wont fit anymore. LS6 heads make more power, Its in the casting. :)
 

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Sent to YOU to be ported? Are you the only shop in the world that ports heads? :gr_jest:

Not to mention, you can port an LS1/LS6 or any other head and maintain stock valves, if it suits your combination. Also, larger valves still fit in the stock seats, within reason. The ever popular 2.02/1.57 combo are setup on the stock seats. Everyone has different goals in mind with their cars, it takes more than a one-size-fits-all approach... A lot of these folks seem to entertain "factory components" more than the F and Y body groups we're used to, so that's another factor.
 

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I know this is an old thread....but would like to revive it for some discussion.

When considering a h/c upgrade, I am kind of confused at should I be looking for improved Ls1 heads, or for LS6 heads?

I have seen some deals on LS1 heads, but I am not sure if I should be looking for LS6 heads instead. I am sure future mods have to be taken into consideration, but I would expect unless a moneybag fell off a Brinks truck all other mods would be genreally bolt-ons (exhaust, TB, etc.) and no plans for s/c type upgrades.

So, considering better valves, springs and pushrods would be in the equasion along with regular street drivability are expected, which makes the best sense?
 

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Another thing I believe they did on the LS6 heads was reduce the port angles to 18* from 22* on the LS1 heads. Those numbers might not be exact. But the concept behind it was to reduce the angle at which the A/F mixture has to turn to go from the intake runner into the combustion chamber once the valve opens.

As to which to use. There really isn't a defined "rule". I have a set of '99 LS1 heads in my garage that I will "work" in the future. The setup on my Camaro were LS1 castings also. Once "worked" the difference in performance between a set of LS1 and LS6 casting heads would be minimal. A lot has to do with the budget. For instance, a year ago when I picked up those heads, I paid $100 for them. Kinda hard to beat that cost. :)

Ples determining your heads also boil down to what compression you want to run, your cam choice and a bunch of other criteria that rely on other factors.
 

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Remember besides LS6 heads there are more options. If that Brinks truck does hit a speedbump you could use an LQ4 head. They are found on I believe 6.0 litre truck engine. Brings your compression ratio to around 9:1, good for force induction. Escalade heads (LQ9) are similar w/ its large 71.06 cc chamber volume. LS6 heads increases the compression ratio to 10.5:1, from 10.1:1. GM direct has a GMPP "Showroom Stock Racing" heads w/ Cham vol. of 63cc, raising compression ration to 10.8:1. good for NA purposes. Bottom line is think a head, theres a head for almost any application.
 

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Sodium filled exhaust valves aren't for their light weight. Although they may be lighter.
They reduce pre-ignition by having a cooler exhaust valve. The sodium liquifies and draws heat aways from the valve face. Thus allowing leaner AFR mixtures and a hotter, less det prone combustion.

Sodium filled exhaust valves work REALLY well on turbocharged cars which routinely run in 1450-1550f EGT range.
 

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Pontiac GTO said:
Interesting. Do you thing stock LS6 heads would out flow Ported LS1 heads?
Stock Ls1 Heads flow about 258 CFM, 10:1 Compression

Stock LS6 Heads flow about 278 CFM and have the lighter valves in 2002 and UP!!! only Chamber is 65cc = 10.5:1 Compression

Ported LS1 Heads Range from 270 CFM to 330 CFM

All CFM @ .550 lift.
 

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I read on one of the LS1 tech boards that the LS1 heads have higher flow velocity at lower lift rates thanks to smaller intake port size compared to the LS6. Leads to more torque. An important issue considering how much heavier the GTO is compared to an F-body. Difference is some 340lbs? Am I correct in that? Hey, I am new to Gen III engines. Have been digesting LS1 tech history and applications for only a few weeks. Pardon me if I am in error. I guess application depends on what the desired total package is being considered?
 
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