Need4Camaro

iTrader: (1)

Both motors are the same displacement...

LQ9's have a CR of 10.0:1 and make 345 HP
L76's have a CR of 9.6:1 and make 366 HP

Is it the heads the L76 have are so much better than the LQ9's that they would have a 50 HP advantage if both engines ran similar compressions? Or is it the tune?

What kind of heads do the L76 use anyway? Are they the L92 heads?

Can I build a LQ9 with L76 heads, tuned for 87 Octane and run a mild cam and hope for 400 HP? or at least 380 and 420 when I run premium gas?

Bo185

You mean the L76 truck motor? Right?

The L76 truck motor has VVT and the L92 heads and 87mm TB. And they are that much better.

You can run the L92's on the LQ9 with the LS3 intake and make that HP with a cam easy. Probley more toward 450hp maybe.

Need4Camaro

iTrader: (1)

I meant the L76 that was in the Pontiac G8 GT but yeah that sounds like it. The LS3 intake, is it as good as the LS6 intake or will the LS6 not bolt up to it correctly or something? And would I beable to run that setup on a conservative tune so I can use 87 Octane if 91 or 93 isn't available without suffering detonation?? Will I be at 400 HP on 87 Octane?

BlueBird346

iTrader: (13)

The LS3 intake is a square port intake, opposed to the LS6 being cathedral port. L92 heads are square port.

the_merv

iTrader: (88)

One is a truck engine and the other is a car engine..the car engine has better Heads & Intake, and a bigger Cam.

Combine them both and make lots of power..

Need4Camaro

iTrader: (1)

I see. basically an LS6 intake will not work in this case correct?

Just curious are their any aftermarket intakes comparable with the LS3 intake?

Using the L76 Top End, won't I be making just as much as a stock L76 (unless I cammed?)

the_merv

iTrader: (88)

The LS6 will not work with the Square-port Heads. Any Cathedral Intake will not work with Square Heads.

Me personally I think the L76/LS3 Intakes are doin pretty good in stock form..I can't justify spending $1k on the FAST stuff when it's not really that big of an improvement.

If you take a LQ4 stock bottom-end and put some L92 Heads on it..mill the Heads & try to match the compression of the L76 Car engine..then you will get close to the same power in stock form. With the correct Cam you will make some nice power.

Need4Camaro

iTrader: (1)

I see, I thought the L76 used the L92 Heads? Why would they need to be milled to match the compression of the L76 for the LQ4 if this is the case? What cam would you recommend that would allow me to use stock valve springs and the like on those heads?

the_merv

iTrader: (88)

Yea, the L76 uses the L92/LS3 Heads. The L76 is the name of that Engine, the Heads are known as L92/LS3 (some people call them L76 Heads..the Engine actually came out in a Holden as a 6.0l L76 before it was here in the states, Holden is Australian)
The L92 Intake is the Truck Engine Intake, the L76/LS3 is the Car Engine Intake.

The L76 Car Engine has higher-comp. Pistons than the Truck Engine does.

What is the max lift on the Springs?

Bo185

The Truck L76 has 9.5:1 CR with dished pistons flycut for VVT

The L92 has 10.5:1 CR. with flat tops flycut for VVT.

Pretty sure the car L76 uses the flat tops as well.


The LQ4 has dish piston hense lower CR. The LQ9 has flat tops more CR. Milling will increase the CR on the LQ4.

Steelo00GT

Actually the cam is not that big in stock form. Thanks to DOD.

L92 heads with the LS3 intake.

hymey

L76 has around 10.4:1 comp says it in the owners manual anyway lol.