Paging Richard.

 

From what I've been reading the L76 is used in the Holdens cars, as well as the new Vortec Max silverado, is indeed a 6.0L.

http://media.gm.com/us/powertrain/en...New/07_L76.doc
http://media.gm.com/us/powertrain/en...lanche_SAE.pdf

 

The new L92 heads will be a nice upgrade for LQ4/LQ9 engines in our trucks. They're still a bit too new to get a sense of what combinations will produce what.
One things for sure, these heads will have fantastic airflow as compared to the cathedral style intake ports. We're working on a CNC program for these heads and at the moment we're focusing on the exhaust port as the flow is a bit low when compare to the intake side. The factory exhaust ports are the best flowing out of the box GEN 3 ports we've seen, but they need another 20-25cfm of flow at the peak.
As far as valves sizes are concerned, our valve vendors are making intake valves 2.160" and 2.180" with the proper length. Believe it or not, the LS7 valve diameters will actually fit quite comfortably (2.205"/1.615"). These of course would have to be used in large bore diameters (4.125" and larger).
I should also mention the price is also very nice. Although I haven't worked out total price packages yet, the cost of the bare castings is very reasonable as compared to aftermerket heads that are now available so assembled heads should be rather affordable.

Richard

 

Richard, arent the L92 heads actually GEN 4 heads?
So they would have the best out of the box GEn 3 exhaust ports, correct?

Yes the Holden L76 is a 6.0.

The Holden Ute SS 6.0L broke the Dodge Ram SRT-10 top speed record by over 10 mph. the Ute SS went roughly 167 mph.

peace
Hog

 

I'm kinda liken the Aussi Ute. Reminds me of my '68 El Camino only smaller and with a modern powerplant. The power to weight of an L76 in a Ute has to be very impressive. I wish the General would bring 'em here.

Hog you're correct about the L92 heads being a Gen 4, but I still catch myself refering to them as LS1 or Gen3 The exhaust ports are the best flowing factory cast finished ports yet. It's just the intakes ports are really, really good as cast. The exhaust has a 62-65% flow ratio and we'd like to see it over 70%. I've been doing some very extensive work on developing the exhaust ports to perform much better than stock yet leave enough material to prevent water leaks from occuring. It's not an easy task. My goal is a 245cfm exhaust port. I believe this will help make for a better street driver than a 360cfm intake will especially in FI applications.

Richard

 

Richard. It looks like this would be a good upgrade from my stock 317 heads. Would this be a plug and play if I purchased the heads, manifold and swapped the 918 springs. How would the cam work with the heads.

Please advise

Thanks

 

Cool Richard, i wasnt trying to be an ***, i am just rtying to keep all the new gen stuff straight in my head.

thanks and keep up the good work.

peace
Hog

 

These heads are still so new that specific combinations haven't been tested yet. The way I see it, the L92 heads in truck applications will make a nice wide power band with cams that are smaller in duration than what's currently being used. The L76 car intake whould be the intake of choice for maximizing the performance from these heads. Ideally the GMPP (Wegner) carb style intake would be the ticket for real hardcore setups.
Mr. Bond: Yes they would make a nice upgrade to the 317's. In as cast trim your compression ratio will decrease ever so slightly. Our CNC'd chamber will increase the chamber size at least 3-4cc. The 918 springs should work with your cam. If they have a lot of miles on them then I would put a new set on to be safe.

Hog: no offense taken here. It is after all, important to keep the distinction between the different engine groups. Thanks for keeping me straight.

Richard

 

Has anyone taken a look at whether the L92 intake flows better than an LQ4/LQ9 intake? I'd also be curious to know if the injector connectors and injector impedance are compatable with the Delco/Delphi Multec II injectors used on the Gen III truck engines.

Steve

 

Great question Steve
A while back I flow tested a L76 car intake, but I didn't have a L92 manifold to test. I'd like to see what that intake is all about. I think I'll root around for one.............

Richard