Bare Straight from GM L92 Heads
Bare Straight from GM L92 Heads Does anyone know if the bare heads from GM are fully machined and ready for assembly? If I dont have to I dont want to buy assembled since I will have to swap the springs.
Thanks Bob
Thanks Bob
LS1Tech Sponsor
Joined: Feb 2006
Posts: 1,170
Likes: 1
From: Rockfield Kentucky
Robin
My set just came in. Like Robin said they are ready to be put together. From the research that I've done these heads kill low rpm torque and power. The ports are so large they don't flow well at low lifts and engine speed. Go figure GM is using them on trucks. I 'm sending mine to The Head Shop and having them Flowed and welded up by hand. You need to get the lite weight LS3 intake valves for them. The exhaust ports don't flow well out of the box, again it was made for trucks. The cam is the million dollar question, if you can find the right grind for these heads they should be the next greatest thing. They will put AFR , TrickFLow etc. to shame. My humble opinion. The stock GM cams are exhaust biased and have a large LSA. Do a Go ggle search for L92 heads and find the Car Craft article on them. They made like 68 hp over a stock 6.0 head but it was all up on the top end.
I bought 2 sets of bare L92 heads, this is my opinion,
Fresh out of the box, they looked terrible. Like they weren't completely finished in the machining. The decks were way rough, same thing for the intake and exhaust flanges.
In the ports, there was clumps of material like slag, a couple of the larger pieces were circled with a paint pen. The valve guides and seats looked great, but the other stuff I didn't like. The first set, I figured were quality control rejects (the paint marker on the slag in the ports). But 6 months later, I had the dealership warranty them for me, and the second set was similar.
So I sent them to Rich at WCCH to get the full CNC treatment, and decking. that took care of that!
Fresh out of the box, they looked terrible. Like they weren't completely finished in the machining. The decks were way rough, same thing for the intake and exhaust flanges.
In the ports, there was clumps of material like slag, a couple of the larger pieces were circled with a paint pen. The valve guides and seats looked great, but the other stuff I didn't like. The first set, I figured were quality control rejects (the paint marker on the slag in the ports). But 6 months later, I had the dealership warranty them for me, and the second set was similar.
So I sent them to Rich at WCCH to get the full CNC treatment, and decking. that took care of that!
Staging Lane
Joined: Aug 2008
Posts: 71
Likes: 0
From: Miami, near the U.S.A.
L92 heads on an LS2 stock short block will drop the compression to about 10.4 to 1. You need to mill to get the compression back, and notch the pistons if you are going to use a decent cam, in order to get performance across the RPM range.
I plan on a stroker kit so I can take care of that problem.
Trending Topics
Staging Lane
Joined: Mar 2008
Posts: 80
Likes: 0
From: ballarat.vic.australia
bcar,
i have been using these cylinder heads in stock condition(except v/spring)for a while now
l76/92/98,they flow very good ,contrary to some people,the main thing is not over cam them.they dont like too much overlap especially genuine 10.5:1 to 11.0:1 comp streeters,
i have a set on a 10.5:1 427,with 236/246@.050",114l/c,it makes 499.5ft/lbs torque under 2750rpm, try 550/550@5300rpm through full exhaust on engine dyno.std l76/92/98 intake used also with 90mm holley t/body.
hope this helps,any questions feel free to shoot a message.
cheers dave
i have been using these cylinder heads in stock condition(except v/spring)for a while now
l76/92/98,they flow very good ,contrary to some people,the main thing is not over cam them.they dont like too much overlap especially genuine 10.5:1 to 11.0:1 comp streeters,
i have a set on a 10.5:1 427,with 236/246@.050",114l/c,it makes 499.5ft/lbs torque under 2750rpm, try 550/550@5300rpm through full exhaust on engine dyno.std l76/92/98 intake used also with 90mm holley t/body.
hope this helps,any questions feel free to shoot a message.
cheers dave
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo I just got my heads today. They look ok out of the box, they have some sharp edges on them. The ports are nice, not much casting flash. The LS3 Intakes valves are lite they weigh 87.6 grams. Compared to the stock LS1's at 101.2 and the LS6's at 73.6. The exhaust weigh in at 90.6 about the same as a stock LS1,and the LS6 at 65.2. I hope to find some lite exhaust valves. The 550 engine horse power is good, I was maikng that with LS6 castings I'm hoping for more with these heads. It looks like your cam grinder has the 92 castings figured out, your torque numbers are good. What rpm do you shift at and is the cam a hyd. roller?
