L-82 Head Upgrade
Thread Starter
Racer
Joined: Jul 2007
Posts: 269
Likes: 0
From: WV
L-82 Head Upgrade
Hey I am looking at buying some new heads for my 75 L-82 but I was wondering what would be a good swap and do I need to change anything in the bottom end I would really like to try and get into the 350-400 HP range. As of right now I have an Edelbrock Performer intake manifold a 600CFM Holley. I have a set of twice pipe side pipes, and the car has a really aggresive cam in it but I am not sure what the specs are on it the previous owner was unsure. The car has a pretty rough idle and a good shake to it. But upon tearing the motor down i plan on taking the cam out and getting it measured to be sure of what it is.
Le Mans Master
Joined: Apr 2005
Posts: 6,355
Likes: 425
From: Seattle Area WA
It sounds like your cam is too big for what you have going on there, all noise and shake for show and no go due to all that nasty overlap and excessive duration. The L-82 is a good forged motor but it has the large chamber heads. I think most folks would agree that a set of 64-67 CC heads would boost your compression and your performance, combine those with a cam that MATCHES the setup. For aluminum its tough to beat the Brodix IK180s. If you want cast iron, the Dart Platinums aren't bad either. You might want to look at a Weiand Stealth intake or RPM. My 2 pesos.
Racer
Joined: Feb 2006
Posts: 324
Likes: 0
From: South Elgin IL
Good points.If you want to keep your existing intake set up, either of those heads will work. I'd lean toward the Brodix IKs myself. The increased compression and flow will help no matter what you do with the cam. But you really need to get your cam sorted out.
Thread Starter
Racer
Joined: Jul 2007
Posts: 269
Likes: 0
From: WV
What is the difference between using cast iron and aluminum heads? Well once i get the cam out I will decide if its functional for what I am doing either way even if i get a new cam I will get the lifters and everything to match it.
Basically, the aluminum heads allow you to run at a higher compression without detonation issues due to their heat transfer rate.
Le Mans Master
Joined: Apr 2005
Posts: 6,355
Likes: 425
From: Seattle Area WA
Your stock L-82 has 2.02 and 1.6 valves so yes, sticking with them is fine. I believe your stock L-82 also is around 8.75:1 compression so bumping it up with smaller heads will require selection of a head gasket and cam that works with the resulting compression, but bottom line, yes you can run pump gas, it may end up being premium. Thats when you need to decide upon 64, 67, 68, 70, 72 cc etc replacement heads with a cam in mind. The stock L-82 cam for example would have no problem with pump gas because of its valve timing, bleeding off some compression. Angle or straight, your pick, it don't matter. I think the IKs are only straight plug.
Last edited by Scott Marzahl; Jan 13, 2008 at 01:53 PM.
