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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by 79-L-82
Before you flame, please give it some thought.
I don't have money for new heads. I can barely afford an intake.
I have heard that the L-82 heads are not very good and prone to cracking.
Mine is a low mileage car and no problems.
I can get machine shop work done very cheap.
Would it be worth it to have some clean up, 3 angle valve job and perhaps mill the heads to achieve more compression?
How much can be done to these castings? Car is not a driver, just a weekend cruiser that I want some more power out of.
I plan on keeping the stock cam, replacing the exhaust and intake.
What can I expect if I have work like this done to the heads?
Thanks.
why not add porting to the heads also....who knows how much more you will get....you will get more then what you have now and those are real modifications....if thats where your money goes the farthest then do it...
If you can get machine shop work done cheap, perhaps you should hunt around for a set of double-hump "fuelie" castings and have them redone.
If you mill the heads, remember that you'll also have to mill the intake to fit the new angle.
With the original heads, the "prone to cracking" issue occurs while they are being machined...you should have them magnafluxed before AND after the work is done.
You will definately get some more HP but I wouldn't do it... there is a risk of cracking them as mentioned above... you already have 9.5 compression ration, there would be a bigger improvement possible if you had the lower compression engine...
Even if you're getting the machine work done cheap, you'll need new gaskets, maybe some new bolts... and who knows what else breaks...
safe your money and get some aluminum heads when your budget allows it, just my 2 cents..
You will definately get some more HP but I wouldn't do it... there is a risk of cracking them as mentioned above... you already have 9.5 compression ration, there would be a bigger improvement possible if you had the lower compression engine...
Even if you're getting the machine work done cheap, you'll need new gaskets, maybe some new bolts... and who knows what else breaks...
safe your money and get some aluminum heads when your budget allows it, just my 2 cents..
What is the combustion chamber size on the stock heads?
the L-82 heads are something along the line of 73-76 cc chambers IIRC...and I think the factory Cr is more like 8.9 or 9:1 not 9.5:1...
A simple valve job isnt going to net you much and the deck thickness on those heads isnt much either, yes you could knock a couple of thou off for a slightly higher CR but depending on the quality of Gas in your neck of the woods that might work against you.
Your best bet would be to get some minor porting done on those heads to improve the flow characteristics of them..stay out of the combustion chamber as any work done their will reduce your CR...but some bowl blending and some work in both the intake and exhaust ports would yield some benefits.. provided they are done for cheap.
Otherwise a set of Vortec heads which are about the cheapest you will find on the market and arguably are better than the vaunted "fuelie" heads would be your best bet for the money.
They are lightweight & have irregular intake ports. Nevertheless, they will work for you. Spend as little as possible on them. The head situation was why World Products brought out their cast iron heads.
the L-82 heads are something along the line of 73-76 cc chambers IIRC...and I think the factory Cr is more like 8.9 or 9:1 not 9.5:1...
I thought it's 8.7CR for the L48 and the L82 has 9.5 ... well, anyway.... if it's only 9.0 CR then you'll see some nice improvements with porting, milling to about 10.0CR and a valve job...
10.0 CR should be fine with 93 octane gas - any objections ??
Objections? You bet! I removed the intake yesterday...and found this:
The intake ports are have a very irregular shape...and there is not enough metal there to grind them to the correct shape, either!
These heads are good for one thing: a doorstop.
I never saw my original heads, it had aluminum heads when I got the car.... I agree, these heads are not worth the time, money and effort ... safe your money for later...
Clean up the valve bowls with a pocket port job if you are tight on cash. Probably worth 15-20 HP on the top end. I would not mill excessively as there is not a lot of material in the deck surface. No other cheap mods I can think of that would be worth the time/effort/money. The factory flat tops make about 9:1 but if you need to bore it, you could buy pop-ups (but I would definately do heads instead)