DucatiDon

Started a new thread.
What started as a new exhaust project turned into a major top end overhaul. 78 Pace Car L82 Auto. Had a slight miss when I bought it. 35k actual miles, in very good condition. Replaced a burnt plug wire, but problem didnt go away. Finally pulled the valve cover and found a rocker arm totally off the valve, pushrod bent. Replaced pushrod, and it bent again. Pulled intake to check lifter, and found it locked solid.

Decided "while Im here" to go ahead and order a set of AFR 195cc heads, Perf RPM and some roller rockers. Going with a .015 head gasket for 10.25 compression. Not replacing cam at this time. If it decides to go, then Ill pull the motor and punch it to 383+.

Oh, and dont have your buddy pressure wash your intake manifold, or it will end up like this:



Factory 2.02 GM 882 heads:


Factory L82 Flat Top Pistons

hugie82

I would use eagle1 mag cleaner for cast aluminum rims. The one that has the warning not to use on clear coat.

Using a .015 head gasket is looking for trouble (leaks) on a well used motor. You're better off milling the head .010-.015 and use a .030 for better sealing.

Question, are those stock L82 pistons? It's been a long time since I've seen a stock one opened up...

DucatiDon

Well, I am assuming those are the stock pistons, although there was a felpro head gasket on it, so perhaps its had a rebuild.

The answer is Yes, stock pistons. No overbore. .025 deck height.


474190 High Performance Piston
This piston is for 71-80 L82. Piston OD 3.998 to 3.999". This 350 standard, pressed pin, high performance piston has a 9:1 compression ratio with 76cc head chamber volume (ID# 336747, 464664 or 464692).

7t9l82

doesn't look right to me. also just so you know you don't "punch" it to a 383. it requires both boring the block and installing a longer stroke crank . hopefully it works out nice project.

cardo0

Yes those are stock forged pistons as the L82 is easily modified for performance and can take it too. L82 had a good performance cam too but weak heads and smog tuned. I wouldn't be surpirzes if there is forged crank inside.
My only recommendation is if u run aluminum heads u need a good head gasket. Do a google search as Aluminum heads don't like every MLS gasket. They seem to work better with a graphite head gasket and/or a deck finish of 25-30Ra (Rh?) - they need to slide around some. Nothing can be done with the block deck while still in the car but the head gasket can be optimized. Or u may want to stay with iron heads but the larger chamber will some power behind - less effective. I like my World Product Torquer II's - pocket ported with 67cc chambers but don't know what c.r. that will leave you with.

Good luck and thx for posting as i was wondering if my bad news diagnose was correct (or just painful).

cardo0

DucatiDon

AFR recommends the Fel Pro 1003. Im going with the 1094 for perfect quench and a bump in compression. Ill take extra time cleaning and scotch brighting the block face prior to install.

redman76

I'm using same gasket with my alum heads. I cleaned surface good with ScotchBrite on old L-48 block. Did 3 years ago and no leaks. Sounds like you'll have a nice setup when done; should put a big smile on your face.

garygnu

use old head bolts to clean out the head bolt holes.screw them in but don't bottom it out.remove the head bolt and clean it off.do it several times for each bolt hole.

DucatiDon

Ive run a thread tap through all the holes, scotch brite and sanded the deck face.
I hope to mock it up and fab the AC bracket prior to install. (HIgher ports means the bracket needs to be modified)

More pics to come.

cardo0

Interesting - sanding the deck. I suppose if using a 2x4 for a sanding block u may get usable results. Becareful of all the sanding debre - u would want to cover the lifter valley and put something in the cylinders to keep the grit and tailings out.
You may a good idea here to finish the deck without machining.
Please post your results,
cardo0

dochorsepower

I'd suggest some more investigation into the lifter problem. Why did it happen? Is there an oiling problem? Is the cam OK at that location?

Good decision to upgrade from the old 882 heads. You'll be glad you did.

DucatiDon

Getting there...

cardo0

Man that looks sweet. What cam did u choose?

cardo0

DucatiDon

Went with a Howard Cams Hyd Roller 230 duration .50/.51 lift.
$200 cheaper than the Lunati.

Didnt want to chance the cam and having to do everything twice.

Next time it will be a 383 rebuild.......

Kinda want to do that to my 63 too.....

DucatiDon

Digging in to replace the cam....
No piston skirts or any other debris in the pan...Excellent!
Oil pan and fuel pump off...Balancer and front cover next...

cardo0

Once u have the dampner off give the crank snoot a tap with a metal wrench. If u can hear it ring it means its a forged piece. Also a forged crank will have large parting lines down its length. Just nice to know what u have to work with.

Man with that much cam and those heads your gonn'a make some real power.

Good luck and post your results,
cardo0

DucatiDon

Im sure its the factory forged internals.

DucatiDon

And in case you wanted to know, Yes the radiator and hood must come off an AT/AC car to do a cam swap. I think its easier to pull the motor to do it btw.

DucatiDon

Good time to replace the oil pump too I guess.

hugie82

Oil pump is a cheap up grade. Just make sure the pick up Tube is secured, weld or screw.
That is a really clean engine! How many miles are on it?