I have a 1980 L82 and I love the fact it was the last of its kind but I know those engines are to say the least undertuned and underpowered. I know the stock compression is a 9.0:1 and as far as upgrades go I have put moroso wires irdium plugs a msd disbutor and a edelbrock intake and 650 carb. I would like to get some decent power and torque from the engine, I know i need to replace gaskets and seals, and I know the previous owner put a cam in it but I can't find the specs for it. Is there a way I can bump the compression to a respectable amount without having to have the engine bored and a new crank assembly dropped in?

 

shave the heads a bit and put the thin felpro gasket on it that will give you a small bump. make sure your distributor is set up with the right curve. they come out of the box lousy.ive seen a lot of guys put a performance distributor in straight out of the box and complain that the car runs worse.

 

You don't have to spend bushels of money and change everything.
Replace the stock air cleaner element with a K&N type, and recurve the distributor. Do what you can to free up the exhaust flow. If your state will allow it, install headers and a pair of high flow mufflers. Use an air/fuel gauge to set up your carb.
300 HP. Easily.

 

Should i look at rebuilding the heads in anyways or fashion and Im going to put on some sidepipes

 

I did a Performer intake and carb on my '79, along with new MSD distributor, K&N filter, and Corvette Central exhaust (patriot headers, true dual pipes, and Magnaflow mufflers). It runs ten times better than stock, but I am thinking about also swapping the stock rocker arms for 1.6 ratio full roller rockers, as long as I can get ones that fit under the stock valve covers. If I can get a little more power this way I will put off a full rebuild or new crate motor for another year or two.

 

The honest truth is that the stock L-82 heads are very prone to cracking - all smog heads are and the L-82s, with the 2.02/1.60 valves are significantly more likely than the L-48 heads. I'd go with the advice of re-curving the distributor and setting up a good exhaust system, that will be a huge increase. Not sure about 300hp, but it's probably not far off the mark. I'd expect an easy 30-40hp boost from it.

 

The L82 engine has the large valves in the heads. Leak down the motor to find out if everything is sealing well. If the leakdown test is good, and you're not burning oil or using coolant, the heads are probably fine.
Sidepipes are a great visual, but a 2 1/2" true dual exhaust, a pair of high flow mufflers and a balance pipe under the car will probably flow better, make more HP, (less noise, if you care) and use less fuel.

 

My 78 L-82 (66,000 miles, 4 speed with 3.70 gears) has been on the dyno 2X in the last year with the highest RWHP, NOT Net or Gross HP, of 233 RWHP and another pull resulting in 273 RWTorque with the following:

Internally the engine is totally stock L-82 with OEM crank, L-82 cam, rods, pistons, 882 heads etc. Nothing changed inside-never opened-YET.
No pollution control at all
McJacks shorter headers, Monza Turbo Mufflers and 2.5 inch duals
Holley 4175 650CFM spreadbore with the lightest vacuum secondary spring.
OEM dual snorkel air cleaner housing with K&N air filter
Comp Cams 1.5 roller tipped rockers

233 RWHP is about 275 NET HP which is how cars since 1972 have been rated-Not bad BUT I do have a weak #6 cylinder with only 90 PSI versus 160-165 PSI on the others-the dyno pulls were all done with the weak cylinder so the actual RWHP is something higher than 233 RWHP, probably around 240-245 RWHP with 8 strong cylinders.

I am planning to remove the 882 heads after a leak down test since I think that I have a head problem-blowing smoke through the passenger side valve cover breather. Assuming it is a head problem, I am thinking of replacing the heads with AFR 180 65 CC heads and a Howards roller cam with an operating range of 1200-1400 to 5,500-5,600 RPM-OEM bottom end and don't plan to rev to 6,000 or beyond. I intend to use the Felpro .015 head gasket and combined with the 65 CC heads along with the L-82 Flat top pistons, I am hoping for a compression ratio just north of 10:1. Hoping for around 310-325 RWHP-Not Net or Gross. Almost all crate engines are highly inflated HP ratings since they are rated at Gross, not even Net.

Bottom line-a stock L-82 with essentially headers and a good 2.5 dual exhaust ( no emissions) should make close to 300 Net HP. You would need about 255 RWHP on a dyno for about 300 Net HP.

 

Just curious, does the car have a point where it feels like "it comes to life"? You mentioned that the previous owner allegedly did a cam swap. If the torque converter is not matched to the cam, the car will feel like a mutt.

 

Good news is with a change in dist. and carb your not a it must be all original person. As mentioned 80 exhaust is pitifull but you need to get rid of the 76cc chamber heads for 64cc chamber aftermarket heads. not only better compression much better chamber shape and worlds better airflow through the heads.

 

Your statement is correct, aside from the discussion of chamber size. A 64cc head does not necessarily perform better than a larger chamber head, in fact, a larger chamber head may perform better. Just not the OEM smog heads.

 

The chamber shapes in all aftermarket heads regardless of chamber volume are worlds better then what was put on back in the 60s, 70s. The 64cc volume simply raises compression which is another good thing needed for a smog era 350.

Buy yourself a set of aftermaket heads get rid of the 60s, 70s crapola. Theres 50 yrs of knowledge gained on runners and chamber shape advancements already cast into them and if your willing to pay enough everything from chambers cncd to ports.

AFR, Dart, Edelbrock have constantly been upgrading there heads. Brodix has a IK180 totally cast head but its many yrs old without any improvements. But any of these heads are light yrs better then what was done by the factory 40,50 yrs ago.

Bronz guides were created to fix the SBC **** poor valve guide wear problems lol.

The old factory 2.02/1.60 valve heads flow 195cfm the lowest one i mentioned on airflow the Brodix IK180 flows 245 cfm. Thats roughly a 25 percent increase in airflow, add in a bump in compression, well compression is extra torque. Torque X rpm even more horse power. You buy an AFR head you could be up there 30 percent or more on airflow. You can buy new american made quality heads for less then $1000.00 now that outflow the Brodix IK180 head.

 

I agree with you 100%. Just wanted to point out that the first statement was misleading due to the mention of chamber size. I knew what you meant.

 

I replaced my crap 624 heads on my 84 C4 with some Summit 152123 large valve cast iron heads which are made by dart for $630. They have modern fast burn 72 cc chambers, screw in rocker studs, .525 lift springs, and angle plugs. I also have a zz4 intake, 600 edel. carb, stock factory shorty headers, isky z-20 cam, true dual exhaust with no cat. No dyno numbers or dragstrip time but the seat of the pants increase in power is awsome!

 

My L-82 in my 79 is has a bone stock bottom end, an unknown bigger cam (the engine was rebuilt by the PO, and he couldn't find the paperwork on it, but it has a noticeable rumpity idle) headers, true duals and no smog. It also has a q-jet and recurved stock replacement HEI. I'd be willing to bet it's putting out right at 300HP. I'd really like to upgrade to new aluminum cylinder heads for the above mentioned reasons. I'd love to have the car fast enough to run solidly in the 13's.

 

With heads and a cam why don't you put it in the 12s?

 

check out competition products for head prices.consider comp cams ex268h,nice power gain with good street manners.

 

I guess i never got over a forum member taking a set of factory 1.94/1.50 heads and spending $500.00 on them at a machine shop putting in 2.02/1.60 valves even though that might have been two yrs ago now lol.

 

A lot of people here spend a lot of money trying to save money on engine builds.

I saw some flow numbers for LT-1 heads... horrible. Putting money into a set of late 70's heads makes no sense at all for a performance build.

Vortecs are leaps and bounds better than LT-1 heads, let alone smogger heads, and they're junk compared to just about any U.S. made aluminum head. (ProComp, I'm looking at you...)

 

Don't forget the tranny, as friend of mine with a 79' L82 4 speed 3.70 axle car, put in a Keisler TKO 5 speed tranny kit with 3.23 1st & 5th od 0.68, with true dual exhuast, and really woke it up, not to mention much better highway cruising. Lars Grumsrud was coming though town with his $150 tuning seminar, and offered to take the car for him, got got forgotton. He later spent about $600 bucks at the dealer to have the Q-Jet and dizzy tuning done. I have his original L-82 GM dyno pull, showing the rated 225 hp@5200 rpm, with a little more hp@5600 rpm. If interested, PM an e-mail, and I'll send it. Mark