l82 performance parts
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1st Gear
Joined: Sep 2011
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l82 performance parts
newbie here. Just picked up a 78 vette with 96k miles. Have lots of questions. Im pretty sure my car has the l82 motor. but 220bhp is not enough for me. I looked around and cant really find too much info on these motors nor can I find many performance parts. Can anyone give me some links? What would yield significant performance without costing my right test? Cams, heads, exhaust, etc?
Le Mans Master
Joined: Oct 2010
Posts: 6,930
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
you didn't search really hard! the L-82 is actually. about 300 h.p with a good dual exhaust. the rating system was changed in 1972 and implies a lower rating. the L-82 has a 4 bolt main block a forged crank good rods and forged flat top pistons and the 350 h.p 350 cam. it also has the large valve heads so its a strong foundation. if its in good shape and nobody has changed anything i would suggest advance the cam 4 degrees a good dual plane manifold headers and dual exhaust. also set up your distributor curve. if that doesn't put a smile on your face there are endless possibilities. good luck
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Le Mans Master
Joined: Sep 2004
Posts: 5,116
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From: Livonia MI
As mentioned, you've got a pretty good foundation there, but also some miles too. You seem to be on the right track on the mods you mentioned, but really think I'd pull the motor, and have it rebuilt. Think the biggies you mentioned are uncorked non catted dual exhaust, and higher compression heads/pistons. Talk with some of cam manufacturers on more modern designs for you new set up. Dont forget carb rejetting.
Le Mans Master
Joined: Jun 2004
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From: Seattle WA
St. Jude Donor '14
Agreed with most of your comments, but this one I'd push back on.
Advancing the cam just moves the power peaks down about 500 RPM or so. Depending on gears, etc. it might feel like it has more grunt, but it's a heckuva lot of work for such a small change IMHO.
Advancing the cam just moves the power peaks down about 500 RPM or so. Depending on gears, etc. it might feel like it has more grunt, but it's a heckuva lot of work for such a small change IMHO.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
This is the key - bazillions of parts and everything fits
A budget really helps steer here, but typically the path to more power is a good tune followed by intake/exhaust...and then heads/cam. As noted, it's a darn good engine in it's own right and a good foundation to build on.
Money = HP. Tell us how much money you want to spend, and we'll tell you how much power you can make
Le Mans Master
Joined: Oct 2010
Posts: 6,930
Likes: 843
From: melbourne florida
2023 C3 of the Year Finalist - Modified
advancing the cam in this case is putting the timing where the cam was designed to run. back in those days they retarded the cam for emissions killing power and cylinder pressure.push back if you want but on 6 different L-82 engines it was a consistant 3 tenths with no other changes. no reason to think today is different.that is a good return in my book.
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Le Mans Master
Joined: Oct 2010
Posts: 6,930
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
no question a modern cam would have more potential, but I've seen people change cams and loose power too. my 78 back then ran a 13.80 at 99 m.p.h at 75-80 dragway in Maryland with my then girlfriend driving. i was racing elsewhere that weekend and didn't know that till last November. but still that's great for a "STOCK"car.
Instructor
Joined: Jun 2010
Posts: 131
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From: Shreveport Louisiana
no question a modern cam would have more potential, but I've seen people change cams and loose power too. my 78 back then ran a 13.80 at 99 m.p.h at 75-80 dragway in Maryland with my then girlfriend driving. i was racing elsewhere that weekend and didn't know that till last November. but still that's great for a "STOCK"car.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Le Mans Master
Joined: Oct 2010
Posts: 6,930
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
this goes back to 1979-80 but if i remember correctly i advanced the cam pocket ported back cut valves shaved the heads thin gasket headman headers with side pipes,a transmission shift kit L-t1intake 780 Holley and 3:55-1 rear. i may have missed something but don't think so i know i put a Vega converter in it at one point.
Drifting
Joined: Jul 1999
Posts: 1,542
Likes: 43
From: Plano TX
The L82 cam was good in it's day but more modern cams should be considered. The bottom ends are strong but at 90K miles mine needed a rebuild due to piston slap and wear for the forged pistons. Also the L82 heads are old gen and not worth rebuilding.
I decided to pull the L82 for a rebuild later and went with a ZZ4 with modern roller cam. Wow what a difference and there's more potential in the engine.
I keep thinking of rebuilding the L82 block into a more agressive/track day motor but keep thinking of going with a later roller cam block instead of a roller retro-fit kit. This way I can keep going from one motor to the next as I fix them up with only swap time keeping the car of the street or track.
I decided to pull the L82 for a rebuild later and went with a ZZ4 with modern roller cam. Wow what a difference and there's more potential in the engine.
I keep thinking of rebuilding the L82 block into a more agressive/track day motor but keep thinking of going with a later roller cam block instead of a roller retro-fit kit. This way I can keep going from one motor to the next as I fix them up with only swap time keeping the car of the street or track.
Le Mans Master
Joined: Apr 2007
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From: Graceland in a Not Correctly Restored Stingray
Good foundation, but IMCO a complete precision rebuild is needed. This just isn't the place to cut corners if the word "performance" is operative.
As well as being out-dated, the particular L82 head castings used circa '78 have earned the nickname "crack-o-matics" for a reason (BTDT), so I'd be looking seriously at a set of AFR 180's or 195's. I'd put the CR at ~10:1 and cam accordingly (tired of debating what that means). Suggest a 112* LSA if you wish improved manners and flatter torque curve; less if a lumpier idle is a higher priority. Either way, I agree with billla not to get radical with advance. My $.02
As well as being out-dated, the particular L82 head castings used circa '78 have earned the nickname "crack-o-matics" for a reason (BTDT), so I'd be looking seriously at a set of AFR 180's or 195's. I'd put the CR at ~10:1 and cam accordingly (tired of debating what that means). Suggest a 112* LSA if you wish improved manners and flatter torque curve; less if a lumpier idle is a higher priority. Either way, I agree with billla not to get radical with advance. My $.02
Le Mans Master
Joined: Sep 2004
Posts: 5,116
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From: Livonia MI
Agree, cam selections really gotta be matched with the whole set up, such as intake, compression, head flow and exhaust. Thats what cam manufactures phone tech lines are for. Keep in mind a couple things. Most of these places will do a slightly different grind for wider LSA and such. Also, some street grinds already have advance built in. Check the cam card before dialing in any more. I use a degree wheel, dial guage, and offset bushing set when assembling mine.
6th Gear
Joined: Apr 2011
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I'm a new member and also a new owner of a 1979 Corvette L82. I should say I think it is a L82 but I have some questions. I just check a list of casting numbers and to my suprise it looks like it is a 2-bolt 305. I'm not very happy! the casting number is 14010202. I can't understand although it does have the alum. intake the electric fan switch on right side of engine and the large therm. switch on left head. Could someone please help bring some light on this matter.
Le Mans Master
Joined: Mar 2008
Posts: 5,948
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From: Oxford MA-----You just lost the game!!!!
I'm a new member and also a new owner of a 1979 Corvette L82. I should say I think it is a L82 but I have some questions. I just check a list of casting numbers and to my suprise it looks like it is a 2-bolt 305. I'm not very happy! the casting number is 14010202. I can't understand although it does have the alum. intake the electric fan switch on right side of engine and the large therm. switch on left head. Could someone please help bring some light on this matter.
Anyway, without being there to look myself, it looks like you may have a NOM (Non Original Motor) It's not uncommon, these are pretty old cars. Go and start a new thread, call it something like "How can I tell if motor is original?" something like that, and try to give as much info as you can. Good luck, and again, welcome to the forum!
Scott
