L82 vs 350?
03-26-2016, 03:07 AM
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L82 vs 350?
Hi guys.. its me again. lol so the chevy I bought does't have the original l82 engine.. instead it has a 350 stock they say? I dont know anything about engines.. I was just wondering what are the differences and which one is better... help? what if I want more horsepower? feels fast but I wouldnt mind faster 
03-26-2016, 07:00 AM
#2
Melting Slicks
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An L82 is a 350...just not the base 350 for any given year. The base engine would be the L48. The L82 was to be a hydraulic valve train version of the solid lifter LT-1. Besides the horsepower difference, the L82 would have a 4-bolt main for the crankshaft as opposed to a 2-bolt for the L48, a forged crank as opposed to the L48's cast, an aluminum intake manifold, different camshaft profile, heads and a number of other differences. Depending on what model year...there could be 20 or more horsepower difference...the L82 being the stronger.
It's still a 350...just some different parts and specs.
It's still a 350...just some different parts and specs.
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djllort (03-26-2016)
03-26-2016, 09:27 AM
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03-26-2016, 02:01 PM
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An L82 is a 350...just not the base 350 for any given year. The base engine would be the L48. The L82 was to be a hydraulic valve train version of the solid lifter LT-1. Besides the horsepower difference, the L82 would have a 4-bolt main for the crankshaft as opposed to a 2-bolt for the L48, a forged crank as opposed to the L48's cast, an aluminum intake manifold, different camshaft profile, heads and a number of other differences. Depending on what model year...there could be 20 or more horsepower difference...the L82 being the stronger.
It's still a 350...just some different parts and specs.
It's still a 350...just some different parts and specs.
03-26-2016, 02:02 PM
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03-26-2016, 02:17 PM
#6
Depends on your point of reference.
Compared to the higher compression L46 350 of earlier years it was not as powerful so people of the era grumbled about it. Compared to the other contemporary "smog" 350 engines of the era though (L48, L65, LM1) it was the best Chevy offered.
The L82 had good bones though (4 bolt, an okay cam, etc) so swapping to higher compression heads really woke it up back to L46 level of performance.
If I owned a 1977 L82 and it otherwise was running fine (no leaks, good oil pressure, etc) I would install a set of Vortec aluminum heads from a C4 Corvette on it for the effective 10:1 CR it would give (.050 head gasket), along with a corresponding aluminum intake manifold, and headers. call it done. HP is additive though so maybe you just want to start saving for a crate 383 now. :-)
Last edited by Dynra Rockets; 03-26-2016 at 02:28 PM.
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djllort (03-26-2016)
03-26-2016, 03:31 PM
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Depends on your point of reference.
Compared to the higher compression L46 350 of earlier years it was not as powerful so people of the era grumbled about it. Compared to the other contemporary "smog" 350 engines of the era though (L48, L65, LM1) it was the best Chevy offered.
The L82 had good bones though (4 bolt, an okay cam, etc) so swapping to higher compression heads really woke it up back to L46 level of performance.
If I owned a 1977 L82 and it otherwise was running fine (no leaks, good oil pressure, etc) I would install a set of Vortec aluminum heads from a C4 Corvette on it for the effective 10:1 CR it would give (.050 head gasket), along with a corresponding aluminum intake manifold, and headers. call it done. HP is additive though so maybe you just want to start saving for a crate 383 now. :-)
Compared to the higher compression L46 350 of earlier years it was not as powerful so people of the era grumbled about it. Compared to the other contemporary "smog" 350 engines of the era though (L48, L65, LM1) it was the best Chevy offered.
The L82 had good bones though (4 bolt, an okay cam, etc) so swapping to higher compression heads really woke it up back to L46 level of performance.
If I owned a 1977 L82 and it otherwise was running fine (no leaks, good oil pressure, etc) I would install a set of Vortec aluminum heads from a C4 Corvette on it for the effective 10:1 CR it would give (.050 head gasket), along with a corresponding aluminum intake manifold, and headers. call it done. HP is additive though so maybe you just want to start saving for a crate 383 now. :-)
So its juts better to upgrade to a 383? because I do have leaks
Last edited by djllort; 03-26-2016 at 03:31 PM.
03-26-2016, 03:33 PM
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St. Jude Donor '05
If you got the means do it
Most factory heads intake etc suck same with cams.
They were ok way back then but by todays stds pretty slow
Know a 383 can swallow more head cam and intake.Youll never go back to a smaller size engine again. Bigger is better
Most factory heads intake etc suck same with cams.
They were ok way back then but by todays stds pretty slow
Know a 383 can swallow more head cam and intake.Youll never go back to a smaller size engine again. Bigger is better
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djllort (03-26-2016)
03-26-2016, 03:39 PM
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recommendations?
03-26-2016, 11:24 PM
#10
Race Director
I can make your car loud with a pipe cutter.
To go fast, heads and a cam will go a long way. A proper engine rebuild with matched components and you can go real far. AFR 210s, a roller cam in the 230s, high rise intake manifold and 10.5:1 compression or higher and you'd be looking at near 500hp.
To go fast, heads and a cam will go a long way. A proper engine rebuild with matched components and you can go real far. AFR 210s, a roller cam in the 230s, high rise intake manifold and 10.5:1 compression or higher and you'd be looking at near 500hp.
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djllort (03-27-2016)
03-27-2016, 12:20 AM
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I can make your car loud with a pipe cutter.
To go fast, heads and a cam will go a long way. A proper engine rebuild with matched components and you can go real far. AFR 210s, a roller cam in the 230s, high rise intake manifold and 10.5:1 compression or higher and you'd be looking at near 500hp.
To go fast, heads and a cam will go a long way. A proper engine rebuild with matched components and you can go real far. AFR 210s, a roller cam in the 230s, high rise intake manifold and 10.5:1 compression or higher and you'd be looking at near 500hp.
03-27-2016, 01:06 AM
#12
Find a local engine builder near where you live. Do you have the skills and tool to pull the motor? If you can do it, talk to the builder and tell them what you want. Speed is a question of money, how fast can you go?
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djllort (03-27-2016)
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Sav Sim Tech (07-17-2022)
03-28-2016, 12:18 AM
#15
Melting Slicks
Better also consider rebuilding the transmission (and a new clutch if 4sp) when you do the high power engine swap.
Back in the day I had a '77 L82 4sp with 3.70 rear gears. Was stock except I had headers/dual exhaust installed. It went pretty good.
Back in the day I had a '77 L82 4sp with 3.70 rear gears. Was stock except I had headers/dual exhaust installed. It went pretty good.
03-29-2016, 09:14 PM
#16
Race Director
Ibanez is right. I built mine to be fast and reliable. Dart SHP 400 block, forged crank, rods, pistons. AFR 195 heads. Roller cam and decent lifters. Nothing crazy exotic. The bill was around $8k(which also included dyno time, a new clutch, hi-po water pump and scatter shield).
You can re-use stock stuff or scavenge to find things and take a lot of cost out. The parts that I mentioned, heads will be $1600-2100 depending on whether you go as-cast or performance ported. Roller cam plus lifters, expect $500-800 for "decent". Intake around $250. Headers around $250. Pipework from the headers back probably around $1K.
And you haven't touched the rotating assembly yet. A good reliable forged setup will probably run you another $2K or so. Machining may be soaked into that cost. So you're getting close to around $6k. You haven't touched the transmission, differential, half-shafts, tires, etc. But you will have a 500hp car.
If you re-use the stock stuff, you'll still need new pistons but you could probably cut that bill in half including machine work. If your block already has a forged crank and rods you'll be slightly ahead of the game. If it's a 2-bolt w/ cast rods and cheap rods, I'd put cash into better stuff at the 500hp level.
You can re-use stock stuff or scavenge to find things and take a lot of cost out. The parts that I mentioned, heads will be $1600-2100 depending on whether you go as-cast or performance ported. Roller cam plus lifters, expect $500-800 for "decent". Intake around $250. Headers around $250. Pipework from the headers back probably around $1K.
And you haven't touched the rotating assembly yet. A good reliable forged setup will probably run you another $2K or so. Machining may be soaked into that cost. So you're getting close to around $6k. You haven't touched the transmission, differential, half-shafts, tires, etc. But you will have a 500hp car.
If you re-use the stock stuff, you'll still need new pistons but you could probably cut that bill in half including machine work. If your block already has a forged crank and rods you'll be slightly ahead of the game. If it's a 2-bolt w/ cast rods and cheap rods, I'd put cash into better stuff at the 500hp level.
Last edited by Shark Racer; 03-29-2016 at 09:15 PM.