Increasing HP
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Originally Posted by bobs77vet
just add money............
Headers cam and heads good intake and carb will put you at 300 to 350 HP.
Melting Slicks
Joined: Jan 2004
Posts: 2,672
Likes: 1
From: New Cumberland PA
[QUOTE=captainmorgan]What would need to be done to a stock 77' 350 L82 motor to get it to 300HP?[/QUOTE
You didn't mention where you wanted the 300HP, the crank or the wheels. The stock L-82 should be somewhere around 210HP with accessories and cat-exhaust. People tend to forget that horsepower was rated differently back in the old, old days. Although I do not have numbers, a 69 350HP would be much less if measured by todays standards.
The first thing is to get a performace exhaust system. That will get you perhaps the most bang for your buck. No matter what engine mods are done, this will have to be done so you might as well do it first. After that the next upgrade is normally cam and heads. If your target is 300HP or over, then you should be able to get away with changing the heads. The bad news is that heads will cost $500 on up while a cam/lifter kit can be purchased for well under $200. By doing the exhaust, cam, and heads the engine will be on par with the performace of the early C3 small blocks.
You didn't mention where you wanted the 300HP, the crank or the wheels. The stock L-82 should be somewhere around 210HP with accessories and cat-exhaust. People tend to forget that horsepower was rated differently back in the old, old days. Although I do not have numbers, a 69 350HP would be much less if measured by todays standards.
The first thing is to get a performace exhaust system. That will get you perhaps the most bang for your buck. No matter what engine mods are done, this will have to be done so you might as well do it first. After that the next upgrade is normally cam and heads. If your target is 300HP or over, then you should be able to get away with changing the heads. The bad news is that heads will cost $500 on up while a cam/lifter kit can be purchased for well under $200. By doing the exhaust, cam, and heads the engine will be on par with the performace of the early C3 small blocks.
Team Owner
Joined: Jul 2001
Posts: 182,997
Likes: 88
From: Lakeland, FL
Cruise-In IV-V-VI-VII-VIII Veteran
St. Jude Donor '03, '06, '17
Exhaust, Heads and Cam 
If you do the work yourself - it won't cost and arm and a leg and you can easily get up to 400 HP..
You can find World Product Torquer Heads fully assembled for less than $500.
Just add a nice cam with about .480 to .500 lift and 220 - 230 degrees .050 duration (probably $150 for the cam+lifters) and a true dual exhaust and you'll be in the high 300's for output ... and you won't spend too much over $1000 - $1200 for everything...
If you do the work yourself - it won't cost and arm and a leg and you can easily get up to 400 HP..
You can find World Product Torquer Heads fully assembled for less than $500.
Just add a nice cam with about .480 to .500 lift and 220 - 230 degrees .050 duration (probably $150 for the cam+lifters) and a true dual exhaust and you'll be in the high 300's for output ... and you won't spend too much over $1000 - $1200 for everything...
Last edited by GrandSportC3; Dec 22, 2004 at 08:44 PM.
Le Mans Master
Joined: Oct 2004
Posts: 5,269
Likes: 54
From: Orlando Florida
St. Jude Donor '05
Well, I guess everybody would recommend what he/she has installed... I'm very happy with my Edelbrock setup: Performer series 64cc heads, cam, intake and carb.... runs great, very smooth idle, good throttle response and fast enough for now.... I will work on the bottom end next year and stroke it to 383 with forged pistons....
One more thing: I have the L48 with original 8.7 or so CR - your compression is higher than mine (I think 9.5) so you should see better HP numbers with these modifications..
One more thing: I have the L48 with original 8.7 or so CR - your compression is higher than mine (I think 9.5) so you should see better HP numbers with these modifications..
Last edited by MYBAD79; Dec 22, 2004 at 09:03 PM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Le Mans Master
Joined: Jan 2004
Posts: 8,295
Likes: 30
From: one night in Bangkok you are never lonely
Originally Posted by RedBad1979
Well, I guess everybody would recommend what he/she has installed... I'm very happy with my Edelbrock setup: Performer series 64cc heads, cam, intake and carb.... runs great, very smooth idle, good throttle response and fast enough for now.... I will work on the bottom end next year and stroke it to 383 with forged pistons....
One more thing: I have the L48 with original 8.7 or so CR - your compression is higher than mine (I think 9.5) so you should see better HP numbers with these modifications..
One more thing: I have the L48 with original 8.7 or so CR - your compression is higher than mine (I think 9.5) so you should see better HP numbers with these modifications..
I have the same Edelbrock set up with new bottom end around 9:1 compresion runs great.
Melting Slicks
Joined: Jul 2002
Posts: 3,128
Likes: 3
From: Deltona (son of Deland and DAYTONA) FL
don't do the rest without doing the heads. I warmed up an L48 with cam, headers, properly jetted too. The heads had to be the restriction as the car still turned 15's, just lower 15's 
Not to sure some compression wouldn't have helped too.
Not to sure some compression wouldn't have helped too.
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
This kind of engine is screaming for a low to moderate boost single turbo system. You can pick up reman turbos on e-Bay for $250. The header companies sell "bends". That is, pre bent exhaust pipe sections for the runs to and from the turbo. Get some steel tubing for oil lines and you got it made. A setup like this would get you 350 to 400 HP and you would never know it was there until you hit the loud pedal.
I'll bet you could do the whole thing for $1000.
Hope this helps.
BigBlockk
Later.....
I'll bet you could do the whole thing for $1000.
Hope this helps.
BigBlockk
Later.....
Thread Starter
Pro
Joined: Sep 2004
Posts: 611
Likes: 0
From: Minnesota
Originally Posted by BigBlockk
This kind of engine is screaming for a low to moderate boost single turbo system. You can pick up reman turbos on e-Bay for $250. The header companies sell "bends". That is, pre bent exhaust pipe sections for the runs to and from the turbo. Get some steel tubing for oil lines and you got it made. A setup like this would get you 350 to 400 HP and you would never know it was there until you hit the loud pedal.
I'll bet you could do the whole thing for $1000.
Hope this helps.
BigBlockk
Later.....
I'll bet you could do the whole thing for $1000.
Hope this helps.
BigBlockk
Later.....
Thanks
Le Mans Master
Joined: Oct 2004
Posts: 5,269
Likes: 54
From: Orlando Florida
St. Jude Donor '05
Originally Posted by cmashark
77 L82's are 9to1 C/R with 76cc heads. if he puts 64cc heads on, he will be at 10.3to1 C/R. better make them aluminum so you can run the cheap gas.
chris
chris
Le Mans Master
Joined: Oct 2004
Posts: 5,269
Likes: 54
From: Orlando Florida
St. Jude Donor '05
Originally Posted by page62
The L82 cam isn't bad: .450/.460 lift with 222/222 duration. The same cam used in the '69 350ci/350hp engine. Do the heads before the cam...they're the weakest link!
I agree, that cam isn't bad. You can do the cam later but it's not that expensive and you already have the engine apart when doing the heads... some heads require longer pushrods, you might want to to change the lifters and the cam at the same time.... anyway, the heads will be a huge improvement.
Thread Starter
Pro
Joined: Sep 2004
Posts: 611
Likes: 0
From: Minnesota
Originally Posted by GrandSportC3
Exhaust, Heads and Cam
If you do the work yourself - it won't cost and arm and a leg and you can easily get up to 400 HP..
You can find World Product Torquer Heads fully assembled for less than $500.
Just add a nice cam with about .480 to .500 lift and 220 - 230 degrees .050 duration (probably $150 for the cam+lifters) and a true dual exhaust and you'll be in the high 300's for output ... and you won't spend too much over $1000 - $1200 for everything...
If you do the work yourself - it won't cost and arm and a leg and you can easily get up to 400 HP..
You can find World Product Torquer Heads fully assembled for less than $500.
Just add a nice cam with about .480 to .500 lift and 220 - 230 degrees .050 duration (probably $150 for the cam+lifters) and a true dual exhaust and you'll be in the high 300's for output ... and you won't spend too much over $1000 - $1200 for everything...
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
There are all kinds of heads to choose from at Summit Racing or Jegs. Just add the "www." and ".com" to those names. I chose the Summit-brand heads for my swap (coming soon). Go to Summit Racing and search for SUM-152123
