L48 modified engine
Thread Starter
Racer
Joined: Aug 2005
Posts: 315
Likes: 0
L48 modified engine
What I need to know is how much extra HP it would give me(approximatly).
Started with a stock L48 and this has been added.......
CAMSHAFT....Part# 12-238-2 by comp
Specs...Gross Valve Lift.......0.462->0.469
Duration @ 0.050.....218->224
Lobe Seperation......110
COMP PUSH RODS
LIFTERS
VALVE SPRINGS(981-16)
DOUBLE ROLL TIMING CHAIN
FLAT TOP PISTONS
Stock Q-Jet
K&N FILTER
Does anyone know how much extra horsepower this setup would give.
I think the 1980 L48 came with a crappy 190HP....
TIA Guys
Started with a stock L48 and this has been added.......
CAMSHAFT....Part# 12-238-2 by comp
Specs...Gross Valve Lift.......0.462->0.469
Duration @ 0.050.....218->224
Lobe Seperation......110
COMP PUSH RODS
LIFTERS
VALVE SPRINGS(981-16)
DOUBLE ROLL TIMING CHAIN
FLAT TOP PISTONS
Stock Q-Jet
K&N FILTER
Does anyone know how much extra horsepower this setup would give.
I think the 1980 L48 came with a crappy 190HP....
TIA Guys
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Your HP gains will be in the heads. Airflow in and out is what makes the HP.
With those mods you will be in the 230 to 250 range. A better set of heads would push you closer to 300. Estimate
The only thing there is a cam change. The rest is just add ons. That cam is close to L82 specs.
With those mods you will be in the 230 to 250 range. A better set of heads would push you closer to 300. Estimate
The only thing there is a cam change. The rest is just add ons. That cam is close to L82 specs.
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
If this engine doesn't have headers on it that cam will do almost nothing. That cam is close to L82 specs but with stock compression it's the wrong way to go about things. Headers should be the first modification of any '70's era Corvette. Your engine would like that cam a lot better if it had 10/1 compression.
BigBlockk
Later.....
BigBlockk
Later.....
Melting Slicks
Joined: Apr 2000
Posts: 3,341
Likes: 6
Originally Posted by BigBlockk
If this engine doesn't have headers on it that cam will do almost nothing. That cam is close to L82 specs but with stock compression it's the wrong way to go about things. Headers should be the first modification of any '70's era Corvette. Your engine would like that cam a lot better if it had 10/1 compression.
BigBlockk
Later.....
BigBlockk
Later.....
A decent intake manifold would also be helpful.
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
For what it's worth...
The only "improvement" you've made is in the cam. That's a very nice street cam for someone that doesn't need a lot of rpm and will work well with the factory heads and manifolds and compression ratios at or below the 9:1 level. It would work a lot better with an updated head and headers but will still show a noticeable improvement in your bottom and midrange. While the specs appear close to the L-82 cam, it's really a lot different. Duration is close but the lobe separation angle is a lot tighter. Lift, in this instance, is irrelevant since the factory heads poop out at around .420.
The best thing you can do to complement the cam is to make sure that you tend to the tuneup and that your engine is performing as best it can.
It's almost never productive to "guess" about how much horsepower you've gained over stock. You have to use scientific methods, like an engine or chassis dyno or speedtrap calculations. There are too many variables. Besides, it's easily possible not to see a gain in peak horsepower but significantly improve the car's performance or driveability by altering the torque average and curve below peak horsepower.
If the car works the way you want or hoped for, then that's how you measure the improvement. Sounds like a nice, streetable engine.
The only "improvement" you've made is in the cam. That's a very nice street cam for someone that doesn't need a lot of rpm and will work well with the factory heads and manifolds and compression ratios at or below the 9:1 level. It would work a lot better with an updated head and headers but will still show a noticeable improvement in your bottom and midrange. While the specs appear close to the L-82 cam, it's really a lot different. Duration is close but the lobe separation angle is a lot tighter. Lift, in this instance, is irrelevant since the factory heads poop out at around .420.
The best thing you can do to complement the cam is to make sure that you tend to the tuneup and that your engine is performing as best it can.
It's almost never productive to "guess" about how much horsepower you've gained over stock. You have to use scientific methods, like an engine or chassis dyno or speedtrap calculations. There are too many variables. Besides, it's easily possible not to see a gain in peak horsepower but significantly improve the car's performance or driveability by altering the torque average and curve below peak horsepower.
If the car works the way you want or hoped for, then that's how you measure the improvement. Sounds like a nice, streetable engine.
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