How much power out of a 283?
10-06-2012, 09:36 PM
#1
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How much power out of a 283?
Just wondering, how much hp and tq can one get out of a 283 / 4 speed with a single 4bbl carb and still be able to run well on the street with 91 octane? What parts combos would you recomend?
10-06-2012, 10:09 PM
#2
Team Owner
Well 315HP with fuel injection was the tops in '61...however I run 270HP with my 283ci with dual quads all day long and that's 9.5:1 compression ratio allowing me to run 87 octane. It has a Duntov 097 cam and is bored .030 over.
10-06-2012, 10:59 PM
#3
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2020 Corvette of the Year Finalist (appearance mods)
C1 of Year Finalist (appearance mods) 2019
They used to build road racing and drag racing 283 blocks to 400+ horsepower. 
10-07-2012, 10:41 AM
#5
Race Director
what would be the reason for wanting a 283? A guy in south america built a 370hp 283 because importing even a 350 was SO EXPENSIVE. He was very motivated and spent 400 HOURS on porting the cyl heads! Now years later he imported a 400 and is building a 406.
Last edited by Matt Gruber; 10-07-2012 at 10:50 AM.
10-07-2012, 10:59 AM
#6
Instructor
We used to run a '61 Corvette at US30 Dragstrip in NW Indiana. With the engine bored over 0.030", heads CC'd and ported/polished to 11:1 compression ratio, single plane intake manifold and high performance cam .... about 400hp. If you don't go crazy with the camshaft you can still drive it on the street.
10-07-2012, 04:38 PM
#7
Safety Car
You can easily get there with a high revving solid roller with high lift (estimate in .550-.575 range using the right ratio rocker arms) and durations in the 230-240 range on a 110-112 LSA. If so, then you should do better than 400 net flywheel.
Last edited by 65tripleblack; 10-07-2012 at 04:52 PM.
10-07-2012, 04:52 PM
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10-07-2012, 05:04 PM
#9
Race Director
a 283 lacks torque. when i had a 283 i had to slip the clutch.
w/355 i just let the pedal up at 800 rpm and it pulls right out.
if the OP wants torque he needs cubes.
if he wants to rev it to 7000 he wants HP.
w/355 i just let the pedal up at 800 rpm and it pulls right out.
if the OP wants torque he needs cubes.
if he wants to rev it to 7000 he wants HP.
10-07-2012, 05:18 PM
#10
Team Owner
No slipping of clutch since I put the Tremec in to get my 283ci (3.70 rear) rolling; even up inclines. So, not sure what that's about.
A stock 283ci is no 'barn burner' but can be beefed up to run with the big dogs to some extent. Having said that...it's easy to reach the 'tipping point' price-wise where you could have bought a crate motor, with a warranty, and saved a lot of anquish.
A stock 283ci is no 'barn burner' but can be beefed up to run with the big dogs to some extent. Having said that...it's easy to reach the 'tipping point' price-wise where you could have bought a crate motor, with a warranty, and saved a lot of anquish.
10-07-2012, 06:35 PM
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Maybe your generator was pulling too hard to run those four cooling fans and pulled all the power away from moving the car?
283's came from the factory with 2.20 transmission gears as standard equipment. So did 265's.
Back then, they also had a three speed with a 2.94 first gear and if you had a 4.11 or 4.56 rear end, there weren't many street cars around that could beat you off the line and for the first couple hundred feet at least.
283's came from the factory with 2.20 transmission gears as standard equipment. So did 265's.
Back then, they also had a three speed with a 2.94 first gear and if you had a 4.11 or 4.56 rear end, there weren't many street cars around that could beat you off the line and for the first couple hundred feet at least.
Last edited by MikeM; 10-07-2012 at 06:44 PM.
10-07-2012, 08:57 PM
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The reason I was wondering was to keep the originallity of the car, but have a little more power. I might as well pull the motor, protect and store it and run a different motor/tranny setup, maybe a LS motor?
10-07-2012, 11:36 PM
#14
Instructor
Don't try to run 2.02 intake valves on a 283 (3 7/8" bore) without clearancing the top of the cylinders. 1.94s barely clear and then they are shrouded. The best heads for a hot 283 street engine today seem to be the 305 H.O. heads. The small (58cc) chambers will give you a good bump in compression and they flow pretty good for the engine size.
Tom
Tom
10-08-2012, 07:36 AM
#15
Race Director
Maybe your generator was pulling too hard to run those four cooling fans and pulled all the power away from moving the car?
283's came from the factory with 2.20 transmission gears as standard equipment. So did 265's.
Back then, they also had a three speed with a 2.94 first gear and if you had a 4.11 or 4.56 rear end, there weren't many street cars around that could beat you off the line and for the first couple hundred feet at least.
283's came from the factory with 2.20 transmission gears as standard equipment. So did 265's.
Back then, they also had a three speed with a 2.94 first gear and if you had a 4.11 or 4.56 rear end, there weren't many street cars around that could beat you off the line and for the first couple hundred feet at least.
Generator? U must be kidding? in 1975 it already was converted to an alt!
Last edited by Matt Gruber; 10-08-2012 at 07:44 AM.
10-08-2012, 07:45 AM
#16
Team Owner
Not sure an LSx is a simple swap...most I know that run them in older vettes do so on a restomod frame.
10-08-2012, 09:58 AM
#17
Race Director
my vote is to maintain the character of the car, period correct. Dual quads is way cool and makes +20hp over 1.
I like the simplicity of 1x4.
a 383 would work well with a 3.08 rear. no need for OD.
An LS conversion is just a poser. not a real one anymore
Just my opinion, don't get upset if u have one. it still looks nice.
I like the simplicity of 1x4.
a 383 would work well with a 3.08 rear. no need for OD.
An LS conversion is just a poser. not a real one anymore
Just my opinion, don't get upset if u have one. it still looks nice.
