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HP gain from roller rockers?

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Old Jan 18, 2003 | 06:13 PM
  #1  
colonboy14's Avatar
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From: Gainesville, FL
Car: Trans Am
Engine: 305
Transmission: T56
HP gain from roller rockers?

I have read a bunch of different posts and the quotes range from none to 30 HP gain. How munch HP can I expect from either 1.5 or 1.6 rr? The only real engine mod I have is the Super Comp headers.

If you have actually done this and you KNOW, it would be preferrable to if you just think you know.
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Old Jan 18, 2003 | 09:30 PM
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rezinn's Avatar
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I think I put a on that 30hp post. You're not going to see that kind of gain unless your old rockers are bent and give a 1:1 ratio or something Probably not even on a very powerful engine. There was actually dyno floating around here somewhere that netted 14hp changing stamped steel to full roller. I don't think it was a stock engine, though.
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Old Jan 19, 2003 | 09:58 AM
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colonboy14's Avatar
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From: Gainesville, FL
Car: Trans Am
Engine: 305
Transmission: T56
anyone else have numbers for me?
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Old Jan 19, 2003 | 10:48 AM
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1991 RS 305's Avatar
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I am hoping for about 10-15 hp when I put 1.6 's in mine this spring. The Tech at Comp Cam told me 15-30 HP with my set up is possible......I figure maybe half that is more realistic. I'm changing my valve seals anyway, ( tired of smokey start-up), so whilst I'm there, I.m planning to go with Comp Cams Magnum roller tip rockers (#1416) on my 85 TPI (non peanut cammed). I'll also put in fresh Comp pushrods(#7812) and valve springs ( either Comp Cam # 981, or GM #3911068) to prevent float.

Last edited by 1991 RS 305; Jan 19, 2003 at 10:56 AM.
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Old Jan 19, 2003 | 01:37 PM
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From: British Columbia
Car: 90 IROC 5.7 hardtop
Engine: L98
Transmission: T5 swap
Axle/Gears: Yup -- they still work
Without a dyno it is subjective to say the least but here goes...

I installed Comp Cams 1.6 rockers on a 305 and the seat of the pants feel was similar to what I felt when I installed the u-drive pullies. Now the u-drive pullies are supposedly anywhere from 8 to 12hp on a 305. I wouldn't be surprised the rockers gave 10-15hp on a 305-350.

my .02 cents worth,
RP.
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Old Jan 19, 2003 | 01:55 PM
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From: Fairview Heights Illinois
Car: 1986 Irocz
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: 3.25:1
I know someone personally that gained 25hp by switching from 1.5 rollers to 1.65 rollers. This was on a pretty big small block with ported aluminum heads.
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Old Jan 20, 2003 | 11:08 AM
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From: Gainesville, FL
Car: Trans Am
Engine: 305
Transmission: T56
cool, thanks for the info
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