Theory?: How do larger roller rockers affect....
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
Re: Theory?: How do larger roller rockers affect.... (George West)
The 1987 Corvette advertised 240 HP, up 10 from 1986. The reason? - roller rockers!
Are you sure you're not talking about roller lifters?
Le Mans Master
Joined: Mar 2001
Posts: 9,464
Likes: 1
From: Modesto CA
Re: Theory?: How do larger roller rockers affect.... (STL94LT1)
The 1987 Corvette advertised 240 HP, up 10 from 1986. The reason? - roller rockers!
Are you sure you're not talking about roller lifters?
Are you sure you're not talking about roller lifters?
Instructor
Joined: Mar 2002
Posts: 239
Likes: 0
From: Fredericksburg VA
Re: Theory?: How do larger roller rockers affect.... (USAsOnlyWay)
Sometimes increasing the rocker ratio on the exhaust side will over-intensify the blowdown, and cause a power decrease. Only so much wave energy is needed to make the header to do its job.
It is good to know what rocker ratio to use on the exhaust side before you purchase. For more aggresive cams the best ratio is not always the higher ratio on the exhaust. But the engine will like all the radicalness your pocketbook can stand to give it on the intake side.
It is good to know what rocker ratio to use on the exhaust side before you purchase. For more aggresive cams the best ratio is not always the higher ratio on the exhaust. But the engine will like all the radicalness your pocketbook can stand to give it on the intake side.
Instructor
Joined: Oct 2003
Posts: 147
Likes: 0
From: Holbrook NY
Re: Theory?: How do larger roller rockers affect.... (STL94LT1)
Boy, you guys don't miss anything....
I should have quoted the text I was reading, not misinterpreted it for you. Then it would have read:
"....(design considerations)....resulted in rollers being added to the hydraulic lifters, along with rocker arm covers with raised rails to forestall oil leaks."
I read it a little too fast, I guess. Thanks - I would have gone through life thinking that in 1987 Chevy added roller rockers to the Corvette. Now I know better.
George
I should have quoted the text I was reading, not misinterpreted it for you. Then it would have read:
"....(design considerations)....resulted in rollers being added to the hydraulic lifters, along with rocker arm covers with raised rails to forestall oil leaks."
I read it a little too fast, I guess. Thanks - I would have gone through life thinking that in 1987 Chevy added roller rockers to the Corvette. Now I know better.
George
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Re: Theory?: How do larger roller rockers affect.... (George West)
Going from non-roller lifters to roller lifters is the same principle as going from non-roller rockers to roller rockers. You are eliminating another point of friction and parasitic horsepower loss.
