roller rockers
04-29-2006, 09:13 AM
#21
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For valid dyno data go to Vinci's website and check out what the AFR head test data on Beckers corvette. Part of that test shows how a 1.8 rocker on a shorter duration, shorter lift cam makes more power throughout the range than a bigger duration/higher lift cam. Both setups achieved the same net valve lift. In fact at that point in the evaluation, both the 1.7's and 1.8's are Cranes.
BTW, your use of the universal adjective/adverb/verb/noun only shows up your lack of understanding about engines. The point is you just don't get it ...it is what is happening at the valve that counts, not at the cam lobe. You aren't taking into account pushrod flex, valve lofting, rocker bolt/stud deflection or rocker operating arc.
Thank you for your eloquent response, you have made my point for me!!!
BTW, your use of the universal adjective/adverb/verb/noun only shows up your lack of understanding about engines. The point is you just don't get it ...it is what is happening at the valve that counts, not at the cam lobe. You aren't taking into account pushrod flex, valve lofting, rocker bolt/stud deflection or rocker operating arc.
Thank you for your eloquent response, you have made my point for me!!!
04-29-2006, 10:46 AM
#22
I can vouch for the effectiveness of the 1.8 rockers - I had my cam installed originally with the stock rockers, then came back a few days later and installed the Crane 1.8 rollers, and noticed a huge difference.
If you think about it, you can only get so much ramp out of a cam. The higher lift and higer ramp rate of the cam, you are slamming the lifters around that much more. If you take the load and spread it out across the entire valvetrain you put less wear on everything - the only thing that doesn't see a difference is the spring and valve. You can decrease the lift and ramp rate on the lifter while achieveing the same lift and duration by giving some of the responsibility to the rocker.
I don't have any "proof" or hard data to back it up other than by good ol' butt-o-meter, but it was definitely happy with the result
If you think about it, you can only get so much ramp out of a cam. The higher lift and higer ramp rate of the cam, you are slamming the lifters around that much more. If you take the load and spread it out across the entire valvetrain you put less wear on everything - the only thing that doesn't see a difference is the spring and valve. You can decrease the lift and ramp rate on the lifter while achieveing the same lift and duration by giving some of the responsibility to the rocker.
I don't have any "proof" or hard data to back it up other than by good ol' butt-o-meter, but it was definitely happy with the result
04-29-2006, 11:23 AM
#23
Originally Posted by QuietTahoe
For valid dyno data go to Vinci's website and check out what the AFR head test data on Beckers corvette. Part of that test shows how a 1.8 rocker on a shorter duration, shorter lift cam makes more power throughout the range than a bigger duration/higher lift cam. Both setups achieved the same net valve lift. In fact at that point in the evaluation, both the 1.7's and 1.8's are Cranes.
BTW, your use of the universal adjective/adverb/verb/noun only shows up your lack of understanding about engines. The point is you just don't get it ...it is what is happening at the valve that counts, not at the cam lobe. You aren't taking into account pushrod flex, valve lofting, rocker bolt/stud deflection or rocker operating arc.
Thank you for your eloquent response, you have made my point for me!!!
BTW, your use of the universal adjective/adverb/verb/noun only shows up your lack of understanding about engines. The point is you just don't get it ...it is what is happening at the valve that counts, not at the cam lobe. You aren't taking into account pushrod flex, valve lofting, rocker bolt/stud deflection or rocker operating arc.
Thank you for your eloquent response, you have made my point for me!!!
I understand. But I still dont see the point of dropping that much coin on rockers for only the little amount that they do. Stock rockers are fine... Until the needles fall out. $1100 dollars for an "average 25hp gain" seems a bit pricey to me. Money that can be better spent in alot of other areas.
04-30-2006, 03:51 AM
#25
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The thing is guys, a lot of cam manufacturers do not recommend the use of 1.8 ratio rockers. I'm sure this is for a good reason.
Also, some of us that are doing our cam swaps just want a higher quality roller rocker over the O.E. rockers.
How much are these Vinci adjustable rockers anyways?
They sound expensive.
Jim
Also, some of us that are doing our cam swaps just want a higher quality roller rocker over the O.E. rockers.
How much are these Vinci adjustable rockers anyways?
They sound expensive.
Jim
04-30-2006, 01:53 PM
#26
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They are about $700, and that includes pushrods. All SBC valvetrain used to be adjustable until recently. Non-adjustable doesn't make it necessarily "better", but cheaper to manufacture based on production labor. Nothing to be afraid of using adjustable valvetrain components.
04-30-2006, 02:30 PM
#27
Originally Posted by Okie5.3
They are about $700, and that includes pushrods. All SBC valvetrain used to be adjustable until recently. Non-adjustable doesn't make it necessarily "better", but cheaper to manufacture based on production labor. Nothing to be afraid of using adjustable valvetrain components.
