1.7 rocker questions
06-16-2012, 12:21 PM
#21
Staging Lane
Join Date: May 2012
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I am no expert but I have reasearched this topic.
Many years ago the late John Lingenfelter told me to only run steel rockers since aluminum expanded and were not as stiff or reliable as steel/chromemoly. He recommended Comp cams pro magnum. The ss high tech are the more up to date parts from that family line.
On paper a 1.6 should get 10-12 hp over 1.5.
I do not see why a 1.7 would not net 20-25 at the crank.
As far a valve train geometry an lt1 or lt4 cam with 1.7 puts you at apprx .500 lift, which is smaller or near many aftermarket cam lifts with 1.5, so the gross valve lift is not any different than a bigger cam.
The only thing I was not sure of is since the pushrod cup moves closer to the stud if the hole in the cyl head is deep enough for this angle change.
Sounds like 2 have run this with no prob. Would like to know how many miles they have on setup.
Also makes sense to go to 7/16 stud. They should bolt right in. 26918 beehives will wok, comp recommended this to me, the lighter smallr retainer will add less stress to valvetrain.
Other thing to watch is higher spring pressure with stock timing chain.
Use comp cams rockers and dont look back. They are the best. John said so.......
Many years ago the late John Lingenfelter told me to only run steel rockers since aluminum expanded and were not as stiff or reliable as steel/chromemoly. He recommended Comp cams pro magnum. The ss high tech are the more up to date parts from that family line.
On paper a 1.6 should get 10-12 hp over 1.5.
I do not see why a 1.7 would not net 20-25 at the crank.
As far a valve train geometry an lt1 or lt4 cam with 1.7 puts you at apprx .500 lift, which is smaller or near many aftermarket cam lifts with 1.5, so the gross valve lift is not any different than a bigger cam.
The only thing I was not sure of is since the pushrod cup moves closer to the stud if the hole in the cyl head is deep enough for this angle change.
Sounds like 2 have run this with no prob. Would like to know how many miles they have on setup.
Also makes sense to go to 7/16 stud. They should bolt right in. 26918 beehives will wok, comp recommended this to me, the lighter smallr retainer will add less stress to valvetrain.
Other thing to watch is higher spring pressure with stock timing chain.
Use comp cams rockers and dont look back. They are the best. John said so.......
Last edited by HighMileageC4; 06-16-2012 at 05:57 PM.
