isky adjustable pushrod guide plates
Moderator: Team
isky adjustable pushrod guide plates
i got some 220 canfield heads that have the offset intake stud mounted rockers, but with standard guide plates some of the rockers are still not lined up correctly with the valve stem. what i would like to know is would the isky adjustable guide plates correct this problem,and also is it nessary to weld the plates together after they are fitted.
-
bigjoe1
- Show Guest
- Posts: 6199
- Joined: Thu Aug 24, 2006 8:16 pm
- Location: santa ana calif-92703
- Contact:
Isky guideplates
YES, it will fix the problem, NO, you do NOT have to weld them.
JOE SHERMAN RACING ENGINES
JOE SHERMAN RACING ENGINES
It took me a long time to figure out why Isky made adjustable guide plates. Finally I realized it's because the stock Chevy lifter-pushrod-rocker-valve setup is "knock-kneed" because the valve centerline is wider than the lifter centerline. I'd never really noticed until I got a set of high ratio lifters that sat off on the sides of the valve stems, no matter which way I moved the plate.
High ratio rockers generally have shorter pushrod sides, which splays the valve sides further apart. So you use the adjustable plates to make the rockers line up with the valve stems.
For some reason a lot of people don't seem to notice, or don't care, or don't know what to do about it if they do.
This is a particular problem with the 351 Cleveland, where the rockers may be anywhere from 1.7 to 1.75 ratio, and are often just big block Chevy rockers, which are almost-but-not-quite the same as Cleveland rockers. I learned to do the rocker/valve alignment check very early, so MIG spatter cleanup isn't an issue. And I also learned to number the plates after cutting and welding, because they never seem to fit properly in any other location...
High ratio rockers generally have shorter pushrod sides, which splays the valve sides further apart. So you use the adjustable plates to make the rockers line up with the valve stems.
For some reason a lot of people don't seem to notice, or don't care, or don't know what to do about it if they do.
This is a particular problem with the 351 Cleveland, where the rockers may be anywhere from 1.7 to 1.75 ratio, and are often just big block Chevy rockers, which are almost-but-not-quite the same as Cleveland rockers. I learned to do the rocker/valve alignment check very early, so MIG spatter cleanup isn't an issue. And I also learned to number the plates after cutting and welding, because they never seem to fit properly in any other location...
-
judgement_impared
- Member
- Posts: 112
- Joined: Wed May 09, 2007 3:24 pm
- Location: Deep in the woods of Texas
-
Mike Thompson
- New Member
- Posts: 14
- Joined: Sun Feb 17, 2008 8:52 pm
- Location:
I was going to use them with my crane gold .150 offset intake rockers. I then realized how bulky they are. Its possible to have a clearance issue between the plates and studs.
So I had a buddy make me a custom set of plates on a EDM machine which turned out mint. Then I had to pay to have them case hardened.
In the end it worked out fine but I wish I would have spent the money on offset rocker shafts and been done with it.
So I had a buddy make me a custom set of plates on a EDM machine which turned out mint. Then I had to pay to have them case hardened.
In the end it worked out fine but I wish I would have spent the money on offset rocker shafts and been done with it.