While planning my current motor I heard all the problems occurring due to broken rockers(due to being cut to fit around large valve springs) or improper valve springs. On my engine builders advice we chose a longer than stock valve stem to get the 2'' installed height,which is a correct roller cam spring from Comp Cams. These springs are 1.550 in diameter. To properly clear the springs I chose T&D rockers that are mounted in individual pairs on a smaller shaft and use a SB Chevy rocker arm that will facilitate a 1.625 spring diameter. The rockers mount to a sub-plate which is bolted in by the head bolts.This prevents the threads being pulled out of a pedestal or worse,the pedestal being broken. The sub-plate is billet steel which recieves the billet pedestals. With this set-up in place you can race with the piece of mind of having some of the best parts available and correct for the application. My motor sees 6800rpm in the eyes and the springs test perfect after 75+ qtr. mile runs.
The valve stem angle is 15 degrees.....Standard to Buicks. The rockers are a SBC (1.65). The system uses the sub-plate/pedestal to adjust for proper geometry. For initial ''moch-up,''I trusted the heads to T&D since it was their set-up.They removed the production pedestals,And using Valves provided by me,they prepped the heads for their hardware.
Gary, I *think* Dave Benisek did this a couple years back with good success, but he had to have custom valve covers made. Awesome and reliable deal. $$$ though... J
There are a few Buicks out there with this system,and as with any "race" part it is not a ''bolt on''. I think what T&D does is adapt their SBC rocker arms to the Buick head for avalbility. In this case a 15 degree application.One of many available for the Chevy. Jesel has a similar system that I have only seen once,so i'm not as familiar with it. My point was that this set-up can be adapted to a Buick head and allows you to run a proper sized valve spring w/o compromising integrity due to clearance issues the standard roller rockers present.
Jim I was thinking Daves was a T&d Set up too. I remember him looking at my t&d stuff a couple of years ago and telling Bruce that I had the same set up as them. But I'm not sure if they still run the same rockers or not.
Mine T&D's did with 3 gaskets and a little tapping. At a glance you couldn't tell. I have upgraded to pretty aluminums now but I have old pics of my motor with them.
One things I will say about clearing the stock valve covers.....I did slot the cover holes too. BUT when I went to longer valves, it moves the rocker closer to the intake and up so if you plan to go .100" longer on the valve, then no way will they clear. Jesel rockers are just about the same demensionally but they do not incoperate the head bolt to hold down the lower plate like the T&D's do. I have pics of both but it will be later before I can post them.
Thanks Rick, please post your pics when you can. We ordered the Jesels today and if we get them to work I will let everyone know the part numbers etc. so they can duplicate.
I just priced the Jesels today for a friends set of Stg 3 heads that I am porting. The rockers alone are $1479 and $500 to install them. They are not cheap but worth it in my opinion. I will be pricing Harland Sharps system tomorrow. Later
