Re: When are shaft mount rockers needed?

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Because of cost of jesel and T&D and other shaft rockers i have stayed with my stud roller rockers Angus is what i have. Now for some good info, i run my BBC 454 and 541 to 9000 rpm,s ok iam crazy but the point here is what is the limit of a stud rocker. I have a 302@.050 289@.050 .820 int .790 exh roller. I run 385 # on the seat and 960 open 1.670 triple springs installed at 2.300 on a set of oem iron 990 heads. At this point studs bend alot so gridle is manditory. Studs next to intake ports have weaker stud bosses. These heads and replacement 088 heads are alike and suffer with bad geomerty from cylinder to cylinder as much as .100 in push rod length and not assoc. with spring pressure its all about placement of valve guide, stud angle and rocker arm fulcum, so each one needs to be check. I have found that incorrect push rod length of .100 will break a alum stud roller rocker because were the load is placed druing the cycle of the geometry. With proper Geo. breakage goes away and all just humms. I have also found that when cnc process of trunnions are done the drilling of the bottom of stud hole breaks thur unevenly (top is flat and bottom of hole is circle) so the drilling chips the hole as it exits hole, bottom of exit hole is also very sharp, sharp =,s a place to break, there left like that and hardened and with high spring pressures and bad Geometry they will break at the chips in the trunnions. I took them all apart and hand ground them with nice radius and reinstalled them and end of problems. So yes it can be done with proper understanding of what causes what and blueprint your parts. As far as push rods go i use 3/8 good ones and its a trade off between weight and stiffness. Yes you loose lift, so what by doing your geomerty correctly you will gain more then youll ever loose. Yes jesel and T&D are great pieces and quality but a buget is a buget. But a racer well never let that slow him done. You learn and get the job done.



P.S. I believe that shaft rockers get alot of attention because it fixes problems that people dont even know they had and then it runs right.

P.S.S. I maybe knocking on the door of roller rocker limitations or i may not be but point is you can go shopping for studded valve train parts and save a bundle or you can pay the pipper and there is no bargins with jesel and aT&D. You can however if your talented look and learn and make your own stands and buy used rockers or parts. replacing bearings is no biggee just make some round tool pushers on a lath.


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Last edited by star393; Yesterday at 07:39 PM.