Inliners International Forums General Discussion Hi Performance rocker arm options

I havent posted for a while but have watched for a while. My little dragster with the 292 has been happily buzzing along.
last year pushed a pushrod through a rocker no big deal changed it and kept on trucking this year another failed broke in the middle looks like the classic too much lift on a stamped rocker and maybe lack of enough lube. I dont know how big the cam is but its big by just looking at the valve movement on top plus hd springs equals trouble. Has anyone used 1.7 ratio bb chevy roller rocker in place of the stamp steel units. I know would be giving up some lift but minimal. I have tried to search and dont fonf much I looked at the harland sharp 1.75 units but are pricey

BBC rockers share the same geometry as the 194-292 engines, so there is no problem there. Since the lose of ratio is directly proportional to the lift, you really don't know how much your losing, but any lose is still a lose. You could also use 1.8 ratio instead of 1.7 if you were concerned about the loses.

Are any kind of guide plates required looking at the size of the pushrod holes i would say not 1.8s interest me but more valvetrain pressure I swear this all started when i switched to the tall mercruiser style valvecover starting to think oil is being lost off the rockers

I have a set of Crower steel roller rockers on my 250 with the 1.75 ratio. The main thing about using aftermarket roller rockers is that a lot of them use a larger diameter rocker stud than the stock rockers do. The Crower rockers can be ordered with either size rocker stud, which does make life simpler. However, most roller rockers are also taller than stock rockers due to the locking adjusters supplied with the rockers, so you may need either a different valve cover or a spacer to get clearance for the roller rockers under the valve cover. I didn't need guide plates on the 250, and the lift with my cam is 0.499".

Comp Cams Ultra Pro Magnum 1.75 BBC roller rockers are super nice. They are available as a 6 cylinder set from Tom Lowe @ 12bolt.com Sweet looking roller rockers imop and tough.

Both Crower and Comp Cams offer steel roller rockers that will fit the Chevy 194-292 series engines. Crower rockers are stainless steel, Comp Cams' rockers are 8650 Chromemoly steel. Unless you plan on changing the stud size from 3/8" to 7/16", order the part number for 3/8" studs. Crower part# is 73629-12, and Comp Cams part# is 1629-12. An interesting side note is that the rockers with 3/8" studs are listed for Chevy 348-409 motors, and the rockers with 7/16" studs size are listed for 396-454 BBC's. Apparently GM used the same rocker geometry for both engine series as well as the late model six cylinder motors, the only difference was the stud size.

Besides Tom, you could get either brand of rockers from Summit Racing, JEG'S, or the manufacturer's websites. I'd try Tom first, since he's one of us and there probably isn't much difference in prices for any of the retailers.

I looked at the 409 stuff too as i have screw in studs and have decided to go to 7/16, it gives me lots of choices for rocker arms. Its a big difference up here for price and also i have a better chance at getting a partial set of bbc rocker arms.
I am also contemplating making a oil deflector that will mount on the inside of the tall valvecover to keep oil down on the rockers i really think that is also part of the problem time to do a lift check on the cam thats in this thing.

Just to let you know lift at cam 315 across the board so gross lift with 1.75 551 and 1.7 drops to 535 man 1.8 rocker arms look good at 567