Thread: Roller rockers ?

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For roller tipped rockers without guide plates there is some mention of a need for clearance in the pushrod hole on SBC heads when using 1.6 ratio rockers. I bought both 1.5 and 1.6 ratio sets. I am hoping for less heat with the roller tips because there is tremendous scuffing friction with the stock rockers. At present I am going to use the 1.5 ratio rockers mainly to run a cooler engine, but how can I check for pushrod binding with the 1.6 ratio rockers? If there is side rubbing of the pushrods with the 1.6 rockers, what is acceptable or should there just be no contact with the edge of the hole to be sure I won't bend a pushrod? I should have clearanced the holes when the heads were rebuilt. I have a very low lift cam with only 0.390 intake and 0.410 exhaust and hoped to add lift with the 1.6 rockers but since I have read that the stock rockers are often close to 1.4 ratio, using the 1.5 ratio rockers should give a slight increase in lift with less danger of bending a pushrod. I am sorry to keep asking questions about my engine which I have not started yet but I am working on the car every day and will eventually get to the engine where I plan to start out using the 1.5 roller tipped rockers from Speedway. (Today I installed the rear bumper, adjusted the stalk Model-A taillights and started installation of the LED turn signals.)

Don Shillady
retired Scientist/teen rodder

well thanks to everyone for the tips seeing as i have a blown sbc in a 2,700 pound car and a blower cam has more exhust lift i thought about rocker arm ratios to make up for the small cam cheap and easy . ill keep it all in mind though

Jason SBC Blown Datsun 280z

roller rockers are great if you put an aftermarket cam in and without you would rip the studs out of your heads...... they dont really make HP alone, but with a roller cam, roller lifters, roller rockers, full roller chain with rolling cam plate... then they all help each other out to make things wind up quicker... not neccisarily more HP but they reduce friction to help the engine accelerate faster

Also keep in mind that about half the time you go to a 1.6 rocker the pushrod holes need to be elongated so the rods don't rub/bind on the head, not hard to do but it does need to be done on the bench.