MY QUESTION: My current (SR20DE) stock cams have pitting on their lobes. I have cleaned out the oiler tubes (let them soak with carb cleaner inside). I want to replace the camshafts.
Given that the cams are pitted, I take it the rocker arms should be replaced, as well. I am looking to find a donor head and use its ROCKERS AND SHIMS in place of my current ones. Do I have to use the cams from the donor head, or could I use an aftermarket set of cams with the DONOR ROCKERS AND SHIMS?
Can I use a set of hydraulic lifters I pulled from a junkyard SR20DE, or MUST I use the original ones in my car?
The ones I pulled are newer and have a smaller hole on top, which I understand is the updated version.
Someone commented that it is NOT advisable to switch out a set of rocker arms and their corresponding shims with those of a donor head. But after reading some more, I have the understanding that it is alright to do this when installing a new or 2nd hand replacement cam, so long as it is for a street car, but not alright to do if the application is a race engine (higher rpms on a regular basis).
The member's question was "can I just take the shims and rocker arms off another sr20 head in order and put it in my car in the same order?"
Is it that the rocker arms, shims AND CAMS MUST all come from the SAME head if non-original rocker arms/ shims are to be used at all with the new cam?
If so, Why then do camshaft manufacturers advertise "drop-in" or "bolt-on" cams that they claim are "compatible with stock valve trains" and "require no adjustments me made?
Is it just understood that when installing a new camshaft, the new cam's lobes are going to wear down a bit in order to match the shape or level of the existing rocker arms? (assuming no re-shimming is required?)
Or, is it ALWAYS NECESSARY to re-shim when a new CAMSHAFT is installed in place of a damaged one?
Last edited by Cheezit
on 2021-03-12
at 20-29-57.