OK so here is the deal. I am getting ready to screw a motor together. The block is new enough to be a roller block but it is still a motor that we would use in a HAMB friendly car. That was the back story. ^^^^^ Now the discussion came up about using roller lifters on a flat tappet cam. This was just a general discussion. Before someone gets all self righteous about this question bear in mind that roller cams have been around since gawd knows when. Anyway I am no expert on the subject and have not tried it yet (I have run roller moors since as long as i can remember). But my thoughts are that the cam shaft and the lifters will not care. I could be wrong. So what are your thoughts or better yet experience in this subject. Please play nice and don't fight. Remember drama is your enemy.
That’s a hell of a question beaner. My concern would be some flat tappet cams have the lobes machined slightly tapered to control end thrust. That may cause one side of the wheel on the roller to dig in? Other then that I can’t see why it wouldn’t work other then losing the more aggressive ramps we can get away with on roller cams.
I would have thought that however a flat tappet cam is ground to induce lifter rotation would not work with roller lifters. The roller lifters would want/need a flat surface.
Flat tappet cam lobes have an angle on their surface to spin the tappets, roller cam lobe surfaces are ground parallel to the cam.
If using roller rockers with a flat tappet cam, then yes! If using roller lifters on a flat tappet cam, no way!....
There's also a metallurgy issue; roller lifter rollers/cams are made of steel, flat tappet cams are cast iron. The steel will eat up the cast iron. If cast iron would work, the OEMs would use it but they don't.
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