Is there any reason that i could not run a a cam designed for flat tappets with a roller lifter? My block is a roller block and i can get a flat tappet cam from a friend for a good price and it is about what i am looking for with lift and duration.

 

The lobes on flat tappet cams are tapered.

 

if you don't mind the end results there's no reason you couldn't do it, on the other hand if you didn't want to would be reason enough not to do it. there's a reason one's a flat cam and one's a roller, they don't mix and match. there is no reason you can't run a flat cam and lifters in a roller block without problems.

 

I don't build any motors without roller cams these days. The power under the curve is just too much better with the roller profiles. Hell, plug them both into desktop dyno (not super accurate, but not too bad for cheap). I seriously doubt you'd be happy with the tradeoff anyway. 2c

 

Yes, there is a good reason, the cam WILL be destroyed in very short order, flat tappet cams have a taper on the lobe designed to make a flat lifter rotate, a roller lifter roller is flat, so the lifter will be contacting the lobe on a tiny point and will quickly wipe out the cam. just spend a little more money and get the proper roller cam for it, thay can be bought cheaply on e-Bay.