What is needed when you convert to roller lifters? Do you have to change the cam, pushrods, rocker arms....ect

 

You have to change:

• Lifters (duh), they're the thing that has the roller.
• Cam, since it's designed differently; you can't put roller lifters on a flat-tappet cam, or vice-versa.
• Push rods, must be shorter because the roller lifters are taller than flat-tappet ones.
• Cam button, has to be added because "flat" tappets aren't flat, they're slightly convex, and the cam lobe isn't flat either, it's angled slightly such that the rear edge of the lobe is taller than the front edge. This places the contact point between the cam and lifter out at the edge of the lifter, which forces it to rotate; and it provides the retention for the cam, to keep it from "walking" out the front of the block. The cam button is a little thrust bearing that goes between the timing cover and the nose of the cam.

Factory roller systems are way different from all this. For some reason, when the factory finally hipped up to roller lifters, they decided to use a design the looks like some loser's college engineering project, instead of adopting the nice, simple, tried-and-true system that the rest of us had been using successfully for decades. They invented this big "spider" thing that bolts into the intake valley and has D-shaped holes that the lifters fit into to keep them from turning, and a special retainer plate that retains the cam instead of the cam button; so they had to retool their blocks. Real roller lifters are joined in pairs by a link bar to keep them oriented correctly. No block modification of any kind is required, the whole thing is a simple drop-in. So simple it's almost embarrassing. I can't understand why the factory re-invented the wheel, in the shape of a triangle, on that one.

You don't "have" to replace the timing chain or rockers, but it never hurts to do that. Roller rockers have lower friction losses, last longer as a result, and lower the oil temperature by 10 to 15° in most engines.

------------------
"So many Mustangs, so little time..."
ICON Motorsports

 

thanks for the info, that really helps. I know what you talking about with those retainers between to lifters, it is a really stupid design in my opinion, I had to shop around and ended up buying them straight from GM because the local hot rod shop wanted $600 for those damn things. Thanks again

 

Well, one thing I can say, being that I work for a company that makes stampings for GM, is that they're probably paying $0.05 or less for that "spider" part. They undoubtedly looked at dozens of different ways of keeping the rollers straight, and this just happened to be the cheapest way to do it. Steel stampings are really, really cheap in the quantities automakers buy in.. that's why cars are made mostly of stamped steel

Lots of the stuff GM has us do for them seems to defy logic. In the end though, it always boils down to the cheapest way of getting something done.