It's really not confusing.


First keep in mind a hydraulic roller lifter (because of the roller) is taller than a standard hydraulic lifter. Second, hydraulic lifters (flat tappet) rotate as they move up and down. And obviously because of the roller wheel on a hydraulic roller lifter, it must not rotate.


There are two method to prevent the hyd roller lifter from rotating. An OEM style bolt down retainer system or a tie bar connecting two lifters together.


A hydraulic roller compatible block has taller lifter bosses to accommodate the taller lifters and the bolt down retainer system. Here is the key, since a non hydraulic roller compatible block has shorter lifter bosses, for an OEM type bolt down retainer system to fit and work, the lifters must drop down farther in the lifter bores. To get the lifters to drop down farther in the lifter bores, the cam lobes and the lobe base circles must be smaller. This is what it called a retrofit hydraulic roller cam.


The better approach is to use tie bar style hydraulic roller lifters. The tie bar prevents lifter rotation and an OEM style retainer system is not needed. Without the need of an OEM style retainer system, tie bar lifters do not need to drop down farther in the lifter bore of a non hydraulic roller compatible block. Thus, a standard (non retrofit) hydraulic roller cam can be used in a non hydraulic roller compatible block.




Mike

 

Hey JTB,
We put the Edelbrock Top End Kit in our 351W - 400hp & tons of torque.
There is even a hotter kit that goes 450hp(?). It's a pretty lumpy cam - no smooth idling here..
My only recommendation would be to go with case hardened push rods - the engine will chew up
non hardened rods before you make 1,000 miles. (Ask me how I know),

We don't race our truck so not sure 400hp is really necessary. I'd probably just go with some minor mods from stock for a solid cruiser if I had it to do over again.

Good luck over there.

Ben in Austin
1950 F1

 

Anytime you have pushrod guide plates and/or use roller lifters (they do not rotate) you need to use hardened pushrods. 400 hp is pretty easy to obtain with a 351W. A hydraulic roller cam will provide smoother idle quality and more engine vacuum at idle than it's hydraulic flat tappet cam counterpart. It's all due to the limitations of lobe profile with a flat tappet cam.

 

Thanks Mike got it!! I have choices to make, probably budget based. I'm not looking for a hot rod/drag truck so for cost purposes I'll probably stick with the hydraulic flat tappet. I'm thinking a top end kit as Ben suggest from either Edelbrock or TFS. I had good results with TFS heads on my roadster 306 build (rollers in this) so a one stop shop will probably be the best approach.
Thanks all.
John

 

Yeah, I'd go with TFS over Edelbrock as well. AFR's (Air Flow Research) has excellent cylinder heads for small block Ford's as well. They're very popular. More so than TFS for small block Ford's. Haven't read anything negative about them. I'd go to a cam manufacturer as well for the cam, lifters, etc., like Lunati, or Crane.


Edelbrock has some good stuff. Just my opinion, like a few other manufacturers, I think their marketing is better then the product.