Thanks for clarification
Dave

Dave.  ...Just to recap what has been previously shared
- the surface of each cam lobe on your cam shaft has a slight taper from the front of the engine toward the rear...
- each valve lifter face that contacts the camshaft lobe has a convex (crowned) surface...
- the valve lifter crowned face makes a line of contact with the slightly tapered cam lobe face it mates with...
- the taper on the cam lobe mating with the convex crown of the vale lifter causes the valve lifter to rotate in its bore as the camshaft rotates to actuate the valve...
- the rotating valve lifter causes the connecting pushrod between the valve lifter and rockerarm to also rotate...

New or properly resurfaced valve lifters have a convex face.  They do not have a flat face.  A valve lifter with a concave face is WORN and will ruin a cam lobe quickly.
New camshaft lobes are slightly tapered from one edge of the cam lobe to the other.

My understanding is that...
- the machined surface finish of the cam lobe and the mating valve lifter face are important
- the machined taper of each cam lobe is important
- the machined convex form of the valve lifter face surface is important

Recommendation
- new camshaft, use new or properly resurfaced valve lifters
- do not resurface used valve lifters yourself;  use someone with the correct equipment and experience for the work
- use of proper assembly lube for lobes and lifters
- use of proper engine oil containing the correct amount of zinc additive for solid type lifters
- follow engine break-in procedure described earlier in thread for new camshaft and new or resurfaced valve lifters

Hope this helps.    


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

 I realize this is an old thread but was thinking about resurfaceing a set of lifters for my 312.
   I thought the lifters were flat and cam lobes were tapered or not "square" to promote the lifter to rotate.I remember from auto mech coarse where an instructor told me to always check a new cam shaft for taper because he has found out of the box jobber cams that were flat causing premature wear.Or is this different on a Yblock?(concave lifter face)We planned on using a very old valve machine which has a flat stone for doing flathead lifters.
Dave 

all flat tapet camed engines hyd or meckanical have convex lifters,even diesel engines.the cam grinders hear in vancuver have a fixture for doing the job.last set i had machined it was 5 dollers per lifter. they ar fusey about which ones they will do

They're not that expensive, if you are going through the work to pull them out a new set will be worth eliminating one way to wipe out the cam.
Cheap insurance if it avoids tearing it apart again.

Mike Rizzo

1963 F100 "Rudy"

Daniel Island, SC

I think the hardest part is finding a machinest that can re radius them or even understands what that is. Sort of a Y-Block thing I guess. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

So is there any issue with having them re ground does it take off enough to cause a push rod issue does it hurt them to be reground ?

The lifters are not flat,  they are machined with a slight convex so that they rotate on the camshaft.



South Australia

Forgive my lack of knowledge but what is reradiusing the lifters?

Ray, there will be variable opinions but has been industry practice since the 60,s to re radius the lifters, same as regrinding crankshafts.


  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia