ROLLER CAM BEARINGS ?

Hey, guy's:
I have a 460 block with rollerized cam bearings in it, the current cam is a Comp Cams XR292R mechanical roller. I'm contemplating converting it to a hydraulic roller set up - will this work with the rolllerized cam bearings?

Wayne (SAWDOFF) Pearce

I think as long as you stay with a steel cam core you will be fine.

Are all hydraulic roller cams cores steel? Sorry if this is a dumb question, but it's going to be a fairly expensive switch and I don't want to throw my money away on a bad choice.

Wayne (SAWDOFF) Pearce

Wayne Pearce wrote:Are all hydraulic roller cams cores steel?  Sorry if this is a dumb question, but it's going to be a fairly expensive switch and I don't want to throw my money away on a bad choice.

  Wayne (SAWDOFF) Pearce

NO ... even a few solid roller cams will vary.
Nitrided ductile iron or complete Austempered ductile iron or induction hardened lobe SADI cast steel cores are very commonplace with hydraulic roller camshafts.
They certainly can and will be made of billet steel if one wants to pay the extra price; some already are.

What would the harm be in just swapping the lifters and leaving the solid lift cam?

Will that work? I would think that the spring pressures might be a bit stiff for hydraulic lifters. This engine was built ten years ago, and I don't remember what springs are in it, what ever Comp Cams recommended for the XR292R cam.

Wayne (SAWDOFF) Pearce

Well either way, if the valve springs have been in it for 10 years, it's time to change valve springs. Yes, you will need a softer / milder valve springs for hydraulic roller lifters. Charlie

I’ve never personally done it. Heard tale of it being done. I was hoping one of the pros would weigh in and either confirm or deny the plausibility. I was told you could put hydraulic roller lifters on a solid cam but not the other way around. Seems believable, if you put the two beside each other they’re not that much difference in the shape. Now if the solid cam were a very radical race grind then I may not be so quick to try it.

stanger68 wrote:I’ve never personally done it. Heard tale of it being done. I was hoping one of the pros would weigh in and either confirm or deny the plausibility. I was told you could put hydraulic roller lifters on a solid cam but not the other way around. Seems believable, if you put the two beside each other they’re not that much difference in the shape. Now if the solid cam were a very radical race grind then I may not be so quick to try it.

I can say that a lot of competitors in the Engine Masters Competition for different years have used hydraulic roller lifters on "tight lash" solid roller cams. It was a slight performance downgrade however, that type lifter was the rules.

Thanks, everybody for your replies. One last question, aren't the hydraulic roller lifters taller than the mechanical roller lifters causing increased angularity in the push rods?

Wayne (SAWDOFF) Pearce

Wayne Pearce wrote:Thanks, everybody for your replies. One last question, aren't the hydraulic roller lifters taller than the mechanical roller lifters causing increased angularity in the push rods?

  Wayne (SAWDOFF) Pearce

YES ... by about .625" higher pushrod cup.

Thanks, Randy. I'm by no means a mechanical engineer, but has anybody ever approached the idea of a "low profile" hydraulic roller lifter to negate the acute push rod angle? In my "simple" mind, it seems like a simple fix.

Wayne (SAWDOFF) Pearce

Wayne Pearce wrote:Thanks, Randy.  I'm by no means a mechanical engineer, but has anybody ever approached the idea of a "low profile" hydraulic roller lifter to negate the acute push rod angle?  In my "simple" mind, it seems like a simple fix.

  Wayne (SAWDOFF) Pearce

There is really no way to do that and still have a working hydraulic piston mechanism within the lifter.

Maybe it could be shortened by .200" or so, but that is not worth the expense for any company to spend a lot of money designing and producing something which will work well hydraulically; and still be taller than a solid.
Part of the hydraulic cavity within the lifter body is already lost to the space where the upper side of the roller wheel needs to displace.

Thanks, Randy. I couldn't ask for a better explanation. Can you tell me if it's a worthwhile expenditure to do the conversion? The engine was originally built for a Pro Street 50 Ford Coupe. Now it resides in a 60 Starliner that's built to be a "cruiser", not a bad ass pro streeter. The engine is pretty mismatched for the car, but it's all I had.

Wayne

Wayne Pearce wrote:Thanks, Randy.  I couldn't ask for a better explanation.  Can you tell me if it's a worthwhile expenditure to do the conversion?  The engine was originally built for a Pro Street 50 Ford Coupe. Now it resides in a 60 Starliner that's built to be a "cruiser", not a bad ass pro streeter.  The engine is pretty mismatched for the car, but it's all I had.

  Wayne

Not with any type stud mounted rocker arm system unless it is very temporary.
They work OK with "Bolt Down" or "shaft mounting".

Sorry, Randy - but your last statement left me a bit confused (not unusual). Are you saying stud mounted rockers are not preferred for a hydraulic roller cam set up?

Wayne

Wayne Pearce wrote:Sorry, Randy - but your last statement left me a bit confused (not unusual).  Are you saying stud mounted rockers are not preferred for a hydraulic roller cam set up?

  Wayne

YES, studs are NOT preferred.; neither "rail rockers" or those using guide plates.