Slider cam with rollers?

[shadow88]

Anyone ever tried this? I'm messin' with it at work, and I think I'm near the final product. I know slider cams with roller rockers = the rocker not touching the cam on the base circle. I think I may have calculated the needed shim thickness.
Any thoughts on this?

[rbryant]

Some have said that the roller cams had to be harder in order to survive the smaller contact that the roller rocker has with the cam. If this is correct, the roller follower would wear a groove in the slider cam.

I am not sure about the shims or rocker ratios but they could also be a problem.

Why do you want to do this? An 88TBI cam gives you pretty much all of the duration that a slider had anyway if that is your goal and it is a nice proven option.

-Rich

[tryingbe]

Roller rockers will EAT the slider cam.

Seen it in junkyard.

[RoadWarrior222]

Every so often I find people claiming it works. I have a theory that it works on used slider cams. Meaning they surface harden in use with sliders over time and then will survive the rollers. So, if you want a funky profile, I guess you have to hunt for a used one with 40,000 or so on it. Could send a new slider profile off to get surface hardened or cryoed I guess.

[johnl]

Don't cha wanna centerline it and check it for timing and lift before you run it? It's gotta be weird since the geometry is different.

[Birddog]

I could point ya in the direction of a few brand F guys that use roller cams with sliders but not slider cams with rollers..

[turbovanman²]

You have two problems.
1) Roller cams are alot harder due to the wheel.
2) The design of the lobe is different-if you look at a roller cam, the nose is rounder, more gently, the flat type is pointy, the roller won't be able to follow it and will bounce causing an unstable valves and at rpm, things could go boom.

[shadow88]

Ok, here's the how and why. I have a new MP super 60 cam recently found in the garage. I always liked the performance of that cam, but didn't like the wear characteristics.

I have a mock up engine at work and I thought I'd drop in that cam with old used lifters and rollers and did some close-up inspections. The roller follows the cam profile perfectly, (at hand driven speeds) things may not work as good at 6000 rpms but it looks promising.

If hardening is the issue for use with rollers, that's just a vendor away.

[2.216VTurbo]

Ok, here's the how and why. I have a new MP super 60 cam recently found in the garage. I always liked the performance of that cam, but didn't like the wear characteristics.

I have a mock up engine at work and I thought I'd drop in that cam with old used lifters and rollers and did some close-up inspections. The roller follows the cam profile perfectly, (at hand driven speeds) things may not work as good at 6000 rpms but it looks promising.

If hardening is the issue for use with rollers, that's just a vendor away.

One thing is for sure, if you do it and it works out well, it'll put some of the 'theories' to rest I'm all for your test, the car is not your DD though right ?

[tryingbe]

You think S60 with slider rocker arm wear fast. Wait until you put some roller rocker arm in there, the rocker arm will make DENTS on the cam shaft.

Like I said, I've seen it in junkyard.

[shadow88]

You think S60 with slider rocker arm wear fast. Wait until you put some roller rocker arm in there, the rocker arm will make DENTS on the cam shaft.

Like I said, I've seen it in junkyard.

What would you say the "dents" were caused by? Do you think hardening the cam could fix that or do you think there may have been other issues with the junkyard engine. Was the J/Y engine torn down for further inspection?

2.216vturbo- It's not really my DD, I have a neon for that, but it does get driven a fair bit when the weather's nice.

[RoadWarrior222]

I'd figure any dents would have come from that previously mentioned problem of the lobe tip being too sharp on slider profiles, the rollers skipping off the tip of the lobe and landing at various points according to engine speed.

[shadow88]

Well, this would be using the proper valve springs to keep the rocker arm in contact with the cam lobes.

Cut me some slack, I don't do everything half-a$$ed

[tryingbe]

It was on a rebuild cylinder head. The slider camshaft was brand new. For whatever reason it was put onto the head with roller rockers. All the contact area on the camshaft with the roller are dented.

Roller camshaft is only around $200 a piece. Is it really worth the hassle trying to use the S60 cam with roller rockers?

http://www.fwdperformance.com/store/...alog=Camshafts

[RoadWarrior222]

That would seem like a fix, however, call me Captain Obvious, but adding contact pressure to a situation where extreme wear might already be expected, does not seem like a smart move.

[shadow88]

It was on a rebuild cylinder head. The slider camshaft was brand new. For whatever reason it was put onto the head with roller rockers. All the contact area on the camshaft with the roller are dented.

Roller camshaft is only around $200 a piece. Is it really worth the hassle trying to use the S60 cam with roller rockers?

http://www.fwdperformance.com/store/...alog=Camshafts

Ok, I have a theory on this one. Way back when I started to modify my shadow, I bought a "314" cam and used my roller rockers. At higher rpms (5000) the rocker arm would fall off and usually break off a lifter. I later noticed the roller rockers do not ride on the cam when on the base circle. This may be a reason for the accellerated wear of the cam. Essentially, the rockers have a chance to make contact while not dead flat on the roller surface. This could cause gouging and easily wipe out a cam.

I'm going to guess the link to FWD P is the selection of regrind cams. Even though they seem like a quality peice, I already have the cam and I just want to try to make it work. If it costs about $100 for shipping and cryo treatment, then I'm still out ahead.
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That would seem like a fix, however, call me Captain Obvious, but adding contact pressure to a situation where extreme wear might already be expected, does not seem like a smart move.

Captain Obvious, The higher lift springs are installed because they're needed for a .499 lift cam.
I really doubt a rocker arm can "skip off the tip of the lobe" Now, it may be possible, but with the spring tension and the rpm limit of about 6000 rpm's, I don't see it happening.

[turbovanman²]

Ok, here's the how and why. I have a new MP super 60 cam recently found in the garage. I always liked the performance of that cam, but didn't like the wear characteristics.

I have a mock up engine at work and I thought I'd drop in that cam with old used lifters and rollers and did some close-up inspections. The roller follows the cam profile perfectly, (at hand driven speeds) things may not work as good at 6000 rpms but it looks promising.

If hardening is the issue for use with rollers, that's just a vendor away.

Hand speeds? thats not even close to real rpm. See my post on why it doesn't work properly. You can try it but be ready for alot of broken parts.

If you want a roller S60, buy the Taft S2 cam, its the exact cam but rollerized.

Ok, I have a theory on this one. Way back when I started to modify my shadow, I bought a "314" cam and used my roller rockers. At higher rpms (5000) the rocker arm would fall off and usually break off a lifter. I later noticed the roller rockers do not ride on the cam when on the base circle. This may be a reason for the accellerated wear of the cam. Essentially, the rockers have a chance to make contact while not dead flat on the roller surface. This could cause gouging and easily wipe out a cam.
.

Again, see my earlier post on why that happened.

You can try it but be wary of the resulting carnage.

[tryingbe]

Some have to learn it the hard way.

[shadow88]

Hand speeds? thats not even close to real rpm. See my post on why it doesn't work properly. You can try it but be ready for alot of broken parts.

If you want a roller S60, buy the Taft S2 cam, its the exact cam but rollerized.




Again, see my earlier post on why that happened.

You can try it but be wary of the resulting carnage.

Hand speeds and 6000 rpms aren't the same thing? REALLY? It was just to see how the roller followed the ramp, nothing more.

The profiles are similar, but not exact see here http://web.archive.org/web/200412082.../camshaft.html

I'm always ready for broken parts, and yes, I found the best lessons are learned the hard way.