Roller Rockers

[Ron Hyslop]

I'm putting a Mopar rebuilt cylinder head on my 87xj 4.0L and got to wondering about installing roller rocker arms. I see Quadratec sell some made in Autralia by Yella-Terra(who-ever they are). Any body have any experience with these, or any others for that matter?

[DeftwillP]

This more of a aftermarket mod than OEM, but you might wanna ask over on street and performance. I don't believe anyone has tried them yet, but they are discussed some.

[5-90]

Any particular reason you want them?

I don't have anything against roller rocker arms - they do have their uses - but they're usually the sort of mod that you do to complement other mods, rather than in and of themselves. They're great for high-speed and/or high-endurance engines - but for general use and street engines, it's an awful lot of money for little benefit. Of course, if you were working on SBC/SBF engines, you wouldn't have to spend so much, either.

At something like $400 a set, I'd probably look for something more useful to spend the money on (tyres?) than roller rockers on what is probably an otherwise stock engines.

Now, if someone would come up with a roller camshaft...

5-90

[devildog0]

I have to agree with what is stated above. The only reason I would use them is if a)they were given to me or b)I was building a 4.0L for Jeep Speed competition for endurance runs. Find something better to spend 400 bucks on if it is a DD/Trail Rig.

[old_man]

Try gas :laugh3:

[John(XJ)Jeep]

I would be interested in them though I don't know too much about them. Will they benifet greatly if the purpose is for high RPM tolerance? The route I'm going will have parts geared for higher RPM.

[old_man]

If you are building for high rpms, headers and exhaust will do the most bang for the buck. Roller rockers really come into play when you are running very high lift cams and want to run fairly high rpms and high spring pressures. They cut the force required to open the valves and reduce the lateral strain on the valve stems. That is why valve guides don't last as long in a performance engine. If I was running roller rockers, I would also look into a roller cam.

It yeilds a few HP, but not all that much.

[John(XJ)Jeep]

That makes sense. So I would benifit from rollers if my engine was running high RPM's for long periods then? I'm not looking so much for a HP gain, I just wanted something for endurance and tolerance.

[TiRod]

Yes - if your engine was running high rpms for a long time, but that is a relative statement. An I6 is not the best hi rpm design and is usually built for low rpm and torque. Roller rockers are nice, just not in the design envelope for an idling off roader. Some argue that anything can be built, but I see no inlines in Nascar since the Hudson.

This may also apply to the new "beehive" valve springs with mini retainers. The cost to get them may not justify the high rpm addition of power for most of us daily driver users. As time goes by, all these enhancements eventually prove out and become stock factory components. Just compare a '66 271 hp 289 to a 90's 5.0 roller motor. So I am hoping Detroit adopts real engineering gains to some engines so I can use the parts.

I'd like a stock roller cam, too, but Jeep spent the money on a transfer case and front axle. I like that when it snows.

[Dr. Dyno]

A roller cam would be nice but I don't think any cam manufacturer will produce one simply because there isn't enough demand and they'll cost a small fortune.
As far as roller rockers go, I think it was JP magazine who ran an article on the Mopar Performance units a long time ago and I believe the dyno result was a paltry 1.5hp gain.