Thanks

 

"Full-roller" ones have a shaft and roller bearings where the rocker rocks at the stud, as well as a roller at the tip.

The advantages are numerous in any application with high valve spring loads and high RPM. In every single racing engine with ball-seat rockers I have ever torn down, the seat area of the rocker was turned blue from heat. In fact, some people have reported as much as 20° lower oil temperature from making that one change.

Roller rockers require less lubrication. Further reductions in oil temperature can be made by restricting the flow of oil to them, since the hottest place in the motor is on top of the heads (the exhaust ports are right under the rockers) and therefore the less time the oil spends there the cooler it can stay. Additionally, there is less HP loss due to friction, and the geometry of the valve train overall is more stable.

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"So many Mustangs, so little time..."

 

Real easy...
full roller = rolller bearings at tip and pivot.
roller tip = roller tip (standard pivot ball)

 

roller tips are basically worthless because the roller actually slides on the valvestem so you don't gain anything. the fulcrum is where all the friction is at and the full rollers take care of that

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Kyle Osterholt
Okarche, Oklahoma
ASE Master Certified
86 T/A 383 TPI
89 TTA #1002 T-top/Leather
89 TTA #1358 Hardtop/Leather
80 T/A Pace Car
73 Opel GT

 

I'd have to disagree with that statement. Roller tips relieve the side load imparted by the non-roller rockers sliding across the valve stem tip, and therefore reduce wear on the valve guides compared to non-rollers. Sure, overall full rollers are better, but don't say there is no value to roller tips.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.73 unlimited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, TBD heads, exhaust, paint, etc.).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

To expand on five7's comments...

One unspoken assumption about "roller-tip" rockers always seems to be that the only benefit is the roller tip, and the change in ratio if any. Yes, those things are true. However, every single motor I have taken sheet-metal rockers off of and put decent ones on, ran smoother and quieter. The ratio of sheet-metal rockers is pretty much random and each of them deflects a different amount from the others on the motor. The net effect is taht when you put ones on where all 16 are actually the same, then all the valves open the same amount. What a concept.

So really, roller-tips are a significant upgrade from the grocery cart version, and the roller-trunnions are a further upgrade from that.

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"So many Mustangs, so little time..."

 

When watching a roller tip cycle a valve up and down, the roller does not actually "role". This ovservation makes people think that there is no benefit by using them. What they don't realize is the roller only rides on one third of the tip. If the right pushrods are used, it will be the center of the tip. Therefor, the rocker will not impart a thrust to the valve stem as a stamped rocker will. So there are gains to be made with roller tips.

The roller tip rockers are about $150. Full rollers can be purchased for under $200 and Comp Mags, which are an outstanding rocker are about $250. With the minor cost difference between the two, I just dont see why anyone would buy the roller tips.....just thinking aloud.

 

How hard are roller rockers to adjust?

 

Actually, coming from an engineering standpoint, the roller tipped rockers eliminate most of the sliding friction between the rocker arm tip and the top of the valve. This sliding friction is more detrimental(cost more power) than the ball pivot which is somewhat more free to move "pivot" than the friction from the contact between the tip of the rocker and the top of the valve.

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'84Z28/'92 305TPI
'92 complete rear suspension/PBR disc/Posi/3:42
Light weight 34.5mm stabilizer bar in front
23mm sta. bar in rear
rear lowered 1" by cutting 1 1/4 coils of '84Z28 springs
comp cam, flowmaster
TB coolantbypass/shutoff valve to heater core
MAT relocated
Ram-Air(home-made) gutted air-box
IROC ground effects/wheels GY245/50's
700R4 superior shift kit/ corvette servo(excellent shift kit BTW) Rebuilt engine and transplanted it myself. Love this engine!
LOW performance people should drive low performance vehicles!

 

What about durability? I have a set of rollers for my buildup. But.. IM wondering how they will hold up in the long run? Ive never used them before, will they last the life of the motor?

Thanks!

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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!

 

Either roller-tip or roller-trunnion rockers can outlast the rest of the motor easily, as long as they're not aluminum. Those are not really appropriate for a street motor because the aluminum will fatigue and crack over a period of time and multiple heat-cool cycles.

Use steel ones, not stamped sheet metal with roller tips graunched in. Comp makes investment-cast steel ones which are an excellent value, at about $175 or so.

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"So many Mustangs, so little time..."

 

RB83L69,
Extruded aluminum rockers will last a long time. GM puts them on all the later LT1's and LS1's.