FCar2000TA

iTrader: (7)

If I understand it correctly, the reason for roller rockers is to keep the valves from moving due to the stock rocker arm sliding on the top of the spring vs a roller rocker rolling across the top of the spring..... is that pretty accurate?

I am going to be getting heads next year, and I am looking for inputs on replacing rockers with stock rockers with a trunion upgrade or going with roller rockers like Harland Sharp 1.7 or Scorpion 1.7.

G Atsma

How much lift on the cam to be used? Generally, if it's .600 or over, roller tip rockers are a good idea, but less than that, not really necessary. Then just do a trunnion bushing upgrade.

FCar2000TA

iTrader: (7)

I think the cam is .590/.610.

I'll stick with the plan for roller rockers.

A.R. Shale Targa

iTrader: (2)

valves ARE supposed to rotate in the guides during up/down movement so as to keep the valve job concentric
Roller rockers are traditionally very heavy at the valve because of the amount of material needed since aluminum is
generally such a weak alloy..........Yella Terra being the accepted premium brand
Hollow valves AND titanium retainers will help plus bad *** valve springs are a MUST

Jontall

I would order the heads with GM powdered metal valve guides (not bronze) and use stock rockers with bronze trunnion upgrade. Zero problems and low cost.

FCar2000TA

iTrader: (7)

Do roller rockers keep the valves from rotating? I thought they were to keep the valves from rocking side to side with the sliding of the stock rocker head.

A.R. Shale Targa

iTrader: (2)

I must have misunderstood your wording here
Yes less guide wear is the purpose....the tip of the factory rocker just plain runs out of geometry when trying to move the valve more than .600"

FCar2000TA

iTrader: (7)

Is there an advantage to roller rockers vs stock rockers and powdered metal valve guides?

vettenuts

iTrader: (4)

Roller rockers can provide a narrower wipe pattern if the time is taken to correctly set them up. Many skip this step. The rollers do not roll, they slide. The smaller wipe pattern is what reduces the valve guide wear. The stock rockers, due to their geometric design, won't provide a narrow wipe pattern. So a wider wipe along with stiffer springs accelerates valve guide wear. Powdered metal wears slower than bronze.

Focus on the total setup. Larger OD pushrods help was well. Hardened pushrods are not stiffer.

HappySalesman

iTrader: (3)

out of curiosity, what lifters are you planning on running?

FCar2000TA

iTrader: (7)

Morel 5315

99 Black Bird T/A

iTrader: (4)

For roller rockers the best ones seem to be Jesel, T&D or Yella Terra otherwise I would trunnion upgrade the stock rockers.

big hammer

Roller rockers

PhoneniX

I went with the comp trunion upgrade. You have to be honest with yourself on your build and be able to draw the line when enough is enough $$.
If it helps the trunion install was really simple with a regular bench vice.

JakeFusion

iTrader: (7)

I'd just do the CHE Bronze Trunnions...

FCar2000TA

iTrader: (7)

Roller rockers don't roll across the valve/spring retainer? I thought that the wheel on the tip of the rocker actually rolled across the retainer.

When you say "wipe pattern" does that mean the surface area of the retainer that the rocker slides across?

G Atsma

How could it roll across the retainer when the valve tip is ABOVE the retainer. IF it rolled over the retainer, the valve would pop loose the first time it happened. You might want to read up on how valves are kept in the head....

FCar2000TA

iTrader: (7)

Since I do not feel comfortable swapping out rocker arm trunions, I am going to buy new rockers when I get the heads done.

Scorpion roller rockers claim 100% stock replacement and lifetime warranty. About $150 more than new stock rockers with trunion upgrade.

FCar2000TA

iTrader: (7)

I mean whatever the tip of the rocker touches. I thought the roller rocker wheel rolls across it.

nj02z

iTrader: (6)

Comp Cams trunion upgrade. I have at least 400 plus runs on them with .602 lift. What more could I say.