roller rockers

[NOT A T5]

Hi All! I've decided to go with rocker rollers for my 302 Windsor. What do you guys run for roller rockers? Which ones are decent or are junk? Which side of the rocker should the oiling hole be, I've seen roller rockers where oiling hole is on the roller side, others have hole on push rod side? Quality, Price...Made in USA perhaps! Thanks!

 

[Ed Raver]

I have used Harland - Sharp brand roller rockers on my 69 Boss 302 for years. Trouble free.  Ed

 

[Hemikiller]

The oil supply hole for an SBF, 335 or 385 series engine will always be on the pushrod side, as oil is fed up through the lifters.

I've run Crane Gold Race rocker arms on my 351Cs with great results. I've also heard excellent things about Sorpion and Yella Terra (Big $$).

Don't buy some no-name rocker. Had a friend who almost lost a freshly built Pontiac 455 to several failed cheapo rocker arms.

 

[c9zx]

I've had trouble free results using Crane, Scorpion, Crower, Yella Terra, Ford Racing, and Dove. You will see small variations in Geometry from one manufacturer to another requiring push rod length to obtain optimal valve train geometry. Chuck

 

[turtle5353]

I always run Harland Sharp.

 

[tony-muscle]

Scorpions

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[Mister 4x4]

I have a set of CompCams Hi-Energy roller rockers in my 351C-2V to go along with the rest of my CompCams goodies (roller lifters, rods, and 274/274 .566" cam) and Crane 7/16" screw-in rocker studs - so far, so good.

 

[Ryunker]

What is the benefit? I have comp cams magnum rollers in my M code. Their web claims 15 to 30 up increase. How when the ratio remains at 1.72? 498 lift cam.

 

[Don C]

Friction reduction.

 

[Mister 4x4]

Less friction on the valve train (or any other part of the engine) is never a negative.  But, you're right: you won't see any significant power increases simply by eliminating friction in a single location.  That's why I went with a total package (roller "everything").

 

[Don C]

Frictional force is directly proportional to the applied load. In other words, if you decrease the friction required to open the valves by 25% the frictional force (the force required to overcome the static friction -stiction- and kinetic friction -friction when it is moving) at the metal-to-metal connections is also reduced 25%. As the valves open the load on the valve train components increases significantly. The largest to smallest friction load, between the camshaft and valves, is on lifters (at camshaft), rocker arm pivot, rocker arm tip at the valve stem, side load on the lifters, push rod tip at the rocker arm, and push rod tip at the lifter.

Installing roller lifters and full roller rocker arms reduce reduces the frictional force considerably, freeing up horsepower to the flywheel, instead of being consumed by friction.

 

[c9zx]

Frictional force is directly proportional to the applied load. In other words, if you decrease the friction required to open the valves by 25% the frictional force (the force required to overcome the static friction -stiction- and kinetic friction -friction when it is moving) at the metal-to-metal connections is also reduced 25%. As the valves open the load on the valve train components increases significantly. The largest to smallest friction load, between the camshaft and valves, is on lifters (at camshaft), rocker arm pivot, rocker arm tip at the valve stem, side load on the lifters, push rod tip at the rocker arm, and push rod tip at the lifter.

Installing roller lifters and full roller rocker arms reduce reduces the frictional force considerably, freeing up horsepower to the flywheel, instead of being consumed by friction.

   I don't disagree, that in the general case, there may be some reduction in losses due to friction being less. However, I have never seen any sort of remotely scientific test that demonstrates how much. The advantage to roller lifters is primarily that it allows much more aggressive lobe acceleration rates and profiles (after about .050 lift) compared to a flat tappet lobe. There are many cases that in order to achieve the power characteristics and levels desired, a roller cam and valve train is the only way to meet the goals (I have one, SR). On a typical 500HP the gains seem to be 15-20 HP, assuming the flat tappet cam was as well matched as the roller cam. There are some down sides to a roller valve train; significant increases in valve spring pressures, increased stud/shaft deflection, increased push rod deflection, increased valve train weight, and a large increase in cost overall. A lifter failure of either type is usually catastrophic but, the case could be made that tiny steel needle bearings moving through an engine can do more damage.

   Roller rockers may also reduce frictional losses some amount and increase the resulting power but, not the numbers tossed around in magazines and the internet (15-30HP). The ball/sled fulcrums do generate significant friction and a roller trunion does help (see new GM LS rocker arms and old Ford OHO roller trunions). Any significant gains come from more accurate stock ratios, less distortion, or increased ratios (that is why I use them). Rockers that are supposed to be 1.73 can be all over the place. My friend, who owns a racing machine shop, a has done a lot of testing and has seen from 1.64-1- 1.80 on  "1.73" rocker arms. This is one reason why when changing rockers, of the same ratios, with rockers from different manufacturer I've always ended up needing pushrods of a different length. I just saw this again on a recent build.

   I'm not against roller valve trains, I just feel the reduction in frictional losses is way overstated buy people selling roller valve train products and Magazines selling advertisements for those products. Just my 3 cents, to long to be 2 cents. Chuck

 

[Don C]

I don't disagree, Chuck. I also think that 25 horsepower is optimistic. It would be interesting if someone did an apples to apples test, same engine, same cam grind, the only difference flat tappets vs. rollers. Easier to do with roller rockers vs. pedestal rockers.

 

[red351]

I do favor a roller tip rocker. It has to help with valve guide wear. HP no. The more moving parts, the more parts too fail. High lift and steep ramp cams and roller lifters. Is a gamble. For the long run, I stay flat tappet. Keep it simple my friend. The most I would trust is full roller rocker

 

[NOT A T5]

Thank you for all the input guys. So I got a set from Jegs the other day and boy they were already disarranged in their packaging with the poly locks all over the place and the roller pins were already rusted. What a disappointment! They are going back ASAP! Now on the bay I saw some roller rockers that have 2 oiling holes, what's up with that? Roller rockers were recommended by a friend of a friend of mine, less friction he states and it's not so much about increased horsepower to me as long as my car goes and it does. I'm not going to race her, she's just a cruiser LOL!

 

[tony-muscle]

Another advantage is the easier break in.

From all I have read it is very difficult to see an apples-to-apples comparison between flat and roller rockers. A roller cam of same duration as a flat cam will have a more aggressive profile, which will increase power. So it is hard to separate the power gains from the loss in friction compared to the gains from an aggressive profile.