Roller Rockers in Stock

[SSDiv6]

Originally Posted by Steve Calabro

I have a question. Is it not true that both Ford and Chrysler motors with hydraulic lifters came with stamped steel rocker arms NOT the iron ones that most racers use that came on the solid lifter motors only?

Mopars, with the exception of the Max Wedge and 273 engines, they had stamped steel shaft rockers from the factory. I would say that approximately 20 years ago, they were allowed to use the ductile iron rockers based on their availability in the same engine family: 273 and 426 Max Wedge. (Big Blocks: 361, 383, 400, 413, 426 and 440) (Small Blocks: 273, 318, 340 and 360). Ford 390, 427 and 428 had ductile iron shaft rocker arms from the factory.

[Jeff Lee]

Originally Posted by SSDiv6

Mopars, with the exception of the Max Wedge and 273 engines, they had stamped steel shaft rockers from the factory. I would say that approximately 20 years ago, they were allowed to use the ductile iron rockers based on their availability in the same engine family: 273 and 426 Max Wedge. (Big Blocks: 361, 383, 400, 413, 426 and 440) (Small Blocks: 273, 318, 340 and 360). Ford 390, 427 and 428 had ductile iron shaft rocker arms from the factory.

And to ad to that, you won't have to dig too deep to find a MOPAR racer that had problems punching out pushrod cups on his stamped steel rockers prior to the allowance of these non-OEM ductile iron rockers by NHRA. I believe that occured in the mid-to-late 1970's (1978?). Interestingly, this was a problem BEFORE dwell-nosed cam lobes and super high tension valve springs were the mainstay of fast Stock Eliminator cars of the last decade. No, this is not a new problem!

[Steve Calabro]

So which combo's use the " as produced " valve train? Completely stock?

[Jeff Lee]

Originally Posted by Steve Calabro

So which combo's use the " as produced " valve train? Completely stock?

Anybody that wants to...

[SSDiv6]

Originally Posted by Steve Calabro

So which combo's use the " as produced " valve train? Completely stock?

Prior to the new rule that allows the use of studs and guideplates the following makes still use "as produced valve train": Oldsmobile, Buick, Ford Small blocks. One exception with the Ford small blocks is the 289 HP and the Boss 302/351 (stud/guideplate), and the Non-Boss Clevelands, that are allowed to use the Crane Cams conversion kit. All other makes have stud/guideplate provisions; Chevy and Pontiac have a great selection of rocker arm options.

[Jeff Lee]

Speaking for the few AMC racers out there, all applications use a stamped steel rocker arm over a ball / stud assembly with no guide plates (prior to last week). Looks just like a SBC arrangement but the rocker folcrum cenerline to tip is about .200" longer and offer's a 1.55 ratio (my testing found 1.53 typical). AMC uses a 5/16" pushrod and a 3/8" screw-in stud. Upgrades can be made to a 3/8" pushrod and a 7/16" rocker stud from a BBC. Bracket racers typically use a modified Pontiac guide plate if neccessary.

As stated by SSDiv6 ..."Chevy and Pontiac have a great selection of rocker arm options"
Yes, especially Pontiacs. I suspect a Pontiac racer or two might not like everybody else having roller rockers because that opens up the door to everybody having the same ratio's available. I'm not personally aware of any conclusive evidence that shows a 1.65 rocker ratio has a decided advantage over a 1.5 rocker ratio (both theroretical ratio's) in a Stocker application (both offering the same gross valve lift) but I would suspect there is some advantage although miniscule. Personally, I always built a cam around the rocker ratio.

[SSDiv6]

Originally Posted by Ed OBrien

Steve
There are no good after market rockers foe the 455 Buick and I don't think there are any for the 350 Buick either but you can buy some at auto zone and I think the ones I found were some old seal power they had
left over but no one makes any good ones other than roller rockers.

Ed is correct...Buicks get the short end of the stick in regards to rocker arms.

[Steve Calabro]

As stated by SSDiv6 ..."Chevy and Pontiac have a great selection of rocker arm options"
What are they? Are they good? What about adjustable pushrods? Did they come from the factory?

[SSDiv6]

Originally Posted by Steve Calabro

As stated by SSDiv6 ..."Chevy and Pontiac have a great selection of rocker arm options"
What are they? Are they good? What about adjustable pushrods? Did they come from the factory?

Steve, the aftermarket has lots of offerings for both makes with better materials and treatments. The adjustable pushrods did not come from the factory and were allowed by NHRA many moons ago, to give an option to other makes of engines that did not have adjustable valve train. My own preference, although more expensive, I would rather have custom made pushrods in lieu of running an adjustable push rod due to its weight.

The funny and interesting part of this discussion is that many of you are bringing up issues that have been in the rule book for over 20 years such as adjustable pushrods and the ductile iron rocker arms in Mopars and at the time, no one made an issue of it until now. Do not get me wrong, I recognize many of you have devoted most of your life to a few makes of engine manufacturers and are not knowledgeable on other makes.

[Steve Calabro]

Steve, the aftermarket has lots of offerings for both makes with better materials and treatments.

I have tried them all at great expense. The bottom line is that they are still stamped steel and not made to do what we are asking. As many have stated roller rockers are not a performance advantage. Don't you think the adjustable pushrod is a performace advantage that was allowed? Adjustable rockers on cars that they never came on? ETC.

The funny and interesting part of this discussion is that many of you are bringing up issues that have been in the rule book for over 20 years such as adjustable pushrods and the ductile iron rocker arms in Mopars and at the time, no one made an issue of it until now. Do not get me wrong, I recognize many of you have devoted most of your life to a few makes of engine manufacturers and are not knowledgeable on other makes.

SSDiv6: This is just the point i'm trying to make. Thing are allowed when there is a problem. Stamped steel rockers are a big problem.