Bigger Pushrods & Guideplates Legal in Stock now

[Alan Warman]

I am a "newby" to stock eliminator racing, but when I was building my motor, it would have been a lot easier and cheaper if I had been able to use roller rockers. It wasn't all that expensive for me to buy rocker arms, and adjustable push rods for my Olds, but I know the big block Chevrolet guys spend a small fortune on yours. Though I'm sure all the purists here have a point as well when they say that using roller rockers is getting away from stock racing.

[LNorton]

I know a lot of you guys get killed by the stock rocker rule. We have it pretty easy as the 3800 has roller rockers from the factory.

[Jeff Lee]

"Killer" yet legal valve-train for Stock:

1) Steel billet camshaft
Options: large cam journals (babbit or roller bearings) , change in firing order.
Cost: upwards of $1500 parts / labor (includes boring cam tunnel).

2) non-OEM lifters
Choices: Schubeck carbon composite heel or body, OEM style altered plunger conversions (available through various sources), tool-steel lifter bodies.
Options: various coatings to reduce wear.
Cost: upwards of $850.00

3) "Any size" pushrods
Choices: Manton as primary source, single or dual taper 7/16" to 3/8", .120" to .168" wall construction. Larger sizes available.
Cost: approximately $30 per pushrod or $480.00 per set.

4) rocker arms
Choice: BBC using 9/16" stud mount and 8.1L BBC rocker arms, various other treated / coated assemblies also available.
Cost: approximately $750.00

5) valve springs & retainers
Choice: Beehive or traditional to deliver 400-450#'s open pressure. Available from various suppliers. Retainers: tool steel
Cost: approximately $450.00

6) Guide plates
Choice: OEM to aftermarket.
Cost: ? $150 ?

Any Sportsman reps want to comment on why a roller rocker rule would "ruin" the sport?
Next to guide plates, your $289.00 Crane "Gold" rockers are the cheapest parts here yet the only parts that lead to engine longevity.

[Alan Roehrich]

You're a little high, on several of your prices.

You left out 8620 bar stock rocker shafts found in more than a few of the shaft rocker engines.

You ignore the fact that roller rockers, especially on engines with shaft rockers, will allow ANOTHER escalation in tappet velocity, increasing both performance AND strain on other parts, especially for engines with larger diameter lifters.

Where does it end? $1K Jesel or T&D systems? Any tappet diameter? Roller lifters? No lift rule?

[Jeff Lee]

If I'm off on total pricing, it can't be more than 10%.

If you fix the "wobbly" end of the spectrum (the stud mounted rocker arm; as found on GM / AMC / FORD), I really don't see that it will increase strain to a point of breakage anywhere else on the engine. If the goal is limiting the performance or adhering to "Stocker Purity", i.e., valve-train limitations, then everything mentioned in my list should be banned outright and all components should resort to OEM parts and specifications only.

But I've always been lost on the concept of allowing full-bore race modifications and parts as listed below, but keeping one breakage prone part which can (and does) lead to complete engine failure.

I guess the wording of a rule would read something like "mounted in same configuration as OEM"

Where does it all go? I've often thought Stock will (regarding engine) eventually be limited to restrictions on factory valve lift, factory carb, intake, valve sizes, piston configuration, bore and stroke. If I missed something, I 'll assume you get my meaning.

[Dwight Southerland]

A cheaper alternative for all this would be to go back to old time stocker specs of OEM duration, overlap and valve springs specs. The problem, and thus the explanation, was always that the tech people were not trained well enough to measure all that intricate stuff. Well, I dare say that we have all spent way more money than it would cost to have developed a management, education and certification system for NHRA tech people to do their job. I would easily agree to addition fees for setting records or tear-downs to fund better administration in the tech department for Stock and Super Stock.

[SSDiv6]

Originally Posted by Dwight Southerland

A cheaper alternative for all this would be to go back to old time stocker specs of OEM duration, overlap and valve springs specs. The problem, and thus the explanation, was always that the tech people were not trained well enough to measure all that intricate stuff. Well, I dare say that we have all spent way more money than it would cost to have developed a management, education and certification system for NHRA tech people to do their job. I would easily agree to addition fees for setting records or tear-downs to fund better administration in the tech department for Stock and Super Stock.

I totally agree with Dwight, and it would require a lot of the specs issued by the OEM to be realistic!!! If can recall correctly,I remember the Chrysler 440 and 340 cam specs having something like 240 degrees of overlap and unreal durations specs. The same applied for other makes.