Re: Roller Rockers in Stock
 

Yep...I totally agree!!!

Re: Roller Rockers in Stock
 

Alan -

Your argument on the basis of logic whows a bias toward yourself, as well as most of the arguments presented here. Just because "Holroyd's rockers" are available from GM doesn't mean anything; GM is more capable of producing high quality race parts than aftermarket suppliers (more budget, bigger staff, bigger economic base to absorb R&D costs and a product that will make no profit.) Before the new rule revision, you BBC racers enjoyed an advantage of being able to cross breed some factory race parts that were never specified as even replacement parts for the engine combinations you are racing. So it is with most engine combinations, especially when you get into the higher classes that require engines that produce enough power and RPM to exceed the capability of OEM, assembly line specified parts. Allowing roller rocker arms at this point willl make so little difference in the playing field (unless you are afraid of some of the engine combinations mentioned that use shaft rockers) and will provide a way to eliminate breakage for you and everybody else.

It's the open valve spring rule and the elimination of requiring stock duration that is killing the budget for stock cars, not roller rocker arms or big push rods. If you had to retain stock valve spring pressure, rocker arm breakage is not a big issue, and there would be no 8000 RPM+ engines.

Re: Roller Rockers in Stock
 

Dwight, we both know full well that the rockers Clark Holroyd sells are plain old stock rockers originally designed for truck engines, during a period where Chevrolet didn't have much interest in racing, and certainly not big block engines in drag racing, at least outside of Pro Stock. Clark Holroyd just has studs and adjusters made anyway, he just happened to see the rockers on a replacement engine, and thought "hey, I could use bigger studs with those". GM didn't design a "race piece" and then sit back and wait for Clark Holroyd or someone else to "discover" them.

No, a lot of the 396, 427, and 454 engines did not come with 7/16" pushrods and guideplates.

I agree, the open valve spring rule is what has caused this. We cannot "unring the bell", they'll never go back. The duration rule didn't cause this, because the shorter duration you're allowed the more you try to accelerate the lifter within the duration allowed. If you had the open valvespring rule without the open duration rule, it'd be even worse than it is.

The roller rocker rule is just another step towards a slippery slope, and it will make the playing field even less level than it is now. And where do we stop?

I have a friend that makes roller rockers, if the rule comes in, I can always have him make me a few sets that use 9/16" studs and be right back to where we are, because we aren't breaking rockers. But then I go from a $65 set of rockers to a $400+ set of rockers. And again, where does it end? Bigger lifters for all? Roller lifters for all? No lift rule?

Re: Roller Rockers in Stock
 

Enough of this. Everyone here aspired to race stock, no one held a gun to your heads, everyone knew what they were getting into, and chose a car based on that.

If you want to run roller lifters, roller rockers, dry sump oil systems; if you think your engine has to much factored horsepower; if your car has too long, or too short of a wheelbase; if you think your car carries too much, or too little weight; if your car doesn’t have a hood scoop and you think it should; if you car does not have traction control and you think it should; if your car needs wider tires to be consistent; if your car did not come with aluminum cylinder heads but the factory thought about them, or you think they should have put them on, or at least thought about putting them on; then I have some great money saving suggestions.

First, in light of today’s fuel prices then do not race. The car will be extremely consistent. Also, I can guarantee if the engine is never turned over your valve train/rods/block/oil pump/ will not, and can not break. Bearings won’t spin, distributor gears won’t tear up, and (I know I’ll take a hit from the engine builders on this next one) the freshen job on the engine can be put off from 100-400 runs to every 4-5 years. Ultimate reliability, consistency, and cost savings in on package, and you can talk about how fast and consistent you car is (or would have been).

Second, if you HAVE to race, then race a local bracket race. Just think how much fun it would be, and the cost savings; no accepted rod or piston list, any head, any trans manual or automatic, heck, you can run pump gas or bio-diesel if you wanted. Plus, you will save huge amounts on hotel/motel bills, tow vehicle fuel. You won’t even need a motorhome since most bracket races are one day events. The big advantage is there are very little rules (meaning if you want roller rockers your competitor won’t care, he may even sell you his old set to help you get started).

Third, continue racing stock, and save money where you can to get the car/engine/transmission you really want. We started racing in the "Street" class at Emerald Coast Dragway and save for three months to buy a no frills AutoMeter tach for the car, then much later a Play back tach. The car originally had a ten bolt, sloppy turbo 350, and a weak throughly thrashed slapped together (by the previous owner) SBC 350. It took us a long time and the help of a lot of friends and family to get where we are today (Bob and Bobby Lundholm, Jimmy Parker, Woodro, Arnold Greene, Paul Forte, Lee Tuttle, DJ Raiser, Tim Sloan, and many manufacturers...the list goes on). This group has been instumental in guiding our efforts and kept us from wasting money (well I am hard headed and did waste some money, but not as much as I would have). We started with a plan (worked from the back of the car forward), and have kept to it. It has taken ten years to reach where we are now. Friends and family what more can be said.

Everyone chose to build a car for different reasons, money, engine size, class factor, class size, uniqueness, and even the cool factor. But a Trabent will never fit into A, B, or C, much less F, G, or H, even with roller rockers, superchargers, or roll bar/cages, you will have to change cars. Racing costs money. The old adage is still true today, “How fast can I go? – How big is your wallet.” Rule changes cost everyone money even if it is as easy as removing the button from the steering wheel.

Stop the rule changes!

Re: Roller Rockers in Stock
 

One more question. Who are we going to get to police the trick custom roller rockers that have the pushrod cup and the roller tip moved around in relation to the fulcrum? Got any idea what kind of games you can play by altering that relationship? Do those of you campaigning for roller rockers realize that rocker arms are NOT constant ratio?

Okay, so that was more than one question. And yes, I know that NHRA can easily check for maximum lift. But how often do you see them do that? Besides, it's not more maximum lift you get by playing with the relationship between the pushrod cup, the fulcrum, and the roller tip. It's the ratio on either side of maximum lift. You can radically alter the lift curve. It's easy for the shaft rocker guys to experiment with and play with, just shim the stands, or shorten or lengthen the pushrod, and then plot the lift curve again. Go ahead, see what happens.

Oh yeah, how many sets of trick rockers do you want to buy, and how many trick cams do you want to try to take advantage of them? Think about THAT before you decide how much cheaper and easier you think roller rockers will make things.

Re: Roller Rockers in Stock
 

Alan...the Ford and Mopar guys have been doing this for years with the ductile iron adjustable rockers. Also, it is legal to shim the stands, lengthen/shorten psuhrods or use adjustable pushrods.

Trick cams? There are many already using the larger core cams, needle/roller cam bearings and switched firing orders.

Re: Roller Rockers in Stock
 

Again, Alan, my point. I'm not arguing for or against, just stating a fact. Some will spend more money, some will not spend more. Some will gain an advantage, some will not. Everything else is smoke and mirrors.

Gosh, if we allow aftermarket rocker arms, everybody could have 9/16" studs. (or 1" studs!)

(If you don't see the satire in that last satement, don't respond.)

Re: Roller Rockers in Stock
 

http://img257.imageshack.us/img257/732/shockid8.gif

Re: Roller Rockers in Stock
 

Believe me, I know that already. Yes, it is legal. I'm not arguing that point at all.

I know about the big core cams, trick bearings, and firing order swaps. I'm not arguing that point either. That's not what I mean by trick cams.

Re: Roller Rockers in Stock
 

I understand your point Dwight, and yes, I see the satire.:D

I'm just not convinced that roller rockers will be good for the class. With the options it opens up, I think it will hurt those people who don't have an unlimited budget, and those who build their own engines and don't have the knowledge or resources to take advantage of those options. I do not agree that allowing roller rockers won't change things a great deal. If it wasn't going to bring about considerable change, no one would ask for them.

There's a lot of smoke and mirrors involved, you're right about that.

If nothing else, this has been a great discussion, with plenty of good points, and few, if any, personal attacks. I may or may not agree with what has been posted, but I do respect and appreciate the majority of it, and I can see where it is coming from. Regardless of what happens, I hope the discussion at least helped more people see more of what goes on. I've had my say, and I will now respectfully bow out of the discussion.

Re: Roller Rockers in Stock
 

For what it is worth. I had never broke a rocker until last week broke two warming the car in shop to check springs and lash and this last weekend in Brainerd broke two more. I was lucky and did not explode a lifter and did not hurt motor? Lost some ET and MPH pulling motor to check it out. So with that being said, if we we had a vote, count me in.

Re: Roller Rockers in Stock
 

Yes, an excellent discussion and for the most part, stayed on track! :)

Re: Roller Rockers in Stock
 

This thread has been an exceptional read. I really enjoyed it. From my background in class racing (superstock), I see stock going too modified. Each new allowance (rule change) creates new weak links. My first engine had independent or stud mounted roller rockers. As I learned I went with larger cams, spring pressures approaching 300 on seats and started breaking the roller rockers. Ended up with a Jesel shaft system, then the 350 plus seats were cool. All I worried about then was the lifters and springs going away. Stockers are going rpms that my engine went. I think it's gone a little too far. Although the times they go is mighty impressive the cost factor is going to end up like superstock maybe with more breakage though. We, in superstock, could lighten some things in the rotating assembly. For what it's worth, and one who wants to build for stock, I vote stock to not allow the roller rockers and maybe for the eliminator to regress somewhat. Reduce the spring pressures, go back to stock size pushrods, etc. Superstock costs are high and I hate to see stock go there as well. Just my opinion.......

Re: Roller Rockers in Stock
 

Jesse-
I wish it could happen.

Re: Roller Rockers in Stock
 

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?

Re: Roller Rockers in Stock
 

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.

Re: Roller Rockers in Stock
 

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! :eek:

Re: Roller Rockers in Stock
 

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

Re: Roller Rockers in Stock
 

Anybody that wants to...

Re: Roller Rockers in 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.

Re: Roller Rockers in Stock
 

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.

Re: Roller Rockers in Stock
 

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

Re: Roller Rockers in Stock
 

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?

Re: Roller Rockers in Stock
 

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.

Re: Roller Rockers in Stock
 

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.

Re: Roller Rockers in Stock
 

Steve, I agree, stamped steel rocker arms are the big problem. You do not have an idea how much research, test and analysis I have done on the current stamped rocker arms. My conclusion is the inconsistency in metal thickness and low grade materials and poor quality.

Re: Roller Rockers in Stock
 

Well SSDiv6, you may have access to scientific instruments and labs, but I knew from the get-go :confused: when I took a Speed-Pro/TRW AMC rocker and "thunked" it with my fingernail and it went "dunk" :mad: and the OEM rocker went "diiiinggg" :), then surely the factory offering was better :eek:. Although that did lead to a rockwell hardness test which confirmed a huge difference as I suspected...

Re: Roller Rockers in Stock
 

The lab test allowed me to see the variation on materials and try to find the solution. Yes, you can do it the "Redneck" way via the resonance test, however, I was trying to find how much variation between manufacturers, its ductility and malleability. What I also found with the replacement stamped rocker arms is that in addition to the cycles and loading they are exposed to, the heat affects the malleability.

Re: Roller Rockers in Stock
 

As I see it from the technical stand point the stamped steel rockers are inferior to the ductile iron rocker arm. Then why would the Chrysler and Ford guys running the iron instead of the stamped steel (ORIGINAL) rockers want it for the Chevy guys WHEN THEY HAVE THAT ADVANTAGE? We have no option!

Re: Roller Rockers in Stock
 

Steve, in addition to Mopar and Ford, there are Chevy, Olds, Buick and other makes, asking for the change.

Re: Roller Rockers in Stock
 

Steve, i can`t speak for the MoPar guys, but every production Ford FE (332,352 thur the 427 & 428`s), came from the factory with iron rocker arms. There was never a stamped steel rocker arm made for the FE Ford. There were 2 different versions of the FE iron rocker arms, the hyd. lifter engines had non adjustable rocker arms, the solid lifter versions had adjusting screws. The non adj. rockers were rated at 1.73 ratio, the adjustables were rated at 1.76, but like most factory rocker arms,advertised vs real world ratios don`t usually jive. The adjustable rockers I checked were normally under 1.73.
The same situation with the SB Ford stamped steel rockers, my 5.0 Mustang rockers normally test at 1.53-1.54, Fords spec is 1.60. I would imagine that the GM and MoPar OE rockers normally don`t compare favorably with the factory specs either.

Re: Roller Rockers in Stock
 

Rory, Thanks for the info. The rocker ratio is not the problem. You can make it up with cam lobe, pushrod length, and as a Ford guy by shimming the stand. You can also put the adjustable rocker on a non adjustable (hydraulic) non factory non stock valve train! All i'm saying is that many combos can use non OEM valve train parts that are more reliable so why not roller rockers for the GM guys or evereyone if they stop breakage and major expense if they do?

Steve

Re: Roller Rockers in Stock
 

In general, if you are experiencing rocker arm failure, you are experiencing extreme valvetrain lash during operation. The extreme lash causes very rapid impact loading and the rockerarm fails due to too much stress.

The rockerarm failing is a result of the valvetrain being asked to do something it was not designed to do, specifically the CAMSHAFT DESIGN was intended for a LOWER RPM given the rest of the valvetrain system.

Let me try this analogy. You have a wheel and tire combination that is not balanced and the imbalance is very noticeable at 80 mph. From experience, if you run below 80 mph, the imbalance is not very noticeable and nothing in the suspension fails. But the closer you run to 80 mph, the more severe the imbalance becomes and at 80 mph, it feels like the entire wheel and tire is almost jumping off the ground. If you run an extended time at 80 mph, eventually something in the suspension will fail such as a strut, bushing, ball joint, etc. Since wheel and tire imbalance is a well known phenomenon, we instinctively know the root cause of the problem is the imbalanced wheel and tire, not the strut or ball joint that failed.

In the suspension failure above, the failure was the ball joint, but the root cause of the failure was the imbalance in the wheel and tire.

A valvetrain is very similar to the suspension example above, but the “imbalance” in the valvetrain is a fundamental component in the valvetrain that cannot be eliminated. The imbalance is the camshaft design. If the camshaft is designed to operate at a lower rpm, but is operated at a greater rpm, it is just like the imbalanced wheel and tire above. Below a particular rpm, everything is ok, but exceed the specific rpm of the system, all hell breaks loose and valvetrain components begin to fail. With most combinations in stock eliminator, the rockerarm is the weak link and fails due to an improper valvetrain design causing impact stress.

In the valvetrain failure above, the failure is the rocker arm, but the root cause of the failure is the camshaft design for the valvetrain system.

If you’ve read this far, I’ll give my take on roller rockers in stock. Stock eliminator is supposed to be difficult. Your not supposed to be quick immediately. The majority of the fast guys have been doing this as their main hobby/pastime/business for the past 20 to 40 years. You cannot and will not duplicate their results unless you spend an extreme amount of money WITH THE RIGHT PEOPLE (Woodro Josey, Jim/Matt Morgan, Bub Whitiker, Don Little, Greg Luniack, Jimmy Bridges, Parson and Meyers, etc) and LISTEN to their advice or you will not be anywhere close to competitive in class.

Rocker arm failure is a result of poor camshaft and or valvetrain design, point blank. Roller rockers would just be a Band-Aid to your larger valvetrain problem. If you are experiencing valvetrain problems, talk to your camshaft/valvetrain guy and try a different grind. Please do not ask for a rule change that is not warranted as an existing LEGAL solution is available, you just have to work at it.

Sincerely,

Re: Roller Rockers in Stock
 

[QUOTE=Chris Hill;72195]In general, if you are experiencing rocker arm failure, you are experiencing extreme valvetrain lash during operation. The extreme lash causes very rapid impact loading and the rockerarm fails due to too much stress.{/quote]

Chris, the dynamics are not the same for between a hydraulic or solid lifter.

This may be correct for an OEM cam, however, we are talking about a camshaft that is strictly designed for racing. Yes, the OEM valvetrain can fail with a racing camshaft design. The OEM valvetrain in earlier engines, was not designed for high RPM operation.

Chris, your analogy cannot be applied here because the dynamics are different. Again, you have to look at the valvetrain from the point of view as a system. By the way, it is not the camshaft design...the lobes I have designed for others, are more gentle in the valvetrain that earlier designs. I have spent many hours plotting lobes in the computer and also graphing lobes from actual measured data with the Cam Doctor. Many of my cams did not break rockers years ago, nevertheless, they have been breaking rockers in the past 3 years. The lobe did not change, however, the quality of the rocker arm did.

A few of the engine builders you have mentioned, build engines that are already use a good rocker arm (Mopar and Ford Big Block), some of the other racers have shared they use ealier stuff when they can find it and have also experienced failures.

...and...I stand on the fact that a well designed cam, can and will break rocker arms. Do not compare the your current race engine or your Dad's to other applications. Your V-6 engine does not have the power output of other engines, and your Dad's engine is a big block Mopar, probably running the ductile iron rocker arms.

Re: Roller Rockers in Stock
 

A good friend of mine came up with this so I figured I would share it with you guys. If guys are pushing for Roller rockers, fine. Let's limit valve spring pressure, say to 150 on the seat. This would limit the RPM and no body would need roller rockers. The second they give us roller rockers we will start seeing 9000 RPM bigblocks, with 350 PSI on the seat if guys arent doing that allready. What happens then? When the engines start coming apart, are these guys going to start pushing for a light bottom end so they can turn the RPM with out having to risk running over the crankshaft about the 1000 ft mark. How fast will cars go then AA car will run the low nines and then we will need rules for people to feel safe, and all that nonsense can start up again. This is a bad idea and will add up to another nail in the coffin for stock. Lets just leave things alone and race for a few years.

Re: Roller Rockers in Stock
 

Todd, many of the stockers are running high pressures with Schubecks and many engines are already turning high RPM's. How are you going to check for springs pressures on every car at every race? Don't you realize that what you are proposing would create more engine failures? Do you know the definition of "valve float" and its consequences?

Re: Roller Rockers in Stock
 

Chris,
In E/Stock I originally had Don Little build my first set of heads and provide me with a camshaft. Those rockers also failed. In previous posts on this subject, back about a year or so ago, Woodro Josey cam out and stated as an engine builder he was all for roller rockers in Stock. That's two names on your list you probably didn't consult. My camshafts were always the work of Chris Padget at this point and we went thru at least a half-dozn different grinds. One was even a Bullet grind. Most made the car faster and the trend was definetly more aggressive lobes. All experienced rocker failure.

By the time I was in D/S my car was decidedly faster. By now I was having Bud Yancer build my engines. He is an accomplished Comp engine builder and is recognized in P/S ranks and was formerly building engines for a top-ten team in the '90's after finding an un-heard of 25HP for the team in his first year. Bud not only designs his own cams (based not only on his experience but a $25K program that is a few levels above the Cam Doctor program), but he builds his own cams on his own cam grinding equipment. I don't think anybody in your list can lay claim to that level of skill.

And by the time we left D/S and moved into SS/H, I had the fastest D/S car in the country with official times of 10.55 @ 125. So I would say that in the end we wern't a bunch of idiots struggling with an engine. And spring pressures, surely no where close to OEM were as high as 225#'s on the seat and 425#'s open (.457" lift). Those rates actually helped breakage as indicated by SSDiv6 to Todd H. But still, breakage occured and it was almost a requirement to check lash every other pass. Not race, pass! And yes, Chris, I would agree with you that is a result of excessive ramps but then again the results of our efforts was a fast car.

Rockers tried over the years were OEM used, OEM NOS, Crane Nitro for SBC, OEM, cryogenic, OEM coated. Rocker balls were 3/8" and 7/16" both OEM and aftermarket, grooved and non-grooved. Oh yea, also tried PVS rocker arm system with powdered metal rockers and balls.

I have about 5 sets of various length pushrods due to one grind over the other.

Lifters tried over the years ranged from Comp Cams race hydraulics to Shermans, composite body Schubecks, composite base / steel body Schubecks and even chilled-iron flat tappet converted to "hydraulic". Cams ran from standard cast to billet steel. Are you totalling the price tag in your head? Yea, it wasn't for lack of funds either. And in the end, we pretty much had a better system but still had to stay on top of lash every other run and still had failure. Speaking of failure, my one and only final round in a National event was paved by one single in the quarter-final. Guess what? A rocker arm broke! Good thing it was a bye-run. So think about that. Had I had an opponent and lost due to breakage, how much would that have cost me?

But that's my point. Given all the altered, non-OEM parts allowed by NHRA to the valvetrain, why should anybody have to go down this path of broken engines and light-weight wallets? Either go back to 1965 valve-train rules or finish the job. The only part of the valve-train that is not stock is the rockers. And you know as well as I do, NHRA will not rescend the rules in place today.

Todd,
396/375 engines in Stock exceed 8,000 RPM today. They have the same technology I had in my engine's valve-train. Additionally they have 9/16" studs and 8.0L rockers. That's about a $750.00 upgrade above what I ran.

So I want to ask the Small-block Chevy and SB Ford racers something. Since the LT4 and 302 Cobra engines used factory roller rockers as OEM installed, why hasn't somebody from each camp petitioned for allowance of their use on the other SBC and SBF's? The precedant is there and that is all NHRA needs. That's how the beehive springs came into play (LT4) and larger pushrods and guideplates (SBC rail-type rockers). That's also how SB and BB Mopars with stamped rockers got ductile-iron Isky rockers (273 SBM and 426MW BB Mopar). Wake up!

Re: Roller Rockers in Stock
 

Sure, I know the definition of Valve float. When the valvetrain cant keep up with the valve opening and closing the parts kind disconnect and hammer against each other causing impact damage and so on. That being said, You can design camshaft lobes and be easy on parts thus reducing valve train failure. Right now it's a risk and reward, guys want to run big agressive lobes and make big power. The reward : an engine and revs high and makes big power throught the range, resulting in Fast ET's, good quailfying stats. The Risk: unstable valvetrain a chance for catastrophic failure. The racer will have to decide whats is more important, Running fast or running safe. You can have a guy in Tech have an on the car valve spring checker. He he pulls it on the car and the pressure is way over he's out.Guys back in the 70's and 80's had no Shubecks, or big valve springs. They survived and raced. What happens when engines are running super high RPM and they start coming apart, will guys start lobbying for lightend bottom ends because it's a safety factor??? I'm sure of it. This is not an easy game, guys been playing for along time within the rules and being succesful. SOME of the racers of today don't want to make what they have works, so they Bitch and cry for rule changes because they ran out of talent, money and the will to make due with whats available. This is what stock is about.





Todd, many of the stockers are running high pressures with Schubecks and many engines are already turning high RPM's. How are you going to check for springs pressures on every car at every race? Don't you realize that what you are proposing would create more engine failures? Do you know the definition of "valve float" and its consequences?

Re: Roller Rockers in Stock
 

Oh boy...you have a lot to learn about camshaft design; agressive lobes are not required to make lots of power. Not every stocker cam grind works the same because there are lots of factors that need to be taken in consideration.

Another falacy...there are lots of engines that do not need to be twisted to higher RPM's to run fast because they are limited on its design. Ask anyone that races a Buick engine or a late model Mustang 302 F.I....they cannot spin their engines due to breathing limitations.

Keep dreaming.

I do not know how old you are, but I have been doing this for a very long time. In the early days, even with the spring limitations and old cam specs, you still had failures.

Why do you think NHRA put weight limits on the reciprocating mass?

Like I said, I have been in this sport for over 35 years and playing for a long time and have seen the evolution of the rules. When there is a rule change, you adapt to be competitive.

Your statement is sort of an insult to many of the well respected engine builder in Class racing that are busting their asses. They have expereinced rocker arm failures too like everybody else. Just do a search, read the posts and edify yourself.

In a nutshell, if you read many of my earlier posts, I have made it VERY CLEAR, that the problem with stamped rocker arms is the QUALITY of the product. We live in a global world were parts manufacturers are outsourcing parts overseas. The process is not the same as in the early days, they are producing a lower quality product, with cheaper labor and processes. By the way, I know of two particular cars that are running a cam grind that was designed before the camshaft rule change and they are also breaking rocker arms too.

Re: Roller Rockers in Stock
 

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