Certified Stock "Qualifying Numbers"

thanks brian .

 

casey , these are cars that were certified ???

sorry , i am sure that this thread wasn't meant for questioning the posted info .
, or was it :rant:

 

Certified Engines

For those people that thought that their was a bunch of cheating going on it is amazing how close the engines are to stock numbers. I've had numerous conversations with friends that have not really gotten into this side of the hobby and feel that the cars just can't do what they do.

The certified cars to me represent what the cars could do today using the casting and machining process of the manufacturers today. If people want bones to pick on the certified cars or the pure stocks in general it should be with the tuning for traction and making the cars work for 60 foot times. If that is a big deal then show me any racing where it is totally hands off? :eek2:

Jim :3gears:

 

Jims right, alot of the motors, including mine, are very boring bigblocks, nothing exotic about them. lots of people could get there cars runing good times at the strip if they would concentrate on the basics of tuning and take-offs at the starting lines. Later Jim :Smarty:

 

Do Dan and Bob have a list of what they actually check and the leinency provided/tolerance? Now that some of the cars specs have been posted I have noticed some part # discrepencies and measurements that are out of spec on the certified cars. Also do the certified rules change year to year?

 

I agree that a well-tuned engine and paying attention to detail during the build can wring a lot out of these stockers. But just to stir the pot, let's not confuse NHRA (and PSMCDR) "stock" with factory stock. Just because these engines certify, doesn't mean they are the same as when they left the factory.

An easy example is deck clearance. I can't speak for other makes, but for Olds engines you tear apart an unmolested engine, you typically find the pistons at least .020" down in the hole. But the NHRA stock specs allow .002, and as you can see, Casey (for example) takes advantage of that. More compression, more quench, more power.

And I hesitate (ok, not really) to even bring up cams. Just because the lift measures the same as what the factory used ...........
How many Pure Stockers can honestly claim they are running factory cams? I'm talking about cams with factory casting and stamp marks on them. Or as an alternative, a newer cam which they know for fact was ground with the exact same lobe profile as the factory cam (not just the same timing events)?

I'm not trying to start any fights here, just don't want people thinking these cars are as pure as the day they drove off the dealer lot. :bglasses:

 

I run the correct GM 151 cam in my Vette :3gears:

 

Who,what,where,why???

I always run "Factory" cams in my car's, as well as 100% "Factory" built
parts :Smarty:






I'm just not saying which Factory :laugh:

 

Ok, but is it worth 1/2 to 3/4 of a second the quench area reduced by decking the block? I think not. The cams are being checked by Dan and Bob for duration as of the last 2 years. If it doesn't check at .050 and up it's not to pass.

Jim

 

what he said

exactly what i was getting at .

lets take a couple of mopars , one thats posted ,and one i was going to build at one time . :Smarty:

a 906 head taken off an untouched from the factory engine NEVER even remotely measured the NHRA spec of 79.5 cc , the ones i have checked to date have been 90-92 cc , to get to 80cc you have to take at least .050 off the deck .

the 69 440-6pk above is showing it certified with a cam LARGER than stock and pistons WITH valve notches added , the 69 440 6pk was a flattop piston with no notches , and the NHRA data shows this also .

i was (actually am , but the heads won't certify and i'm not building another set :error: ) going to build a 69 383 4bbl , 335HP . according to the NHRA data the piston spec is .021 ABOVE the deck . i have an original 383 335hp piston , it measures 1.932 CH , if you do the math , on a perfect deck height block it should be ZERO deck , where does .021 above the deck come from ?

i'll be pulling the heads off my 55k mile original never rebuilt 383 engine soon , i am expecting the piston to be BELOW the deck surface ...

i'm all for wringing everything out of one of these cars , but to call them factory stock ou:

 

Aha! Brian you should know that some of the cars that left the factory were indeed bluprinted....take for example, hmmmm, let's see...... :Smarty: A W31! Agreed on deck height, they were typically .026-.028, but the head gaskets were .017 compressed. I think you have to add the deck heights and the compressed gasket thicknesses to make the determination of whether this is enhancing performance or not. Put a Felpro .040 on a non decked engine (especially a high revving small block with a very big factory cam (like, say, a W31 :Smarty: ) and you just killed it. I ran that exact combo in the backup motor the last 2 years and it ran a best of 101 MPH. Putting it back to factory steel shim head gaskets would have raised the compression a half point or so and probably good for a few tenths and MPH. Believe me, that engine would certify anywhere as it didn't have any aftermarket parts in it anywhere. It was a NOS short block (including NOS factory cam) with all the original non adjustable valve train from my Ramrod.

BTW, I don't think Casey's compression is that high with the thick head gaskets. Stock was 10.5 on these. Doubt he's much more that that.

However, you are absolutely right on 95% of the average muscle cars (and non muscle cars that were built in mass production back then. Castings alone can make a big difference, especially in the heads.

Sawruk, what are you doing entering a certifying discussion? Are you in this year? Show you mine if you show me yours! :laugh: :beer

 

jim i heard that they weren't checking them , but planned to this year . if they follow the NHRA line as they do with the rest of the car , as long as the lift is stock, anything goes duration wise . which is what is making them run that fast , add to some non stock torque convertors , x pipes and larger than factory exh systems ...

i know a guy that built a 68 383 330hp engine to factory stock specs , he got a little wild on cam duration and the engine had -.010 piston to valve . at that point he said screw it , put in the valve notches to get the clearance , and it dynoed at 435hp with headers , everything else was NHRA legal , heads , intake and puny 600cfm carb .

is there a weight requirement and or is it checked check ???

 

We're running the factory 143 cam...and WHY in the heck would anyone run a "non stock torque convertor", on these tires?? I don't know about anyone else, but THE last thing we want coming off the line is for our 427 to build up a head of steam due to a loose converter...it's gonna be good night Irene, 'cause it WILL spin the tires in a bad way. Been there, done that...we're running the factory 2200 stall converter, but if I was to change it I'd go the other way, and try and pull some bottom end out of it with a truck converter...

 

No problems from me. Go ahead and use my numbers.

Let's use your hypothetical numbers of .020" in the hole. And a known thickness of a factory Olds steel shim gasket of .017". That yields a .037" overall, correct ?

Then we'll just pop over and take a look at my numbers. At .000" in the hole, with a .040" head gasket (mine actually measured .045"), but we'll use the smaller of the two ....... you yield a .040" clearance. So mine, Certified, is actually LESS than stock. :grin: p

 

either looser or tighter , its not the convertor that the factory speced and bolted behind the engine

 

Lead a horse....can't make 'em drink

This is cool.......

I like the fact Casey posted the cert numbers.

One statement is that the cars are not as they left the factory........no kidding....my car is 41 years old! I'm 39 and not as I left the factory either! :laugh:

If a car ever....ever had a service in it's life like heads or block...heck even a carb rebuild or anything, it's not going to be the same as it left the factory!

The NHRA numbers are a guidline....and if they are way out there, like the NHRA listed 14:1 low riser engine option for my car, or if they omit something original like the valve reliefs.......or if another carburetor was offered that is documented but not on the NHRA list....work it out with Dan an Bob! It's really pretty easy.

The really big point I get out of listing these certs is that the typical Hot Rod mods everyone of us has heard for decades.......are not required to run the numbers or make the power folks at the P/S drags are! :TU:

Keep em coming Case!

 

ya , but

brian i assume your car is a solid cam ? if so is that the difference between your certified spec and the NHRA listing , the lash setting ?

if not then is this another case of the NHRA being wrong ?

i would think with all the updates that they would have corrected incorrect info 30 plus years later :error:

edit ... i like the fact that casey posted the numbers also , it confirms to me that the main difference between factory stock and factory appearing is the cubic inches of the engine :Brow:

 

"The really big point I get out of listing these certs is that the typical Hot Rod mods everyone of us has heard for decades.......are not required to run the numbers or make the power folks at the P/S drags are!"

But didn't those Hot Rod mods arise because, for the average kid in 1968, it took a lot less time, skill and money to bolt on an aftermarket cam/exhaust/carb/intake/ignition/whatever than to completely disassemble and carefully blueprint his engine to optimum stock specs? And today, while the P/S cars are certainly cooler in my book, is a top-running P/S car any less purpose-built than cars racing in other sportsman classes? Meaning you've paid careful attention to every component and aspect of the car, with rule book in hand...

Mike

 

I would disagree John. That's a pretty broad brush stroke that you just applied. You can ask the FAST and Factory Appearing guys, and they will readily tell you that there is A LOT more going on besides cubic inches. :Smarty:

 

Hey, glad I could wake everyone up! It was getting awful quiet around here. :grin:

Casey, sorry I didn't notice you were using the thick Fel Pros. I didn't even bother checking that data line, because I thought you were smarter than that. :Brow:

I'd like to see some more cert numbers -- don't care whose. Keep them coming!