Certified Stock "Qualifying Numbers"

i know that but i caught your attention didn't i ?

but its not hard to see that a few of the things i pointed out are going unanswered :error:

 

Nope. I'm still the same idiot .......... uzzled:

 

yeah, little things like

ported heads

ported intakes

extrude honed exhaust manifolds

roller cams

roller rockers

light weight batteries

electric fuel pumps

removed choke plates

line locks

are irrelevent, it's just the cubes..................

 

Im sure I wont be to popular for this, but the big difference between factory stock and pure stock in my opinion, is the weight of the pistons, type of rings, and other non-testable items.

Most guys do use factory cams, but does anyone use factory GM/TRW slugs? I bet J/E pistons are 150grams lighter???????

I dont know these are what I think are the differences. If there aint much difference Ill put trw's in my L78.


Great info on the specs, seems like every combo posted has alittle left to make them more stocker..........

 

Casey....
You can post my specs if'n ya like. And for the record.... stock TRW's were in the motor. Stock untouched converter that it came from GM with. Both JJ and I have used nothing but the stock over the counter cams from the General in my Camaro, JJ's Nova and JJ's Vette. I think only the Mopar guys are using "made up" cams! :Brow: :spank: :grin:
Peter

 

The problem with the GM TRW's is not the weight, it's the fact that the domes came up significantly *short* of their advertised number...

And I don't mean for this to sound rude, JohnRR, but have you ever built & ran a Pure Stock car, or even a *certified stock* car? The reason I ask, is your point of view sounds similar to those who are on the outside looking in, saying it can't be done...heck, some of the certified guys (myself included!) had that very opinion until they gave it a shot...

 

Here's Peter's numbers:

 

Head porting, alot of grinding and welding, roller cams, huge compression ratios, lightened gears, clutchless transmissions, lightening of cars, aluminum drums with steel liners......... :shock: ............should I stop? Oh you ment Pure Stock, I thought Factory APPEARING stock tire. :laugh: You need to have some fun every now and then. :Comp:

Jim

 

both NHRA factory stock and IHRA pure stock MUST use stock heavyweight parts , if they get teched and the part numbers don't match the spec sheet :spank: nhra even gives minimum weights for connecting rods

as far as what the factory stock being discussed here allows ??? the guys that built the engines are the only ones that know since being certified does not require you to bring the engine in in a box .

the 383 i'm building is using the speedpro 2315 piston , which is the NHRA spec piston and this piston is .012 shorter than the piston its replacing , though i'm told it may be lighter than the stock cast slug . the old TRW forged slugs , i was told , were actually heavier than stock ?

 

don't worry about being rude to me or anyone else , no one else seems to worry about it :Brow:

no i haven't built one , so i guess that makes me unqualified to question what i see being posted ???

i'm actually putting together a certifable short block right now, but the heads i have to use won't pass , they are cut below spec and the bowls have been worked , i don't have an extra $1000 to do another set of heads , so it won't pass .

i have been tossing the idea around in my head for the last few years , theres alot of empty space up there . once i looked at the NHRA allowed specs for my particular combo and how much they differed from what actually rolled off the assembly line and then talking to my local engine builder about doing it and him telling me what he has gone thru to build one to NHRA specs . he told me about a BB chevy he did for a guy , using trw slugs, they had to buy 8 sets of pistons to get 8 pistons that were all the same and actually met the spec (luckily he was able to send back the other 7 sets) , go thru as many heads as i could get my hands on to get 2 in raw form that flowed the best , expect to drop a big chunk of change when all was said and done .

i'm still curious how an engine that DID NOT have valve reliefs when new , and the piston speced out by NHRA does not have them either , is certified with valve reliefs ?

 

Not at all, I am not online at home so I answer when possible at work.

Good questions

I'll say again the NHRA numbers are a guidline and sometimes research is required.

Regarding the valve reliefs that was answered some posts ago.

Ford made one 425hp cam from 1963 to 1967 part number C3AZ-6250-AA

NHRA lists the 425hp lifts as:

1963 .525"
1964 .500" the lift in question
1965 .525"
1966 .525"
1967 .525"

The 1964 Ford Mercury service manual in section 8 page 118 lists the 425hp lift at .524"

I had an nos C3AE-6250-AA run on a cam doctor, it read .525"

Crane cams makes a "bluprint" C3AE-6250-AA cam part number 340321 that has .524"

What does the evidence show you? It showed Dan and Bob that NHRA had goofed.

My cam lift was checked at zero lash and read .526"

NHRA also does not show a head gasket for the '64 425hp...but I assure you the factory used one :laugh:

 

brian , the second valve relief question was not about you , i did see your reply above and thanks for claifying the cam . my question is if NHRA updated the specs as late as 2003 why haven't they corrected it ? not that it matters . thanks for the reply .

my valve relief question is about the 69 440 6 pk engine , no valve reliefs from the factory and not in the nhra spec . they didn't get valve reliefs till 1970 . never mind the larger lift spec on the exh side . o No:

i'm sure as we speak i'm being BLACK LISTED :moonu:

 

On the contrary...the questioning is more than acceptable. But, it does disqualify you from making broad generalizations about what Certified Stock is or isn't (ie. "a stock appearing engine with less cubes"). As I stated before, I was among the doubters, until I tried it myself...

And as Brian eluded earlier, don't put too much faith in what the NHRA says...these are the same folks that brought you such great brainstorms as Edelbrock heads & carbs & other mythical combinations in STOCK no less, and just recently broke their own "500 cars produced" rule (for no other reason than "because we can) and allowed the '64 1-4bbl "NASCAR" Hemi into A/Stock. The NHRA numbers are simply an easily obtained guideline, but I think you'll find most of the CS cars will lean more to the factory *advertised* specs...

-------------------------------
Hillbilly Racing Team
"Home of the obese Camaro..."

 

John,

I don't think you're being black listed at all. Quite honestly, this type of dialogue is one of the reasons that I posted this topic to begin with. This is also why I am only posting the numbers that I'm given the "OK" from the owner. So that if there are questions as to the specs, etc., the owner can reply to them accordingly. Brian's cam question is a perfect example. :3gears:

 

Certing Motors

First off Casey you can print my 340 Six Pak motor info. from this fall.

I just built a RA IV and 440 6bbl motor with Dan and we dyno'd them. They will be in upcoming articles but to give a bit of info. up front here is what was done and done with Dan over my shoulder to make sure everything was correct.

The 340 motor has correct heavy NHRA pistons in it. When you do so on a small block mopar you can not even reach the actual NHRA compression limit with out smacking said pistons into the head. So just becuase it is on paper does not mean you can achieve it.

Dan measured the cams during certing and he will not allow for more than 1% variance in the original cam duration from the factory spec at .050. The lift must match on NHRA lift numbers. So his new cam checks for the past two years are tighter than NHRA and mostly force you to use nothing but originals.

Secondly we tested three cams that all meet certifing specs on the R/A IV. And the cam that made the best power was the original T cam I had. And that is run in the Judge also. So the factory has it better figured out than a twinked on Comp Cams cam and a Lunati stock replacement for the RA IV.

The 440 6bbl ran yesterday on the dyno and for grins we kicked in multi pulls with Hooker 2" primary headers. This is a CORRECT MOTOR. Heavy legal pistons, stock rods, no valve job, mild compression 440... We gained a grand total of 1 hp at the same rpm and 2.8 lbs of torque 100 rpm earlier! Granted we were a bit lean on the jets for headers and likely smaller primary tubes would have bumped it a bit more. But the piont is that the best motors from the factory really were set up well.

By the way the Judge runs stock replacement pistons (+.030), stock cam, stock 72 cc heads, stock head gasket, and one pass to square up a slightly wigglely block deck. I had to go with +.030 pistons as the number 7 cylinder had been bored over sometime in life to +.030 and only had oversized rings. Not the best solution. This motor is as close as it gets to what GM created. And it runs 12.8's at 111+ consistantly. You could not get any closer to stock on a 35 year old car. So it really is just good tuning/detialing that makes them work. And that is what the guys who cert' cars do the best. Those guys are always quicker than the rest of us.

Cheating is easy, and the cheaters usually are not the fastest guys there each year.

Sorry for going on a pisser there everyone.

I hope this clarifies items a bit for everyone.

Mark

 

Here's the numbers for Mark Weymouth's 1970 Dodge Challenger T/A -- 340 6PAK

 

:bglasses: Mark said it ....... not me ........ p

 

Here are the numbers for Rob Clary's 1969 Yenko Camaro -- 427/425 L-72

 

The valve reliefs on my old, heavy TRW pistons lose compression. My new motor wont have any notches and if you look at the poor rocker ratio, you will see that even with a hair more lift it still wont come out to factory lift. Jim Spetzman

 

Another good question. o No:

It could be that no one gives a rip about running a '64 Ford or Merc in stock class, so no one has pointed it out. o No:

Hmmmmmm maybe no one gives a rip about it in P/S too? :laugh: