Accepted S/SS Cylinder Head Volumes
 

Wondering how a cylinder head gets treated if it is listed on a "Blueprint Spec Sheet" but not list on the "Accepted Products Sheet" with a correlating volume?

The obvious, current events, example would be the D7OE-DA cylinder head for a 1977 Ford 302.. ONLY D7 head listed is D7EE-CB..

Dissecting this part # would be 1977 "Unknown E" "Engine Part" -CB(revision/tooling #)

D7OE-DA not listed.. Common sense says that the -DA version would be accepted at the same volumes as the -CB, but then again wouldn't one assume the -CB is legal than? Or if in fact the -CB was deemed illegal why not change the "Accepted Products Sheet" to match the newly deemed legal -DA version..

In a similar situation until recently for the 88-95 Ford 302 in a Mustang-- E7TE-PA and F1ZZ-B have been listed as legal.. Recently the F1ZZ-B number (which is only a book number not a cast number) was updated to read F1ZE-B which would be the number cast on the head.. "1991" "Mustang" "Engine part"... "Accepted Products Sheet" lists only "E7TE" no mention of the -PA (no other suffix exists so this isn't a huge problem), but no mention of this F1Z(ZE)-B.. there is a F1ZE-AA (which is an entirely different head and has different volumes listed from the E7 version) again common sense would say the -B head is legal at the E7 volumes but why not list it?

I'm sure there are many more examples of this.... maybe there isn't.. I'm just familiar with these two so I'm able to elaborate on them a bit, but during a tear down what does NHRA do in this situation?

Brad

Re: Accepted S/SS Cylinder Head Volumes
 

My Pontiac 01 head was poured in a Natl. Event teardown YEARS ago. The numbers still aren't published in the Blueprint Spec. Sheet.

Re: Accepted S/SS Cylinder Head Volumes
 

If the head in question casting number is listed in the blue print specs it is a legal head to run.
Just because there is no runner volumes published doesn’t matter. It is not racers responsibility to publish them. It’s NHRA job.
They gave you a list of legal heads to run and it’s there job to publish specs on head.

RJ

Re: Accepted S/SS Cylinder Head Volumes
 

RJ this is how I've always interpreted the rule.. My reason for asking I guess is for the heads not listed on the "Accepted Products Sheet" meaning they have no cc spec.. how are you supposed to know what cc is legal? Does NHRA have the specs and just not post them for every one of these heads? Are these people essentially getting a freebie for teardown and the spec is then set based on the first head poured in teardown?

In Billy's 01 Pontiac case was he poured and compared to a known unpublished value to determine legality or was he poured to "set the standard"?

Re: Accepted S/SS Cylinder Head Volumes
 

My head for 307 Olds stocker had a cc volume in the books and I checked and my head matched their specs. Intake and exhaust

Re: Accepted S/SS Cylinder Head Volumes
 

I think your giving them too much credit....
If they don’t post runner volume on a head that is posted as legal don’t worry about it.
Just be sure that the head you run is exactly the same number listed as a legal head per NHRA....
If it’s a D70E- DA make sure it’s reads the same in blue print spec.

When did a racer set the runner volume that’s listed in”NHRA Approved Products” list ?????
It’s up to NHRA

RJ