NHRA 2020 Rule Amendment SS Intakes???

[Tom P]

I am curious why it's always been worded as "must hold volume" and no mention of maximum.

"Cylinder head must be able to hold combustion chamber, intake and exhaust runner volumes per NHRA Specifications"

The way I interpret that is a five gallon bucket will hold a gallon but a one gallon bucket won't hold five. So ports can be larger than their spec but not smaller.
Obviously they want the combustion chamber to hold all of the 72cc or whatever spec is but they want that 205cc port to hold NO MORE THAN 205cc.

Why wouldn't they just say that?

A lot of the rulebook seems to have been written in 1952 and they added extra words instead of rewriting the whole thing. The previously mentioned pinned studs for example.

[Bob Smith]

Again:

http://nhraracer.com/content/general...728&zoneid=132

[Nick Heath]

Originally Posted by Bob Smith

Again:

http://nhraracer.com/content/general...728&zoneid=132

So if I analyzed those blocks of text correctly, here's what's changed:

* Angle milling of cylinder head, exhaust and intake mating surfaces permitted.
* Additional intake manifold bolts holes permitted.
* Spacer plates between intake manifold and cylinder head permitted.

[Rich Biebel]

Good thing pinned studs are still legal......All the racers with them can breathe a sigh of relief...…..LOL

P.S. I did pin a lot of studs but it was at least 30 years ago and a lot more....

[Tom Broome]

Originally Posted by Rich Biebel

Good thing pinned studs are still legal......All the racers with them can breathe a sigh of relief...…..LOL

P.S. I did pin a lot of studs but it was at least 30 years ago and a lot more....

Yeah......about that. I also hadn't pinned any studs in a long time either. Racers moved on to better options.

Then......the Magazines and the Internet "Experts" convinced all these streetcar folks that they needed Vortec heads as a "budget" performance option. You put one more ounce of spring pressure or cam lift on those things. and the studs seem to fly out. Once they see that the guides have to be cut and new seals installed, there's no room in the "budget" for screw-in studs. Now pinning becomes an option again.
P.S. I can't describe how much I dislike pinning studs nowadays.

[bert powell]

Who is going to be the first to take a bbc oval port head and mill 1" off the intake flange of head below the valve cover bolts? Should gain 50-60cc to open up the port.