Titanium Valves in SS

[BBF67]

Originally Posted by Alan Roehrich

Too bad about what your engine builder thinks. He's merely escalating the cost, and the RPM, in a class where both are already out of control.

My cylinder head man is Jimmy Bridges, he runs SS/B with a 396 in a Corvette, he's been going as fast as anyone, and winning races, for 55+ years. Jimmy isn't asking for titanium valves, so I think we'll all get along fine without them.

How does a 396 Corvette fit in SS/B? Class guide shows its natural class is SS/D.

[Alan Roehrich]

Originally Posted by BBF67

How does a 396 Corvette fit in SS/B? Class guide shows its natural class is SS/D.

When they refactored the aluminum head combination to 411 a few years back (that's 16HP over the iron head combination, which is a natural SS/D car), they allowed the aluminum head combination to move to SS/C, from SS/D.

[fredjohnston]

Originally Posted by Alan Roehrich

When they refactored the aluminum head combination to 411 a few years back (that's 16HP over the iron head combination, which is a natural SS/D car), they allowed the aluminum head combination to move to SS/C, from SS/D.

When it was adjusted to 411 in 2013 the factor changed to 7.65 which made it a natural D car as you stated. This car hasn't been able to run SS/B legally since this change but yet continues to do so.. It's a SS/C, SS/D, SS/E only car.

[nhramnl]

I had 2 of my customers tell me I was getting bashed on class racer. I dont really call that bashed, I am a little tougher than that. Thanks for the kind words from a few. Truth is, I havent looked at CR in a year. It seems like mostly complaining about non issues, not really sure what I had to do with Ti valves, but I will say, thats a dumb idea in my opinion. We blew up 6 motors in a year and a half because of broken intake valves. We went to the spintron, fixed it in like 2 days, and havent broke one since. Steve Comella put 100 runs on an engine last year, I put new valves in it. As far as my PS program, its sitting here. My work load has increased alot lately (thanks Mr President), and I dont have time for much right now. I bought a new DMG mill last year, and am trying to make money with that. I dont have a problem with people that enjoy spending countless hours on the internet, to each his own, but my interests are in making things, solving problems, and putting $$ in the bank.
later,
and remember, your keyboard is never going to bring you a trophy.
cw
My post was completely misinterpreted, but such is life. What I implied was that supposedly everybody gets 15 minutes of fame and that you've had yours. You're now below the radar, doing whatever you want to do, and in today's world, the names of celebrities (even in drag racing) get forgotten all of the time, sometimes in weeks. Christ, if that's "bashing", you've got some mighty sensitive customers. The part about liking you and admiring your skill and intelligence was also true, but unfortunately, that ship has sailed.

[BBF67]

Originally Posted by Alan Roehrich

When they refactored the aluminum head combination to 411 a few years back (that's 16HP over the iron head combination, which is a natural SS/D car), they allowed the aluminum head combination to move to SS/C, from SS/D.

From the 2018 NHRA rulebook====NHRA-accepted aftermarket cylinder-heads carry a horsepower penalty that is calculated to the weight of the vehicle and does
not change the class of the vehicle.

[Billy Nees]

Originally Posted by BBF67

From the 2018 NHRA rulebook====NHRA-accepted aftermarket cylinder-heads carry a horsepower penalty that is calculated to the weight of the vehicle and does
not change the class of the vehicle.

The BB Corvettes had an aluminum head option. Always been there and it stands by itself. The head that they use is a GM head OR a GM REPLACEMENT head not an AFTERMARKET head.

[BBF67]

Originally Posted by Billy Nees

The BB Corvettes had an aluminum head option. Always been there and it stands by itself. The head that they use is a GM head OR a GM REPLACEMENT head not an AFTERMARKET head.

Correct starting in 1967 with no penalty. Prior to that the GM or 401 aluminum head gets the horsepower penalty.

Where does the class guide show the 396 Corvette with a natural class of SS/C?

[Billy Nees]

Originally Posted by BBF67

Correct starting in 1967 with no penalty. Prior to that the GM or 401 aluminum head gets the horsepower penalty.

Where does the class guide show the 396 Corvette with a natural class of SS/C?

It doesn't. I didn't say that it did.

[Greg Hill]

I don’t think the 65 Corvette had an aluminum head option. Looking at the classification guide the aluminum head is listed as a replacement head and the weight break is 7.67. Hard to get to 6.5.

[Dwight Southerland]

Originally Posted by BBF67

Correct starting in 1967 with no penalty. Prior to that the GM or 401 aluminum head gets the horsepower penalty.

Where does the class guide show the 396 Corvette with a natural class of SS/C?

According to the class guide, the P/W factor is 7.65. That is SS/D.

The confusion may have started because of the two different methods to determine class when replacement heads are given a different power rating.

Method 1: If you say that the calculation is based on shipping weight, then the classification for the aluminum head is calculated by the different power rating divided into the shipping weight and results in a new P/W factor not listed in the Class Guide. (65 Corvette 396 shipping weight is 3022 lb / 411 = 7.35 or SS/C. The car can run in SS/B, C or D. This may be how Jimmy is getting the car classified in SS/B.)

Method 2: If you say the calculation is based on the P/W factor listed in the Class Guide, then the classifications stay the same as indicated in the Class Guide, but the weight changes. (65 Corvette 396 P/W factor is 7.65 SS/D so it runs SS/C, D or E. The minimum weights for the classes is based on the power factor with aluminum heads aluminum heads.).

I have had this ongoing conversation with people from NHRA tech for several years and the opinion/answer changes. The last statement from them was number 2.