OLD Modified Corvettes

Todd Bailey · 12-13-2013, 03:27 PM

Ed,

Do you remember what the minimum weight was for the class when you ran?

Ed Wright · 12-13-2013, 09:13 PM

Quote:

Originally Posted by Todd Bailey

Ed,

Do you remember what the minimum weight was for the class when you ran?

Don't remember if there was one or not.

Dwight Southerland · 12-13-2013, 11:56 PM

The first SM class was 9.5 lbs/ci including driver and 3000 lbs for small blocks, 3250 for big blocks. The next year, when they expanded to A, B & C/SM, the weight breaks were 8.5, 9.5 and 10.5. A was for big blocks with a 3250 lb minimum (or was it 3300?), B was for small blocks with a 3000 lb minimum and any OEM cylinder head, C was for small blocks, true wedge head (valves in a straight line) production only. A allowed an 850 cfm carb, B & C used a 750 carb.

Ed Wright · 12-14-2013, 08:40 AM

^^^^^ There ya go!

Dwight Southerland · 12-14-2013, 09:52 AM

Correction to my earlier post - minimum weight for A was 3350, according to 1981 rulebook.

Originally, the head limitation was the big deal. You could do anything to the combustion chamber except weld. Limited to 1" porting below the valve seat and 1/4" at the intake port opening. SM racers "found" the 461X heads for C/SM with bigger ports. B class Chevies ran the 292 "Turbo" head with angle plugs. Short stroke big block Chevies were common in A. The Cleveland Mavericks were the scourge in B: Garley Daniels and the Chevy IIs were the ones to beat in C.

Some of my observations for the new class discussions:
1) The spec head idea is good. Something to eliminate limitless spending on heads.
2) Consider limiting to steel valves.
3) Single 750 carb.
4) How about a 10 1/2" tire limit?
5) Hood scoop maximum of 7" above the hood surface at any point. Cut out the goofiness and that gives a little advantage to older bodies.

randy wilson · 12-14-2013, 10:46 AM

Some very good ideas Dwight. The only one I have a real issue with, is the 10.5 tire. And that reason being, mine, and other SS type cars will look awfully goofy with those on because of the current width of rearends. Most, if not all, would have to change rearend housings. I was looking at a more realistic 12.5. And, maybe I misunderstood your post, but I think the older cars are at a disadvantage because of the new cars with the laid back wind shields, and less frontal area. I don't think it matters much in the 1\8th mile, but in the quarter it does matter.

Ed Wright · 12-14-2013, 11:27 AM

The correct back spacing wheels will put the 10.5" tires back out where they look fine. Guys were doing that "back in the day" to save weight & unsprung weight.
Sounds like fun, but I don't know how many guys like me with later cars would build another car to run it. Don't know about requiring a stick car, either. Lingenfelter ran an automatic back then. Sticks sure as heck won't do bigger wheel stands for the crowds. LOL

12-13-2013, 03:27 PM	#1
Todd Bailey Member Join Date: Dec 2003 Location: Houston Posts: 312 Likes: 31 Liked 33 Times in 17 Posts	Re: OLD Modified Corvettes Ed, Do you remember what the minimum weight was for the class when you ran?

12-13-2013, 11:56 PM	#3
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 2,002 Likes: 64 Liked 783 Times in 195 Posts	Re: OLD Modified Corvettes The first SM class was 9.5 lbs/ci including driver and 3000 lbs for small blocks, 3250 for big blocks. The next year, when they expanded to A, B & C/SM, the weight breaks were 8.5, 9.5 and 10.5. A was for big blocks with a 3250 lb minimum (or was it 3300?), B was for small blocks with a 3000 lb minimum and any OEM cylinder head, C was for small blocks, true wedge head (valves in a straight line) production only. A allowed an 850 cfm carb, B & C used a 750 carb.

12-14-2013, 08:40 AM	#4
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: OLD Modified Corvettes ^^^^^ There ya go! __________________ Ed Wright 4156 SS/JA

12-14-2013, 09:52 AM	#5
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 2,002 Likes: 64 Liked 783 Times in 195 Posts	Re: OLD Modified Corvettes Correction to my earlier post - minimum weight for A was 3350, according to 1981 rulebook. Originally, the head limitation was the big deal. You could do anything to the combustion chamber except weld. Limited to 1" porting below the valve seat and 1/4" at the intake port opening. SM racers "found" the 461X heads for C/SM with bigger ports. B class Chevies ran the 292 "Turbo" head with angle plugs. Short stroke big block Chevies were common in A. The Cleveland Mavericks were the scourge in B: Garley Daniels and the Chevy IIs were the ones to beat in C. Some of my observations for the new class discussions: 1) The spec head idea is good. Something to eliminate limitless spending on heads. 2) Consider limiting to steel valves. 3) Single 750 carb. 4) How about a 10 1/2" tire limit? 5) Hood scoop maximum of 7" above the hood surface at any point. Cut out the goofiness and that gives a little advantage to older bodies.

12-14-2013, 10:46 AM	#6
randy wilson Senior Member Join Date: Jan 2007 Location: N/A Posts: 882 Likes: 0 Liked 22 Times in 22 Posts	Re: OLD Modified Corvettes Some very good ideas Dwight. The only one I have a real issue with, is the 10.5 tire. And that reason being, mine, and other SS type cars will look awfully goofy with those on because of the current width of rearends. Most, if not all, would have to change rearend housings. I was looking at a more realistic 12.5. And, maybe I misunderstood your post, but I think the older cars are at a disadvantage because of the new cars with the laid back wind shields, and less frontal area. I don't think it matters much in the 1\8th mile, but in the quarter it does matter. __________________ don,t have one

12-14-2013, 11:27 AM	#7
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: OLD Modified Corvettes The correct back spacing wheels will put the 10.5" tires back out where they look fine. Guys were doing that "back in the day" to save weight & unsprung weight. Sounds like fun, but I don't know how many guys like me with later cars would build another car to run it. Don't know about requiring a stick car, either. Lingenfelter ran an automatic back then. Sticks sure as heck won't do bigger wheel stands for the crowds. LOL __________________ Ed Wright 4156 SS/JA