found this interesting article THE HISTORY OF MOUNTAIN MOTOR PRO STOCK


The article says ...

“In those early days it was really hard to find the blocks, so you did whatever you could to make the engines bigger,” Leonard said. “The camshafts – you’d put more stroke into it and your rods would hit the camshafts. It was a headache.”

http://www.competitionplus.com/drag-...otor-pro-stock

Heavy also had CanAm Engines

I don't know what MPH a 430 inch Pro Stock ran back in the day, but HP is calculated by MPH over 1320 feet, and 139 MPH for example is 622 HP @ 3010 pounds. I would find it very hard to believe 1970 Pro stocks made over 700 HP on todays dynos, but the tunnel ram does help.


Although, 149.7 is over 770 observed crankshaft HP @ 3010, based on the information on page 4. Typically a A/S 375 HP 396 makes 620s for HP on my dyno, can run 9.80s @ 3450 @ 135 MPH. So a factory ZL1 making 601 seems very reasonable to me, although I'd like to see the 7300 RPM peak myself, seeing the 375 HP stocker peaks just under 7000 RPM but is run to 7800 RPM plus.

the NHRA Pro Stock records are

1970 144.48 mph

1971 146.10 mph

1972 149.50 mph

I put 700 hp and 3010 lbs in the calculator and came back with ...
Your ET / MPH computed from your vehicle weight of 3010 pounds and HP of 700 is 9.47 seconds and MPH of 142.68 MPH.

TQ.......does not win drag races, hi RPM HP wins drag races................Example

https://youtu.be/YvEwFnPx8rs

The question is are you using the right calculator? You can't go wrong with the Moroso power speed calculator, lines right up with my dyno/track testing.
Take a look at this MPH calculator its close. http://www.wallaceracing.com/et-hp-mph.php


I get 707 HP for 145 MPH @ 3010, big power back in 1970!

Joe and Mark, one main issue is that the MMPS and "Match races" were not at 3000+ lbs? They took the weights out, used bigger engines and ran them! This why the 1970 times were 9.90 or there abouts and the Match racers were around 9.40's.

Don't forget that most of the cars in 72 were small blocks and lighter, not the 3000+ lbs like the 70/71 years.

So to use the 144+ MPH is NOT the 427430 inch motors? These were the match race 490/500+ inchers that ran light.

Just putting the MPH/Weight ratio into prospective.

DragList shows numbers for "Pro Stock Classic" with a 430 cu in limit and "Pro Stock Mountain" with a 500 cu in limit

I was using the record numbers for PS Classic


example for 1971 they show ...

PS Classic 1971 Records: 1/4 Mile: 9.485 ET, 146.10 MPH

PS Mountain 1971 Records: 1/4 Mile: 9.265 ET, 149.76 MPH

its difficult to keep track of all the rules as they changed them a few times

here is a one quote ...

"In 1982, the NHRA did away with the weight break system and implemented a 2,350 pound minimum weight, 500 cubic inch maximum rule across the board, due to the popularity of the Mountain Motor IHRA Pro Stock cars, which have unlimited displacement."


I remember reading that the engine displacement was well over 500 cu in with the tall deck blocks. At one time they called them "car blocks" and "truck blocks" and the tall deck blocks had to carry a 100 pound weight penalty

in 1972 some people were still running 1969 Camaros as you can run a car up to 3 years old

Is that Kip Martin in the mustang? If so he was one of the very best with Ford engines. Years ago he could wring out the horsepower on a 352FE like no other.