!970's Pro-Stock Camshaft Spec.'s

[piston guy]

The small block stuff was 106/108LSA and when the Big blocks hit the LSA went wide like Mike said. Teams used to outdo each other by having the slowest Idle speed.

[maxracesoftware]

I'm surprised nobody has dug up their dog-eared copy of Grumpy's SBC race engine book from the mid-70s where he goes into a lot of detail on what he ran for cams...

in that Book , Jenkins was using mostly 109deg LSA
on the 331cid engines + 355 and 358 cid

[swampbuggy]

Hey Mike, there was a Roy Hill, it seems like he was the one who drove for the Petty Drag Race Entry from North Carolina . This would have been between appx. 1974 and 1984 is my guess ?? Mark H.

[maxracesoftware]

Hey Mike, there was a Roy Hill, it seems like he was the one who drove for the Petty Drag Race Entry from North Carolina . This would have been between appx. 1974 and 1984 is my guess ?? Mark H.

Roy-Hill_Pro243_B.jpg

[hoffman900]

I'm surprised nobody has dug up their dog-eared copy of Grumpy's SBC race engine book from the mid-70s where he goes into a lot of detail on what he ran for cams...

in that Book , Jenkins was using mostly 109deg LSA
on the 331cid engines + 355 and 358 cid

If those were with Harold's lobes, don't have too much crossover to a symmetrical profile, but you know that

Same goes for anyone's lobes / valve lift curve that isn't symmetrical.

[Stan Weiss]

Might want to take a look at this thread.

Early 70's modified or gasser camshafts
viewtopic.php?t=43881

Stan

This is from the link I posted on page 1. The data was gotten with a degree wheel and a dial indicator at that time. The 320M is a single pattern cam while the 321 Roller is a dual pattern cam. The 320M was done when new. I got the 321 used. Both are asymmetrical.

Stan

I run this in the earlier 70's GK Flat tappet 320M 372L and this was before Brookshire was at GK.

CAM_______Lift______Opens___Closes__Duration
_________________Deg_BTDC__Deg_ABDC_____________Area
_________0.00600____95.00_|_143.33_|_418.33_|__39.34
_________0.01000____80.00_|_125.00_|_385.00_|__39.20
_________0.02000____53.33_|__95.71_|_329.05_|__38.72
_________0.04000____35.88_|__76.67_|_292.55_|__37.99
_________0.05000____30.00_|__70.00_|_280.00_|__37.99
_________0.10000____14.05_|__53.79_|_247.85_|__36.35
_________0.15000____-1.43_|__38.57_|_217.14_|__33.42
_________0.20000___-15.71_|__24.12_|_188.40_|__31.45
_________0.25000___-30.00_|__10.00_|_160.00_|__29.12
_________0.30000___-46.55_|__-6.67_|_126.78_|__23.53
_________0.35000___-70.00_|_-29.00_|__81.00_|__16.92

Stan


PS - This is GK Roller C1R321B 321R-434L 336R-424L from around that time. Thinking about it a little more this maybe more '74.

Intake
CAM_______Lift______Opens___Closes__Duration
_________________Deg_BTDC__Deg_ABDC_____________Area
_________0.00600____80.00_|_120.00_|_380.00_|__41.81
_________0.01000____70.00_|_110.00_|_360.00_|__41.73
_________0.02000____55.56_|__91.43_|_326.98_|__41.42
_________0.04000____39.44_|__75.00_|_294.44_|__40.69
_________0.05000____33.89_|__69.05_|_282.94_|__40.30
_________0.10000____14.14_|__48.86_|_243.00_|__38.42
_________0.15000____-0.51_|__34.72_|_214.21_|__36.35
_________0.20000___-13.17_|__22.14_|_188.97_|__34.37
_________0.25000___-25.95_|__10.00_|_164.05_|__31.98
_________0.30000___-38.75_|__-3.16_|_138.09_|__27.48
_________0.35000___-54.14_|_-17.74_|_108.12_|__22.59
_________0.40000___-74.74_|_-36.52_|__68.74_|__14.84


Exhaust
_________0.00600___149.67_|_127.00_|_456.67_|__43.58
_________0.01000___133.00_|_113.67_|_426.67_|__43.43
_________0.02000___103.00_|__77.00_|_360.00_|__42.97
_________0.04000____82.47_|__43.43_|_305.90_|__41.86
_________0.05000____77.21_|__36.47_|_293.68_|__41.47
_________0.10000____58.16_|__15.75_|_253.91_|__39.60
_________0.15000____43.56_|___0.89_|_224.44_|__38.19
_________0.20000____30.37_|_-11.37_|_199.00_|__35.52
_________0.25000____17.05_|_-24.62_|_172.43_|__31.67
_________0.30000_____3.00_|_-38.59_|_144.41_|__28.78
_________0.35000___-14.78_|_-55.00_|_110.22_|__22.08
_________0.40000___-40.08_|_-78.33_|__61.59_|__12.51

[CamKing]

Hey Mike, there was a Roy Hill, it seems like he was the one who drove for the Petty Drag Race Entry from North Carolina . This would have been between appx. 1974 and 1984 is my guess ?? Mark H.

I think that's the driver, but I think it was after 1985, but before 1990.

[swampbuggy]

Thanks to Larry for the Picture of the Roy Hill driven Mopar, and Thank you Mike ( CamKing ) and every body else who contributed to this thread, it was a dream back in time and was enjoyable. Mark H.

[maxracesoftware]

Thanks to Larry for the Picture of the Roy Hill driven Mopar, and Thank you Mike ( CamKing ) and every body else who contributed to this thread, it was a dream back in time and was enjoyable. Mark H.

i just uploaded a full-size picture of Roy Hill's ProStocker
i think i took this Pic at Houma,LA ( Southland Dragstrip )

click the + icon to see all the Pic
and it sure looks like Bill Jenkins in the Blue Valvoline Decal Shirt sitting in Roy Hill's Trailer )

Full-size image Link here : ( the orginal Scan is 3 times larger than this pic , probably need a 50" or 60" TV to fully see all of it )
https://i.postimg.cc/s34Ydp0B/Roy-Hill-Pro243-B.jpg

alternate Pic link on my Public Forum here :
https://www.maxracesoftwares.com/forum/ ... f=39&t=287

[treyrags]

It's hard for me to really get the picture in my head that today my 422 flat top piston, single 4150 carb, powerglide, sbc 72 camaro is as fast as those 1st gen tunnel rammed,4 speed big block Pro stock cars that I went to see at a match race in the early 70's.

You can thank those guys for their hard work and being the r&d through those early years that allows you to have the information and ready to go parts to go this fast so easy

[BradH]

Thanks to Larry for the Picture of the Roy Hill driven Mopar, and Thank you Mike ( CamKing ) and every body else who contributed to this thread, it was a dream back in time and was enjoyable. Mark H.

Re Roy Hill; one saw him race once, the U.S. Pro Stock Open in either 1976 or 1977. He and his Duster weren't the fastest car that night, but he won, which was even cooler since I drove down to MIR w/ my friend in his immaculate 1971 Duster 340.

Also found this a little while ago: http://competitionplus.com/drag-racing/ ... y-accident

If you scroll to the bottom of that article, there's a Legend of Drag Racing episode about him linked to it. I have no idea how old it is...

[maxracesoftware]

General Kinetics GK 321D Cam Lobe Profile :

full size Pics on my Public Forum here :
https://www.maxracesoftwares.com/forum/ ... f=28&t=288
 

IntakeOpen.jpg

IntakeClose.jpg

ExhaustOpen.jpg

ExhaustClose.jpg