"Old School" Stocker Cams

[Cbrinson47]

Originally Posted by Dwight Southerland

Actually the original cheater cams came about when Bill Jenkins could not get a new OEM camshaft from Chevrolet to pass NHRA's specs. (For the "Monster Mash" 55 Chevy I believe.) He went to General Kinetics with the problem and they ground a cam that would pass. In the process, they also added in some area under the curve and voila!

TRUE......I miss Da Grump !

[SSDiv6]

Originally Posted by James L Miller

Any of the Mopar 340 guys ever run either of these cams? I think the Lunati is from the 1990s, GK maybe the 1970s?

That GK cam was the low-lift version from the 1980's. The GK 041/560 was the higher lift version.

[Lyn Smith]

Dwight, I think it was a west cost cam company that did the Grumps cams. One of the secrets to the performance of his engines along with ring combinations, and plate honing.I don't think you could buy a cam without getting a complete engine in those days.

[djm670]

Originally Posted by Lyn Smith

Dwight, I think it was a west cost cam company that did the Grumps cams. One of the secrets to the performance of his engines along with ring combinations, and plate honing.I don't think you could buy a cam without getting a complete engine in those days.

Lyn, I vaguely remember seeing Jenkin's name on order forms at GK in the old days when visiting Teweles's shop. But don't totally remember.

GK was located in a less than prime area down near the University of Detroit. Don was way ahead of his time when it came to camshafts back then, was not as much of a business man; but sure fun to work with on cam shaft designs. He was a real innovator. Valve springs were an issue, but he was good at working with the stock spring pressures. While Isky was acknowledged as a leader in the polydyne cam profile. Don Teweles wrote his masters thesis on on the polydyne principle and I personally believe he had more to do with it than Isky. As have mentioned in the past, wish we had taken good notes on all the things that were done. Don's were the only cams I ever ran in the Camaros, Ford and the Mopars. Any car I ran always had a GK cam decal on it. Don love to hear stories of setting class records and going to tech teardowns. I vary seldom paid for a camshaft there. Maybe helped pay when a new master lobe was required. Don was a very generous and kind man.

[djm670]

Originally Posted by GTS340

I remember we put what was called a 7000 plus Cheater cam in a 1868 Dart GTS 340. This was around 1975. Best camshaft way back that I had was a G K that McElroy had something to do with. That was around 1980.
Had Rhodes lifters and 273 adjustable rocker arms. With some pencil neck pushrods compared to todays. Those good old days when tuning was an art and records were set.

Paul Haszlauer

Paul you have me laughing, you would never see 7000 rpm with one of GK's cam's ... those we came up with were low RPM with lots of torque - 6200... maybe 6400 rpm... living with stocks springs was a treat. The Chrysler specs that were turned in for the 340's and 360's were a treat to work with after working with the limited spec's on the chevrolets.

Originally Posted by Cbrinson47

I would say 150 lbs seat pressure and 350 lbs open pressure max !

And smart engine builders will get 8000+ RPM out of those pressures.

[Ed Wright]

Originally Posted by djm670

Paul you have me laughing, you would never see 7000 rpm with one of GK's cam's ... those we came up with were low RPM with lots of torque - 6200... maybe 6400 rpm... living with stocks springs was a treat. The Chrysler specs that were turned in for the 340's and 360's were a treat to work with after working with the limited spec's on the chevrolets.

I shifted my ‘56 Chevy “Jr Stocker @7500. About the same at the finish line. The factory springs, on the seat at Stock specs (79 lbs) were weak open. I discovered PAC (?) springs, still needed new springs each race. The cam looked like a roller cam, with those nearly square lobes. Red Anderson shook his head at cam check time during tear downs. Not difficult to change the springs with the heads on the engine. TRW springs, out of the box, checked much better than GM springs. The better springs may have been Comp or Lunati. I can’t remember names well since I got so old. I apologize for that.

[sammy pizzolato]

Originally Posted by ss3011

Also part of the spec was "checking clearance" The duration was measured after the lift at the valve hit the opening checking clearance then finished when the lift was at the closing checking clearance . It was good to have" big" checking clearances sent in by the factory . Overlap was checked the same way . NHRA tech had a really trick Degree Wheel that simplified the checking process .

i have one of those NHRA checking wheels. Mr Red Anderson built them for nhra and i was luckey enough to talk red into making one for me.and i still have it today.it's priceless!!!!!!

[Ed Wright]

Originally Posted by sammy pizzolato

i have one of those NHRA checking wheels. Mr Red Anderson built them for nhra and i was luckey enough to talk red into making one for me.and i still have it today.it's priceless!!!!!!

I still have mine too. And his Deck Checker, uses a dial indicator.

[Frank Castros]

Originally Posted by Ed Wright

I still have mine too. And his Deck Checker, uses a dial indicator.

Great thread!