Re: "Old School" Stocker Cams
 

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

Re: "Old School" Stocker Cams
 

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

Re: "Old School" Stocker Cams
 

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.

Re: "Old School" Stocker Cams
 

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.

Re: "Old School" Stocker Cams
 

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.

Re: "Old School" Stocker Cams
 

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

Re: "Old School" Stocker Cams
 

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.

Re: "Old School" Stocker Cams
 

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!!!!!!

Re: "Old School" Stocker Cams
 

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

Re: "Old School" Stocker Cams
 

Great thread!

Re: "Old School" Stocker Cams
 

I have one of Red's deck checkers also,nice looking piece for back when. My friend John Turley gave it to me.
Terry Hindsley

Re: "Old School" Stocker Cams
 

Ed,
Can you post pictures?


Stan

Re: "Old School" Stocker Cams
 

DON was by far ahead of Lunati-cam dynamics ect. Joe Lunati needed my cam to design a flat nose in early 70s mid 70s big block stocker chevy from GK--Don T was the guy!!!

Re: "Old School" Stocker Cams
 

We found an Erson spring in 1.250" diameter that went in at the installed height with 20 pounds too much spring pressure.

On Record Runs or Class Finals the way we fixed that we to put it on the floor a few times on the return road and by the time we got to teardown they would magically test LEGAL at the installed height...

I think that the Statute of Limitations has run out, at least I hope so.....

Re: "Old School" Stocker Cams
 

We run the old Isky Square Cams that are the same ones
as we ran in the 80s. They were designed Al Etter ( Ken's
Dad RIP) and Don Studley ( Shane's Dad RIP).

We have spent Thousands on Stocker Cams but always
go slower!

These Old School Cams are BRUTAL on the Valvetrain
and we do not recommend them to most people!.

Re: "Old School" Stocker Cams
 

Those old school cams are still used by many. I believe that when Don closed GK, John at Bullet Cams purchased some of the tooling. Cam Dynamics was also ahead of their game with dwell lobes too. Do not know what happened to Cam Dynamics tooling after they were split and acquired by other companies. Glen Steyer's was the man at Crane Cams for Stock Eliminator cams. Glen now has his own camshaft business and still makes some great cams.

With the advent of the spring rule allowing higher spring pressures, it allowed racers to take full advantage of the dwell lobes, called by many, square lobes. As a result, rocker arms and lifters subsequently became the next weakest valvetrain component to fail and as a result, the rule change to allow solid lifters and aftermarket rocker arms.

Those that have access to and pay for Spintron testing, will find and discover they can make more power with less aggressive lobes and less spring pressure.

Reducing reversion before TDC is the key. Earlier intake valve openings allow for higher pressure exhaust gases. The less reversion, the earlier airflow starts after TDC. When camshafts have an optimized area at mid-lift and higher lift, it allows the valve to have more time to fill the cylinder with an air/fuel mixture with higher inertia.

Re: "Old School" Stocker Cams
 

Remember going from a "C.D. 7000+" to a G.K.,it was a brutal valve train experience!!
From getting over 7000rpm to struggle to get it running over 6000 and lots of broken valve train parts,but it was a good thing to learn first hand that higher spring pressures not necessary gave you more trouble as you thought some 30+ years ago, braking parts is not the best way to spend your Racing-money but to find out and learn things that way is what keeps us interested keeping doing this, well for me anyway(nowadays I know that :D ) If it was the driving part I think there are lot better options for that :cool:

p.s.
My experience is the same as Johns about newer Cams,I never found much, with that said I never had or worked on a Stocker "induction system" that benefitted from 8000rpm so I must have some real junk :confused:

Re: "Old School" Stocker Cams
 

Can you please explain how that works?

Thanks,
Stan

Re: "Old School" Stocker Cams
 

When I look back 35 or so years ago when I started doing this stuff with a 283, I remember when Stock meant more stock than I care to think about--OEM or OEM replacement valves, cast OEM pistons, OEM rods, etc. and very close to pure stock heads, it proves we pushed the limits of the laws of physics every time we attempted to do this. It's amazing we never had any fatal engine failures more often than we did. I remember running that very close to original stock engine to nearly 7000 RPM many times. If you stayed in low gear a it too long and you heard the engine putter a bit, it obviously was floating the valves, get it into the next gear ASAP and hope you didn't bend anything or have any portion of the valve train bend or start to break. Then, the cam and spring rule change came in around 1988 or so, add about 800 more RPM to what we were already doing to the same engine combo, add more rear gear, and then note any increase. If we knew then what we know now, it would have terrified us to think of what was going on inside of that motor at 7000+ RPM. The stuff we have now to work with is so much superior to what we had then, it's unbelievable. I'm not bemoaning the departure from the old concept of a "Stock Eliminator"motor,I'm glad that most of the technology since then has resulted in vastly increased engine life as well as power outputs unheard of 35 years or so ago, so I am among the first to embrace technology that will improve the sport. Besides, it's fun to go faster!

Re: "Old School" Stocker Cams
 

In many of the Stock, Super Stock and Comp Eliminator engines I have been involved, one of the typical issues that were common with some of the profiles issue with exhaust reversion. Clues of exhaust reversion were sooty intake manifold plenums and exhaust ports.

It has been a known fact and proven that any valve opening event or lift that takes place prior to TDC will effect the performance of an normally aspirated engine.

The intake event during overlap at BTDC, can expose and contaminate the intake charge with exhaust gas all the way to the TDC event when the piston reverses direction and starts down on the intake stroke. The reduction of reversion improves port velocity and improves cylinder filling.

Many years ago, friend asked for help with his new Comp engine that supposedly made enough power in the dyno to make him top of the class. It did not happened and when the engine was put in a different dyno, it did not make the power claimed by the builder. The problem was reversion. Based on his cylinder head and intake flow data and other details, I had a new camshaft ground with different timing events. The result of both the camshaft change and intake plenum volume change was 89 HP. Moreover, the engine required less timing, and although the cam had more duration, the engine had more PTV clearance with the new cam. After the camshaft change, the intake plenum volume was also reduced and the engine picked up 89 HP with both changes.

Re: "Old School" Stocker Cams
 

Back in the scary days of the early '70's, I worked at a Chevy dealer beginning in 1975 up till about mid 1980. The cars they made between those years were not exactly exciting as to drivability and gas mileage. Beginning in 1971, the typical 4 barrel 350 that you got in most cars, came with 9.0 to 1 compression by using a piston with a small dish and a large CC combustion chamber in the heads. The '71 engine had the same camshaft as the 67-70 engines, .390" intake lift, .410" exhaust lift. Those cars still ran pretty well. It seemed that NOX emissions were a real concern, and excessive heat or combustion produced it, so the quick fix was to drop the compression down to 8.5 or so to 1, pull ignition timing out of it, and they ground a different cam with more lift,.398I,.430E, as per the NHRA engine specs in the guide. The problem was that the exhaust valve opened early and closed late. Also, the exhaust system in the car was quite restrictive. The sleeve on the right side exhaust manifold where the exhaust do-nut went had a noticeable restricted opening. This was an attempt to cause back pressure in order to trap a portion of the exhaust in the combustion chamber as a precursor to the EGR systems that came out in '73. Also, the presence of an inert gas in the mix combined with the retarded timing (4-6 degrees initial ) was designed to get the NOX emissions low enough to pass some federal standard. This resulted in a car that just didn't have it compared to its predecessors. This also was the start of a rash of 350 Chevy motors that used to get flat camshafts in about 20-30,000 miles. The factory replacement cam was the earlier cam, so when the line mechanics at the local dealer got one of these cars,'72-80 for a camshaft and lifter replacement, the earlier cam went in, and the customer got his car back with a noticeable improvement in drivability. We always set the timing to the factory specs and marked it so that the state smog gestapos wouldn't come visit the dealership and fine us for "tampering". In 1970-72, we had no idea the horrors awaiting the auto industry regarding upcoming emission control constraints! Now, if you have a Stock Eliminator car, all attention is being paid to making all the cylinder pressure and thermal efficiency you can for maximum power at the wheels when the car needs it most. The whole science of camshafts and their effect on engine performance is a huge field, and sometimes understanding what it takes to make an engine work better is to review why some engines didn't work right in the first place.

Re: "Old School" Stocker Cams
 

You are correct. There are many variables from one engine manufacturer and year to the other. One limiting factor, especially in Stock Eliminator is the lifter diameter. The lifter diameter on GM engines limits the lobe and ramp when compared to Ford, Chrysler and AMC that uses a larger diameter lifter, hence, allowing more aggressive lobes.

Re: "Old School" Stocker Cams
 

Maybe, that could explain why so many small block Chevy cams went flat all through the '70s and 80's. It's also a possibility that a cam vendor had problems with quality control that caused a lot of problems. Seems to me that some Ford engines in the late '50's and early '60's had a bunch of issues like that, too. I think it was with the onset of the FE engine and the MEL engine, 352,390,430's, etc.

Re: "Old School" Stocker Cams
 

It was the Ford Y-Block (272 292 312s) they had a nail head (mushroom) style solid lifter.

Re: "Old School" Stocker Cams
 

It wouldn't surprise me if Chevy tried to save a penny or two by changing the "recipe" of the steel or iron that the cams were made from. The vendors only adhered to the provided spec. Short term quality problems were more likely a vendor issue.
I say this from my experience working at a vendor that provided tooling and stampings for the big three. We would order steel that was to the customers spec ("recipe"), and it was checked by QC. It would then rust through in a few years until Japanese competition magically made UAW stuff better (late 80's,early 90's). If there was a vendor QC issue, we worked to get it back to the customer's standard, whatever that may have been.

Re: "Old School" Stocker Cams
 

The Chevy blocks, cams and lifters were all soft and brittle iron back in the 60s and 70s. The cams didn't have the large oil drain back area the Mopars had directly over the lobes nor the larger lifters and with the rocker/stud setup always loosening up they didn't last long. Back in 72 I rebuilt a 65 283 for a friends 62 Corvette and a 60 413 for myself. After removing the 283 cam which was missing a few lobes, I threw it up in the air on the asphalt road and it broke into about 50 pieces. I did the same with the 413 cam but it just bounced around without a break, I then at 17 yo using a good amount of force took it over the concrete curb with my hands and whacked it at least 20 times and couldn't even break it in half, the only way that 413 cam was coming apart was with a saw or a torch.

Re: "Old School" Stocker Cams
 

The Mopar had a much better camshaft core (Stamped CWC on the
cam ) with much better service life!

Re: "Old School" Stocker Cams
 

We received new camshafts back in the day in a cardboard tube with the GM logo and part number on them. Once in a while, we would open the tube and find the camshaft was broken in two right in the package. Also, dropping a camshaft was a real sure fire way to break it. If one rolled off a workbench and hit the ground it was usually done for as well. When Chevy went to the steel hydraulic roller cams, that ended a multiplicity of problems. Actually, a flat tappet camshaft was kind of antique technology even a long time ago.

Re: "Old School" Stocker Cams
 

Ford 292 lifter:

https://www.rockauto.com/info/8/BSE_..._ANG__ra_p.jpg

Re: "Old School" Stocker Cams
 

Seems that many an engine assembler putting together a 292 or a 312 would get his bare block on the stand, stick in the cam, the crank, the front cover and balancer, then put in the pistons and the rods, button things up, install the pan, pickup and the pump, then turn the engine over and start to install the lifters and then discover one of Ford's better ideas. It was the FE engine that went with a conventional lifter which Ford stayed with ever since. The lifters went into the block on the Y block first, then the cam slid in, then the rest of the bottom half went together. Lots of Ford line mechanics had a set of spring clothespins in their toolbox to hold those lifters up so they could replace a camshaft in the car if need be.

Re: "Old School" Stocker Cams
 

Mushroom lifters were used in the early days of NASCAR, allowing camshaft profiles with more aggressive lobes. Direct Connection used to sell mushroom lifters for Mopar applications and also the required tool to modify the block.

Many years ago I heard the story of a racer that was running mushroom lifters in 15 lifter bores and left one bore with a normal size lifter in the event he was asked to pull a lifter to show tech.

Re: "Old School" Stocker Cams
 

Seemed to me that an old GM Performance Parts catalog used to show a mushroom cam and lifter for a small block. Also, doesn't the tech guy sometimes tell you which lifter to pull at random?

Re: "Old School" Stocker Cams
 

Probably expected the Tech Inspector to say, "Just pull or hand me any lifter" :D

Re: "Old School" Stocker Cams
 

Me too, still have both; have used them when dialing port timing on two cycle Ski-Doo snowmobiles in my later years. No more hernia's from carrying heavy blocks and heads.

I believe Harry Doolittle had at least one of every checking tool Red made.