any dyno testing on NHRA cheater cams ?

[madcowl]

You must be talking about the "cheater" cams of the past.
Which means that the companies which offered them, now put them in mothballs.

Today, NHRA only has a stock "valve lift rule".

it was in the 90's , the valve lift was a rule then also , you had to have stock rocker ratio also . but they change the shape and opening closing to anything they want . it is a fussy cam that needs a loose converter to get the best results . we ran it in our dirt car later and had a 3800 stall converter in our turbo 350 trans , (rules said auto trans with working converter ) , and a 6.50 rear gear .

[tenxal]

so you can change spring diam or maybe run extra springs instead of a single with a damper like they had back then ? can you notch the pistons now ? and what is the rule on the lift ? is it 105 within stock lift ? my friend ed vickroy has one of those older square lunati 4.10 lift 350 cams , it looks bizarre . he has not tried it but he got it from a so cal stocker guy with chevy 350's

-Can't change spring diameter but you can run any spring you like.
-You can't notch the pistons. Valve reliefs must still remain O.E. depth, number of valve reliefs must still remain O.E.
-Lift can be no more than factory spec. for engine horsepower claimed.
-You are allowed to use aftermarket rockers but mounting type must be the same ie: no shaft rockers on SBC's, etc.

[madcowl]

2.1 seconds and 15MPH......on a cam change alone.....that's one set of truly "Magical Lobes" you found there.....not sure I'm buying that.....

believe what you want , i drove the car with both combos and the cheater cam was like a whole new engine from 3800 rpm up . in fact the 12.90 run only had a horrible 2.10 60 ft because of the tight converter .

food for thought , go take the cam out of a record holding stock eliminator and bolt in a typical name brand cam from summits catalog with the same lift . . the 10 sec car running 120+ mph is now running 12's at 105 ?
i would love to win the lotto and actually buy a record holding stock elim. car just to see the difference in a reg. store bought cam .

we got one for a kid with a 360 mopar out west who ran no better than his street cam with it . he swore it was degreed in at 99 degrees and i offered to buy it back since i ordered it and knew it was the right grind . i found out from his racer buddies that he STUCK IT IN AND LINED UP THE DOTS !!! he didn't even know how to degree a cam .

life is hard , and even harder if you are stupid , i believe john wayne said something like that

[madcowl]

so you can change spring diam or maybe run extra springs instead of a single with a damper like they had back then ? can you notch the pistons now ? and what is the rule on the lift ? is it 105 within stock lift ? my friend ed vickroy has one of those older square lunati 4.10 lift 350 cams , it looks bizarre . he has not tried it but he got it from a so cal stocker guy with chevy 350's

-Can't change spring diameter but you can run any spring you like.
-You can't notch the pistons. Valve reliefs must still remain O.E. depth, number of valve reliefs must still remain O.E.
-Lift can be no more than factory spec. for engine horsepower claimed.
-You are allowed to use aftermarket rockers but mounting type must be the same ie: no shaft rockers on SBC's, etc.

cool info , on the springs , i know one of the stock class drivers way back in the 90's had mopars , fords and chevies in his collection . he showed me the stock 350 piston from his original non touched corvette engine he was rebuilding . he compared it to the nhra legal replacement and showed me that the maker had moved the notches to line up with the valves better , because the original location did not provide enough clearance . that change allowed more dur. and that meant more hp , it seemed really biased against the other brands who had no notches because if they even tagged a valve on the piston , they were told to replace it since it was now a valve notch , even though it was one or 2 and not the whole set . he was told if it had any notches during a teardown , he was gonna be tossed for it . he was then nicknamed random because they tore him down randomly on a reg. basis . their harassment was bad , he became a steward or driver's commissioner , not sure what they call them ? and i would guess he had to be voted in ?

[madcowl]

here is a pic of the shape of a cheater vs a street type cam .

street type vs nhra stock elim .478 lift cam .jpg

imagine how much more air is getting through the engine with the cheater compared to the pointed cam

[madcowl]

here is another car we put one in , watch the video link below . it was running high 14's at 93 mph with a typical .520" lift hyd cam . the 454 was another junker low compression engine with the modern small port heads . i think they call them peanut heads ? it was a tired used engine . no port work , not even a stock rebuild or valve job . it went 12.70 at 107 mph but a piston broke right after this run . i did the same grind as our sb had , the mopar 340 stocker grind of 256 -264 dur . and a .468-.479 lift ( i have a cam card here , but i'm sure those were the lifts ) . not sure if the newer smog 454's had the bigger rocker ratio ? early ones were 1.7 correct ? i dont recall checking this one , but we put it in at around 100 degrees , and i still had to cut a notch in the piston with a drill and the cutter tool from isky . they were old stock cast pistons and it's probably what helped it break . you can see in the video it sounds bad . 12.70 at 107 was as good as the best a stock new high compression 454 chevelle was in all the magazine tests back in the day . for a smog 454 with garbage parts , high 14's to 12.70 , i'd say it was quite an improvement . maybe the lower compression reacts better ? maybe the cam design adds compression ? i dont know , but i would still love to see my 400 with the 230 darts , a bunch of compression , and the 1050 dominator on the motown intake with the cheater cam on the drag strip .

https://www.youtube.com/watch?v=Ny9tperwT6o



..

[Jeff Lee]

The same guys that won’t believe the cam makes such a great improvement also refuse to believe the flow #’s on a NHRA Stock Eliminator pair of cylinder heads using stock head & stem diameters and no porting; past the allowable cutter depth on the valve job.
It is rewarding to take your Stocker to the line on a test-n-tune run against some tunnel-rammed, plexiglass-glassed & tubbed something or other and blow his doors off with your OEM carb, cast iron intake, OEM lift cam, 9” slicks, etc.!
I once had a street ’72 ‘Cuda with a ’71 340. That 340 had a pair of Bob Lambeck prepped Stocker heads, a DC .484” hydraulic cam with a cast intake & ThermoQuad, 1 3/4” headers, 2800 convertor & 3.91 gears. I built the engine and it was nothing to brag about as it was only my 2nd full engine build. Ran 12.80’s @ 106 on street tires. Everybody’s always looking for the NOS when you do that. I always attributed the most power on that car to the Stocker heads.
My AMC stocker heads flow #’s that most say “BS” to. But the proof is in the times.
On the cams...I believe you would not last a 100 miles on a street car with todays most powerful Stocker cams. It would beat the crap out of the entire valve train. OK...now your allowed aluminum roller rockers. That would help. Same with Schubeck lifters. But even with these parts, your on the ragged edge.

[madcowl]

The same guys that won’t believe the cam makes such a great improvement also refuse to believe the flow #’s on a NHRA Stock Eliminator pair of cylinder heads using stock head & stem diameters and no porting; past the allowable cutter depth on the valve job.
It is rewarding to take your Stocker to the line on a test-n-tune run against some tunnel-rammed, plexiglass-glassed & tubbed something or other and blow his doors off with your OEM carb, cast iron intake, OEM lift cam, 9” slicks, etc.!
I once had a street ’72 ‘Cuda with a ’71 340. That 340 had a pair of Bob Lambeck prepped Stocker heads, a DC .484” hydraulic cam with a cast intake & ThermoQuad, 1 3/4” headers, 2800 convertor & 3.91 gears. I built the engine and it was nothing to brag about as it was only my 2nd full engine build. Ran 12.80’s @ 106 on street tires. Everybody’s always looking for the NOS when you do that. I always attributed the most power on that car to the Stocker heads.
My AMC stocker heads flow #’s that most say “BS” to. But the proof is in the times.
On the cams...I believe you would not last a 100 miles on a street car with todays most powerful Stocker cams. It would beat the crap out of the entire valve train. OK...now your allowed aluminum roller rockers. That would help. Same with Schubeck lifters. But even with these parts, your on the ragged edge.

i agree it is not a long life set up , and they do it because they have to . but after seeing a 340 demon with an iron intake , carter carb , and legal parts go a 1.40 60 ft , 1.88 at 121 mph . it was the same grind we made on the chevy core . he said he was revving 7400 rpm in the lights . someone mentioned how different the newer cams are from the old 90's stocker cams ? i dont know how much different the newer cams could be (for the older engines i am talking about , 340-360 mopars ) if they cant do notches for more room ?

[SupStk]

Need extra valve clearance on exhaust since the piston is chasing the valve.
Can't go bigger diameter springs on a stocker. There are some good choices for the application for most engines.
No valve notching permitted unless they recently opened that up. Know of a guy that was recently bounced in teardown for having notched Buick pistons which normally have no notch.

[Truckedup]

Need extra valve clearance on exhaust since the piston is chasing the valve.
Can't go bigger diameter springs on a stocker. There are some good choices for the application for most engines.
No valve notching permitted unless they recently opened that up. Know of a guy that was recently bounced in teardown for having notched Buick pistons which normally have no notch.

Obviously advancing the cam a lot is going to affect the power curve with the earlier intake valve closing...

[tenxal]

... someone mentioned how different the newer cams are from the old 90's stocker cams ? i dont know how much different the newer cams could be (for the older engines i am talking about , 340-360 mopars ) if they cant do notches for more room ?

The difference is the newer lobes are designed around the valve spring pressures we can now run, versus when we had to run the mfgs. spec'd spring pressure.

A bread and butter SBC stocker now runs around 225 lbs on the seat and we push 425 lbs+ over the nose on these little .390/.410 cams. With .050 durations from 262 to as much as 270, it's always a struggle to balance camshaft advance/retard, CL, LSA, etc. all while keeping just enough valve to piston clearance. Needless to say, the exhaust clearance can get pretty herky. Properly sorted out and with the right lifters, a hydraulic lifter .390/.410 SBC will buzz 7,400 in the lights, if need be (and atmospheric conditions allow it ).

The increased valve spring pressure comes at a cost....need to break in with light springs, nitriding, tool steel lifters, etc. All at a time when some of the oils we'd like to run don't have the anti wear properties needed.

But we get by....

[ZEOHSIX]

The same guys that won’t believe the cam makes such a great improvement also refuse to believe the flow #’s on a NHRA Stock Eliminator pair of cylinder heads using stock head & stem diameters and no porting; past the allowable cutter depth on the valve job.
It is rewarding to take your Stocker to the line on a test-n-tune run against some tunnel-rammed, plexiglass-glassed & tubbed something or other and blow his doors off with your OEM carb, cast iron intake, OEM lift cam, 9” slicks, etc.!
I once had a street ’72 ‘Cuda with a ’71 340. That 340 had a pair of Bob Lambeck prepped Stocker heads, a DC .484” hydraulic cam with a cast intake & ThermoQuad, 1 3/4” headers, 2800 convertor & 3.91 gears. I built the engine and it was nothing to brag about as it was only my 2nd full engine build. Ran 12.80’s @ 106 on street tires. Everybody’s always looking for the NOS when you do that. I always attributed the most power on that car to the Stocker heads.
My AMC stocker heads flow #’s that most say “BS” to. But the proof is in the times.
On the cams...I believe you would not last a 100 miles on a street car with todays most powerful Stocker cams. It would beat the crap out of the entire valve train. OK...now your allowed aluminum roller rockers. That would help. Same with Schubeck lifters. But even with these parts, your on the ragged edge.

The OP said nothing about any other changes.....he said he put in the "Magic cam" and ended up with 2.1 SEC ET improvement and 15MPH trap speed.....myself, I had a 340 Duster.....I was a dumb kid when I owned it....drank the D.C. "Koolaid" and bought a Purple Shaft at the Dodge dealer....went from 14's to 13's but also put LD340 and 750 Holley on the motor....took out 3.55 gears and swapped in 3.91's.....from there I needed to do bunch of chassis changes (Super Stock springs, slicks, 90-10 shocks) I then put a set of 273 rockers on the car Crower solid lifter cam, with ported heads (J heads 2.02/1.60 AMC valves) and 4.30 gears to get down into low 12's in a daily driven street/strip car....I also worked at a machine shop at that time and was lucky to know some successful Mopar stock Eliminator racers who helped me out.

You aren't going to install a cam on a worn out motor and experience 2.1 seconds and 15MPH with a cam swap alone....guy sounds like a typical "Internet Keyboard Operator" to me.....I'm still calling BS! on the OP claims of "magic cam" and I'm very familiar with NHRA "cheater cams" they take a lot of work to make them work correctly....carb, exhaust, ignition tuning...they can be very sensitive to exhaust system, header diameters, collector lengths.....besides N2O kits, I don't know many speed parts that just "bolt on" and add results like the OP claims he saw.....in fact the prices on "cheater cams" might make a simple N2O system a better bargain than some cam that destroys valvetrain parts in its operation. When you increase an engines power output you start taxing marginal systems in that motor....maybe the OP is omitting other mods done during the cam swap but if you put a big cam into a worn out motor your not going to see the full potential of its increased cylinder filling if your cylinder heads and ring seal in your motor are marginal.

As far as making Chevy's run....much easier than Mopars! I have a 1972 LT-1 Vette.....at one time it had a 355 cu/in motor in it with the factory carb/intake and some hand ported cast iron rams horns exhaust.....12.55ET@113MPH through the mufflers with sticky tires on the back....I used to like to see the head scratching in the staging lanes as I had the hood up revealing the stock appearing LT-1 sitting in the engine bay.....a motor I had put lots of time and a modest amount of $$ into to get it to run like it did....many people thought I had a 383 or 406 motor.....it was a 355 motor. I destroyed $90 worth of carbide burrs porting the rams horn manifolds alone.....later with just a change to Headers the Vette went 12.20's@117MPH still through the mufflers but all these runs were on a motor with excellent ring/valve seal that helped make the changes effective.....on a worn out motor with bad rings/valves.....you aren't going to create "magic".

I know they create "MAGIC" on TV with cars sitting for 20-30-40 years by just adding a new battery and changing the oil but in the real world when stuff sits around....things rust and valve springs go bad....at least that's been my experience during my time on this planet. My machine shop buddy used to joke "Spring is in the air! and all across America boats are dropping valves on the lakes after sitting all Winter long...Ca Ching! $$$"

[CamKing]

We run the dwell nose cams in these classes, because it's the only band-aid for the lift rule. It you don't have a lift rule, or spring rule, you could make much more power with a mild roller, and it would be much more reliable.

[1972ho]

I did the same as the op I had a 428 scj engine in a 1969 mustang back in 1996 and ordered a stocker cam from compcam and installed it in a factory stock 428 engine and made no other changes to the engine except the cam that car would run 12'Os to 12:10 at 110 mph it had 4:56 gear and ATI 10 inch converter and slicks with hooker header and mufflers with full 3 inch exhaust.And after I spun a rod bearing in the 428 I built a truck block 390 with Edelbrock heads and performer rpm intake with the same stocker cam and the car still ran the same ET and MPH.And when I sold the car I took the cam out and kept it still have it today

[wwmtlineman]

The reason they made them change the pistons after the valves hit is because guys used to take old valves, put them in the heads and hammer them into the pistons to create valve clearance. We used to have to run our D/S 68 Z28 at .050 exhaust piston to valve clearance back in the stocker oem stock piston days