any dyno testing on NHRA cheater cams ?

[madcowl]

it's been a few years since we played with the drag car stuff but we had used a cheater cam in several engines and i felt they were impressive . the most fun was the low buck high mileage beater 80's chevy 350 engine we put one in . it was very well used with the orig. pistons ,and the heads , i'm guessing are 305 heads ? since they had a 1.78" intake valve . we got the used engine to drop in a 69 nova we had sitting there just to make it driveable . we put headers on it , and a small 480 lift hyd comp cam in it with a torker II intake and 750 dp carb , with 3.91 gears (chrysler a-body 8-3/4 rear ) . it had a 28" tall sticky tire , and a turbo 350 and stock tight converter (did not like to idle in gear with the cam ) . the best we could get from that combo was 15.00's at 92 mph . i had played with several mopar bb and sb cheater cams in bracket cars , so i knew the mopar grind they used in f/sa with a 360 sb mopar . i had the cam comp. put that grind on a chevy sb core .i dont have the cam card handy but it was a hyd , and had 256-264 dur at .050" and the lift was only .479" i believe . it was advanced a ton , ground on 108 but installed at 99 . they normally run it way advanced to clear pistons in their class . the car blew some of the local kids minds since it went 12.90's at 107 mph all the sudden . the 60 ft time was horrendous , at 2.10 . all the local kids called me a liar and doubted every word . i even offered them the engine for 1500.00 dollars which made them wonder but nobody would buy it . we ran it quite a while , and i even did some street miles with it . (light spring pres. since we didn't rev it hard , 5500 shifts ) . finally we had changed the converter to a 3800 stall to help the 60 ft . , but the car had sat outside a few seasons before we did the converter , and it was down on power and sounded lazier . it ran at 1.68 60 ft now , and slowed down to 102 mph and 13.00's . we tried new springs , plugs , carbs etc but it had fallen off on 1/8th mile mph also . we did a compression test , and had 2 holes were horrible bad , and then a leakdown test . it was leaking around several valves and the 2 cyls were getting past the rings . we pulled the thing apart to find the valve guides were super sloppy worn out , and some broken piston rings . my brother lost interest in the car and sold the body . that engine is still here in pcs the way it was , but we used that cheater cam and trans/converter in our dirt circle track car with a 400 sb and iron eagle heads . the circle track car flew but the lobe went flat eventually (a known risk with these cams ) . i know we would have went 12.30's or so with the converter since we picked up 4 tenths in the 60 ft alone . my buddy , ed vickroy in fontana calif. flowed the stock tired 350 engine's heads prior to putting it in the nova , remember , that head with the 1.78 valves . ed said they were the worst he had seen . he blended the bowls and they flowed at 114 ft @ 10" @.500 lift , other than that he did not do anything else on those heads . i also had one of the local kids want to try one , he had 4.10 gear , 3500 stall conv. and it was in a 85 cutlass . his engine was a 350 , 9 to 1 comp. 1.94 camel back heads , and his car ran 13.30's at 99 mph . so we pulled his .530 lift cam and put the same cheater cam grind in , and the kid was blown away with a 12.68 at 108 mph and a slower 60 ft than his cam , now a 1.70 vs a 1.60 before . he had a 3310 vac holley , and a performer rpm intake and headers but other wise stock . i know it's a long story but just wondering if any of you have used these ? in a car or on a dyno . i know it is not meant for what we do with them , but i want to try one with a 1.7 rocker arm and 5500 stall converter one day !

[Walter R. Malik]

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".

[HDBD]

The cheater cams from my days (Jr Stock NHRA) had no place in a street car. They tore up parts and lofted valves purposely

[wyrmrider]

I know where lots of dyno info is but see HDBD's comment X2

[tenxal]

Since NHRA went to the 'lift only' rule on Stocker cams and allowed any valve spring pressure (the spring still has to fit the unmodified spring seat), lobes have gotten even more aggressive on Stocker cams.

Comparing my old Lunati RL929 (.390/.410) to my new Comp or Bullet offerings is fun........

[racear2865]

just make the lobe square and your in the ball park and there is new meaning to lofting and bounce.
reed

[Truckedup]

they normally run it way advanced to clear pistons in their class .

Advancing the cam always reduces intake valve to piston clearance...

[Diodedog]

they normally run it way advanced to clear pistons in their class .

Advancing the cam always reduces intake valve to piston clearance...

And increases the exhaust valve clearance which is the critical issue.

[Truckedup]

they normally run it way advanced to clear pistons in their class .

Advancing the cam always reduces intake valve to piston clearance...

And increases the exhaust valve clearance which is the critical issue.

Why is the exhaust more critical than the intake in this situation?

[nhrastocker]

Most Stock Eliminator cams have what is called a "Dwell" lobe.
One of the characteristics of these cams is they do increase cylinder pressure.
To improve your 60' times, you need gearing and a loose torque converter.

[ZEOHSIX]

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.....

[F-BIRD'88]

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.....

Must have flipped the air cleaner lid too.

[peejay]

Why is the exhaust more critical than the intake in this situation?

Sounds like the valves aren't closing when the cam says they should be closing

[madcowl]

just to clear the air , with our nova being street driven , it only went to the gym about 5 miles down the highway and back with that cam . the cheater cam was never intended to be used in a street car . the 350 engine was a used low comp. truck engine with a .480" street cam we put in it .we put in the car to play with it some for giggles and to see how quick it could go with plain old no-dollar parts . we had all the parts there from other projects or the long beach swapmeets . later after we had moved here to michigan in 1997 the car was way too slow , the only thing i bought new was the cheater cam with the mopar specs ground on a chevy core and some new valve springs 1.25 diameter . we planned on just doing some fun drag tests . after going to the local hillbilly dragstrip , i was convinced it could be played with to beat many of the locals who seemed way to slow for claiming they had roller cams and ported heads etc . and only running 13's at 100 mph . with our car only running 15's with the normal comp cam , horrible low compression , and 1.78" intake valve heads , they laughed at our car . when i told them how small the valves were ,and how low the comp. was , they all said throw that engine away . i told them about the cheater cam i ordered ,and that i had seen huge gains in the past with it , they said how stupid it was to go smaller on the lift , and it was a waste of time . again , i know it is not a street cam , and did it just for a fun test , but that no-dollar 350 smog long block smoked those guys with the cheater cam in it with 12.90's @ 107 mph . of course they said i was hiding a bottle . i had one of the doubters here at my shop when i did the the leak down and then engine tear down down showing all the issues , rings guides etc . the kid could not believe his eyes when he saw those tiny ass valves ! and the stock pistons way down in the hole . he also saw the hyd. lifters , stock stamped rockers , stock baby pushrods , and the odd non pointed cam . as crazy as those kids thought i was , this kid saw the proof . (we put one in his sb powered 80's cutlass and went from 13.30's to 12.60's with 9 mph gain over a .510 lift typical cam )
years passed , and i had a bunch of health issues and surgeries , so no racing until we jump to 2006 my bro wanted to go dirt track racing . he lost interest in the nova years before and sold the body . (i still have that junk 350 sitting here in pcs ) we put that cheater cam from the nova in our circle track 400 sb chevy , but sadly it wore a lobe off , after the first season , but it was a screamer before it went away . all the racers thought it was big money 434 engine , lol . it was a real cast crank 400 with an ebay $749.00 engine kit with the cheap sir rods , and a hyperutectic 11 to 1 piston , rings , bearings , gaskets etc . the heads were dart iron eagle premium 230cc heads with 2.08 valves , but i had future plans to move up in class and compression . that pair of iron eagles was also an ebay deal of $799.00 shipped . ( i still have that whole 400 and the heads but some better internals for it now and a better intake etc. ) the cam i replaced it with is from jr motorsports , a prc 109 i believe is the number . .580 lift or so . it runs good but not as strong as the little lift cheater did . it has smoother power but on a drag strip the cheater would run quicker and more mph .

[madcowl]

Since NHRA went to the 'lift only' rule on Stocker cams and allowed any valve spring pressure (the spring still has to fit the unmodified spring seat), lobes have gotten even more aggressive on Stocker cams.

Comparing my old Lunati RL929 (.390/.410) to my new Comp or Bullet offerings is fun........

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 10% 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