[Tom Vaught]

Originally Posted by ursusarctos

Sounds like a typical NHRA cheater cam from 1968-up (or maybe even before that?)

Do you think that cam was the one in the March 1964 Car & Driver "389" GTO vs Ferrari article? Or did the cam & the 455+ replace the 421ho in later years?

The post above was to answer the question above, mods.
The stock 744 cam was better than the 068 camshaft for performance in the 1970 time frame.

Tom V.

[Formulajones]

Originally Posted by Steve C.

After retirement he stated, "I wish we could have used roller technology back then. It would have cut friction and allowed us to improve performance and street manners, but it wasn't available at that time."

I wonder what he means by that "back then" because roller cams were around as early as the 50's and were more widely used when the 60's rolled around. The tech was there.

[PAUL K]

Originally Posted by Formulajones

Yep, they are commonly paired with 454 chevelles and hemi cudas and do fairly well.

The RAIII on the other hand, not so much LOL

Weren't the 69 and 70 Firebirds heavier than the 68? It'd be intersting to see a RAIII compared to RA2 using a stock GM 13" torque converter, original exhaust and same weight car.

[PAUL K]

Originally Posted by Tom Vaught

I have one of those Milt Schornack 744 camshafts that he ran in the 455+ engine in the Wangers 64 GTO.

I had it profiled by the Camshaft Machine Camshaft people (Don Hubbard) who was a Vice President there.

The only thing that matched the STOCK PONTIAC 744 camshaft was the "H" stamped on the nose of the camshaft.

The Cheater Cam was made by Lunati Camshafts for Milt.

Specs were more like 248 @ .050 Intake, 254 @ .050 on the Exhaust lobe.

Just Saying.

Tom V.

Interesting Tom, funny they'd remember to put the letter code on the front. I have a similar grind that came out of Ray Hunts SD455 stocker but it was ground by another cam company, not Lunati.

I thought most the camshafts Royal & Leader used came from General Kinetics??

[PAUL K]

Originally Posted by Formulajones

I wonder what he means by that "back then" because roller cams were around as early as the 50's and were more widely used when the 60's rolled around. The tech was there.

Can't speak for him, but roller technology couldn't have been that stellar compared to today standards.. All the old Pontiac roller grinds I've come across from the 70's were ground on a cast core, limiting spring pressure but atleast they didn't require a bronze gear.The valve spring technology has advanced a crap ton also. Unless it was an all out race effort I can't imagine there was a ton of power in a roller cam for a Pontiac back then.

[Steve C.]

McKellar says the division limited gross valve lift to just over 0.400 inch in most instances simply because it was less stressful on the valvetrain.

He went on, "Our heads had good port velocity and larger valves, so we didn't always see the need to increase valve lift and press our luck on durability. You have to remember, too, that not all of our engines went into performance applications."

According to one source it was 1949 when the first roller cam was manufactured for the performance automotive engine and it was Chet Herbert who designed and ground it.
GM first began installing roller cams in some Chevrolet small-block, V8-equipped cars in 1987.

.

[PAUL K]

Originally Posted by Steve C.

According to one source it was 1949 when the first roller cam was manufactured for the performance automotive engine and it was Chet Herbert who designed and ground it. GM first began installing roller cams in some Chevrolet small-block, V8-equipped cars in 1987.

.

Good info Steve. I'm betting he hasn't changed his lifter design since

[Formulajones]

Originally Posted by PAUL K

Weren't the 69 and 70 Firebirds heavier than the 68? It'd be intersting to see a RAIII compared to RA2 using a stock GM 13" torque converter, original exhaust and same weight car.

Yep. My 70 RAIII Formula scales 3690 without me in it and a full tank of gas (spare and jack removed). 400 turbo, PS and PDB are the only options. It's 3890 going down track with my butt in it.

I think 69's fall somewhere in the middle. Not a firebird but basically the same chassis and size, our 69 Z/28 scaled 3420 lbs, with the spare and jack and full tank. The SBC might be a pinch lighter than a Pontiac engine.

The 67's-68's are typically lighter yet, as you stated.

I set my Formula to run PS years ago and have been racing it ever since. I think I've done about all I can with it at this point. Engine is stock, 068 cam, exhaust manifolds, no porting, just a good solid rebuild with a few simple things, lots of tuning and chassis tweaks that are allowed per rules.

With a reproduction Gardner exhaust on it, it would run a best of 14.0's and teens and mph was stuck at 98-99. Pretty much what was posted of the road tests earlier in this thread ironically. That was back when I was living in Ohio and racing it at the muscle car drags.
Upgraded to a 2 1/2" mandrel exhaust, still with transverse muffler (allowed per rules) and the car immediately went upper 13.60's at 102 mph. From there I just worked on suspension and 60 foot times, tried a coupe engine tweaks, and shaved that down to 13.10 at 104 mph. Still with the stock 13" converter. I've been pretty much stuck right there for the last 3-4 years. I did install an L88 converter about 2 years ago but oddly enough, it didn't do anything for me. Still 60 foots the same. Been a best of 1.89 on stock tires.

I would guess a similar equipped 69 RAIII bird would be a pinch quicker given it should be lighter to start with. I know the 68 d-port RA birds are running in the mid 12's in that class, and they should be a good 250-300 lbs lighter than mine.
Here it is today, still running the same lol I think it's time for a major change
https://youtu.be/er1z7PpqsnY

Dennis and his brother Dan are way more familiar than I am with what those cars have done but I know a RAIII is really no match for a round port RAII bird or a RAIV bird. Not even a match for those engines in a heavier A body either. The RAIII is just way outclassed. I consider mine running really well for what it is, but I know a well tuned RAIV with a good driver would/should hand me my a$$.

I would love to build a RAIV for the car, sort of a "what if" Formula and pursued that for a while, but couldn't find a good set of 614's that didn't cost my first born. I couldn't justify the expense for an experiment. Never did ask Dennis if that would have been class legal since those cars were never built, but I think I know the answer, so that was another reason to not do it.

[PAUL K]

Originally Posted by Formulajones

Yep. My 70 RAIII Formula scales 3690 without me in it and a full tank of gas (spare and jack removed). 400 turbo, PS and PDB are the only options. It's 3890 going down track with my butt in it.

I think 69's fall somewhere in the middle. Not a firebird but basically the same chassis and size, our 69 Z/28 scaled 3420 lbs, with the spare and jack and full tank. The SBC might be a pinch lighter than a Pontiac engine.

The 67's-68's are typically lighter yet, as you stated.

I set my Formula to run PS years ago and have been racing it ever since. I think I've done about all I can with it at this point. Engine is stock, 068 cam, exhaust manifolds, no porting, just a good solid rebuild with a few simple things, lots of tuning and chassis tweaks that are allowed per rules.

With a reproduction Gardner exhaust on it, it would run a best of 14.0's and teens and mph was stuck at 98-99. Pretty much what was posted of the road tests earlier in this thread ironically. That was back when I was living in Ohio and racing it at the muscle car drags.
Upgraded to a 2 1/2" mandrel exhaust, still with transverse muffler (allowed per rules) and the car immediately went upper 13.60's at 102 mph. From there I just worked on suspension and 60 foot times, tried a coupe engine tweaks, and shaved that down to 13.10 at 104 mph. Still with the stock 13" converter. I've been pretty much stuck right there for the last 3-4 years. I did install an L88 converter about 2 years ago but oddly enough, it didn't do anything for me. Still 60 foots the same. Been a best of 1.89 on stock tires.

I would guess a similar equipped 69 RAIII bird would be a pinch quicker given it should be lighter to start with. I know the 68 d-port RA birds are running in the mid 12's in that class, and they should be a good 250-300 lbs lighter than mine.
Here it is today, still running the same lol I think it's time for a major change
https://youtu.be/er1z7PpqsnY

Dennis and his brother Dan are way MORE familiar than I am with what those cars have done.

Good info.... I think the deal breaker would be a true stock 13" converter. The RAIV cam is pretty much dead below 3,000 rpm in a 400 and I believe the RAIII would have a bit of a compression advantage over the RA2.

I don't follow pure stock that closely but for a long time the RA2 Firebirds seemed to out run the RAIV cars. I'm guessing their must be "a reason" or I could be wrong from what I recall reading in magazine vs. fact.

[jhein]

I can't remember the exact number but my car weighed in right around 3650, full tank, no driver. 70 TA that was all stock at the time.. That's a factory no AC, no console, no radio and no spare in the trunk car.

[Formulajones]

Originally Posted by PAUL K

Good info.... I think the deal breaker would be a true stock 13" converter. The RAIV cam is pretty much dead below 3,000 rpm in a 400 and I believe the RAIII would have a bit of a compression advantage over the RA2.

I don't follow pure stock that closely but for a long time the RA2 Firebirds seemed to out run the RAIV cars. I'm guessing their must be "a reason" or I could be wrong from what I recall reading in magazine vs. fact.

I think the RAII birds are a more advantageous package. The 68 birds are lighter as you stated so that's a big plus. I think the RA hood package is much more simple and therefore works a little more efficiently. I think they also use the long branch manifolds (I know 69 birds do) and they've shown to be a bit better than the A-body style RA manifolds that the 70 birds are stuck with.

The 69's got a little fatter and the RA system a little more complicated. I'm out of the loop but don't recall any of the 69 RAIV's in pure stock running close to the times the 68 RAII birds have. I feel the 68 RAII's have shown to be one of the best packages from Pontiac, at least as far as the pure stock drags go.

[Formulajones]

Originally Posted by Steve C.

According to one source it was 1949 when the first roller cam was manufactured for the performance automotive engine and it was Chet Herbert who designed and ground it.
GM first began installing roller cams in some Chevrolet small-block, V8-equipped cars in 1987.

.

Yikes that's further back than I thought.

[Tom Vaught]

Originally Posted by PAUL K

Interesting Tom, funny they'd remember to put the letter code on the front. I have a similar grind that came out of Ray Hunts SD455 stocker but it was ground by another cam company, not Lunati.

I thought most the camshafts Royal & Leader used came from General Kinetics??

Much later timeline for the 744 Cheater Camshaft in the Milt S 455+ Cheater Pontiac engine installed for the Drag Strip "Exhibition" runs Milt ran at the different tracks.

Royal/ General Kinetics was not involved in that engine.

Tom V.

More info: Scroll down to post by autie1969gto

https://www.gtoforum.com/threads/wan...-d-gto.138430/

All of above being later history, I posted pictures of the red cars engine block showing the 421 Pyramid at the back of the block.
When the CD article was written.

[scott70]

I would think it would be hard to hide a cheater cam with 250@ .050 duration at a idle. That would be pretty choppy.

I know some other combos of drivetrain called for a 067 cam if auto trans and if manual it got the 068.

[PAUL K]

Originally Posted by Formulajones

I think the RAII birds are a more advantageous package. The 68 birds are lighter as you stated so that's a big plus. I think the RA hood package is much more simple and therefore works a little more efficiently. I think they also use the long branch manifolds (I know 69 birds do) and they've shown to be a bit better than the A-body style RA manifolds that the 70 birds are stuck with.

The 69's got a little fatter and the RA system a little more complicated. I'm out of the loop but don't recall any of the 69 RAIV's in pure stock running close to the times the 68 RAII birds have. I feel the 68 RAII's have shown to be one of the best packages from Pontiac, at least as far as the pure stock drags go.

I agree, that's why I suggested comparing them in the same weight car. One could also compare dyno numbers. At the end of the day a RAIV would kick the crap out of a 2 or 3 and the SD-455 would be the winner in race form. Just like a Hemi is superior to a 440 six pack. Apple's need to be compared to apples. As far as pure stock classes go, I recall Jim Mino's car winning the first two Muscle Car show downs.... Over the years PS RA2 cars have went considerably faster, little of that improvement came from the power output of a "stock" engine.

[Formulajones]

Originally Posted by PAUL K

I agree, that's why I suggested comparing them in the same weight car. One could also compare dyno numbers. At the end of the day a RAIV would kick the crap out of a 2 or 3 and the SD-455 would be the winner in race form. Just like a Hemi is superior to a 440 six pack. Apple's need to be compared to apples. As far as pure stock classes go, I recall Jim Mino's car winning the first to Muscle Car show downs.... Over the years PS RA2 cars have went considerably faster, little of that improvement came from power out of a "stock" engine.

Yes Jim Mino was the pioneer with that car and everyone took notice. He knew early on it was a good package for that type of racing. Now you see several of them in pure stock racing with Rick Mahoney running in the 11's with one.

Mine is probably the worst of the firebirds to start with for that type of thing as far as 67-73 birds go. A good running 455HO or SD is quicker these days than my 70 RAIII. 25 years ago I had them covered but they have figured those cars out. Most of them I think are now well into the 12's.
For giggles I even went beyond the rules to try and squeeze that last tenth out of mine just for a 12 on a piece of paper. Simple things like putting aluminum wheels on it, that's usually worth a tenth on other cars I've done that to, but the DA never cooperated.
Then put drag radials on it, but oddly it only picked up 1 hundredth to the 60 (they were too tall). In the end I couldn't get it done. I've just hit a wall with the car. I could put more gear in it but I like it too much as a nice driver.

I need a better package to start with.

[Tom Vaught]

Originally Posted by scott70

I would think it would be hard to hide a cheater cam with 250@ .050 duration at a idle. That would be pretty choppy.

I know some other combos of drivetrain called for a 067 cam if auto trans and if manual it got the 068.

I drove a 400 cid engine with a 255/260 solid flat tappet Comp Camshaft with .560 lift on the street for years and with the Exhaust cut-outs closed the average person walking by the car when it was idling never knew the difference. It sounded like the Cheaters idle in the Commercial.

There is choppy and then there is noticeable. Roy McKenny speced that camshaft for me.

Mike and Roy McKenny info:

"Roy McKinney was the VERY first NHRA Super Stocker running in a GT class of Super Stock with a 400 cubic inch engine to run in the nines back in 1997. Roy deserves that mention. He's one very smart NHRA racer. You may remember his 1968 Firebird in the CompCams ad almost straight up at Indy..."

Facts vs "I Think".

Tom V.

[Formulajones]

The solids loose about 10 degrees of duration right off the bat from lash so there's that. Plus if it's ground on a wide LSA, and then installed with an ICL that's pretty far advanced, you could mask a lot of what that cam would be perceived as sounding like. Couple that with a decent amount of initial timing and a generous idle circuit in the carb and it could actually be very streetable and docile.

[Steve C.]

"The solids loose about 10 degrees of duration right off the bat from lash so there's that."

Related, here was a question and the answer from Mike Jones / cam designer:

Mike, you may have already tried to explain it, but why the added duration for a solid lifter cam vs the same spec. hydraulic-cam??


If you want the valve lift curve to be the same, the solid(Mechanical) lifter cam will be bigger at .050".
That's because with the hydraulic lifter you start opening the valve at around .004"-.006" lifter rise, so .050" lifter rise is .044"-.046" above the point the valve is opening. Now, with the mechanical lifter you start opening the valve at the hot lash point divided by the rocker ratio(normally around .012"-.016" lifter rise), so .050" lifter rise is only .034"-.038" above the point the valve is opening. So if you only look at the lift above the point the valve is opening, you're trying to compare the duration @ .045" on the hydraulic cam, with the duration at .036" on the mechanical cam.


.

[Tom Vaught]

Excellent Post Steve and thanks to Mr Jones for his Cam Designer knowledge.

Tom V.