[ursusarctos]

Was 1970 400-RamAir3 the 068 cam or 744 cam?

In learning all the complexities of Pontiac history I came across the specs in Angeles & McCarthy:
For 1970, the 400 RA3 is shown as ALL with 068 cam, downgraded from the 744 cam.
Did that really happen?

Quite a few road tests of the 1970 GTO RA3 or TransAm with 400/345hp (ASSUMING those were RA3)
These are all 4-speed cars:
14.60 at 99.50 TA Mar 70 Sports Car Graphic
14.60 at 99.60 GTO Apr 70 Car Life
14.50 at 99.40 GTO Apr 70 Motorcade
14.10 at 103.20 TA Jun 70 Car & Driver
13.90 at 102.00 TA Feb 70 Hot Rod (Chestnut says this was a RA4 car in his top 50 ebook)
14.77 at 94.40 GTO Apr 70 Road & Track

Then a 1970 Auto trans
14.80 at 101.00 TA Mar 70 Road & Track (about eqial to 103mph in a 4speed car)

Finally a couple 1970 RA4 4speed
14.02 at 98.90 GTO Nov 69 Car Craft
14.50 at 99.00 TA Feb 70 Motor Trend
I’m noting those RA4 cars because
1. Since the RA4 Firebird was rated 345hp for 1969, but for 1970 the RA3 was rated 345hp and the RA4 at 370hp, it seems that might cause confusion as to which engine, RA3 or RA4, a 70 Firebird “345hp” had, let alone which cam.
2. It also seems the RA4 didn’t MPH any better than the RA3 at least per these road tests, making it impossible to tell what was under the hood, an 041-RA4, a 744-RA3, or an 068-RA3, just from the road test MPH.

I thought the list of Road Test might be fun (some are not even in Mike Noun’s list!) but mainly wanted to be sure the RA3 did in fact get downgraded for 1970 to the 068 cam across all transmissions.
Is that right?

[Formulajones]

All RAIII's for 1970 were 068 camshafts.

Those old road tests can be very misleading. If you noticed most of them are during winter months or much cooler months, and most of the time those magazines would find a track at sea level, with conditions sometimes giving DA below sea level. Like ATCO for instance. Couple that with the fact that they were also known to tinker with some of them.

[Ram Air IV Jack]

Originally Posted by Formulajones

All RAIII's for 1970 were 068 camshafts.

Those old road tests can be very misleading. If you noticed most of them are during winter months or much cooler months, and most of the time those magazines would find a track at sea level, with conditions sometimes giving DA below sea level. Like ATCO for instance. Couple that with the fact that they were also known to tinker with some of them.

Documentation showed Pontiac stopped placing the 744 cam in RAIII engines in 1969 because of starting issues in cold weather. Pete McCarthy reports the 744 cam was used through engine number 709185. The 744 cam was hotter and performed better than the 068 cam which was the TriPower cam from the 389. Then of course you had the 041 RAIV cam which was just wild.

[25stevem]

You need to consider this when looking at these differences.
1) v8 4bbl motors in the F body cars where always outputting less power then the A body cars because there Carbs where limited from opening all the way.

This due to a GM front office rule that governed / limited hp by the weight of the car.

2) the no mph gain from the RA3 to RA4, all RA4 motors came with 3.90 rear gears mandatory, with 4:33s optional.

I would have to dig out my info, but I believe the only RA3 motors in 69 that got the 744 Cam where the manual trans cars, and then even that was dropped for 1970.

[ursusarctos]

Wow thanks for all the quick replies, that answers that!
Indeed McCarthy pg 45 notes that even the 1969 RA3 dropped the 744 cam after engine 709185, so the 744 cam being gone for 1970 makes sense.
I guess the logic was that anybody going for an 041-cam RA4 better be well aware it would be a handful in the winter especially, so they kept the RA4 and its wilder cam, whereas the RA3 was becoming more of a daily driver.

I've had a hobby of "Gonkulating" (my own codes) engines, road tests, and NHRA for many years, so aware of many of the caveats, and how sometimes you can infer things, and sometimes not.
Ideally I like to collect DOZENS of road tests on a given engine, then just step back & try to make sense of them (which of course leaves many questions open).

[Formulajones]

Originally Posted by Ram Air IV Jack

Documentation showed Pontiac stopped placing the 744 cam in RAIII engines in 1969 because of starting issues in cold weather. Pete McCarthy reports the 744 cam was used through engine number 709185. The 744 cam was hotter and performed better than the 068 cam which was the TriPower cam from the 389. Then of course you had the 041 RAIV cam which was just wild.

Yep, I think you meant to quote the OP

[carbking]

Originally Posted by ursusarctos

Ideally I like to collect DOZENS of road tests on a given engine, then just step back & try to make sense of them (which of course leaves many questions open).

In the 1950's, 1960's, and early 1970's, I believed the magazine road tests.

As I grew older (and hopefully, wiser), I learned that most of the road tests were pretty much bogus; in fact, Road & Track did a huge article, including the cover "Chevrolet, can we build one for you?" in one issue.

Seems they caught Chevrolet shaving tires on their test vehicle for better traction, and fuel economy. Chevy was by no means the only cheater. Remember Pontiac's distributor advance (1971??) that changed with engine temperature?

Generally, the driving impressions will be good, and possibly the vehicle weight. Everything else was/is suspect!

Jon.

[dhcarguy]

What were the specs for the 041 cam , vs 744 cam

[jhein]

I wonder if they didn't downgrade to the 068 in the RA III in order to make more of a difference between the RA III and RA IV motors, hence justifying the upgrade, and the whole thing about cold starts was just an excuse.

[Formulajones]

Cold starts had more to do with the lean calibrations they used in the carbs. There were quite a few types of cars through that period guilty of that. A good tuner would have a lot of that straightened out without too much effort.

I was never a huge fan of the 744 lobe design. They are often referred to as a square lobe cam, similar to the old McKellar cams in the early 60's. Valvetrain control on that deal becomes questionable, needs a decent spring on it, then longevity comes in to question. Probably not ideal in a mass produced vehicle with a warranty. Likely more than one reason that cam went away.

Lots of duration with low valve lift is more along the lines of what you end up with in NHRA stock eliminator to abide by the stock lift rule.

[25stevem]

The RA4 cam was the first one that Pontiac engineering design with the aid of a computer, in fact I have heard that it was the first such cam done that way in the whole of GM.

Of the many differences it has over the 744 cam is another 11 degrees of overlap which took it up to 87 degrees of overlap .

This is not a pansy ass overlap amount for a production vehicle!

This is a full 24 degrees more overlap then the 068 cam , so this is a huge difference and is the main reason why 3.90 rear gears where mandatory with the RA4 motor and on top of that you could not order AC in a car with the RA4 motor option.

It’s quite a beast in a 400 cid motor with out 3.90 gears and Rhoads lifters and less then a true 10.5 compression.

A blueprinted RA4 motor with 11.5 comp or greater is still a impressive runner on the 1/4 mile even today .

[johnta1]

Cam Specs:

Stamp IDur. ICL 1.50:1 1.65:1 O.L. EDur. ECL 1.50:1 1.65:1 Part

S ---- 288 113 .407" .447" 63 302 119 .407" .447" 9779068

H ---- 301 113 .407" .447" 76 313 118 .407" .447" 9785744


T ---- 308 112 .470" .516" 87 320 115 .470" .516" 9794041

[PAUL K]

I built a 70 RA III engine for a 76 Formula I owned in the late 80's. It was a quality rebuild using a 744 cam with 1.65 rockers and headers. The car screamed! I was impressed with the 744 cam power wise and it sounded great.

Milt Schornak states in his book that the 744 cam was designed to help their cars pull through the quarter mile rather than lay down around the thousand foot mark. He was quite fond of the 744 grind and seemed confident it worked better than the RAIV cam in their 389 & 400 builds.

[Cliff R]

For sure compression is your friend in a 400 build with a cam having 87 degrees of overlap. I'm not certain but the 308/320 advertised duration and the 87 degrees overlap are measured close to the lash point and not at .004-.006" tappet lift. So it looks bigger on a cam card than many comparible "modern" offerings.

In any case it's difficult to outrun the RAIV cam in a 400 build with round port heads and optimum compression, and not surprising that the lighter FB's and the RAII/RAIV engine combos are top competitors in Pure Stock drag racing......

[Formulajones]

Originally Posted by Cliff R

For sure compression is your friend in a 400 build with a cam having 87 degrees of overlap. I'm not certain but the 308/320 advertised duration and the 87 degrees overlap are measured close to the lash point and not at .004-.006" tappet lift. So it looks bigger on a cam card than many comparible "modern" offerings.

In any case it's difficult to outrun the RAIV cam in a 400 build with round port heads and optimum compression, and not surprising that the lighter FB's and the RAII/RAIV engine combos are top competitors in Pure Stock drag racing......

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

[ursusarctos]

Originally Posted by dhcarguy

What were the specs for the 041 cam , vs 744 cam

Also at the more standard .050 lobe I have

200-210-111.3 066 cam
200-213-113.5 067 cam
212-225-116.0 068 cam
224-236-115.5 744 cam
231-240-113.5 041 cam

On the 067 cam, the only place I've seen that is on Ron's page so not as sure as on the others

http://ronspontiacpage.com/reference...ckcamspecs.htm

[Tom Vaught]

Originally Posted by PAUL K

I built a 70 RA III engine for a 76 Formula I owned in the late 80's. It was a quality rebuild using a 744 cam with 1.65 rockers and headers. The car screamed! I was impressed with the 744 cam power wise and it sounded great.

Milt Schornak states in his book that the 744 cam was designed to help their cars pull through the quarter mile rather than lay down around the thousand foot mark. He was quite fond of the 744 grind and seemed confident it worked better than the RAIV cam in their 389 & 400 builds.

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.

[Steve C.]

From the internet...

The No. 041 was often touted in vintage sales literature as the division's first "computer-designed" camshaft. Of that, McKellar says, "That's somewhat true-but not totally. We used a computer to generate the blueprints, and computer technology was hot at that time, so advertising decided to incorporate that. The No. 041 was a great performer, but I feel the No. 10 was a little better. Its solid lifters allowed for more low-end and midrange power than the hydraulic 041."

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."

Fast forward in time, it would be interesting to ask if he would use those lazy lobes today designing a hydraulic flat tappet cam. I doubt it, and suspect it would go beyond cutting friction


.

[ursusarctos]

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.

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?

[Tom Vaught]

I believe the Camshaft in the Wangers RED Car at the time of the March 1964 Car & Driver "389" GTO vs Ferrari article, was the "L" camshaft 9770543 (used in the 63/64 421 engine HO engine). This is based on comments by Tom Nell years ago.

1963-64 421 HO L 293 113 .407" .447" 63 301 119 .407" .447" 9770543

The camshaft from Lunati and the 455+ engine came after Mr Bill Sherman bought the red car from Wangers. The time frame for that would have been in 1997-1998 when Milt also had "Birdie" port a set of 64 Tri-Power cast iron GTO heads to where they were flowing in the 230 to 245 cfm Intake port range.

Those heads and the Lunati camshaft as well as the LARGE engine allowed Milt to run well into the 11 second range with the car.

Tom V.