Ram air 111 cam
 

I`m just about to pull the trigger and order a RA111 cam and wondered if low end torque is there like the 068.

421 cube 9.6 compression
3.36 rear
Wide ratio Muncie

I don`t want to end up with no low end like the RAIV cam. 3.36 rear gears are as low as I want to go.

This was educational reading for me: http://www.bafb.org/1968firebird.org...harticles5.htm

I think with your combo, you'll barely notice the slight loss of low end torque. I assume you are talking about the 744 cam.

Several years ago I built a 1969 YS 400 to put in my '72 LeMans (actually bought the motor before I had a car to put it in). I started out with the Melling SPC-3 (744) in a bone stock, standard bore, ringed and bearinged shortblock. Heads were #62's with some bowl work and 3 angle valve job (back cut valves too).

I lost a lobe/broke a rocker stud on the way to the drag strip for the first time so had to abort the mission. When I replaced the cam, I decided to try the SPC-7 (068). The vacuum was better but the idle was too smooth for my liking,LOL. I eventually went back to a 744 cam for the "meaner" idle and higher RPM power band which ultimately took it's toll on the stock rods :(

With the 744, TH-350, and 3.23 gears, the car ran a best 1/4 mile of 13.44.
I never got to run a full 1/4 mile with the 068, but 1/8 mile times between the two cams were pretty close with the 068 being very slightly better in 60 foot times and 1/8 mile.

I think you'll like the 744 better.

Ron.

Also,
don't be alarmed by the "squared off" noses on the lobes of the cam. Apparently, that is how the 744 is ground, I assume it's the only way they could get all that duration while keeping the lift low.

Most folks using the #744 cam don´t realize this cam MUST have valvesprings with 125 lbs at installed heigth due to the square lobes.
With std valve springs the #744 is dead above 4500 rpms.

Also, the #744 is the Ram-Air cam and the #068 is the H.O. cam (used in late 1969 and all 1970 Ram-Air III Engines).

The 744 cam (Melling SPC-3) has TERRIBLE valve train dynamics. This is indeed due to the "square lobes" which are in reality just the nose of the cam lobe being concentric with the centerline of the camshaft in order to increase duration without increasing lift. You are much better off with a cam with a "modern" profile such as a Summit 2802 (224 deg duration at 0.050 on intake) that has good valve train dynamics. There are many others. The extra lift is not a problem so long as you know about it and set of the springs accordingly.

Craig I guess you have me confused. Summit advertises the specs for the 2802 as a power range range of 2200 to 5500. I have 3.36 gears and WANT OFF IDLE AND UP POWER. The description calls out for much lower gears as well. They also want a high stall converter which is nothing I have. I have a Muncie wide ratio 4 speed, what the 744 was designed for. Maybe you misread my thread starter????

I have a RAIII cam in a low compression '63 2bbl engine (now tripower) and I don't think I can feel any difference in low end torque from the cam that came in the engine. It has a nice little lope to it. From looking at the specs it looks to me like the 2802 is very close to a RAIII but with a little additional lift. If it were me and I already had the RAIII I would use it; if not I would get the 2802. JMO.

My car is a 4 speed with 3:23 rear end gearing.

No, I did not misread your thread starter. With the 421's 4IN stroke, you have too much torque for 3.36:1 gears when using a stock cam like a 068 and wide-ratio 4-speed. A 744/2802 will allow a harder launch and still be pulling at 5500. But, as I posted above the 2802 has vastly better valve train dynamics than the 744. Also, the 744 was used in the 400CID (3.75IN stroke), not the 421/428.

You don't believe everything you read on the internet do you? Particularly a generic recommendation by Summit compared to "expert" Pontiac-specific advice you will usually find on PY.

What is best cam for a stock compression, 69 RAIII 400, M20 wide ratio Muncie 4 speed,3.55 geared 69 GTO?
Also assuming ,this engine will run 94 octane pump gas.

Feedback appreciated.

Well Craig if Summit is totally wrong with their description and yours is correct regarding the 2802, it doesn`t make me real comfortable. Ok, how is the idle? A little choppy or smooth? I would also like to add that the 421 is in a 2200 lb Tempest which you didn`t know and not in a 5500lb wagon. Not trying to argue anything here, its just that you didnt know the weight of the car or size tire to say "too much torque." Hell I may have a 6800lb Pontiac Bonney hearse. My 1966 Master Parts Catalog shows the 1966 GTO XS engine used the 744 and of course in later years like you mention.

Thanks 61-62. That was closer to the answer I kinda needed.

The #744 specs were used in the 455S.D. also.
I wouldn´t worry using the #744 in a 421/428.
Just use the correct valve springs and you´ll be fine.
I´ve had the #744 in my 455 (.030) since 1997 with no problems after replacing the std valve springs with valvesprings from a set of #48 heads.
With the std valve springs the engine died at 4500 rpm´s, with the correct 125 lbs valve springs from the #48 heads the engine pulls strong until the TH400 shifts at 5400 rpm´s.
BTW, the late Pontiac engine engineer John Sawruk thought the best street performer was a 400 with the #744 camshaft, FWIW.

400 vs. 421
 

A 744 or similar cam in a 400 will have a much more noticeable lope than in a larger cube engine. The rev range given by Summit is more than likely for a 400. The range in a larger cube engine will be lower. They are just salesmen, not engine builders. And just an FYI, I would trust Craig....

While at H-O Racing in the 1970s I made thousands of Pontiac-specific cam recommendations and sold a like number to satisfied customers.

The fact that this is going into a 2200lb Tempest does make a big difference. What you essentially have is a 1963 Tempest 421SD. I've personally owned two 1963 Tempests, one with a 428 and one with a Ram Air III 400. Also, I personally know Jim Christensen who owned the ex-Mickey Thompson #749 A/FX Factory 421 Tempest drag car. I know from where I speak.

Given the additional information, the Summit 2802/744 is not enough cam for your combination. Pontiac used the McKellar #10 mechanical flat tappet cam (essentially a Ram Air IV) in all of their 1963 A/FX cars. Summit does not make a hydraulic flat tappet with enough duration for what you have. Therefore the 2802 will seem mild in your setup.

But, it's your car and your $. Do what you want. I have nothing further to say on the subject because I told you what I think and I don't sell cams anymore.

Thanks Craig. My typo was a HUGE error. I met 3200 lbs. Sorry. I must reread stuff for sure.
Great thing about 3.36 as I found out with a stock 66 SS396 Chevelle, is how the gear is flexible. A set of small dia or larger dia can put you exactly where you want if heading for the strip or a 300 mile interstate road trip. The Chevy had 3.31 but you get the idea.

A leading Pontiac performance builder and distributor of Pontiac performance parts suggested the 067.
McCarthy in his books liked the 041 and said ANY Pontiac could use this and mentioned street/strip as its use. (1.52 rockers)
Jim Hand I think has a 4000+ wagon and regardless of the torque put out by the 455, he runs 3.55 gears!!!
It looks like it will back to trial and error. The variables are just too great for anyone to predict the correct cam or even come close.

My thanks

OK, with the above correction, I have one more thing to say. A few years ago for my personal use I restored a 1979 T/A W72 (400CID, 8.2:1 CR, 6X-4 heads) with B-W Super T10 and 3.23:1 rear gear. Because I wanted a driver, I installed a Summit 2801 cam (like a Pontiac 068). In retrospect, it was not enough cam. One barely knew there was a cam in it. A few years later, I sold it on ePay.

This statement is completely wrong.

The Summit line of camshafts, as good as they are, are NOT the same/comparable as/to the Pontiac OEM grinds.
Summit cams got less LSA, more lift, less overlap and less time on the lobes.

And for the McKellar #10, they have even more squared lobes than the #744, with the RAII/IV duration at .405" lift and 1.5 rockers.

http://www.wallaceracing.com/camcode1.htm

http://www.pontiacpower.org/PontiacCams.htm

http://www.classicalpontiac.com/restoration/cams.html

"The 744 cam (Melling SPC-3) has TERRIBLE valve train dynamics. This is indeed due to the "square lobes" which are in reality just the nose of the cam lobe being concentric with the centerline of the camshaft in order to increase duration without increasing lift. You are much better off with a cam with a "modern" profile such as a Summit 2802 (224 deg duration at 0.050 on intake) that has good valve train dynamics."

+2 and very well said.

The 2802 is a very good choice for a 400 engine with relatively high compression on pump fuel. We have quite a few customers using that cam with great success, including nice street manners and running well at the track.

I use and prefer the Crower 60243 camshaft for manual trans applications with at least 3.55 gears and 400 engines. It works equally as well in 428's with a little less compression, and the 455's down around 9 to 1 compression.

As far as the Summit rating of the 2802 camshaft, they don't even mention what size engine, or the true static compression ratio of the engine. It would be a complete "turd" in a Pontiac 350 engine with anything less than 9 to 1 compression, and nearly perfect for a 400 engine at 10 to 1 compression, for example.

The static compression ratio plays a HUGE role in camshaft selection with any particular engine. For example, the 2800 is a great cam for a 400 engine down at 8 to 1. Idles great, strong off idle, smooth and lower rpm's, and pulls very hard in the mid-range.

For a 9 to 1 compression 400 move up to the 2801 and you will find the same nice qualities from your engine with stronger power in the upper mid-range and top end.

At 10 to 1 compression the 2802 becomes the better cam choice, as it idles nice, strong off idle and pulls even harder in the upper mid-range and top end.

Take the 2802 and put it in a 400 engine at 8 to 1 compression, it's "lazy", idles with low vacuum, "soggy" off idle and not really any useable power below about 2800rpm's. It will still pull really well in the higher rpms, as the static compression ratio becomes less of a player in power production as the events are happening much faster, and power production becomes more about moving air and VE than exactly how hard the engine is squeezing the incoming mixture.

We sort of found this out quite a few years ago with a 455 engine. A new employee at KRE was given the task of hand porting a set of 6X heads for a 455 engine. He spent many hours on them, and did a fantastic job. No one noticed that he had selected a set of 6H heads by mistake, and that the 455 engine was only going to end up being very low compression. They went ahead with the engine build anyhow, using the Crower RAIV clone 60919 camshaft. That cam fairs very well in a 455 up near 10 to 1 compression, but even there is idles pretty low vacuum and real power curve starts around 2800rpm's or so. It will easily make 1hp/cid with 230cfm or more airflow.

Dyno time came and the low compression 455 made nearly the same numbers as a higher compression 455 with the same basic parts. It did however idle very poorly due to the low static compression ratio. Keep in mind when reading this that the dyno pulls started past 3000rpm's, and a dyno has no way to tell us how well an engine will run in a vehicle for "normal" driving.

One also has to remember when it comes to this topic, is that we are trying to build an engine that uses pump gas. The camshaft becomes equally if not more important here than the static compression ratio. We need to choose a cam that will make good cylinder pressure at idle and lower rpm's for decent idle quality and smooth power in the "normal" driving range, but not so small that it pulls all the power down in the rpm range and detonates on pump fuel.

This is why a small cam like the 2800 is a perfect choice for a 400 engine at 8 to 1 compression, but will pound like sledgehammers in the same engine at 10 to 1 compression. It simply does too good a job of cylinder filling and peak torque too early in the rpm range. The engine will act about 1-2 points higher in compression than what it is, and rattle just about everyplace on low octane fuel.

Anyhow, as it relates to this topic, the 2802 cam would be a great choice for the 421 build with 9.6 to 1 compression, manual trans, and 3.36 gearing. In comparison, I built and installed a 428 engine into my Ventura in the early 1990's. It was topped with #96 heads and used the 744 camshaft. It was about the biggest "turd" of an engine that ever sat between the fenders. Idled poorly, "soggy" at low rpm's, and absolutely DONE pulling by 4500rpm's. To this day I don't know if I just didn't have it degree'd correctly, and/or not enough valve spring on it, etc. That engine didn't last long so I built another one, using 6X-4 heads and HC-01a camshaft. The new engine idled better, strong off idle, and would tear your head slam off the entire loaded rpm range. That engine stayed in place for over 10 years until I moved up to my first 455 engine.....Cliff

Cliff
Just to clarify, you have experience that a Summit 2802 cam is an excellent choice for a stock 10.5 static compression 69 RA III 400, M20 4 speed, 3.55 posi 69 GTO that will operate on 94 octane pump gas?

Cliff I was studying the camshaft/manufacturer list that I found on line and I noticed the Crower 60242 and 60243. I think I see why you like the 60243 and the fact that they fall in that 110-112 crank degree group. How would the 60243 be in this 421? I will throw in that the build is running untouched 716 heads(3 angle valve grind). Maybe too much static compression? I recall McCarthy rated these heads as the poorest exhausting, I wonder if the 421/716 will act more like an air compressor storing compressed air with the 60243 rather than a good breathing in and out pump. Then is it a better choice to use the 2802?

Those two cams are actually pretty close in how they behave in these engines. The wider LSA of the 2802 makes it not quite as "aggressive" at idle as the 60243 grind. Both do quite well in 400 engines with small chamber heads managing pump fuel. I've used them and quite a few of our customers use them. I hear horror stories all the time about folks encountering heavy detonation with Pontiac engines. In almost every single case it's from some poor soul who put a small cam with fast ramps and tight LSA into a 455 with 9 to 1 or higher compression.

The 2802 and 60243 seem to be about right for more "aggressive" 400 builds where folks aren't lowering the static compression ratio. Right on the dyno the 60243 cam made 424hp/465tq in a 400 build with unported small chamber heads. Those HP jumped to 450hp with KRE aluminum "D" ports.

One the same subject, we get LOADS of complaints from folks who went to the larger RAIV camshaft in similar 400 builds. Always the same thing, poor idle quality, "soggy" at low rpm's, and no real power below about 2800rpms......Cliff

What CR would you recommend for the 60243 in a .030" over 428 with ported #16's that flow 265/208? How much difference in power could you expect with the same engine with 60919 cam?

Sorry to hi-jack, just wondering. :)

Crane 283801.. Idle sounds like between an 068 and 744. makes more power than the 744.
The SPC 3 specs out like the 744 BUT is a round nose, conventional profile. It has only 2-3 deg. of dwell over the nose, whereas the orig. 744 (H) has 30-32 deg. of dwell. Maybe Craig can post a picture of the 2 cams , side by side. Craig is right about the dynamics. Almost every virgin RA3 engine H-O disassembled in the 70s had a few lobes ground off.

Ken , Please critique my Cam combos in the Signature; 11.00 & 12.00 ETs were 11:1 compr. 12.24 ET is 9.0:1. All idle well, yet how could I have chosen better? Thanks in advance. HIS

what about the lunati 60902 cam? anyone have expericence with this? im going to be building a 400 with #13 heads and am looking at cams in this topics range as well.

I had a Crane 283801 in my '79 T/A 3.23 4 speed, with RAlll manifold and number 62 heads and 70 cast pistons. (better gas back hen) It ran great and would keep up wit my buddies 69 'vette with a similar cam. I used it with Rhodes lifters. Crane said that it wouldn't work with the Rhodes, but I drove it for 4 years that way and had zero problems. It was the 2nd engine. I now have a 4th engine (don't ask) and it has an Elgin cam with the 2800 specs. I broke the 3.23 with the 462 3rd engine and it now has 3:42 gears. With the 2800 cam it is a kick to drive in town. Let off the clutch
stab it and feel your head snap. The compression is around 7.5 so you can just about pee in the tank if you had a few two many beers.

Summit has a 2802 cam and lifter kit at a good price. What about valve spring pressure on this set up? Would like to get everything at once along with keepers and retainers. Maybe somebody knows of a complete kit less timing chain/gears?

it's kind of a pain, but imo you'd be better off in the long run to piece this together with better parts. a summit cam, Johnson lifters, and crower springs would be my suggestion.

Ditto Matt. Too many junk Chinese lifters out there these days, which undoubtedly is what you get with the Summit cam.

Crower or Comp for springs. Been too long since I've set up stock heads so don't recall what the stock installed height is but both companies make springs that will install at stock height and support up to .480-.490" lift easily.

Butler said that Johnson was the only lifter company left and supplies all the lifters if US made. I had nothing but trouble with a Comp Cam "kit" once and a switch to Sealed Power lifters "fixed the bad comp cam lifters." Good idea to be wary of overseas lifters.
I`m considering the Crower 60243. The reason is the larger cube .040 over 421/432ci. Usually in a large cube long stroke engine the idle lope is softened as noted before.

i like to advance that 2802 4 degrees in my 400s

cam choice
 

Hello Craig my name is Brian I know you would be the best to pose this question to.Looking to cam up my 68Gto H.O. I think when the rebuild happened a few years back the owner put in a 066 or 067 cam.Looking for something I don't have to swap out the springs on,I have always used the 068 in most of my Pontiacs great cam-can you recommend something a tad more aggressive.MY combo is 68 400YZ 16 heads automatic trans 355 posi electronic ign. h/o exhaust manifolds. Thanks Craig for all your input over the years. 10.5 stock compression. Brian

I suspect that the Crane 283801 camshaft is the same as the Summit 2802 cam.

CMC grinds most of the cams available from the major suppliers. The end users typically "juggle" the specs slightly to make it look like their own grind.

I say this because I used to have a supplier of engine parts that visited CMC once. Did you ever notice that many camshafts purchased had different colored stripes on each end of them? He told me that the color coding was used to get them in the right boxes as they made their way thru the plant, and this helped the companies that purchased them identify them on their end without having to reference any numbers, etc.

Even if they don't in this particular case, those cams are so close that the end user wouldn't be able to notice any difference in them I the final product....IMHO.....Cliff

"The Summit line of camshafts, as good as they are, are NOT the same/comparable as/to the Pontiac OEM grinds.
Summit cams got less LSA, more lift, less overlap and less time on the lobes."

Same statement applies to a lot of the aftermarket flat cams currently being marketed for these engines.

Unless you buy into the BS that you can reduce seat timing by 20-30 degrees, pull the lobes together some (tighter LSA), drop the valve quickly then throw them off the seats quickly, and advance the intake centerline (earlier closing intake points), then make MORE power at every rpm advertising that we continue to here in this hobby.

If you move up to a roller camshaft some it is possible to enjoy some of these nice features, as the roller lobes can provide a bigger "window of opportunity" to move air thru the engine with less actual seat timing. So you can enjoy improved vacuum at idle, lower rpm's and still make great upper mid-range and top end power with a similar or smaller camshaft.

If you try to do the same thing with an aftermarket flat cam with "modern" lobe profiles and you pick it comparing .050" numbers, be prepared to be disappointed in the end result.....FWIW......Cliff

PS: here is a link to specs on Pontiac camshafts, something everyone should look at when comparing camshafts for these engines:

http://www.pontiacpower.org/PontiacCams.htm