Technical Headers or manifolds ( pontiac ) need a opinon

I looked at the price of headers recently for my Poncho ( 50 Chieftain v D port 455 ) , and since its going to be a cruiser/strip car , I was up in the air about weather to buy a set of the Ram air manifolds ( long branch ) or the standard ram airs , vs the ****** super comps headers I normally buy ( will not by headman or others) as the price is the same for header vs manifold ( I have the filter extensions for both styles of manifolds ) . the car will be a driver and part time track car . but I am up in the air what should I do , IMO the performance should be the same area ( knowing the manifolds are slower ) . I was thinking of the headers and how they rust ( not spending $$$ for coating) vs the manifolds and the look too . what would you do ??

 

I'd run the long-branch manifolds if they'll fit.

One of the best factory exhaust manifolds, next best thing to headers without the headaches.

 

I seem to recall a headers vs Ram Air manifolds dyno test in High Performance Pontiac, IIRC the headers buried the manifolds. I will see if I can find it tomorrow.

 

george these are the repos ( ram air repos 2.5 " outlet ) not the original style ( which are ames , year one 2.25 " )

like I said this isn't like my superstock car which headers made a difference . the motor has a 068 style roller cam in it . and if I remember right the test were about 20 Hp difference , if I want the extra 20 I can grab the big blue bottle

 

Somebody makes headers for a 50 Pontiac? I think your going to have steering box clearance issues with D-port RA manifolds.

 

I consider a 20hp bolt-on BIG, I work hard on windage and rings for that much. As long as you are aware, its all good.

 

I'm an old guy now and have outgrown that "20 more HP over manifolds" hype. I like quite, h***le free. no exhaust leak or burnt spark plug wires type of HP. Stock manifolds would be my suggestion, and if the steering box is close just work a little harder to make it fit unless it's impossible then you have no choice.

Pat

 

I realize the word "horsepower" upsets a lot of guys on here, I think it makes some guys nuts shrink up into their abdomen... But he DID ask...

 

I dont deal in the usual HAMB "hype", BS and old wifes tales, theres enough "old guys" on here spreading that "stuff". I deal in facts, here they are.


Test 5 is open 455 SD manifolds and an 800 QJ, test 10 is open headers and 800QJ. 26 ft lbs of peak torque, and 40 hp. What the op does with this info is up to him. Sorry, you asked for opinions, I dont deal with those on tech threads. What you do with the facts is up to you. FWIW, I'm 56...
Oh, and the timing...timing was adjusted for best power with each combo. In other words, the exhaust manifolds made best power with 38 total, the headers made best power with 34. The reason is simple, and this is also born out by the SUBSTANTIALLY lower BSFC numbers with the headers, there was more combustion residue left in the chamber after the exhaust valve closed with the exhaust manifolds. The manifolds required more timing to fire the more diluted charge that resulted from the increased exhaust restriction.

 

I wouldn't think any off the shelf long branch or header would fit your combination, particularly the drivers side. My advise is to borrow a set of long branches and a set of headers and see what fits or can be made to fit. Buy whatever fits in the hole, then spray a 150 shot on it just in case.

I would LOVE to see some pics of the car.

-Abone.

 

Those factory manifolds were good about burning out inside.
Now if you buy off sore new casting you could be taking a chance in being trouble free.

I do remember reading that there was a good help in torque going from three tube to four tube on the headers but man you better have patience and not have small kids around if you curse.

 

My guess is neither the long branch exhaust manifolds or off-t******lf headers will fit an early fifties pontiac. The steering box will be too close to the exhaust manifolds, I dont think you will even get them in there. I think you will have to build headers for it.
I had actually forgotten just how big the gap was on that 455 test. 40 hp is another friggen universe...And that motor had a cam that was pretty similar to a stock Ram Air IV cam, christ, can you imagine the difference with a serious cam with a narrow LSA??

 

To me it's all about intended use and projected HP numbers. Race or serious high performance, headers.
Cruiser, resto or any mild engine hot rod, manifolds.
A 300 hp engine won't scream for headers, but a 450-500+ hp one will.

Budget, availability and room to work are bigger factors.

 

If it's a wash with the "manifolds/header" debate......=$, And- if the will fit your app, Come's down to "stock looking", or, I'm getting 20 more+ HP. 20 is a big deal for a bolt on....... And the same cost. Hopefully the bolt on's are cheap and easy HP. The faster you want to go, the $ goes up, and the HP(bolt on's) decreases........
ET's and HP cost's some coin.......= What'cha shooting for / How fast you wanna go?
And- Strip car also? I wouldn't think you'de want to have a sub time for your efforts..........
Step up to tubes........

 

Very interesting info Falcongeorge. Says a bunch about headers vs manifolds in this application.
So Stimpy, does your Pontiac have the stock steering box and suspension? Like Pontman, I'd be surprised if there is a header or manifold available that fits that combination but stranger things have happened. I always lean towards a tube header but then I live in sunny, saltless California.

 

I was honestly a bit surprised when I went back and looked at it, I remembered it as being about 20-25hp like the op said, clearly, I was remembering the torque number. 40hp is huge...
The popular mythology grossly over-rates most of these factory high-perf manifolds, Jay Brown did quite a bit of testing on this subject in his book on FE's and found similar sorts of gains, but not quite the 40 hp, thats a ****load on an engine that only making around 400hp. Personally, I couldn't leave that on the table, but then I dont run AC or 500 edelbrock carbs in my cars either...

 

Ditto. A good friend of mine has a '50 with a roller cam (GASP) 383 in it, its a pretty nice car.

 

changed out to 455 V-8 , late model x-f subframe , if I had a straight eight , I would attempt to make them

 

ahem George clean your gl***es , I have a D port ( 4x- head) 455 , not the round port ( #16 SD), it uses a H.O. Base block .. and a RAII style roller cam ( ra4 spec but 1.5 rocker) , would never put a SD in this car it would tear it up unless I jungle gym it ( not that I wouldn't like a SD) , and the SD was supposed to use the RA4 cam (041) but instead went with a RA3 design ("H" 744)because of emissions ( bad enough they got nailed by the Air police for the egr delay in 74) ( we have put the RA 4 CAm in a SD with the 1.6's and its a beast )


, this is more of a daily summer type car and I know already from using the manifolds ( in a O/T F body) it will work against some OEm street cars ( ones that are not heavily modded )

as for looks Abone , it looks like a plain partially rusted 2 door cheiftain sedan painted with gray house paint ( Po did it ) I have yet to start the bodywork as I am doing other things right now ( gathering parts and some design work ).

 

Thanks Stimpy, that clarifies things a bit. Sounds like a great car. Definitely one of my fantasy builds. You just might find a decent header for that combination if you decide to go that way.

 

I noticed that right from the get-go, I doubt it will make much, if ANY difference, unless the d-port exhaust manifolds are a bunch better than the SD's. The difference on the flow bench between the exhaust side of those two heads at low lift is minimal to non-existant, and thats where the majority of exhaust scavenging occurs, blowdown and overlap. Until about .300 valve lift a #48 D-port and a #722 ram air IV head flow virtually identical numbers, thats well past the lift you will see on overlap, blowdown occurs as soon as the valve comes off the seat.

 

Then F-body headers should fit, as long as they clear the firewall.

 

Here's what I did to clear steering box, starter etc. I bought a cheap pair of chevy block hugger headers and cut the chevy mount flanges off and welded a pair of Pontiac flanges on. Had to "m***age" a few tubes to fit but it wasn't too hard. I realize block huggers aren't as efficient as full length ch***is headers but you don't have a lotta choices in a 50 Pontiac ch***is. Jus' sayin.

 

Rocky see post #18, it has an F-body front clip...

 

OOps! no. I didn't see that part. Some firebird ch***is headers will work ok then. Make sure they're 4 tube headers and not the cheezy 3 tube jobs...tests show they're not much or any better than manifolds.

 

I didnt realize that either, kinda changes things on a exhaust post!!

 

they are quite popular up here with the cheap bunch , have bought a few cars with them , log manifolds perform better ...

 

dats A problem , motor scooted back to the st8 indent and indent not wide enough ( since floor not done and have to do trans cover thinking on slicing and dicing the indent and make it look like a statue niche by widening it .) but as is the #6 tube will hit the wall ( looked into A body and F bodys ) and I do not want the trans sticking 3" inot the engine bay ( bad enough if you tried to use the stock sub mounting spots the motor is 6" forward the firewall hense my question about hursts )

 

well ok, THATS not gonna work then...If it were me, I would probably make some fenderwell headers. hedman fenderwell race headers for an S-10 MAY fit if you put a pontiac flange on them, but they are big$$. I would make them.

 

If only one or two tubes hit with a set of out of the box headers, you can probably just move those tubes a little. Maybe route that tube over the frame rail and back with a slip joint like a Buick header?