[Scott M]

So, I recently acquired these #716 heads from Raymond's funny car and was curious as to why the intake ports were joined together. Raymond ran a Pontiac, for half a season in the early 70s when his 392 was out of commission.

Early Pontiac blower manifolds that I've owned, made by Cragar, Edelbrock and Mickey Thompson ALL had their runners cast without port dividers.

Why is this and why did the conventional wisdom of the day dictate that design?

[Scott M]

A few more.

[Region Warrior]

Oh, i dont know, more all flow...

[johnta1]

I think it was more for exhaust emissions.
Some other heads had that setup.
It was short lived, though. (thankfully?)

Hadn't seen any intakes like that though.

[taff2]

I've just done the same to a set of 96 heads for my turbo combo,along with an inlet manifold to match.(a lot of the other makes blower manifolds have siamese port openings). The idea is to relieve the restriction at the pushrod bulge and to also allow the ports to 'pull' from each other. It was done back in the day before aftermarket heads were available. Doesn't work well in a n/a application apparently. My divider walls were cut back only 1" (on TomV's advice), and the leading edges were radiused not knife edged as in your pics.

[baron_]

interesting

[Tom Vaught]

TAFF2 has it right.

Blower cars were assumed in the old days to have very little tuning of the runners therefore if the "pushrods get into the way of flow" make one big volume for the individual valve/ cylinder to draw from.

The Blower cars were all Roots Supercharger deals in the early Beswick/ Thompson Pontiac days.

According to Keith Wilson (Wilson manifolds and I agree) you want the runner divider to have a "rain drop" contour vs a Knife edge. Gaby can reply on this deal too. Looks like someone went back and put a flat edge on the one divider. The work actually looks pretty well done.

Tom Vaught

ps Marty and I looked into that deal but later rejected it for better intake manifold designs once we decided to go turbos.

[Tom Vaught]

Originally Posted by johnta1

I think it was more for exhaust emissions.

I think you been sniffing too much "Emissions" out of your Bong, John, if you truly believe that deal. (:>)

Tom Vaught

[johnta1]

Guess, I should have looked at the pics closer.


I read the post and thought it said 7f6 head.
Like this one:

[Tom Vaught]

I figured as much, I knew exactly what you were referring to, by the way, LOL!

Tom Vaught

[bad69bird]

Originally Posted by Tom Vaught

Gaby can reply on this deal too.

Tom,

Gaby might be delayed in his response. I believe he's at PRI.

[Tom Vaught]

I SHOULD HAVE BEEN at PRI but missed it AGAIN this year due to work requirements. (I want to keep my job!) I can go to PRI when I retire in a few years. George is shooting for the 7s, I am shooting for 35 years in Ford and 39 years of Boosting! (I have 3 more to go).

Tom Vaught

[Rusty4cyl]

Good Luck Tom, You won't know what to do with yourself after you retire. Thanks Rusty

[Steve Barcak]

"Why is this and why did the conventional wisdom of the day dictate that design?"

The answer should be simple Scott. It was for more air flow and I can see why a blown engine would benefit from this in theory.
On the negative side, it would be a bitch to tune the mixture properly cylinder to cylinder.
That was done back in the day before most had or used port nozzles. Imagine trying to tune each cylinder with the heads you bought? Not sure how it could be done properly other than using down nozzles and that would only unsing nitromethane.

Many do not comprehend the turbulance in a blown manifold and its open plenum. For some time, I ran my injector set up the way Enderle built it for me. I had problems with it from the start trying to get my exhaust temps where I wanted them. I ended up moving the port nozzles from the intake to the heads ( which put the nozzles beyond the divider for the ports ). The move was only about 3/4" but it made a world of difference. Further, I added a dribbler system to control idle mixtures even better. All of a sudden, I was able to tune the motor.
This set up would not work if you removed the divider wall.

I hope this answered your question.

Steve
Hosting-
Thur-Sun April 8-11, 2010 12th annual Pontiac Heaven Phoenix www.pontiacheaven.org
Sunday April 11, 2010 8th annual Nostalgic Show & Go! Phoenix www.nostalgicshowandgo.org

[Brian Baker]

Was the person you purchased these heads from Robert Flitsch (spelling)? I purchased some unrelated stuff off EBAY from him about 4-5 years ago (an old magazine I think) and asked him if he was the same R.F. that crewed on the car, he said he was. When I queried him for more info, I couldn't get much out of him. The info that is out there is that Walker ran this car with the Pontiac in it for more than half a season, with the last season(s) he ran it being around 1975-76. Bill Pratt has some info up on Draglist.

[Scott M]

No. And information is sort of hard to come by; it seems as though nobody is around to share any information, since Raymond seemed to have difficulty getting anybody to help him on his car. See, Raymond was a white man married to an African American woman. This situation didn't seem to sit too well with folks in the South at the time.

[Brian Baker]

Originally Posted by Scott M

No. And information is sort of hard to come by; it seems as though nobody is around to share any information, since Raymond seemed to have difficulty getting anybody to help him on his car. See, Raymond was a white man married to an African American woman. This situation didn't seem to sit too well with folks in the South at the time.

I didn't know that about him. Being stationed in the military in the Fort Knox, TN area in the 70's, I can see what you mean.

[Scott M]

Originally Posted by Steve Barcak

The answer should be simple Scott. It was for more air flow and I can see why a blown engine would benefit from this in theory.

Well, on the surface, yes.

Although, I would not think that the thickness of the divider between the ports would play too significant a role.

When I bought Mike Cooper's BDS intake, after he went to a Hogan's, port dividers had been installed in the runners, where BSD supplies the manifold with none, even now. This manifold now sits on The Crusader funny car.

Perhaps BDS just feels that the buyer of a blower intake for a Pontiac just isn't going to care?

[Brian Baker]

Originally Posted by Scott M

Well, on the surface, yes.

Although, I would not think that the thickness of the divider between the ports would play too significant a role.

When I bought Mike Cooper's BDS intake, after he went to a Hogan's, port dividers had been installed in the runners, where BSD supplies the manifold with none, even now. This manifold now sits on The Crusader funny car.

Perhaps BDS just feels that the buyer of a blower intake for a Pontiac just isn't going to care?

2nd and 3rd pics are mine. 2nd pic was to demonstrate the difference in port size between this intake and an unported E-head. Whomever added the port dividers on this intake did a sloppy and incomplete job at welding them. I had them redone at Woolford's (Bruce is like a Michael Angelo when it comes to welding aluminum). Intake was also modified for a SFI burst panel up front in place of the water crossover (which I can't believe Mike ever ran without one, having only using the little spring loaded BDS burst plate at the rear of the manifold). I'll be using 8 jets in the manifold to better tune each cylinder, and 8 jets in the Crower hat just to keep the blower happy.

[Scott M]

Mike Cooper said the manifold modifications were made by Jim Butler Performance.