Vintage Ford Intake Manifold CFM flow numbers

[shelbydoug]

Also, I think here we're getting to enthralled with the existence and possible effects of the "balance-tube", as we're not truly designing or redesigning an intake manifold from scratch; simply consider it as the established necessary concession for better carburetor function and fuel distribution not really having any great effect on flow-bench testing.   

    And considering the dynamics, this probably is one of those things that are better "tested" in actual function, rather than on a bench or on paper.   

    Scott.   

I look at the balance tube as the device added to make the engine able to idle on just the primary carb. Nothing more really.

Considering it was initially conceived of as possibly being a street production item, the initial carbs were vacuum secondaries with progressive linkage between the two carbs so the thinking on the balance tube had to have included a part throttle equalization as well. It truely is a hybrid and all considered, works pretty well and in addition has the flexibility to ditch the vacuum secondaries and go with mechanical 1:1 throttles.

That just may be an unintended benefit but who cares if it was an accident? Take credit for it since if it didn't work someone would for sure have been blamed for being an idiot?

I'm very happy to be a temporary caretaker. I hope the next owners will appreciate it as well?

I know someone who has his sitting on his dresser in the bed room. He looks at it everyday. He doesn't want to get it dirty? I suppose that's another way to go with it? It is pretty and after all, when installed is buried under all of those carbs.

[JohnSlack]

Since Most folks don't know what we are talking about;


C6OA-A Shelby 2x4 Intake manifold with two 9776 450 CFM carburetors, This is a T/A Intake for the 289/302. Bud Moore could not get this intake for the Cougars, FoMoCo wanted Ford to win.


The no part number 1969 BOSS 302 Std. Flange Holley Dual plane 2x4 intake manifold. They tested this intake and according to reports the driver's liked it better than the Dual Dominator intake the team cars got for 1969. Although this intake was rumored to be available to FoMoCo privateer teams it was not. The developement of this intake was stopped when the Dominator Intake got the nod. Notice that the carburetors were moved forward to center the carburetors over the engine equalizing the ports. This intake manifold is flat and the same height as the dominator intake so that if forced by the sanctioning body FoMoCo did have a realistic bullet in their pocket. Also notice the 465 CFM Center Squirter SK carburetors that have their own progressive linkage, Drivabilty was enhanced for the track (Much better than 1:1 for that application). Those carburetors were built by Harold Droste at Holley for either the small block GT40 program or the Tunnelport 302 program. Randy looked them up in his carburetor log book, however he could not identify which they were made for.


An overview of both intakes with the C6OA-A intake in front.


An overview of both intakes with the BOSS 302 intake in front.
When I leave this world I'm taking that intake with me. LOL


John


 

[shelbydoug]

I've got the C60A. The B2 is even better.
 
Do you actually put those on the cars or just sleep with them?


I think that I understand why pictures were always being taken with hot sexy models. The girls were just trying to get someones attention away from things like this and notice them?  I wonder if that worked for any of them at all?


You and Randy thought that there were only 10 of them made?


Did you ever try different boosters on those carbs. The BC-BD's have down legs. I think that helps make them more responsive?

I just put annular's in the fronts of the 1850's and down legs in the back. I haven't tried them yet because the ice and snow are here and today it's a brisk 18° but at least we aren't on fire. Not yet anyway.

[pbf777]

Also notice the 465 CFM Center Squirter SK carburetors that have their own progressive linkage, Drivabilty was enhanced for the track (Much better than 1:1 for that application). 

    Just to clarify:  Whereas other 8V installations common to F.M.C. production were of an intention of the carburetors being "progressive" or of "staged" throttle linkage motion relationship to one another, here I believe the two carburetors 'were' throttle linked as 1:1, meaning the primary throttle butterflies in both carburetors presented equivalent manipulation, just that the mechanical (vs. vacuum) secondary opening in each was of a progressive nature.   

    And, this is as was intended and typical of the "Center-Squirters" linkage set-ups; though in some instances one will find that the linkage plate's profile slot that regulates against the roller for the secondary opening effect gets "profiled" some which can create other unique instances. But also, as was offered through the aftermarket, there were "kits" available to convert the as delivered from Holley progressive secondary opening to a 1:1 process; this being most popular with the 8V tunnel-ram equipped "Drag-Guys". 

    Scott.

   

     

[JohnSlack]

Also notice the 465 CFM Center Squirter SK carburetors that have their own progressive linkage, Drivabilty was enhanced for the track (Much better than 1:1 for that application). 

    Just to clarify:  Whereas other 8V installations common to F.M.C. production were of an intention of the carburetors being "progressive" or of "staged" throttle linkage manipulation in relation to one another, here I believe the two carburetors 'were' throttle linked as 1:1, just that the secondary opening in each was of a progressive nature. 

    And, this is as was intended and typical of the "Center-Squirters" linkage set-ups; but, as was offered through the aftermarket, there were "kits" available to convert the as delivered from Holley progressive secondary opening to also a 1:1 process. 

    Scott.

   

     

Scott,
You are correct these two carburetors were connected so as movement on the front throttle shaft was mirrored 1:1 on the rear throttle shaft, the progressive behavior of the carburetor was through the shape of the slot in the linkage. The secondary shaft has a roller that rides in the slot and provides a very positive action both in opening and closing. During Randy's lifetime he amassed quite a collection of the Harold Droste SK carburetors. When these became available to me I inquired with my friend Bob Harris about them. Bob told me that I should take possession of the carburetors before asking Randy about them.

Randy was very happy for me to have acquired them and was very supportive to me. He provided a lot of details, while asking me to keep low key about them. There are certain details that most don't know about. Believe it or not Randy found most of his Droste carburetors at the Pomona or Long Beach swap meets. Some were just housings that most people didn't know what they were. So I have not shared anything while he was alive.


John

[JohnSlack]

I've got the C60A. The B2 is even better.
 
Do you actually put those on the cars or just sleep with them?


I think that I understand why pictures were always being taken with hot sexy models. The girls were just trying to get someones attention away from things like this and notice them?  I wonder if that worked for any of them at all?


You and Randy thought that there were only 10 of them made?


Did you ever try different boosters on those carbs. The BC-BD's have down legs. I think that helps make them more responsive?

I just put annular's in the fronts of the 1850's and down legs in the back. I haven't tried them yet because the ice and snow are here and today it's a brisk 18° but at least we aren't on fire. Not yet anyway.

Doug,
The C6OA-A intake is not mine, I'm setting it up for a friend for his '66 GT350. Believe me it will be driven and it will be run at full song. Yes using all of the tricks at my fingertips I have port matched that intake to a set of the AFR 205 CC heads, blasphemy? Not really I modified a perfect untouched intake in an area where Dan Case suggested that the Shelby intakes were worked on.

The BOSS 302 intake manifold is going on my 1969 1/2 BOSS 302. for years I kept a fairly complete collection of NOS intake manifolds and carburetors based on being flexible with a focus on the T/A intake manifold combinations. In this regard I recently let go of my Mini-Plenum (traded not sold) as I am settling into my final decision for both cars. They also will be driven.


John

[shelbydoug]

What does the B2 look like without the carbs mounted?

[JohnSlack]

What does the B2 look like without the carbs mounted?

See if this link works;

https://www.boss302.com/smf/index.php?action=dlattach;attach=1208032;image

Follow this link you can see what Randy was discussing about the extreme rear overhang on the SHELBY lettered intake manifold.

https://www.boss302.com/smf/index.php?msg=605843

[shelbydoug]

The UNICORN is aptly named.

I never looked for two balances tubes. It is more obvious on this one.

The pattern makers sure were kept busy. They are all different.

If the Dual Dominator flows 1/2 of the carbs rating, why does it make more power then the Unicorn?


One of the last conversations that I had with Randy was about the DD. He was asking me if I ever could do anything to fix the reversion on the Webers. He had just been working on the car, your car I presume, and talked about a plate installed over the carbs that was intended to accumulate the fuel reversion droplets and drain them to a "safe area".

He knew about the "Weber cam" that Compcams has but said that was not an option for the "race car".


I find it interesting that we all have similar experiences that we have dealt with individually at significant mileage differences. Compodres, brothers from different mothers?

[JohnSlack]

The UNICORN is aptly named.

I never looked for two balances tubes. It is more obvious on this one.

The pattern makers sure were kept busy. They are all different.

If the Dual Dominator flows 1/2 of the carbs rating, why does it make more power then the Unicorn?

Not Sure it does, Randy said more maximum horsepower with the Dual Dominator IF you could keep it in tune.

One of the last conversations that I had with Randy was about the DD. He was asking me if I ever could do anything to fix the reversion on the Webers. He had just been working on the car, your car I presume, and talked about a plate installed over the carbs that was intended to accumulate the fuel reversion droplets and drain them to a "safe area".

Nope, Not my car, Randy knew i liked to be taught to fish, not to be fed already caught fish. So he would drop hints and monitor my frustration with the results. The car was the old Gurney Team Shelby Trans Am car, and the Warren Tope T/A car.

He knew about the "Weber cam" that Compcams has but said that was not an option for the "race car".


I find it interesting that we all have similar experiences that we have dealt with individually at significant mileage differences. Compodres, brothers from different mothers?