Welding intake manifold (Holley Street Dominator)?

[ChargerST]

What precautions do I have to take if I want to weld on an aluminum intake manifold?
I'd like to fill the spread bore pattern on a Holley Street Dominator (make it a square bore).
Is it sufficient to bolt on a steel plate to the carb pad (basically a thick gasket shaped plate) to avoid warping the manifold? Or will it still warp?
Otherwise I would need to fabricate a jig that ties together the carb pad and the head mounting flanges..

 

[496 polara]

Edelbrock 2732 Edelbrock Carburetor Adapters | Summit Racing


Sounds like a lot of work when this will work fine. Yes I have used them on multiple applications.

 

[451Mopar]

Fixturing is a good idea, but I think your still going to have to have the welded up carb base machined flat.
I would grind prep the surface to weld, then clean with acetone, pre-heat to draw out impurities and then re-clean before welding.
Found this, pretty good example:

 

[stage3]

when i modified my crossram max wedge intake i bolted it to the milling machine fixture so as much less chance of heat distortion that the TIG welder would generate. and it got Darned hot...

 

[Geoff 2]

Why would you risk ruining a good intake?? What would be achieved that makes a difference?

 

[ChargerST]

Another option would be to use epoxy to fill the cavities. Or shape an aluminum piece and glue/epoxy it to the manifold. Is this maybe a better option?

 

[hunt2elk]

I had the exact same concern on my Street Dominator intake. Ended up using the Edelbrock adapter plate mentioned above and it works fine.

 

[qkcuda]

I ran an out of the box Street Dominator with a 750 Holley DP with just a gasket and no spacer plate and it worked fine.

 

[33 IMP]

If it were me, depending on how much hood clearance I had, I'd probably run a phenolic four hole spacer, under a square bore carb on that manifold.
Tight hood clearance? Just run the Eddie gasket above.

 

[1967coronet]

The plate that 496polara showed will work fine.
The last edelbrock preformer I bought came with one in the box.
It is only aprox 3/16 thick so it does not create a hood clearance problem.

 

[j-c-c-62]

What precautions do I have to take if I want to weld on an aluminum intake manifold?
I'd like to fill the spread bore pattern on a Holley Street Dominator (make it a square bore).
Is it sufficient to bolt on a steel plate to the carb pad (basically a thick gasket shaped plate) to avoid warping the manifold? Or will it still warp?
Otherwise I would need to fabricate a jig that ties together the carb pad and the head mounting flanges..

Fixturing alum to steel has its own possible induced stress issues because of differing expansion rates of the metals and of course temperature differences.
Fixturing it is not a cure all. Actually, in some cases it makes things worse. For example, if you have a huge steel jig infinitely stiff, when you add alum filler metal fully expanded at over a thousand degrees when item is locked in your relatively cold jig, when the alum cools, the item will shrink or will want to when removed/released from jig. Best IMO to accept some clean-up machining if needed post welding before you start the welding solution/project.

 

[PRHeads]

I ran an out of the box Street Dominator with a 750 Holley DP with just a gasket and no spacer plate and it worked fine.

View attachment 1925180

Exactly.

Fundamentally, the BBM SD intake(and the similar M1) can be used with most square bore carbs with nothing more than a regular carb gasket.

 

[ChargerST]

Actually the reason for the intended mods is performance related not about gasket sealing.
I assume it reduces turbulence below the carb.
Hughes once offered the modification.

 

[33 IMP]

If you were building for EVERY LAST HP, for a class car, I could see it. For the maybe five horsepower the mod might make.... I don't see the ROI.
Like I said, I'd just try a four hole spacer to straighten out the airflow into the manifold.

 

[dvw]

Actually the reason for the intended mods is performance related not about gasket sealing.
I assume it reduces turbulence below the carb.
Hughes once offered the modification.

You asume, but unless you are an experienced intake cylinder head guy it's only a guess. Especially a street car. You'll never feel the difference if there was any.
Doug