Good morning , I'm in the process of getting engine parts cleaned up and magnafluxed for a 54 f100 project. I recently traded for a 1957 312 with G heads B intake and Ramhorns. The 312 is stuck and looks as if it has set for years. Just removed the Ramhorns, intake and one head . My questions is, is it nesscesary to magnaflux the intake, are they prone to cracking? All the bolts came out easy enough and threads look good, just has at least three layers of old paint. Thanks.

John

Jmphillips.  I haven't run into cracks in y-block cast iron intake manifolds even on salvage yard pieces.  Water can rest in the thermostat housing area, but I haven't seen cracks there.

In cleaning the intake manifold, after sand blasting or glass beading, you can visually inspect for cracks.  Corrosion of the gasket surface area for sealing the thermostat housing water neck would be the thing I would focus on looking at.  Also, check to determine the condition of the choke heat tube that runs across the exhaust port below the carburetor.  The heat tubes are steel and are prone to rust through.  When the tube leaks, you get exhaust carbon into the carburetor choke bimetallic cap cover.  Replacement heat tubes are available.  Some suppliers may offer them in stainless steel as an aftermarket improvement.

Hope this helps.  


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Thanks for the info. I was aware of the possibility of pitting on the thermostat housing, but didn't realize the choke tube would rot. How do you go about blocking the tube if running a manual choke?

With a manual choke you can block the heat riser on both sides with a very thin piece of stainless steel or similar metal that will not burn through.  I like to use the very old thin putty knife blades that are flexible, and worn out.  Cut the metal to match the gasket hole, and if you really want to get fancy, take the metal ring out of the gasket that seals around the heat riser hole, and place the piece of shim material where the metal ring was and use a sealer to hold it in place.  Joe-JDC

JDC

Hmmm...  I've never blocked the two ends of the intake manifold choke heat tube myself, but I've seen self tapping pan head or hexagon head sheet metal or machine screws used to accomplish it.  Perhaps a blind rivet could be used for a neater appearance.  -I'm thinking of the ones that use a drive pin to stake them rather than the nail associated with a 'pop' rivet gun.

I vaguely recall seeing a later truck application 292 four barrel intake that did not have the heat tube opening holes through it.  The later y-blocks had the choke heat tube coming from the top of the passenger side exhaust manifold instead of through the bottom of the intake manifold.  I don't know what year Ford began doing that on the passenger cars and trucks.  Someone on here will...

As an alternative to a manual choke, you might consider using an electric choke unit.

Changing out the intake manifold heat tube isn't a bad job, but IMO it can't be done with the intake on the engine.  Someone who has been a Ford flat rate mechanic may know a way to do it though.  


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

The exposed heat tube holes on each side of the intake manifold can be tapped with a 5/16-18 tap and the appropriate bolts or set screws can be threaded into the holes to prevent exhaust leakage at those points.  This will allow the heat to still crossover within the intake manifold if so desired without leakage from the 'rusted thru' choke tube holes.  As has already been suggested, both of the heat riser ports can be blocked at the head/intake junctions if wanting to block the heat from crossing through the intake.  If trying to retain the original heated auto choke setup, then replacing the heat tube itself would be an option. 

Lorena, Texas (South of Waco)

If I'm looking at this right, my intake just has one hole on the passenger side exhaust runner. Is this correct . The casting date is 73 W if that helps. I'm not finding a matching hole on the drivers side.

Look closely at the mushroom shaped air intake push-in cap in the attached eBay listing pictures.  Specifically look at pictures #3, 7, 8, and 9.  The hot air choke tube exits the two sides of the intake manifold on the ones I've collected.

http://www.ebay.com/itm/1957-Ford-Y-Block-292-312-4-Barrel-4V-Intake-Manifold-ECZ-9425-B-/182259840447?hash=item2a6f8875bf:g:rkgAAOSwGtRXw3Re&vxp=mtr

Hope this helps.  


NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York

Found it. Thanks guys.

Any advice or a link on where I can buy the kit to replace the heat tube that inside the intake?All the kits I’m finding appear to be to for replacing the exterior choke tube.