What's the best way to prep a used intake manifold?

[OldMercs]

I got a 4 barrel manifold out of a barn full of "stuff" a couple weeks ago. No broken bolts, screwed up threads, cracks or other problems that I can see. Now I want to clean it up, paint it and use it, The first step is probably clean the inside, What's the best way to do that?

[alt63bird]

Aluminum or cast iron?

[OldMercs]

Originally Posted by alt63bird

Aluminum or cast iron?

Cast iron

[paul2748]

If it is rusty, media blasting is one method. Another is chemical bath. With media blasting, make sure the inside is thoroughly cleaned of media.


Electrolysis is another method which can remove rust and other crud.

[miker98038]

I’d see if if the local machine shop could hot tank it first. Then I’d go thru that water passages in front with brushes if there’s any rust left. The last thing I’d check is the exhaust crossover if it was set up for the heated choke. The tubes inside tend to rust out. They can be replaced, or capped off, if using an electrical or manual choke. Might even do that before I tanked it. Check the port surfaces with a straight edge, but I’ve not had a problem there with iron manifolds.

[Ford Freak]

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Originally Posted by miker98038

i’d see if if the local machine shop could hot tank it first. Then i’d go thru that water passages in front with brushes if there’s any rust left. The last thing i’d check is the exhaust crossover if it was set up for the heated choke. The tubes inside tend to rust out. They can be replaced, or capped off, if using an electrical or manual choke. Might even do that before i tanked it. Check the port surfaces with a straight edge, but i’ve not had a problem there with iron manifolds.

x 2 !!

[craig]

I agree with all the above suggestions. However, many years ago I picked up a nice looking factory Ford medium riser dual quad manifold. Spent hours cleaning and polishing it. When I went drop it into place on the engine I discovered that the sides and lower sealing edges had been machined down roughly .040" each. There was no way the gaskets could seal this thing to the heads. Since this engine was more show than go, I stacked 3 gaskets on each side and lots of silicone on the ends. It worked, no coolant or vacuum leaks, but definitely not the way to go.

So, there are two morals to this story. First, buyer beware and second, I always check the fit of any intake manifold new or used before I spend anytime cleaning and painting.

[55blacktie]

Originally Posted by craig

I agree with all the above suggestions. However, many years ago I picked up a nice looking factory Ford medium riser dual quad manifold. Spent hours cleaning and polishing it. When I went drop it into place on the engine I discovered that the sides and lower sealing edges had been machined down roughly .040" each. There was no way the gaskets could seal this thing to the heads. Since this engine was more show than go, I stacked 3 gaskets on each side and lots of silicone on the ends. It worked, no coolant or vacuum leaks, but definitely not the way to go.

So, there are two morals to this story. First, buyer beware and second, I always check the fit of any intake manifold new or used before I spend anytime cleaning and painting.

Good point! Something that's mostly overlooked (Guilty as Charged). Considering the age of OEM parts, and how many times they might have changed hands, you never know. Cutting the intake sides of the heads when surfacing the decks of the head & block, instead of the manifold, will allow using the manifold on other engines that have not had excessive surfacing of the block & heads. On a Ford/Mercury Y-block, you have .030-.050 thousands to work with (if using composite head gaskets), before intake manifold alignment becomes a problem.

[dmsfrr]

Originally Posted by OldMercs

I got a 4 barrel manifold out of a barn full of "stuff" a couple weeks ago. No broken bolts, screwed up threads, cracks or other problems that I can see. Now I want to clean it up, paint it and use it, The first step is probably clean the inside, What's the best way to do that?

Originally Posted by craig

. . . I always check (. . .) any intake manifold new or used before I spend anytime cleaning and painting.

Which 4bbl manifold is it? There are at least 4 different versions I'm aware of.
If it's not a '57+ style ECZ-9425-B or you're doing an earlier year specific restoration it may not be worth the trouble.

[HBoly44]

to keep from burning the paint off u need to get intake manifolds from concours parts which have 'restricted" heat riser ports. concoursparts.com

[paul2748]

You mean gaskets ??

Originally Posted by HBoly44

to keep from burning the paint off u need to get intake manifolds from concours parts which have 'restricted" heat riser ports. concoursparts.com

[HBoly44]

yes I meant intake gaskets.