Repairing 62 340 hp intake

[Larry C.]

Recently sent my intake manifold off for re-skinning, if that is the correctly understood term. The engine had been sitting for several years and I could see after removing the manifold that corrosion from the coolant had eaten into the underside at the rear near the distributor hole where the water passages from both heads meet the intake manifold. As I would expect, those two areas would normally be completely filled and generally smooth.

After re-skinning, the damage can clearly be seen. The drivers side actually has a 1/4+ inch hole all the way through the manifold (see 2nd photo). Suggested repair methods include: 1) welded by a professional experienced in aluminum repairs; or 2) fill the cavities with J-B Weld.

Have researched products on J-B Weld website looking for an expoxy product especially suited for aluminum repairs. Saw nothing. The Original J-B Weld is recommended for all metals and can withstand temperatures up to 550 degrees F. Highheat J-B Weld expoxy withstands continuous heat exposure of 400 degrees and intermittent heat exposure to 550 degrees.

Have other members made similar repairs with good results? The water pressure and heat of the engine should not be issues, IMO.

Also, if welded, is it likely that the exterior surface of the manifold will be discolored?

Any thoughts or other recommendations will be greatly appreciated.

Larry

[Joe L.]

Re: Repairing 62 340 hp intake

Recently sent my intake manifold off for re-skinning, if that is the correctly understood term. The engine had been sitting for several years and I could see after removing the manifold that corrosion from the coolant had eaten into the underside at the rear near the distributor hole where the water passages from both heads meet the intake manifold. As I would expect, those two areas would normally be completely filled and generally smooth.

After re-skinning, the damage can clearly be seen. The drivers side actually has a 1/4+ inch hole all the way through the manifold (see 2nd photo). Suggested repair methods include: 1) welded by a professional experienced in aluminum repairs; or 2) fill the cavities with J-B Weld.

Have researched products on J-B Weld website looking for an expoxy product especially suited for aluminum repairs. Saw nothing. The Original J-B Weld is recommended for all metals and can withstand temperatures up to 550 degrees F. Highheat J-B Weld expoxy withstands continuous heat exposure of 400 degrees and intermittent heat exposure to 550 degrees.

Have other members made similar repairs with good results? The water pressure and heat of the engine should not be issues, IMO.

Also, if welded, is it likely that the exterior surface of the manifold will be discolored?

Any thoughts or other recommendations will be greatly appreciated.

Larry

Larry------


There are at least several ways this could be repaired.

1) I think that JB Weld would work just fine and make for a quick, simple repair. A artfully applied "dab" of aluminum paint where the JB Weld would be exposed through the hole that's formed in the manifold would complete the repair. This repair would last far longer than you're ever going to need it;

2) A repair could also be made using the low temperature aluminum welding rod available from the Cecil Muggy Company. Some radiator shops are adroit in using this method which uses only a propane torch. Contact the Cecil Muggy Company for a shop in your area that uses their rod. Or, you could obtain the rod and do it yourself;

3) Send the manifold to Jerry Macneish. They can perform an expert weld repair. However, the time to have them do this would have been BEFORE you had the manifold finish restored. They could have then repaired the manifold and restored the finish, in that order.

[John D.]

Re: Repairing 62 340 hp intake

Larry, A method I have used on the baseplate/intakes of FI units is to use PC-7 epoxy. The red and black container. Two part epoxy. You need a heat gun to mix it up. When it's hard it's like steel.
Some may suggest All Metal. It's silver and will do the job except for one issue that I have. You better work super fast as it sets up in 3 minutes.
Then after about 15 minutes use course paper to smooth it down some. If you wait longer it's like sanding steel.
All Metal can be drilled and tapped also. Not cheap though. I get a discount at NAPA and don't remember the list price. Wholesale it's about $38.00 a quart. Get an extra tube of hardener.
Someone was using water in your engine. Water and aluminum don't go well at all. Good luck, John

Just studied your pics on my flat screen TV as I-phone screen small. Use the All Metal Larry. You will be impressed. You might have to do it in two applications. Mask the good area off. Then use a wide putty knife to apply the All Metal Epoxy. Don't put too much hardener in it. The directions on the can is for young people. Font is tiny.

[Larry C.]

Re: Repairing 62 340 hp intake

Thanks to Joe and John for your input.

Larry