91 capri XR2 exhaust manifold cracked.

[MTBOX]

Yes I was wondering if anyone has had theirs welded if they could recomend someone?Thanks Fred.

[jglutz]

Where are you located?

Where on the manifold is it cracked? What caused it to crack?

Are you planning on taking the manifold out or having it welded it place?


Just check the yellow pages for a local fab/weld shop or a small/old time/independent exhaust shop. Your best start.

[FB71]

Joe, the XR2 manifolds are prone to cracking, between cylinders 2 and 3, I think.

It is possible to weld cast iron, but it's not the easyist.

There are few methods;
heat saturation welding, where the entire manifold is cooked in a furnace till it's near cherry red, then welded, then cooled very slowly. Expensive and time consuming, but makes a nice repair.
Arc welding at room temp: this one is tricky, but less costly and less pretty. Use an AC arc welder, set around 90amps, with a pure nickle rod. Grind out the crack to a nice void. Weld a spot the size of a pencil-tip eraser, then immediately peen with a chipping hammer. If done correctly, you should be able to touch the spot bare handed, and not feel much heat. Go slow, and move at least an inch away from the weld to the next. Check the temp after each spot. If its too hot to touch, stop until it cools. DO NOT quench. Let it air cool. The repair will be ugly, but that's what grinders are for.

[jglutz]

[quote="FB71"]It is possible to weld cast iron, but it's not the easyist./quote]

Yes, generic electric arc welding technique:
Preheat iron... 1/2 way to red. (rose bud flame will work well)
Use a welding rod containing nickle alloy (some call it by the brand name 'jupiter")
Cover with a blanket to slow cool.
Welding set up: AC or DC; ±polarity; does not matter for a manifold

I cann't explain the metalurgy between iron and nickle...I only know it is a satndard that works in not structural applications.

[kzbill]

Old blacksmith I know welds manifolds for tractors sometimes, preheats them in the forge, welds, I think nickle rod, then buries them in wood ash in a garbage can for eight hours or so. The ash holds the heat longer than the heat blankets and gets in all the nooks and crannys. Still have to check for flatness when done.

[jglutz]

Sorry...Jim...Guilty of not reading your entire post...perfect instructions...Pure nickle big $$$

[FB71]

thanks Joe. That method has worked well for me a few times.

[MTBOX]

Capri XR2 cracked exhaust manifold

Yes Iam located near Memphis Tn. and yes I do plan on taking it off.It is craked between #2 and #3 cylinder thanks for all your information.Thanks Fred.