CRACK In PI intake manifold

[gtxpress]

This is probably not unusual to find but since it is in the heat exchanger area should I bother to have it welded up?  The PO ha addressed a crack around the top hole but it looks like they ground it and did not weld it up.  Any help would be appreciated.

Gary

[machoneman]

That's a serious crack for sure.       Weld it or toss it and get a replacement intake, I say.

[Joe-JDC]

If your heads haven't been blocked off, you need to have that intake cleaned, grind out the crack, and weld it up.  Then do a pressure test to see if it leaks.  If you have Edelbrock heads, or one of the newer aluminum heads without the heat passage, then it is not an issue unless it eventually breaks into the intact track.  Why take a chance?  Fix it right the FIRST time while you have it off.  Joe-JDC.

[cammerfe]

Weld it right. There are a finite number of those manifolds.

KS

[Barry_R]

Weld it and do not run heat crossover any more.  Very good chance that the rest of the area around that crack is paper thin from degradation caused by exhaust gasses.

[Qikbbstang]

My bet is that manifold was dropped/fell over for that cracking. On a flat surface those plugs are what the manifold rests on. That concentrates an enormous amount of force on that aluminum and the stamped steel splash shield is long gone.

[gtxpress]

Weld it and do not run heat crossover any more.  Very good chance that the rest of the area around that crack is paper thin from degradation caused by exhaust gasses.
[/quote

Barry have any manifolds?
Gary]

[cjshaker]

My bet is that manifold was dropped/fell over for that cracking. On a flat surface those plugs are what the manifold rests on. That concentrates an enormous amount of force on that aluminum and the stamped steel splash shield is long gone.

Ummm, the only time the intake is sitting on those plugs is when it's sitting on a table or floor. That hardly qualifies as an "enormous amount of force on that aluminum". What typically causes cracks like that is when some He-Man over tightens the pipe plugs and places too much radial stress on the surrounding area. Pipe plugs should be good and snug, not cranked down until they won't turn anymore.

DON'T pitch it. Either have it welded by somebody competent in welding old aluminum, find another and sell that one to somebody who's willing to fix it or hang it on your wall and tell people it came off of Bill Cosbys AC Cobra when Carrol  Shelby built his Super Snake. You could even tell them you were discussing the car with him and had a couple of drinks with old Bill and the next thing you remember is waking up in the morning and finding that intake next to you in bed.

[gtxpress]

My bet is that manifold was dropped/fell over for that cracking. On a flat surface those plugs are what the manifold rests on. That concentrates an enormous amount of force on that aluminum and the stamped steel splash shield is long gone.

Ummm, the only time the intake is sitting on those plugs is when it's sitting on a table or floor. That hardly qualifies as an "enormous amount of force on that aluminum". What typically causes cracks like that is when some He-Man over tightens the pipe plugs and places too much radial stress on the surrounding area. Pipe plugs should be good and snug, not cranked down until they won't turn anymore.

DON'T pitch it. Either have it welded by somebody competent in welding old aluminum, find another and sell that one to somebody who's willing to fix it or hang it on your wall and tell people it came off of Bill Cosbys AC Cobra when Carrol  Shelby built his Super Snake. You could even tell them you were discussing the car with him and had a couple of drinks with old Bill and the next thing you remember is waking up in the morning and finding that intake next to you in bed.

OMG That's funny

[babybolt]

I had a tripower intake like that once.  It was rotted out in the heat passages badly enough that the corrosion had eaten upwards through the bottom of the center carb plenum.  The aluminum is very contaminated and has to be aggressively ground or blasted to get down to good metal for welding.