Mag intake manifold crack

[Forssling]

Hi All,
I noticed I have a crack on my 901108321R manifold. It is at the base where the nut goes. It has not got through all the way yet.

1) Is this weldable? Or can I leave as is and hope for the best?

I guess 50 year old magnesium parts are a bit fragile.

2) Are there aftermarket products out there that will work with my original setup?

3) I guess someone (me?) over torqued the manifold. I assume there is not much torque needed for this. Could you please give me a torque spec? (Does 18 ft lbs sound right?)

Thanks for any input.
Jörgen Forssling
Gothenburg
SWEDEN

[dannobee]

https://www.ebay.com/p/1024275348

[Forssling]

Originally Posted by dannobee

https://www.ebay.com/p/1024275348

I didn't find the answer to my questions there...

//Jörgen

[jpnovak]

Yes, magnesium can be TIG welded. You just have to find someone capable of doing it.

There are aftermarket manifolds. PMO is one example. Or source a used one.

I plane mine flat and then use a 1/4" (small) ratchet socket set. Usually only tighten to 10-12 ft-lbs. this is usually sufficient with fresh gaskets. They don't need to be super tight.

[Forssling]

Originally Posted by jpnovak

Yes, magnesium can be TIG welded. You just have to find someone capable of doing it.

There are aftermarket manifolds. PMO is one example. Or source a used one.

I plane mine flat and then use a 1/4" (small) ratchet socket set. Usually only tighten to 10-12 ft-lbs. this is usually sufficient with fresh gaskets. They don't need to be super tight.

Thank you! I have a guy here able to do the welding. I was just afraid of that the weld would cause a crack just next to it. But as you point out, they don't have to be torqued too much to work.

I have searched for "PMO Porsche Intake" but can't find any new ones, just used. Are these only available from PMO as a kit with carbs?

//Jörgen

[Dpmulvan]

Tig welding was invented to weld magnesium, it’s not a big deal.

[mepstein]

Ben/MB911 welds aluminum, mag, etc.
Just like the 3.2 aluminum manifolds, it’s easy to crack if you crank down on it. Use a small ratchet with a short handle and just tighten snug, not tight. You can always come back later and check but these parts don’t take much to secure them.