Exhaust manifold installation

BRICH1260

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I am ready to install the exhaust manifolds on my new 5.7 GXI block. I am a big fan of Permatex avation#3 sealant. Would it be a bad idea to apply a thin coating of this sealant around the bare metal ports of the block and manifold while installing the gasket?
 

tpenfield

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The copper Hi-Temp spray may be a better choice, since it is good up to 500 F. The Aviation #3 is 400 F.
 

Scott Danforth

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and none of it needed on exhaust ports with good gaskets
 

BRICH1260

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The engine manufacturer, Michigan Motors, shipped the engine with Mahle exhaust manifold gaskets. Anybody know of their quality. Should I use them or go with Barr or VP gaskets. I don't know if my warranty would be voided if I do not use what they supplied.
 

aimlow

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Mahle is good stuff, but antysteel gasket can rust over time. IF the mating surfaces are good, high temp RTV can be used with no gasket.
 

Lou C

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I have used regular marine exhaust manifold gaskets (no sealer) on the cyl head to manifold joint every time I've had to change manifolds (like 3 times in 15+ years) and never had a leak even on the old cyl heads where the sealing surfaces were not perfect (see old pic). When I installed the new center riser Barr exhaust the Barr tech guy suggested Permatex Aviation with their gaskets for the manifold to elbow joint which I did with no leaks. If you used the Volvo OE manifold to riser gaskets I believe they specified the copper high temp spray.
The cyl head to manifold gaskets only have to seal exhaust gas, the manifold to elbow gaskets have to seal both water and exhaust gas so they are more critical. I'd call them (MM) and ask to be on the safe side if you are installing it all yourself.
 

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BRICH1260

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Does anybody know if it ok to apply the manifold gasket over the painted heads directly or do I need to remove the paint first. I have read conflicting information. Also thread lock on the bolt threads, again finding conflicting information.
 
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Scott Danforth

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paint ok - you are over-thinking it
dont use thread lock - wont work due to the heat, however if you add enough of it, then you will never get the bolts out.
use maalox (or milk of magnesia) - seriously use maalox. the maalox coats the threads, the heat turns the maalox into a powder, the exhaust bolts will not rust into place. - this is an old crusty tip from an old crusty engine builder handed down to this old crusty hod rodder
you can also use copper based anti-sieze.
however never use locking compound
exhaust bolts are retained by proper torque which in turn stretches the bolts to the proper tension.
 

Lubak572

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The engine manufacturer, Michigan Motors, shipped the engine with Mahle exhaust manifold gaskets. Anybody know of their quality. Should I use them or go with Barr or VP gaskets. I don't know if my warranty would be voided if I do not use what they supplied.

Does Michigan Motorz build that long block? Or do they get them straight from Volvo? I am looking at buying 2 of those or their GM 5.7 0r 6.2 vortec long blocks. Are you happy with them?
 

BRICH1260

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paint ok - you are over-thinking it
dont use thread lock - wont work due to the heat, however if you add enough of it, then you will never get the bolts out.
use maalox (or milk of magnesia) - seriously use maalox. the maalox coats the threads, the heat turns the maalox into a powder, the exhaust bolts will not rust into place. - this is an old crusty tip from an old crusty engine builder handed down to this old crusty hod rodder
you can also use copper based anti-sieze.
however never use locking compound
exhaust bolts are retained by proper torque which in turn stretches the bolts to the proper tension.

Milk of Magnesia huh?, that's a first. I appreciate the tip. I probably am overthinking it. I just want to make sure I do it right the first time. Been scouring the internet for information and it seems like everyone has their own twist to things. Like I said a lot of conflicting information out there.
 

BRICH1260

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Does Michigan Motorz build that long block? Or do they get them straight from Volvo? I am looking at buying 2 of those or their GM 5.7 0r 6.2 vortec long blocks. Are you happy with them?

I`m of the impression that Michigan Motors builds them as they are not tagged with a Volvo serial plate. Plus I think the VP motor is about twice the price. I have been pleased with their service. They spent a lot of time with me on the phone answering questions that I had and shipped the unit in a very protective manner.
 

Scott Danforth

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Milk of Magnesia huh?, that's a first. I appreciate the tip. I probably am overthinking it. I just want to make sure I do it right the first time. Been scouring the internet for information and it seems like everyone has their own twist to things. Like I said a lot of conflicting information out there.

your best sources of information should be

factory service manual
old crusty machine shop owner who built more motors/hot-rods/boats/etc. than most people ever dream of
Old Hot-Roders who have been building things for decades

never look at you-tube videos, you can watch 3 and get 3 conflicting bits of information.

the maalox tip came from Fritz - owner of B-B Machine shop in the late 70's when when Dad and I were rebuilding a 327 rambler for a jeep wagoneer. and had to drill out 5 exhaust studs I think Fritz was 80 at the time. he had been using it since it came out in the 40's
 

aimlow

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Does Michigan Motorz build that long block? Or do they get them straight from Volvo? I am looking at buying 2 of those or their GM 5.7 0r 6.2 vortec long blocks. Are you happy with them?

Volvo doesn't build anything except diesels. I'll bet they're just a GM/Chevy production engine, built for "marine" use.
 
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