Pressure checking exhaust mans... how'd U Do It?

[KaGee]

'82 OMC 3.8L Exhaust manifold... I have a mental block as how to seal off the riser end in order to pressure check. <br /><br />Any creative minds out there who want to throw in their $.02 worth??

 

[tommays]

Re: Pressure checking exhaust mans... how'd U Do It?

a piece of hard wood and the orginal gasket <br /><br />a littel work with the drill and there you go just dont get to crazy with the pressure<br /><br />tommays

 

[KaGee]

Re: Pressure checking exhaust mans... how'd U Do It?

Thanks Tom.<br /><br />DUH! (Why didn't I think of that one??) <br /><br />10-15 lbs ok??

 

[navigator336]

Re: Pressure checking exhaust mans... how'd U Do It?

A. Home Depot for a 3/4" MPT to garden hose adaptor. Screw into 3/4" FPT hole in manifold.<br /><br />B. A sheet of rubber big enough to cover the manifold to riser flange (an old tire tube will work).<br /><br />C. Put rubber over manifold flange, mark then cut out bolt holes (or around studs).<br /><br />D. Bolt the riser back to the manifold with the rubber gasket in place.<br /><br />E. Hook it up to the garden hose and wait a few minutes to see if any water appears in the exhaust tubes of the manifold.<br /><br />F. If the manifolds are raw water cooled with salt water, replace them anyway. If raw water cooled with fresh water and older than 8-10 years, replace them anyway. If coolant cooled and older than 12-14 years, replace them anyway.

 

[steve n carol]

Re: Pressure checking exhaust mans... how'd U Do It?

you can use air or water to check this. <br />you can check the exhaust system or the cooling (jacket) system. it may be eaiser to test the manifold with the riser attached. I found it eaiser to test the water jacket side with air. You may be able to use the petcock opening somehow. It doesn't take more than about 20 psi. the first one I checked was in a wheelbarrel with a shop vac on the 'blower' side! the manifold was shot. The riser I checked independently. I fashoned an aluminum plate with a valve off of an old auto rim and installed this on the square end. Installed a 'dollar' plug in the 3" round side and stuck it in a bucket of water. <br />let us know what you came up with on your 'hole in the water'...sl

 

[KaGee]

Re: Pressure checking exhaust mans... how'd U Do It?

I took a piece of 1/2" x 4 oak and drilled it. Cut a piece of rubberized gasket material and bolted both between the riser and the manifold. Had to put a little Permatex #2 around the seams. Added about a pint of mineral spirits to the water jacket. Held 20 lbs pressure for over two hours with no leaks. Maybe the riser gasket was shot? The riser fell right off when I took out the bolts.

 

[steve n carol]

Re: Pressure checking exhaust mans... how'd U Do It?

KG, what about the manifold?..sl

 

[KaGee]

Re: Pressure checking exhaust mans... how'd U Do It?

Originally posted by steve n carol:<br /> KG, what about the manifold?..sl

Nothing leaked into the exhaust ports Steve. Mineral spirits will find any tiny crack, especially under pressure.<br /><br />Riser looks ok too. Maybe the riser gasket let go under water pressure from the garden hose? I don't think i had the hose too high, but maybe??<br /><br />I can't see how else such a volume of water got in. And only on one bank.

 

[tryan]

Re: Pressure checking exhaust mans... how'd U Do It?

does your y pipe have a flapper? could it be stuck?

 

[steve n carol]

Re: Pressure checking exhaust mans... how'd U Do It?

KG, okay buddy. I'll be gone (road trip, hunt & fish) for 2 weeks, when I get back I'm gonna read up on your project. wish you the best. Qustan gave, (gives) good advise!!...sl

 

[KaGee]

Re: Pressure checking exhaust mans... how'd U Do It?

Originally posted by tom ryan:<br /> does your y pipe have a flapper? could it be stuck?

OMC Stringer Tom. No Y pipe.