Technical Can't seal up SBC???

Trying to wrap up the SBC install in my son's '60 Chevy p/u. No matter what I've tried I cannot seal up the thermostat housing to the intake. Whenever I pressure test it or pull a vacuum it leaks between the housing and the intake (near as I can tell??) The housing is a stock chevy piece, the intake is an aftermarket cast iron. I have tried to sand the housing and intake mating surfaces as flat as possible. Tried no silicon, silicon, gasgacinch - can't seem to get it to seal up???
Anyone have any thoughts, tips, trick, ideas???
Thanks-

 

Gasket with o ring built in.. Not sure where to buy them..

 

Well maybe something had a hole in it.

 

Pictures would be a big help.

Does it leak when you fill it with water?

Anyways, with a stock iron housing, and a manifold that's in good condition, I use a normal replacement gasket with Aviation Permatex sealer on both sides, and they seal fine. There are a few things that can cause problems, if you're not careful. Is the thermostat fully seated in the groove? Do the bolt holes still have their bottoms (no holes into the coolant passage) in the intake? Any cracks or rust holes in the housing?

 

Have not tried filling it yet, just pressure test and vacuum test...
I will check the bolt holes in the manifold...

 

Hope the housing you are trying to install is not a Chinese chromed steel POS. I only use GM OEM aluminum housings.

 

A few other things,if see the leak,you know were it is? If gasket is not on a flat,like the housing has its tabs bent a little,lay it on a flat sheet an see if its a little lifted in the center between bolt holes? <can be filed flat.
One of the most common things is a chrome housing=that has not had the chrome ruffed up were the gasket goes=it will not seal well if it's chrome under gasket.

 

Are the chrome Chinese imports even made in steel, or cast iron? I’ve only seen die cast- pop it out of the machine, tumble them to knock off the rough edges and add a bit of flash chrome.

 

Can we see a picture of such animal please?

 

Are you putting the thermostat in the wrong way? Spring side needs to be down.

 

that's pretty sophisticated...I always use good old water to find the leaks in the cooling system.

 

You need to spray it with some soapy liquid while pressure is applied and see where it’s actually leaking. Then you’ll be on the right track. Until then you’re just pissing in the wind. Might be a porous casting or some other defect.

 

Using the pressure or vacuum saves a heck of alot of mess, especially when your having a problem (like I am right now...)
have been using soapy water to find the leak under pressure, that's how I found it...
housing is a stock GM aluminum piece
Included is a pic of the intake...it's an aftermarket cast iron 4bbl for vortec heads, it's originally a marine intake...

 

http://www.henkel-loctites.com/LOCTITE-5699

If it is leaking midway between the ears on the housing, it is banana shaped
The housing is the problem, not the manifold.
Product above is something I use routinely and works wonders

 

Are you positive the bolts are not too long? If they are they bottom out and housing is still loose.

 

Pretty certain, I will double check that though....

 

I had a housing which wouldn't seal, no matter what goop I put in there. Turns out the housing was bent, so I milled it flat, no more problems.

 

Inspirational

 

That is an interesting manifold. Actually from a GM industrial engine.


Power Solutions Inc is in Wood Dale, Illinois.

 

Those housings are made from a metal called "Chinesium".
The metalurgists managed to overcome the impossible and make them brittle and soft at the same time