Question - water/coolant jacket on bottom of intake manifold

[laundromatt]

Hi all - 

 

I'm in the process of swapping out the one-barrel intake manifold on my car with a Cannon intake manifold to go with a Weber 32/36.  Based on the threads here, I'm reinstalling the water/coolant jacket that attaches to the bottom of the intake manifold.  Other than the paper gasket that goes here, do I need anything?  Would gasket sealer do any harm if I put some on there as well?  

 

 

[Mark92131]

A thin coating of RTV should seal it up nicely.  Apply, let it set, and torque to spec.

 

Mark92131

[jireland2002]

If you don't have the gasket just use RTV.

[TobyB]

For coolant, I would avoid the paper- even treated,

it will wick and corrode.  RTV for me.

 

t

[avoirdupois]

23 hours ago, laundromatt said:

Hi all - 

 

I'm in the process of swapping out the one-barrel intake manifold on my car with a Cannon intake manifold to go with a Weber 32/36.  Based on the threads here, I'm reinstalling the water/coolant jacket that attaches to the bottom of the intake manifold.  Other than the paper gasket that goes here, do I need anything?  Would gasket sealer do any harm if I put some on there as well? 

 

I have used both gasket and rtv or even the gooier permatex aviation form-a-gasket.  The only problem with sealing the conjunction of two surfaces is when one or both parts are irregular and do not mate well, impairing any seal, let alone one that is under pressure.  So, if you have the ability to clean and machine each part before assembly, it may go a long way to avoiding future problems.  Too much rtv or any sealant and poorly cut gaskets merely pose the risk of entering the cooling system and clogging things.  Overall, IMHO, the risk tends to be fairly low, unless your system is compromised by years of accumulated gunk and corrosion.

 

With respect to Toby, the notion of corrosion with a paper gasket is minimized if the system is maintained by frequent coolant replacement and regular flushing of contaminants.  There are plenty of other paper gaskets serving a similar purpose, e.g., the waterpump gasket.

[TobyB]

Quote

if the system is maintained

Yuppers, no argument there.

 

But after pulling apart decades of cars,

corrosion on paper gasketted coolant passages

is pretty common...  RTV, a lot less so.

 

Just what I've found,

t

 

[laundromatt]

Thanks all.  The existing intake manifold had the paper gasket, and it's held up.  I think I'll go with the new gasket + small amount of RTV.  If it fails, I'll report back here for the next person who tackles this to see.  

[Fatherof3]

In the Bay area couldn't you skip the cover and necessary plumbing?

[Simeon]

It's not just about cold weather (though that obviously makes it worse). The action of the fuel being vaporised in the carbs reduces the temperature of the charge. This can mean icing of the carbs and the fuel is more likely to condense back out of the charge in the manifold due to the cold.   Long, twisty manifolds like the downdraft one are likely to work better every where with heat. 

[laundromatt]

On 5/24/2017 at 2:52 PM, Fatherof3 said:

In the Bay area couldn't you skip the cover and necessary plumbing?

 

Yeah, I thought about it, but it seems like it could only help, and I have the jacket anyway, so I'm going to go that route.  

 

I should add that it can get into the mid 30s in the winter here sometimes.  I probably wouldn't be taking my 2002 in those conditions, but in case I need to for whatever reason, I wanted to have it on there.  

 

 

[Lorin]

I removed the coolant hoses to the manifold one summer to test it. If it was below 75 degrees here in Georgia, the carb would ice and barely run. I would have to stop and let the carb thaw before i could drive again. The manifold needs water heating in my opinion and experience.