Water Outlet Cracking?

J

jeepguy1948

Well-known member
I have seen it suggested to use RTV instead of a paper gasket for the water neck/water outlet because because they like to crack. Can anyone explain why the like to crack?
 
Many gaskets are too thick and they will compress as the nuts are tightened. The water outlet neck nuts/studs are at each end. When tightened down @ 55# torque, that compresses the very ends and the brittle cast iron neck won't flex, but instead cracks. Les Andrews and others suggest putting a paper match under each end to compensate. I just use RTV on mine with no gasket and no leaks.


Bear in mind that the stock model A cooling system is non pressurized, so a hefty gasket is not needed.
 
Uneven surfaces, on the head where the outlet fits, the outlet surface where it fits the head, uneven surfaces where the nuts tighten against the outlet. I’ve not cracked an outlet and now the next one will :-( ! With all new parts do you think Ford had issues , I think not ! When we cheap A owners are trying to use worn out parts we are the best reason for breaking parts .
 
jeepguy1948 said:
I have seen it suggested to use RTV instead of a paper gasket for the water neck/water outlet because because they like to crack. Can anyone explain why the like to crack?
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Because it is a terrible design having the head studs go thru the thin casting of the water outlet. Notice the design change on the "B" engine in 1932.
 
Bill G. above is correct. Always check the mating surfaces of the water outlet and mating head surface for flatness and use a bit of RTV sealant or a home made very thin paper gasket. The vendor supplied gaskets are much too thick and compress when the neck bolts are tightened.

JLC
 
I think the original were copper with a filler inside like a head gasket. These compressed correctly. No broken water neck. I've used RTV for year with no issues.
 
Some people put a wooden match "cross-ways" on each side across the thin part OUTSIDE of the two bolts. It gives some reinforcement and levels the "compression" across the face of the casting joint.

I've tried it. It "cuts" the wooden match for me.

Joe K
 
Joe K said:
Some people put a wooden match "cross-ways" on each side across the thin part OUTSIDE of the two bolts. It gives some reinforcement and levels the "compression" across the face of the casting joint.

I've tried it. It "cuts" the wooden match for me.

Joe K
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I don’t think this hack ever involved wooden matchsticks. They wouldn’t work, as you saw. The original hack used paper matches, which are thinner.
 
In addition to the uneven block and water outlet surfaces the larger problem is that following the head nut torque sequence doesn't provide for torquing the water outlet nuts at the same time. In other words you are tightening down one side of the water outlet before the other. Go easy on the nuts, tighten them together and the casting will not crack. The same situation exists with tightening the Zenith carburetor to the intake manifold. Draw them tight evenly.
 
For a while there were "aluminum" outlet necks available as a way to overcome this difficulty.


Joe K
 
BB is correct. Instead of going in sequence, I tighten the 2 neck nuts together and use only Permatex, with no gaskets or matches. And never a problem.
 
Snyders carries the copper/asbestos sandwich gasket which they say is for “judged” cars. What are y’all’s thoughts about using that gasket?
 
I hope this discussion has demonstrated that there are multiple ways to do this operation and they all seem to work equally well.

Personally I use the copper gasket and I tighten the nuts together in small increments. See? Lots of ways to do it.
 
I have a water neck (water outlet) that has what I might describe as “webbing” extending out to the bolt holes (that’s a terrible description but it’s the best I can come up with). Does that sound like a “B” style water outlet?
 
jeepguy1948 said:
I have a water neck (water outlet) that has what I might describe as “webbing” extending out to the bolt holes (that’s a terrible description but it’s the best I can come up with). Does that sound like a “B” style water outlet?
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"B" Style outlet is on the water pump itself. Will not work with Model A head.

55280496197_bc84eba926.jpg
 
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My RTV is ready for replacement and there are now so many different ones on the market it’s over my head. What RTV do Y’all’s recommend?
 
jeepguy1948 said:
I have a water neck (water outlet) that has what I might describe as “webbing” extending out to the bolt holes (that’s a terrible description but it’s the best I can come up with). Does that sound like a “B” style water outlet?
Click to expand...


The height of the reinforcing ribs was increased in May ‘29 and again in Mar ‘31. You probably have a late one.
 
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