Rad hose blows off

As I mentioned earlier, even when I was using the stock rad with zero cap pressure, I was getting minor leakage where bottom of hose attaches to the head. Yesterday I examined outlet carefully and it is noticeably out of round in 2 places around the circumference. These areas won't permit the hose to even contact the head. That weakens the adhesion of hose to outlet. The high pressure cap added to the problem. So if someone can let me know where I can buy a 5 lb. cap, I'll get the out-of-round issue looked after, and problem will be solved. Thanks for staying with me on this one.
 
Be sure and let us know how this problem is finally resolved. I think "of of roundness"
is the culprit. If you machine the present hose outlet it will be too small for the hose and make things worse.
 
When you take the head off check it close and the gasket. Sounds like maybe you are getting compression leaking into the cooling system on that side.
 
91A-77B said:
Yesterday I examined outlet carefully and it is noticeably out of round in 2 places around the circumference. These areas won't permit the hose to even contact the head.
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Make repair with JB Weld. You could use the quick set type since I believe that the adhesion to the head outlet would be the same as the slow set, higher strength JB.

Make a dam at the bottom closest to the head. Mark the top of thee outlet with a marker at the position of the low points. Cut a plastic bag or thicker plastic sheet into a strip to cover the JB circumferentially. Cut off a piece of old radiator hose then cut it vertically.

Apply the JB, wrap with the plastic and then open up and slip the short piece of radiator hose over the plastic and wrap with Duck tape. Let it sure remove hose and plastic which won't adhere to the JB Weld and file to suit. I've done this with the plastic on my own repairs.
 
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It doesn't matter if the outlets are out-of-round. If that was the problem you would not be able build up enough pressure to "blow" the hose off. It is the circumstance that is important. Or possibly that the outlet is tapered, smaller at the top.
The pressure is going to be exactly the same on both sides. The pressure will be equalized in the radiator, from both the top tank and the bottom tank. The thermostat on the other side being open or closed will make no difference.
A previous poster asked if the outlets are polished. I didn't see an answer to that.
I agree using JB Weld to rectify the problem, but IMHO you have not identified that yet.
Glennpm's idea makes sense if you need a larger diameter.
 
Udate: I removed head, was able to get closer look at outlet. It appears to have been misshapen by some previous owner or shop putting the outlet part in a vise, as the narrowed sections were directly opposite each other. Presently, we're looking at several options to correct this, including machining neck undersize to repair out-of-round and remove taper at base, then sleeving to original 1.75" specs. Recall I said earlier that with stock rad and no pressure cap, I was getting slight leakage. I acknowledge rad cap pressure was excessive, and am going to source a 5-pounder. Will report progress.
 
19Fordy, I had headwork done, opening chambers to 77cc's. I suspect the individual clamped the head in a vise or other device to hold it while he did his work. We're certainly not going to try squeezing it back! Grinding it down to round it and to remove taper, then sleeve it back to spec. Doing the same on the other head, which presumably was also "vised", but is not leaking. Both heads now at machine shop. Updates to follow. Thanks everyone for your helpful input.
 
91A-77B said:
Grinding it down to round it and to remove taper, then sleeve it back to spec. Doing the same on the other head, which presumably was also "vised", but is not leaking. Both heads now at machine shop. Updates to follow. Thanks everyone for your helpful input.
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Sounds like a good approach. I'd silver solder the sleeves on.
Love to see a picture of the machine shop setup to turn the outlets!
 
Yes, please have machinist take photos of the set up for machining the outlets and installing sleeves. Then post them on Fordbarn for inquiring minds who want to know.
Hope it all "turns" out great.
 
glennpm said:
Sounds like a good approach. I'd silver solder the sleeves on.
Love to see a picture of the machine shop setup to turn the outlets!
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Probably not with aluminum (Navarro) heads. I'm sure there are plenty of epoxies these days that would work fine. Belzona comes to mind as making specialty epoxies for many diverse purposes. I'll bet good old JB Weld would work fine.
 
tubman said:
Probably not with aluminum (Navarro) heads. I'm sure there are plenty of epoxies these days that would work fine. Belzona comes to mind as making specialty epoxies for many diverse purposes. I'll bet good old JB Weld would work fine.
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Yes you're right. Special silver solder would be required. JB weld or another epoxy would be the ticket as long as there is enough gap between the sleeve and the nozzle. I'm thinking red, permanent Loctite may be a way with a tighter gap.
 
Glenn, Do they really make special silver solder for aluminum? I think I would find it very useful. I have used the various "Muggy-Weld" type products and find they work work fine sometimes and sometimes not at all. I think it depends on how well the alloy being "welded" matches the composition of the rod being used. A silver solder type product sounds good to me.
 
That aluminum solder products look like it might solve your problem if you can get the metal clean enough.
 
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