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Old 06-12-2019, 06:21 PM   #41
30 Closed Cab PU
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Default Re: radiator failure

Thanks for the info Joe. I had read somewhere, that an extra 20- 30 degrees of coolant temperature over 212 in a Model A brings oil close to the flash point on the cylinder walls. So you really do not want to go over that temp.

You were comparing a modern 15 PSI to a model A. Am curious, do you really gain much at less than 4 PSI, which I believe what most Model A pressurized systems run? Am asking because I do not know.

My opinion is that if a stock unpressurized A is regularly overheating at 212 water or antifreeze, something is not right and needs attention.

I agree with not using the stupid or similar remarks, if somebody (like myself) posts something incorrect, I appreciate being corrected and educated. I know I've probably learned a lot of things that are not correct by trying to sift through all the multiple and sometimes conflicting opinions. And is why I post a lot, to validate what I think I know.

As far as modified vs. stock - there is room for everyone to enjoy their A as they like and should not be criticized for their decisions.
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Old 06-13-2019, 08:45 AM   #42
Joe K
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Default Re: radiator failure

Nice post above - well said.

My opinion is that if a stock unpressurized A is regularly overheating at 212 water or antifreeze, something is not right and needs attention.
Agreed. As far as the car design itself goes, I consider the 28-29 Model years more susceptible to overheating - simply because of the smaller size of the radiator. Ford himself "cut corners" on the 28-29 radiators - the original radiator being the somewhat advanced "funnel top" radiators, and then a reversion to a more conventional round tube radiator, plain top. The reversion radiator was a good radiator when the car was driven off the lot, but combined with water impurities and grease from the water pump, they were less lived than the original funnel tops.

Pressurization and increased delta T can make a marginal radiator act like a larger radiator. Thus the interest in pressurization - although pressurization is usually done with a NEW radiator, thus removing the cause for overheating on TWO fronts. It may be possible to have a CHEAPER radiator (i.e. less copper surface area) which may be incentive for producers to market pressurization - and gain a premium price for an "improved" product. Which it is - and isn't.

Many have cited use of a "flow restrictor" on a marginal radiator to prevent overheating. Cutting down the pump impeller is another solution.

Most of this I think are done not so much for boiling over, but rather "throwing water" out the overflow which the not funnel top radiators are prone to do on both 28-29 and 30-31 radiators. A near "boiling over" condition might suggest itself by throwing water easier? And one does either of the remedies as a "stop-gap" until finally forced by Physics into a new CLEAN radiator?

The Model A waterpump was designed for the funnel top (wide dispersion of water over the upper tube sheet) and the narrower confine/flow circuit of the later radiators exacerbated the throwing water problem. It makes sense that the radiator might in time with plugging become the "surge tank" for the system as water builds up in the top box - and heads for the overflow. One imagines the flow restrictor/cut impeller as a mal-design mitigation which does not otherwise affect total heat transfer?

It might even increase heat transfer. Lower flow rates through the cooling circuit will cause an increased average motor temperature AND an increased average radiator temperature. Look to that delta T in both cases. We're fortunate with modern oils to have little consequence to increasing average motor temperature.

So yes, by higher average delta T a flow restrictor CAN help a marginal radiator and prevent it from boiling over for a couple of reasons. But, there will be a price in higher cylinder wall temperature, less viscous oil more easily wiped by the oil control ring, and consequently less lubrication/more engine wear.

Interesting "mind-experiment" all of this.

Joe K
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Old 06-13-2019, 03:15 PM   #43
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Default Re: radiator failure

My radiator filler neck broke off with the Quail on it and landed on the road ! I removed the radiator outer shell and cap, Drained the coolant down below the upper radiator tank, , Hung a heat gun I imagine an old style heat lamp would work too my heat gun (Harbor Freight )was about 14 inches above the top of the radiator set to LOW heat aimed at the top of the upper tank hole and heated the area to around 200 to 300 degrees F this is Hot but you must stay below the soldering melting point of the nearby joints. Next I carefully removed extra solder from on top by heating the soldered areas with a small propane torch and wiping off the solder with a wadded up rag (T-Shirt ) I did this quickly so as not to melt solder joints elsewhere on the radiator it was heat-Wipe in a couple of seconds . Then the areas to be soldered were inspected and wire brushed next flux was applied in this case it was Sal Met acid base flux . Lacking the Sal met Flux I recommend plumbing paste flux like is used to solder copper pipes . Now the actual soldering was done using a soldering gun mine is a weller D550 while the heat gun was still on low setting this along with the soldering gun or large soldering iron gives great control .The solder used was 50/50 plumbers solder with out flux acid core solder should work as well . I did this a couple of years ago and looked at the joint yesterday and it looks very good and has not leaked .
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Old 06-14-2019, 06:00 AM   #44
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Default Re: radiator failure

Just had the neck resoldered on my radiator. Had it done right by a professional at an old time radiator shop. My advice, pull the radiator and have it done right, then no worries down the road.
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Old 06-14-2019, 03:48 PM   #45
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Smile Re: radiator failure

Originally Posted by dpson View Post
Just had the neck resoldered on my radiator. Had it done right by a professional at an old time radiator shop. My advice, pull the radiator and have it done right, then no worries down the road.

There has been some interesting accounts and good advise come from this thread. Yes dpson, that is what I will do. cheers, gary
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