Overheating

[1wonton]

I had a Model A a few years ago with the same problem; I couldn't figure it out. The water pump seemed ok but it turned out that although the shaft and propellor turned correctly the shaft was broken behind the packing nut. Everything looked fine but the impellor was sheard off behind the nut.

[whirnot]

Originally Posted by TinCup

Radiator....Radiator....Radiator! Don't start by making this harder than it is. Look for the obvious. Ask yourself the important questions? Is this at least a 3 core radiator? Is it in good shape?

I chased this demon for a couple of years and looked for everything before I realized I had a light duty 2 core radiator that worked fine as long as the outside temp was below 90 degrees. Let it get above that and it could not keep up.

Start with the radiator and if that is it call Gery at Bergs Radiators and get him to build you one.

As I mentioned above, I had the radiator completely cleaned, inspected, and some minor repairs done, by a good radiator shop. It is a triple flat core radiator.

[JOES31]

Bill
Since you found #4 water jacket plugged you have to think that maybe some of that crud might have traveled into the radiator and is restricting flow. I would flush the radiator really well if not have it cleaned, (rodded out), again to be sure.

Just a thought so you cover all your bases.

[Paul from Maine]

Originally Posted by whirnot

As I mentioned above, I had the radiator completely cleaned, inspected, and some minor repairs done, by a good radiator shop. It is a triple flat core radiator.

An engine is only going to produce a certain amount of heat! The total heat output does not rise that much if the cooling passages around a cylinder are clogged! Sure there will be additional friction which produces heat, but how much can that be compared to the heat of combustion? In the case of clogged cooling passages, less heat would be transferred to the coolant, not more! The heat not absorbed by the coolant because of the clogging, would have to be absorbed by the block and radiated to the atmosphere via the outside surface of the block and the oil pan or escape via the exhaust. A radiator with adequate capacity should be able to handle the reduced heat transfer because of a clog! I suspect your radiator even though you have clogged cooling passages! I took my problem radiator to a competent shop and even though they worked on it, they made it clear to me that it was old and might not work! It cost me forty five dollars to learn that lesson!

[tbirdtbird]

an A has marginal cooling at best. so now it is OK to have a clogged block?

[JOES31]

Sponsored Links (Register now to hide all advertisements)

I'm with you tbirdtbird. A clogged block will in my experience cause an overheating problem. A long time ago I had a Fiat X19 that exploded and caught fire. After repair it kept overheating. It was rubber that went into the water jackets that restricted the water flow through the engine. Had to steam it all out and then it cooled perfect.

With the design of the A engine I would think any restriction of water flow could cause an overheating problem including using too much silicone to install the head. Actually I believe there was a thread recently on the Barn that said they had an overheating issue because someone used too much sealant when installing the head.

[Jerry in Shasta]

Be sure to check the intake manifold to block for a vacuum leak.
JB

[tbirdtbird]

Yep.
"The heat not absorbed by the coolant because of the clogging, would have to be absorbed by the block and radiated to the atmosphere via the outside surface of the block"

It is well-established physics that dictates that heat transfer via water is MUCH more effective than via air

[rocket1]

Having the radiator serviced really means nothing unless the tanks are removed and tubes are rodded out,I went through this with a studebaker,changed and checked everything but still ran hot,I finally had the radiator recored,at last normal temp in hot summer.

[pgerhardt]

What does everyone think of waterless coolant. No corrosion and 360 degree boiling point sound like a good idea to me.

[Ed in Maine]

I side with the guys who are telling you to do something with the radiator. Over the years, the water pump was lubricated with the wrong grease. When hot, the grease carries over to the radiator, cools and deposits in the core. I had the top of my radiator off and sprayed Gunk degreaser into each tube and carefully rodded them out, pushing the grease and rust into the lower tank and rinsing it out. A radiator shop could not possibly get enough pressure and velocity flow into each tube to do the job. After the job, the car ran at 160F on the hottest days. Look at other posts in the archives on how to rod out a radiator. Ed

[Tom Wesenberg]

I agree with Ed about how the grease forms in the tubes, and removing the tank and rodding the tubes is the very best solution, but I wanted to try to avoid that if possible. So, I used about half a cup of Cascade and water for 3 days, then switched to pure white vinegar for 30 days. I also removed my radiator and turned it upside down and connected it to a sump pump to backflush it. This did work in my case.

[Paul from Maine]

Originally Posted by tbirdtbird

Yep.
"The heat not absorbed by the coolant because of the clogging, would have to be absorbed by the block and radiated to the atmosphere via the outside surface of the block"

It is well-established physics that dictates that heat transfer via water is MUCH more effective than via air

Imagine the block was completely clogged with rust! How much heat would be transferred by the coolant to the radiator? Little to none! The more clogged your cooling passages in your engine, the less heat can be transferred to the radiator by the coolant! Your engine will overheat with clogged cooling passages because the coolant isn't transferring the heat to the radiator! The block is forced to absorb the heat which is eventually transferred to the atmosphere while your pistons score the cylinder walls and finally seize up! The only heat being transferred to the radiator is by steam in this scenario! It's not he radiator's fault that it is steaming! And the excessive heat is going to be transferred to the atmosphere by the block in this scenario! That's all I am trying to say!

[tbirdtbird]

If you are trying to say that a clogged block will cause overheating then I am with you 100%

[Allanw]

If the engine is blocked, the radiator probably is too!

Ours ran fine most of the time, except steep climbs where it would push water out the over flow and cap.

We had the radiator opened and rodded out, and got about 1.5 cups of crap out of it, just from the mechanical process! They soaked it after that.

Runs perfectly well now, even on long steep climbs in hot weather - we've since added a thermostat(160F) and temp gauge, and worst i've seen since was about 195F on a long steep climb, where I was starting to get concerns about double clutching and actually making it into FIRST gear while moving

[Kevin28sedan]

When you have a problem like this how well do "extra cooling" mods help? Such as more blade fans or fan shrouds? I know it's not fixing the problem but they are way cheaper than a new radiator.

[Mitch//pa]

Originally Posted by Kevin28sedan

When you have a problem like this how well do "extra cooling" mods help? Such as more blade fans or fan shrouds? I know it's not fixing the problem but they are way cheaper than a new radiator.

look at it this way a new radiator is cheaper than a new engine if you running it hotter than it should be with mods
and then in the end youll need a radiator and engine

thats if the block is not clogged

[whirnot]

Well, we finally made it. I cleaned all the block passages, and let the block sit for 10 days, full of vinegar. That got a lot of rust out. I put a flexible light inside the lower tank and could see through the tubes so I knew at least the center ones were in pretty good shape. I noticed the radiator was leaking behind the hood rod mount, and the radiator had guy told me that he was afraid to do anything with it. So I decided to bite the bullet and head to Bert's. Steve explained to me that even though it was a triple tube radiator, because the tubes were all in a line, the rear ones weren't getting much air. Now I have a calm, cool, collected, Town sedan with a beautiful 4 tube radiator.

[Brentwood Bob]

Persistence eventually pays off. Bob