Water Temp

[Terrell460]

I got two questions

First off i just got done rewiring my 51 ford and noticed it had to water temp sending units, one is bad or sonethig so it grounds out totaly and indicates the engine is cool no matter what. ar the sendin units supposed to be exactly the same or or slightly different to make the gage acurate.

Second im havin issues with the cooling system any way. the car seems to be getting very hot. it pushes steam out of the over flow and never replanishes its water. how hot is is the engine suposed to get, what thermestat is it suposed to get and what poundage should the radiator cap be rated at?

I should also not that it has an automatic which im slightly suspicous of for over heating and the engine is brand new and last but not least it has a rich airfuel mixture and some plugs develope soot while others dont.

with all these things added up im not sure of what is causing my problems. its not as simple as a model a

 

[BKW]

There are two water temperature sending units, one in each head.

They are not the same, so do you need the left (drivers) side, or the right (passenger) side?

Nothing this old came with any sort of factory (or dealer installed) coolant recovery tank. Ford first offered one for cars in 1958, for F100's in 1971 (with M/T I-6 only).

Autoparts stores sell a universal "fitz-all" kit.

The parts catalog lists a 7 lb. pressure cap, but Ford also offered a 4 lb. cap.

 

[mtflat]

First what engine/trans are you talking about? Flathead V8? You have to keep it pretty simple for us to give you the right info.

Second, is this a car or truck? I'm not aware of any 51 trucks in stock form with automatics, but I stand to be corrected.

 

[Terrell460]

sorry its the custom 4 door again with the fordomatic drive. It has the 239 flathead with 2 barrel carb

 

[mtflat]

Thanks, they're not much different than a model A, just double the fun.
The one sender actually registers heat, the other is just a hot/cold switch - closed until it gets too hot and then breaks the circuit showing hot on the gauge immediately. The wire on the one with the single post connects to the sender with two posts. Wire to the gauge also connects to the 2-post sender.

A new engine will run hotter until it breaks in, just because of more friction, but it shouldn't run too far above normal. Thermostats should be 180 deg. Rad cap should be 7# or less. Temp normally doesn't get much above 200. Check with an infra-red temp meter or a candy thermometer in the top of the rad tank when hot. (don't remove the cap when hot... remove it cold and run the engine to normal operating temp)

If you're getting steam or frothy water in the radiator you probably have a crack in a head or the block or bad head gasket that's allowing combustion gasses to enter the coolant - whole 'nother problem. It could be as simple as a gasket installed wrong - I did that once.

If you can't get it sorted out, go to this web site - the greatest flathead minds online gather here.

http://flatheadv8.org/phpBB/index.php?sid=3be9a2743a617eff303bb6aa6bf5d399

 

[Terrell460]

It ends up with steam being pushed out of the radiator at a pretty good rate.
i pulled the cap off and it makes bubbles while idoling no froth tho. i also found out today that the cooling system isnt under any pressure (i can remove the cap at high heat after shutting the car off and not even get a hiss from the cap).

if theirs cumbustion gasses making its way into the cooling systm its either the head or the gasket cause i havent found any antifreeze in the oil during oil changes so the block is fine i think. so ill try a new cap i guess to see if the lack of pressure is causing these problems then down to the gaskets.

i take it the two post will be the drivers side head? and since the temp gauge reads hot on the single sending unit that means its getting very hot?

 

[mtflat]

Are you getting any white smoke out the exhaust pipe? That would indicate a cracked cylinder to valve. I have a block that's cracked on #6 between the cyl and intake valve - it'll empty the radiator pretty quickly.

If no white smoke, I'd say headgasket or cracked head. With bubbles and steam like you describe I don't think a new rad cap will cure this one.

Usually the two post is on the driver's side. The single sender wire connects to the short post on the double pole sender. The wire to the gauge connects to the tall post.

What happens if you disconnect the wire on the passenger side? If your gauge goes to normal you know that either the pass sender is bad OR it's overheating on that side.

I think you'd do yourself a real favor to pick up a shop manual for your car or even one for the 49-51 pickups. They have a good deal of helpful info on troubleshooting and repairs.

 

[Terrell460]

it has true dual glass packs and in the winter it would puff out a little white smoke. and clear water and would puff smoke longer from the passenger side. during the summer it has nothing coming out.

my grandpa has the service manual for it so ill get that when i go to hot august nights.

so i take it when an engine is running the water should be unsteady but have no bubbles at all?

should i get a new cap when i order new gaskets any way seing it has zero pressure in the cooling system?

 

[mtflat]

You'd see white smoke in the summer too if it was loosing coolant that way. Your description sounds like normal condensation in cold weather.

You should be able to see movement of the water in the rad neck, but no bubbles - that's a sign of either cavitation at the waterpumps or combustion gasses getting into the coolant. With the steam you're seeing I'd bet on a bad head gasket or crack in a head.

Yeah, I'd go ahead and get a new 7# cap - it needs one anyway.

 

[Terrell460]

well i got curious and checked all the bolts with a torque wrench and all except one bolt were loose in the head. im sure it was supposed to be retorqued like my model a but it didnt get more than 200 miles so it probably wasnt properly torqued from the get go. its still producing bubles at maybe a slightly lesser rate and pushes less steam out but it boils in the radiator. but it probably needs new gaskets after all these years.

im gonna run its fuel level down to half and put stable in the tank and park it till i can afford all the new gaskets and a rear end over haul. i have execive gear lash back there so no point in putting a lot of effort into it now when im broke as a joke

 

[mtflat]

Its a good idea to re-torque the heads at least 2 times after their installed. That might have caused your problem - and by now there might be enough erosion of the gasket that it won't seal.

I know about the lack of funds. If I have money to work on my rigs, I don't have time and when I have time, no $$. Besides that, I always get sticker shock when buying head gaskets at my local NAPA.

 

[Terrell460]

yeah i saw at macs they were 20 to 30 bucks and then i ought to get new bolts. plus the transmission is leaking and like i said the rear end sounds bad and its realy addin up for a burger king salory like mine ha

 

[mtflat]

I hear ya, bolts are way more expensive than gaskets. I bought one new set 10 years ago and have been using them ever since. You can probably get by with old ones - in fact the steel in the old ones is probably superior to new bolts that you might buy.....thanks to China's looser quality control.

 

[Terrell460]

yeah your probably right the only time i broke bolts or studs was on the model a i re did and it was a 30 year old engine so this engine probably hasnt even bothered the bolts. i just got done collecting screws and interior parts all i gotta do is pump gas out of the tank and put it in something that works worth a darn.

next summer ill start working on it again maybe ill get a pickup from 51 and say screw the car ha