Topic: 41 ford overheats


montanalll    -- 06-03-2013 @ 11:23 AM
  I have posted before, and am still hoping for help: So far have replaced the radiator with a new one, replaced both thermostats, flushed the cooling system, without any change. It will be at boiling after approx. 8 miles of driving. Will idle for 25 minutes before boiling. Lastly I removed the muffler and tail pipe which made it worse: boiling after only six miles of driving without the muffler attached. There is no evidence of coolent in the oil, and no sign of head gasket leaks. Since this is a showcar I want to keep it original, hence no electric fan, etc. Any help would be appreciated.


CharlieStephens    -- 06-03-2013 @ 1:59 PM
  What was the last thing you changed before it started to overheat? Have you checked the timing? I had a friend with an overheating problem in a '34. It turned out he was using a fan designed for a bus with reverse pitch. The fan blew against the incoming air. Probably not your problem.

PS, I like the car.

Charlie Stephens

This message was edited by CharlieStephens on 6-3-13 @ 3:31 PM


supereal    -- 06-03-2013 @ 2:52 PM
  That is an interesting situation. Removing the muffler should not increase overheating, in any case. At our shop, we do a "blow down test" for this kind of problem. This allows us to inject compressed air into each cylinder when both valves are closed. We observe the line gauge to see how long it takes for the pressure to drop. It is a much better test than the conventional compression test. Another good test is by using a vacuum gauge. As you have changed radiators and made other changes, the problem is almost certainly inside the engine. The only other problem I've like that is a bad master cylinder that allowed the brakes to build up, causing the engine to labor. Until you open the engine, I doubt you will fix it.


TomO    -- 06-03-2013 @ 5:08 PM
  Here is a link to using a vacuum gauge.

http://www.secondchancegarage.com/public/186.cfm

Post the vacuum gauge readings to give us an idea of the engine condition. Also post compression readings.



Tom


drkbp    -- 06-03-2013 @ 7:48 PM
  It can make it run hot if it is too retarded so since you have tried everything else:

Long suggestion >

Have you set the timing to the engine?

If not, set No.1 to top dead center of the compression stroke. Loosen the screw on the timing plate and slide it to the bottom. Turn on ignition, slide timing plate up until it fires #1 plug, then move a mark higher and tighten the screw. That should be 4 degrees before TDC.

To do the above the points have to be set properly and the plugs out, etc. and turn the engine over manually to find TDC of No.1.

The advance is by the distributor from 4 degrees BTDC with the vacuum providing the brake. That just keeps it from advancing too much and pinging.

Short suggestion >

Move timing plate up a mark and see if it's better.

Y'all have been talking about this one for some time but I didn't think I saw anyone suggest timing. Sorry if the above is a dupe.

Ken in Texas




supereal    -- 06-03-2013 @ 8:18 PM
  Unless the distributor has been modified, or a spring is bent or broken, it is virtually impossible to adjust the timing far enough to create overheating. We set up distributors on our Sun machine, and with today's fuel, the slider can be set at the top of the slot, and the vacuum brake adjusted so it has little effect. If you believe this is the problem, have the distributor set up on a machine to check both point dwell and mechanical advance. It can't be reliably tested or adjusted on the car.


drkbp    -- 06-04-2013 @ 10:43 AM
  Montana,

Where did the new radiator come from and what is it made out of? Brass or aluminum?
Lee over at Brassworks, Paso Robles, CA, makes all the early Fords as well as the '32 through '41 Fords. I would use the four row with the crank hole if that is what stands judging, AND is commensurate with your car. Very nice Ford!
We are talking brass radiators that will work correctly like original, not sort of.

Ken in Texas

This message was edited by drkbp on 6-4-13 @ 10:47 AM


TomO    -- 06-04-2013 @ 2:24 PM
  If he can idle the car for 25 minutes before it overheats, the radiator, may be marginal, but it should cool OK in normal driving. He needs to do some testing to determine the condition of the engine, not just replace expensive parts.

Tom


drkbp    -- 06-04-2013 @ 5:12 PM
  Tom,

I do agree with you and that's why my other post was basically a screw driver only fix/change. I am not sure other folks watching this thread are aware that new, brass, correct radiators are available. That was my point.

Also, back to the problem at hand. I was curious to know if this block had been bored and if so, what to. We always look for another if it doesn't clean up very good before 60. I will stick with some of the early Ford engines at that but only because they carry the serial number of the car and some are quite rare.

Please don't get me wrong. It sounds like Montana is at the end of his rope, <grin> Montana..don't do it!, and I was suggesting something I would walk out and try if it was my car. That's all.

That is a very nice car Montana has and I would drive it, period. It should run fine with stock water pumps, std. (160) thermostats and non pressure radiator cap (I think that one is open). It runs hot because something is not correct or maybe a couple of things and we are just trying to help. Montana talk to us.

Ken in Texas


TomO    -- 06-05-2013 @ 7:37 AM
  Ken,

As far as screwdriver fixes go, he can remove his thermostats and see if that will improve his cooling.

I agree with Supereal that adjusting the timing with the position of the screw on the side of the distributor will not make enough of a difference to cause or relieve overheating.

From his discription of how it overheats, I suspect something like valve timing or water pump cavitation. A vacuum gauge reading and a compression reading will give more clues as to the cause of the overheating.

Tom


Old Henry    -- 06-05-2013 @ 7:54 AM
  It looks like everything outside of the engine is probably right. If there is a lot of build up inside of the engine that can cause overheating. To eliminate that possibility fill the engine with vinegar and leave it in for a week or so before flushing it out. That may help. Also, remove the thermostats.

Old Henry
(The older I get, the better old looks.)


Pauls39    -- 06-05-2013 @ 9:07 AM
  You say that it will idle for 25 minutes with out overheating and that removing the muffler caused the cr to boil quicker.
I believe you may be running lean do to a stuck power valve or clogged main jets. At idle the carb is providing enough fuel, however at speed the mixture runs lean producing excess heat. Removing the exhaust typically causes the mixture to go even leaner which would explain overheating faster.
Check the sparkplugs. If they are bright white after a drive that would indicate a lean condition.
Sounds like the carburator is do for a cleaning and rebuild.


montanalll    -- 06-05-2013 @ 9:58 AM
  Thanks for all of the suggestions guys. I hadn't thought of the carb. I will check that out right away. That would seem to explain the strange faster overheat with the muffler and tailpipe removed. The car is hard to start and requires alot of chocking and pedal pumping to get it to run, that also seems to suggest a overlean situation. Thanks again.


Pauls39    -- 06-06-2013 @ 8:12 AM
  Hard starting may also be a indication of a blown power valve. Bad one will leak fuel with the engine off. The carburator will be empty for the next start causing a delay till the fuel pump refills the bowl.
You may need to check the whole fuel system. Is the pump putting out enough volume of fuel? Is the flex line cracked allowing it to suck air rather than gas? Is the fuel line plugged or leaking? Is the tank plugged with rust or debris?



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