Cooling system help needed
 

After 8 long years, I finally have my grandfather's coupe back on the road.

Drove around a little Thursday afternoon staying around 40-45mph and towards the end of my trip, a little coolant sprayed out of the top of the radiator. It was on a downshift and I chalked it up to that since the temp gauge was reading around 170.

Friday afternoon, Checked Coolant and I drove around some more and decided to push it a little. I didn't have my mufflers on yet so I was running open headers. Got it up close to 60mph and decided that was fast enough and let her coast down. Temp still in the 170 range and coolant really spewed out of the cap. Took a look at the cap (Greyhound repro) and the gaskets were pretty worn so I went to the autocrats store and got a new gasket. It improved things a little but I found that the ears of the cap were corroded to the point that they are not able to grab the ring of the radiator hole and pull the cap down tight.

Saturday after refilling the Radiator, it took about a gallon of coolant, I drove around all day. put about 60 miles on the car with no issues from the radiator. just a few very small spritzes of coolant a couple of times throughout the day and I chalked it up to the loose cap. Throughout the day I checked the temp gauge and the engine block with a laser and they matched up with the block temp reading about 10deg cooler as one would expect.

Sunday, a few more drives with no issues.

Today, I took it to the muffler shop first thing this morning, got the exhaust put on and picked it up about 2:30. The Muffler shop is on a main highway so I pushed it pretty hard on acceleration and cruised at around 50mph most of the way home, about 5 miles. No Issues.

This evening I got in it to drive a little and test out the lights. Drove about the same as I did this afternoon although I did not accelerate as hard. Hit a little over 50mph for a couple of miles on straight good road and came to a 4 way stop. Took a right and about 1/4 mile after taking off coolant began pouring out of the top of the radiator. The temp gauge was around 160. Started heading home and coolant continued to puke out of the radiator occasionally even as I babied it as much as I could. No steam, and the coolant that made it through the cowl even onto my leg was not hot enough to burn me. The car did not run hot until the last half mile when enough coolant had poured from the radiator and only then did I see steam.

What would cause my cooling system to puke coolant under load when the car is not hot?

I guess I have not ruled our overheating, but my measuring tools suggest that is not the case.

As a matter of fact, it happened one time within the first 1/4 mile after leaving my subdivision and accelerating hard.

I have ordered a rebuild kit for the greyhound cap. That is my starting point but other than that, Not sure where to look.

Thanks!

Re: Cooling system help needed
 

Get a thermal temp gauge at Harbor Freight or off the i/net.I don't believe your gauge is accurate. Even if way overheated NO water/coolant should come out from the cap, do the g/hound rebuild and get the temp gun.
Most likely a plugged radiator or corroded cooling system or stuck t/stat(s), if installed.
Others will come in I'm sure.
Paul in CT

Re: Cooling system help needed
 

Fill coolant to just cover the radiator tubes. Too much and it will come out.

Re: Cooling system help needed
 

What happens if you drive with the radiator cap "loose" with no pressure?

Are your radiator hoses literally collapsing, restricting flow?

When you remove the radiator cap and let the engine reach operating temperature, can you see water flowing thru the system?

Could your thermostats have turned sideways inside the radiator hoses, restricting flow.

Remove thermostats and see what happens? Immerse them in hot water and observe the temperature at which they open.

Re: Cooling system help needed
 

I have a laser temp gun from harbor freight and the temps I shoot are about 10 deg cooler than what the guage reads.

I'm not running stats and I don't believe the hoses are collapsing, unless they are doing it while driving. I'll get it up to temp this afternoon and open the hood and rev it by hand to see if there is any signs of the hoses collapsing.

I do see coolant moving in the radiator when the engine is running. I am pretty sure there is little to no pressure from the cap since it needs a rebuild and is essentially not sealing all the way.

I read several threads on here and at the HAMB last night. Maybe I am overfilling.

Thanks everyone for your input. I'll do some more testing based on your suggestions and report back.

Re: Cooling system help needed
 

If you have more fluid going into the radiator than what can flow through it and back to the engine, it is going to overflow. May need to get the radiator cleaned out. Might also try a pressure cap, low pressure, just a few psi and a catch can, just to see if that helps.

Installing thermostats might help as well!

Re: Cooling system help needed
 

I am with post #6 above. My basic theory is if you are having cooling issues and you do not have a full report on the condition of the radiator, then its time to go to your olde timey radiator shop and have them test it/ clean it and provide you with their opinion. This work is not expensive in the grand scheme of things and you will know a lot more than when you started. When you are chasing a bunch of variables, you have to get some solid info on the components involved or it will make you crazy.

Re: Cooling system help needed
 

When I bought my '46 Super Deluxe, I pulled the rad and heater core, to have them inspected, flushed and pressure tested, as I had read many posts about flatheads overheating. The report from the rad shop showed all was good. I replaced the water pumps to new style, all rad hoses, and went with 180 deg. stats. I would suggest that this service should be done on any old vehicle that sat around for many years.

Re: Cooling system help needed
 

I'm with "JSeery" on thermostats. They all came with them from the factory.

Re: Cooling system help needed
 

I didn't think the 33 had thermostats from the factory. Not arguing, I was just unaware.

Re: Cooling system help needed
 

By the way, I do have two water pumps rebuilt by skip.

I really don't know that I am overheating until too much of the coolant comes out for the remaining coolant to keep the engine cool.

What you all are saying about flow makes sense though, could it be that there is enough restriction in the radiator that when running at higher RPM with Skips higher flow pumps that the water cannot move through the radiator fast enough and therefore backs up and out of the cap?

Re: Cooling system help needed
 

Had issues with my 47 Monarch. Turned out the over flow tube was plugged with crud about half way replaced with rubber hose. I used a piece of string off my weed whacker to go through tube. Might want to check it out

Re: Cooling system help needed
 

High flow pumps, no/low restriction in hoses and the "toilet is overflowing" . Report back on what Mr. radiator has to say. You are close to getting this sorted out.

Re: Cooling system help needed
 

That sounds like the issue to me.

Re: Cooling system help needed
 

I did all of the recommended actions, but the most noticeable result was to use the Old Henry method of flushing the block. Amazing amount of cr*p came ot.

Re: Cooling system help needed
 

33 .s have t/stats
Lawrie

Re: Cooling system help needed
 

That cooling system is an open system therefore it can not build any pressure not even with a pressure cap. The overflow tube comes Right out of the top tank .Skip the water pump guy has an in-line 4 lb pressure relief that you place on the end of the overflow tube. Works great.

Re: Cooling system help needed
 

The only time I can recall mine doing anything like that would be because I had the radiator too full , loose cap and the theromsats would not have been open much... gave it too much too soon...

Re: Cooling system help needed
 

The temperature gauge reads only the side it is on, the other side can be overheating. and not show on the gauge

Re: Cooling system help needed
 

I agree with a radiator flush treatment and, filling to just above the baffles and no more than a 3# pressure cap.
With the older Model A's a contributor to overheating was that trusty (?) timing lever. How is the timing with your engine? Does the distributor advance when you rev it?
Just my 2 cents worth...keep the change... Chap

Re: Cooling system help needed
 

I will search Old Henry's block flushing method and try that.

I pulled the radiator last night and will take it to the shop this morning.

I have also wondered if timing was an issue leading to this problem. How do I know if the dist. is advancing? I'll admit I am very ignorant when it comes to timing and advance.

The reason I have wondered about timing is that at idle, I get a consistent "pop" from the exhaust and it is especially pronounced while shifting between 1st and 2nd when the clutch is pressed and the load is removed from the engine. Could these two things be related?

By the way, you guys are great! Thank you so much for sharing your knowledge!

Re: Cooling system help needed
 

You're right they didn't have them in 33 but should have and Ford corrected that in 34 (even if they were probably to low at 150F) .

As mentioned previously they (well at least mine) will puke if overfilled simply due to thermal expansion. Its happy running level may be lower than you think.

Karl

Re: Cooling system help needed
 

Sorry I have put him wrong in my last post -I thought it was only 34's
Always nice to learn something ! Karl

Re: Cooling system help needed
 

I went through all you are with my 35 five window. A new core solved the problem. 80 yr. old cores dont cut it especialy with newer pumps. I just cover the cores cold.

Re: Cooling system help needed
 

Right on with just filling to the top of the cores. Water seeks it's own level in the system. I may have missed it somewhere in the post. Is the radiator original, was cleaned and flow tested. I have seen mice nests in the radiator tanks, and similar debris in the heads of stored engines.

Re: Cooling system help needed
 

Popping out the exhaust means a plug is firing when the exhaust valve is still open.....cross firing in the cap or between plug wires.....or firing order isn’t right....Mark

Re: Cooling system help needed
 

Your not really showing any signs of overheating, so most likely not the issue. There is an adjust on the side of the distributor, but it is somewhat trial and error unless you establish a timing mark to check it against.

The timing is also controlled by the points being set correctly.

Re: Cooling system help needed
 

I like "BMWILLIA" , the original poster (OP) and here is why. He came to this forum with a question about a problem he is experiencing and was clear in laying out the situation. He has studied the various advices and "opinions" presented. He has followed up with answers to our questions.
He then set out on a logical process to identify and isolate and hopefully cure the problem.
Doesn't happen all the time.
Hopefully we haven't failed him. That would be bad.

Re: Cooling system help needed
 

Hi im with "chap 42" on this check your timing my advance played up intermittantly sticking [not fully advancing] and boy did it reek havoc with the temp and a real cow to workout But dont discount any of the other suggestions as they all ring true. PS Keep us up to date its always good to here it worked out for you and what caused it

Re: Cooling system help needed
 

Here is the latest update:

Pulled the radiator and brought it to the local shop. They are looking into it. In the mean time, I am flushing the block. Have the driver side soaking in some rust kill/simple green. Ran out of time yesterday to get the passenger side soaking. Will drain the driver side this weekend, pull the water pumps and flush with a water hose and start the passenger side soak. I also have the Greyhound cap rebuilt with a kit from Mac's. It looks like a much better set up than the one I had.

I have emailed Skip to see about his 3lb overflow check valve but have not heard back yet. will probably have to call him.

After reading FlatFord8's post I'm going to take a look at my plug wires and make sure I don't have any crossed up as far as firing order.

Once I get the radiator back, I'll put it all back together and run it and see what happens.

Re: Cooling system help needed
 

Brad, are you working on adding some thermostats?

Re: Cooling system help needed
 

I have looked for some, but the only ones I have found made like the 33-34 ones are for the Model A. They are 150 degree stats. Not sure if those will work.


Sent from my iPhone using Tapatalk

Re: Cooling system help needed
 

IMO you need at least 180-185 deg or even 190 deg. You about have to use the modern style thermostats or the inline ones by (not sure of the name, LOL). The second photo is the more common way to locate them, or us a sleeve inside the hose and a second clamp.

Re: Cooling system help needed
 

I have a 1935 motor with the pumps attached to the front of the heads so your second photo is not an option.

I'll keep looking for option 1.

Re: Cooling system help needed
 

Hi , have been reading this forum about overheating problems. Also older dated forums here about heat.
I finally saw where the 3pd pressure release thing went. Location Was not mentioned previously in 2013 ending date forum.
Anyhow i just purchased a 1941 super deluxe with a 1951 flathead in it. Darn thing is pretty neat to drive. I have the problem where it can sit and run, come up to temp and be just fine. Temp being 180. Should mention it seems to have a newer type distributor with a vacuum from carb advance.
If you drive it after a bit it pukes water out the overflow, quite a bit actually. It has new pumps, thermostats and water hoses installed from previous owner.
I suspect the radiator may be the problem
as it is the one that has the space in the middle and looks older.
My 1st problem is they do not show one listed my size. It is like 27 tall, 19 wide with double outlets top and bottom. Radiator guy might be able to re rod it but not sure till I get it to him. Would rather just buy new.
I am going to try the deflector idea from earlier post, mayb out of cardboard 1st to see what happens.
Other idea is, Can I just plug the overflow tube for now?
New to flatheads but its gonna be fun.
I guess to summarize my questions as I rambled on there a little
1. Can I pinch overflow pipe closed
2. Should I maybe get different water pumps
3. Where can I find the tall skinny radiator?
Anyhow thanks for your patience

Re: Cooling system help needed
 

NO experience with these, just know they exist.

Robert Shewman
PO Box 163
Kimberton, PA 19442
Email: [email protected]

Re: Cooling system help needed
 

T/stats are easy to do , get a set of modern ones from the store ,get a short length of SS tube the same diameter as the inside of the rad hose,tig weld the stats to the tube ,machine off the excess flange and just push them up into the top hoses.
let me know if you want a pic
Lawrie

Re: Cooling system help needed
 

Why is the second photo not an option?

Re: Cooling system help needed
 

I had the same thought flatjack, but I'm not that familiar with the in-head pumps. If the hoses are the same size (or close) it should work the same.

Re: Cooling system help needed
 

When I had my 46 I put some of that powdered stuff ( was Motorcraft) in the rad and run if for a while it bubbled and foamed and overflowed for a while but it cleaned out the crud and you could eventually see nice copper down the radiator throat. no problems after that.

GB