Technical Heat issue- SBC in 1940 Ford

Hello all, I am hoping to kick ideas around on my 1940 Ford. I bought it this past summer and it runs and drives great. It’s a fresh car with a 283, stock running gear, walker radiator, etc. Pretty basic setup. It seemed like it was running hot, so soon after I got it, I pulled thermostat (160) and changed out to a 180. I also swapped out under dash temp gauge with one I knew worked accurately. The gauge will climb to 220-230 easily, stopped and idling or shut off (like getting gas). On the road it will SLOWLY come back down but never really goes below 200 once hot. It pukes a little antifreeze as well.

I drove it today for the first time in a couple months and even with it being 35 degrees out, I tipped for gas and sure enough, climbed to 220-230 after sitting 5 minutes and didn’t really dip below 200 the rest of the way home. I’m not sure what the issue could be...I’m not familiar with SBC despite them being very basic. I did do a search and most problems pointed to thermostat (which I already changed). I may try running no thermostat and see if that does anything.
I’ve never really had a car constantly run this warm. I know it may be “normal”, but it just seems odd to me. I should check timing, that I have not done. Car does run great however


Any ideas or thoughts anyone has beyond that?

 

Definitely the alternator.



Ok fine. Timing is on? No chance you have an air pocket?

 

Have you checked the water pump / impeller and / or flushed system to remove debris which may be compromising flow ?


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I have not checked timing yet, and this thing is supposed to be all new. Water pump, radiator, hoses, on and on. I bought it from a friend of mine in LA who out about 500 miles on it (in a lot warmer weather), so not sure if/how it could have an air pocket. There is no heater (yet) Installed or anything

 

Air needs to flow through the radiator to pull away heat.
Do you have a fan shroud?
https://cdn.mysagestore.com//fb54f3c5992b96d001bb16e8e92d968d/contents/VA32041-VFF/VA32041-VFF.jpg
Do you have the side shields installed?

I see the opening between the hood latch and radiator. There is an aftermarket shield for that too.

 

Nice clean engine detail and I like the alternator bracket, ‘40’s pose a problem for the alternator with their narrow, tapered hood. I would suggest getting a thermostat housing gasket, pull the 180* ‘stat and drill two or three 1/8” holes in it to bleed out any trapped air as you fill the cooling system. There are commercially available air deflectors that cover that opening at the top of the grill to the radiator, but you could easily fab one, it might help. The fan is driven by the water pump, but how far is it from the radiator core? Maybe consider a shroud. Also, the belt looks like it doesn’t wrap the pump pulley too much because of the high alternator, rev the engine up a bit and observe that the pump is being driven properly. If not then go to two belt pulleys and fit the second belt directly from crank to pump pulley.

 

Also keep in mind, with that many miles its still breaking itself in.

 

SBC which one,what year,what heads,what dist,does it have vacuum advance,is the dist curved always the same question.My buddy has a 1940 ford 4 door sedan,350 sbc chevy,hei I have re-curved the dist ,manifold vacuum ,cast iron ram horns ,AFB style carb ,1/8 hole in tstant in san jose cal runs 160 down the road,get to 200 when stopped in traffic on 90 degree day.

 

Check timing,ck curve ,put a vacuum gauge, tell us what it reads,how does it run?All this have been covered many times.

 

The part that gets me is that it slowly cools down and doesn't go below 200 when driving. The only things that will affect cooling at speed is flow and radiator. I would double check timing, make sure advance vacuum hose is on the correct port, look inside the radiator when it's running and see if you can see the coolant moving when you rev it up and check the radiator for cool spots. After it gets hot shut it off, immediately run your hand all over the radiator front and rear surface looking for cold spots.

 

Just curious why you removed the 160 thermostat for a 180?

 

Is that one of those aftermarket flex fans? If it is, throw it away and get a good stock style fan. Chevy had a good 7 blade clutch fan that would put ice sickles in the coolant. And like was stated, a shroud of some kind will help, as well as the piece on top from the hood latch to the radiator.

 

I'll be putting the 327 in my '40 soon so I'm paying attention...

 

There is no shroud and the fan looks pretty far from the radiator. The fan should be within an inch or so of the radiator, so it may just need a small spacer to get it closer. With the engine running, you should be able to put your hand in front of the radiator and feel air being pulled into it. If the spacer alone doesn't do the truck, you may consider adding a shroud.

It also looks like air could be going over the radiator instead of being forced through it. Adding the sheetmetal piece mentioned above should help with that.

Sweet '40, btw!

 

I would also verify that the water pump is not a reverse rotation pump and verify that the impeller blades are not corroded or compromised in any way.

As mentioned the fans closeness to the radiator is super important. I would run a 160° thermostat in it as well.

It should run cooler at driving speeds as the airflow is greater at speed. It sounds like you have a flow problem.

 

After getting my 327 back from the engine builder. I couldn't keep it cool. New radiator, new Stewart $35 thermo. Nothing worked, always ran near the boiling point. Finally found out the timing mark on the aftermarket damper was 8* off, retarded! Yup.

 

Good point,I set timing with a vacuum gauge.

 

I not gonna cure your problem but just tell you about my 40 standard coupe. I've got a fairly snooty little 327 in it with a Walker Z line radiator with an air condenser and a Cooling Components fan with shroud. I'm running a 180 degree stat and I also do not have a grille deflector. With the air on this summer I would get to around 200 tops and with the air off it stays at about 180. While they're not very traditional I have had several 32's with CC fan and had no heating problems to date. One of the 32's was flathead with a 3 inch shortened Z line, CC fan and it would sit in the shop at an idle and never get hot. I think you might have a combination of problems including timing and flow rate. You can also get the water flowing to fast thru the radiator so it doesn't get cooled down. In reality I don't know a dam thing just bloviating.

 

Check the timing and move the fan closer as others mentioned. I had a case where I got a radiator from a guy, new but sat in the garage. I put it in, and it was fine around town then would heat up in the highway. Pulled the radiator and flushed it, out came all sorts of mice nest crap. Put it back it and has been fine since.


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Thanks guys, a lot of you have mentioned really good ideas and things I didn’t think of! I’ll play with it over winter and see what happens. An early chev in a 40 has been done thousands and thousands of times. It should work.

I’ll heck timing first, and verify pump is correct and mess with fan/spacing. Get more serious if need be. Great ideas

 

Built many 40's with small blocks and ac etc--Cooling Components fan setup,Walker radiator--never had an issue on any.

 

I apologize for how dumb this sounds, but how exactly do you do that?

 

I have a 40 ford running a 10 to 1 sbc with A/C and a walker radiator , runs 185-190 in summer , your answer is 7 blade gm fan and a shroud........ Learn from my mistakes !!!!!!!!! Nuff said !

 

Fordors nailed it ... "Also, the belt looks like it doesn’t wrap the pump pulley too much because of the high alternator, rev the engine up a bit and observe that the pump is being driven properly. If not then go to two belt pulleys and fit the second belt directly from crank to pump pulley".

I had to do exactly that. Not in a 40 Ford but with a SBC running only an alternator that was up high like yours. You need a double pulley on both the water pump and the crank. Your second (the new) belt wraps around ONLY the crank and water pump ... no adjustment available, just get the correct belt size for the job (loosen the water pump pulley to help with the install if you need to). With this set up you get HUGE wrap around the crank and water pump.

Take a look at your present belt and it is barely touching the water pump pulley. This may not be your only problem but it is definitely a problem. Water pump is most likely slipping.

 

Fresh car? I'd check the tune on the engine-timing, initial and total, fuel mixture, etc.

 

Hook the vacuum gauge up to manifold vacuum and adjust timing to the highest setting, chevy had at least 4 or more timing marks and pointers so this is in case the wrong ones were matched up.

 

what dist is in it?

 

Coolant level without a catch tanks should only cover fins inside not full to the top so it has room to expand.

 

I'm running a 390 Cad in my '40 that started with the same heating issues you're having; plus the temp. would start rising after 10 miles on the freeway. I tried a lot of stuff this summer including bumping the timing up and connecting the vacuum advance to manifold vacuum... didn't make any difference. I ended up raising the Walker radiator up an inch which allowed me to install a larger heavy-duty fan, not one of those flex things. Also added a couple of holes at the bottom of the Walker shroud while I was opening it up for the larger fan which seemed to help on the freeway. And I am running one of those "street roddy" air deflectors on top of the grille... All of the above helped and now it seems to stay at about 180-190 on a 180 deg. thermostat. We'll see what next summer brings...
Like everyone else said, check your timing, put a GOOD fan on it that is close to the radiator and make sure all the side plates and lower pan are on the grille.