[Jason34]

Bought my 40 in the midwest and it ran cool till I hit home in Texas! Replaced mechanical fan, added a shroud. Then an aluminum radiator (55 chevy fits perfect). It has an a/c condenser that covers most of the rad. I added a pusher on the a/c condenser. Then I bought an external trans cooler. Next an electric fan/should combo. Due to space it was just 2000 CFM and ran hotter. Deleted fan/shroud and added a 2950 cfm permaflex. Took off large a/c cond fan and added a 10' offset small fan on the condenser. Still runs 205-225. Adjusted carb and timing.
Today I tied the ac condenser away from the radiator and it ran 190 to 210 (I live in Tampa now). It's a stoc replacement crate mtr. Could it be an internal eng prob? i.e. waterpump, intake manifold gaskets? What next? It hasn't boiled over (16lb cap), but 210-225 is too hot.

[Jmark]

It sounds like you have addressed all the normal things.

To me, 210-215 is NOT too hot. I live in AZ and temps now are 110 plus and ALL my vehicles run over 220 and have for years. To me, it's not a problem until any of them hit 240.

Mark

[DoubleVision]

Does the radiator have a overflow tank? if so is it connected? What kind of belt system do you have on it? V belt or serpentine? Is the vac advance connected to a full time manifold source or ported source?

[Jason34]

DV, thanks for the reply! Yes, I have an overflow tank connected. It's a v belt system. The vac advance is connected to the edelbrock carb. Would another location help?

JMark, my understanding is that the newer engines run hotter. This is an older style stock crate motor, not a center bolt one. That may not matter but At 225 or so it pings and there's clearly a loss of power. And it diesels when it shut it off.

[Deuce]

Most 40 Fords with a electric fan do tend to run HOT .. at least in my area ... the Hot,Humid South. I always use mechanical belt driven fans ... ALWAYS .

I have a Edelbrock water pump ( high flow ) and a 6 blade fan ... I do have the exhaust manifolds Jet - Hot coated to help reduce the underhood temperatures.

1940 Fords are a little more difficult to cool than some of the other early models. Make sure all the sheet metal pieces are in place around the radiator. I believe that may be your real problem ... That 55 Chevy radiator may be in the 40 but without all the support factory designed sheetmetal to direct airflow ... it is suffering.

[Deuce]

Here is a diagram of the Ford sheet metal for the front ...

[wildman1932]

We never want to see 220, but if it is not pucking, it is not hot.
The AC condencer will add about 10degs. The photo I see is a manual fan??? The GOOD electric should help, but only below 35MPH. Above that, a cooling system in good order, will run with out a fan.

[Deuce]

Originally Posted by wildman1932

We never want to see 220, but if it is not pucking, it is not hot.
The AC condencer will add about 10degs. The photo I see is a manual fan??? The GOOD electric should help, but only below 35MPH. Above that, a cooling system in good order, will run with out a fan.

The photo is not HIS ...

The one with the mechanical fan does not run HOT ... runs at 180 ... with a 180 thermostat .

[Jason34]

Deuce, thank you for the help and diagrams! I have a Camaro front clip so some of the sheetmetal has been removed. The side and top is good, I could probably add a piece on the bottom. I have stoc exhaust manifolds so I don't think there's too much to gain by coating them, do you?
I'll also go for the Edelbrock waterpump and then try the mechanical fan again.

Do you have a condenser on yours, if so do you have an electric fan on the a/c cond? Thanks for all your help!

[oldbogie]

Originally Posted by Jason34

Bought my 40 in the midwest and it ran cool till I hit home in Texas! Replaced mechanical fan, added a shroud. Then an aluminum radiator (55 chevy fits perfect). It has an a/c condenser that covers most of the rad. I added a pusher on the a/c condenser. Then I bought an external trans cooler. Next an electric fan/should combo. Due to space it was just 2000 CFM and ran hotter. Deleted fan/shroud and added a 2950 cfm permaflex. Took off large a/c cond fan and added a 10' offset small fan on the condenser. Still runs 205-225. Adjusted carb and timing.
Today I tied the ac condenser away from the radiator and it ran 190 to 210 (I live in Tampa now). It's a stoc replacement crate mtr. Could it be an internal eng prob? i.e. waterpump, intake manifold gaskets? What next? It hasn't boiled over (16lb cap), but 210-225 is too hot.

Problem with V8s in these old vehicles is that there really isn't space for enough nor the right type of radiator. Add to that a tight engine compartment that doesn't flow air well, then throw in an automatic and air-conditioning and you quickly run out cooling.

The typical top to bottom flowing radiator requires more face area than a cross flow. Unfortunately most hot rod radiators for these by necessity are top-bottom flow types, where there isn't sufficient space for the necessary face area nor space for side tanks.

The help to this can be a remote mounted axillary radiator under the vehicle; or moving the AC condenser from ahead of the radiator, the heat from it preheats the air flowing into the radiator making it act like it's a hotter day. Separating automatic transmission cooling from the radiator and putting it under the vehicle somewhere is also a big help as is the addition of an engine oil cooler. Cooling the engine oil reduces heat transfer from the piston cylinder walls, bearings, and valve train to the cooling system and provides an additional cooling bath thus relieving the radiator of considerable heat load, this alone will take 10-20 degrees off the coolant temp.

Of course all these remote mounted heat exchangers will require separate fans to move air over their cores. Remote mounted under the vehicle, they will require protection from debris.

A trick that seems to work quite well is a simple large diameter pipe well secured to a frame rail thru which coolant is passed before entering the engine. The cold side of the radiator connects to the pipe with a piece of hose. The pipe runs down the frame well secured to it so the frame rail becomes a heat sink. At the end a "U" fitting connects another length of pipe which runs back to the engine compartment ending by the inlet side of the pipe, then connects to the water pump with a section of rubber hose. This can be fabricated with common plumbing hardware in either steel or copper pipe. It is a more robust configuration than various heat exchangers mounted under the body and works reasonably well, better at cruise since air is moving along the frame than at idle .

Bogie

[Jason34]

Bogie, thank you for all the great suggestions! I have a lot to do this weekend to get it right!

[Deuce]

Originally Posted by Jason34

I have stock exhaust manifolds so I don't think there's too much to gain by coating them, do you?

I got over 30 degrees of under hood heat reduction with the coated manifolds.




On every vehicle I do now ... I have the exhaust coated.
On my latest project ... I had the entire system coated ... all the way to the tips of the tail pipes.

[Deuce]

I copied and pasted this from another forum ...

Originally Posted by UGLY OLDS

Fought this FOREVER on a '39 Ford Standard... Car would idle at 190* in the driveway at 90* ambient with the air on for about 45 min with no issues...Drive it around the subdivision...temp drops to 180*..( Stat temp) ..Drive 2 miles on the highway...220* & climbing.....Park on the shoulder..Let car idle ..190*...AAAAARRRRGGGG :!:
Finally got angry..( Yea,right :lol: ) & used light cardboard & duct tape to seal the front of the radiator to the grille shell...Top..Bottom ..Sides...No air coming in the grille could go anywhere but through the radiator...VOLIA :!: :!: Problem solved... The little rubber pieces on the top on the Ugly Olds radiator support that seal it to the bottom ( underside) of the fenders were worth 15* on the highway..Remember..Air in the grille area is going to take the path of LEAST resistance to avoid the radiator core...Over ..Under & Around..look at the little foam seals on a late model....Sounds crazy but it woiks.... 8) 8)

[sam83k10]

Dude,
Before you buy or do anything else my dad and I had that same problem on his 350 powered 1940 Ford street rod. Was always running hot and changing fans made no difference. We came to find out the the coolant was not 50/50 and that it was more like 80coolant to 20water. Drained the coolant and added a true 50/50 mix and it runs at 170 now. We have had NO overheating issues since the coolant was properly mixed at 50/50. It would be worth a try, might cost you 10 bucks.

[Jason34]

Sam, thanks for the advice. I've been running it 70 to 80 percent water, 20 to 30 coolant. It doesn't hurt to try more coolant.