Hot Rods Quick radiator question

I have the stock radiator in my '40 Dodge that is powered by a '67 Corvette 327. It has a small cam, but nothing earth shattering.

It's running hot and always has in the 5 years I've had it, but I never went very far in it. The 4 back surgeries put trips farther than 20 miles or so on hold for a while.
It never spewed, but the gauge would creep up to 220 - 230 sitting in traffic or at lights.

I see tons of these 40 thru 48's running around of all models and I was just wondering if someone knew where I can find one that will fit right into my radiator's spot? Or should I try an electric fan?

Or should I try an electric fan first? I want to put some miles on him this summer since I'm feeling better. He is getting door handles shaved as I type and I'm hoping new paint is in the near future.

Anyway, thanks in advance. You guys are always the best.

buds!
chuck

 

Lots of variables......some are "timing?", sitting in traffic - Idle RPM?, Shroud on the fan?, is it ok at highway speed?, thermostat rating?, .........before you go spending money, do your best to figure out what the deal is with the temp...... tell us more.......

 

Well, let's start with some background information.
What kind of fan do you have? Is it a flex fan with a spacer? Stock style fan with a clutch, do you have a fan shroud?
We will be glad to help get this issue solved so you can get to enjoying that car now that you feel better.
Tim

 

Thanks for the replies. It's running the stock SBC fan. 6 blade I think. No shroud or clutch. I think the timing is OK. It idles just a tad slow.

I took out the thermostat thinking it might be the problem. When I took it out I grounded out the "guts" of it to just leave a smaller hole. I wanted something to slow the flow a bit. Nothing changed when I did that. I haven't tried running without a thermostat. I have a tranny cooler mounted to the front of the radiator also and these models never had the biggest grill openings anyway.

Highway speed still runs 200 or so.

Thanks again for the replies.
chuck

 

A shroud could make a big difference. That would force air through the radiator instead of just through the fan. From personal experience do not run without a t-stat, it will run hot. Have you tried flushing it? Be sure to run a 50/50 antifreeze mix with a good cap.

Posted using the Full Custom H.A.M.B. App!

 

Start with the basics. Check your timing and set it to factory specs. Install the correct thermostat for the SBC. Next, remount the tranny cooler away from the front of the rad. You have a smallish grille opening so your rad needs all the airflow it can get. A fan shroud is mandatory with a 6-blade clutchless fan. It should encompass the entire rad and the fan should be partially inside the shroud. Flush the entire cooling system. Are you running a stock '40 Dodge rad? If so, it should be hot tanked and reinstalled with a quality rad cap. As stated, a 50/50 mix of good name brand coolant should be poured in and a bottle of Water Wetter wouldn't hurt either.

If that doesn't do it you'll need to step up to a good aftermarket electric puller fan and finally, if necessary a quality aluminum radiator. Check Griffen and BeCool websites. They're online catalogs have all the dimensions and specs. They have every size radiator you could ever want.

 

Thanks guys!!!! Great suggestions. Going through these tips are very first on my list as soon as it gets home from getting the door poppers and panels finished. I got the new door windows late last year so interior is about all finished.

I know many guys are slamming their cars on the ground and I have thought many, MANY hours about doing that also. I think mine would look pretty cool lowered and maybe some skirts and a visor.

Maybe down the road. This year we're gonna go for pretty red paint and finally put some miles on him. It drives great and is comfortable on my back. I'll still be looking for a 28 - 31 unchopped full fendered coupe to mate with a flathead I picked up years ago. But, those are wishes for another day.

Thanks again. This site rocks.
BUDS!

Chuck
(Dead Guy)

 

Block could do with a back wash, accumulated crud over the years is impeding the flow of coolant?

 

What pressure radiator cap are you running?? Just asking as the boiling point is raised 3 degrees for every pound pressure..
So if you have a 13lb cap you boiling point will be up around 150 degrees..
The figures you talk about ( 220 - 230 degrees ) are where my 39 Chev coup with 350 sbc ran, temp wise, and I never had any trouble at all.. I wouldn't change a thing.

 

I have a 1940 Dodge, 318 Poly & cast iron auto, they have been in it since 1973.........firstly are you still using the sheet metal pieces that fit either side of the stock engine, if so remove.......next get the radiator reco'd by a radiator shop and change the top to accept a pressure cap, next reinstall the thermostat, ideally one that opens about 170/180 no more....then install an electric fan, I have a pusher fan at the front of the radiator with a manual override switch only need the fan around town in traffic, otherwise there is enough air coming thru........the radiator I have is not the original, it got chucked 35 yrs ago the ones that in the car is a modified late model Oz GM car one with different tanks.........you can go TOO thick and then it restricts air getting thru, these cars have a fairly small grille and with the hood shut they can run hot.........anyway dunno if this helps..........yep, and mines an Oz built car that used a Plymouth body etc with Dodge bits.........regards....andyd

 

Also meant to add, I have an overflow bottle as you can see in the pic and am running a 13pound radiator cap, I also have an engine oil cooler mounted on the sheetmetal panel in front of the radiator behind the grille and the trans cooler is under the Oz passenger side between the chassis and the rocker with a scoop........I used to have an auto cutin switch for the fan but found it was easier just to have a manual switch and control it when needed.......regarding using/not using a thermostat........we all go thru that little game.....lol.......but in reality without a thermostat the water tends to be sent thru the radiator too quick and doesn't stay in the radiator long enough to get cooled, also as I mentioned about the too thick radiator......when I built this car in 1973 I had a stock radiator for a couple of yrs, then decided to get the thickest radiator I could find........it was 3" thick, LOTS of fins and a huge top tank.......it was o/k, more or less but about 20yrs ago I decided to see what could be done, went to a local radiator shop and 1st thing was told that the core was a little too thick with more fins than needed.......lol......thought this was bullshit...........lol..........anyway after talking to a few other people and other rodders decided to give this guy a go........the radiator is the same overall size as the stock one but about 2" thick with a few less fins, works well and as mentioned I only need the fan in stop/go traffic, once over about 30mph its not needed & is turned off..........in fact if I let the car idle without the fan for 15/20 mins it will get up to around 200 but as soon as I turn the fan on it stops increasing in temp and at idle it will bring the temp down after a few minutes to around 180.........its a 16" diameter fan, nothing special, its not in a metal shround, just the plastic mounting setup...........I also still have the sheetmetal panel that 1940 Plymouths and Oz Dodges use that's between the radiator top tank and the front of the hood........US Dodges don't have this piece, as the hood only goes to the edge of the radiator ................it maybe worthwhile making something like this to help "seal" the area in front of the radiator and help get more air thru..............sorry no pic of this piece........just realised that in the engine pic I posted on the top right hand side you can just see a brown piece of metal in front of the radiator, that's this piece of Plymouth sheetmetal that helps stop air bypassing the radiator core..........trust this helps......andyd