How do I diagnose the cause of my 1940 Ford overheating seems to only be an issue in the summer I guess I need to know how to check the flow of the water pumps or if I should just add a reservoir to increase the capacity of the antifreeze? Any advice is greatly appreciated Sent from my SAMSUNG-SM-G900A using The H.A.M.B. mobile app
Which engine are you running? Also, has it always overheated or did this just start (last summer, I presume)?
No I believe it has done it for a long time idk when it started believe in the 90's sometime. It is the original flathead in it. I am currently doing a flush and running straight vinegar through it as I was told it was the best option without damaging any gaskets. Correct me if this is the wrong info. Sent from my SAMSUNG-SM-G900A using The H.A.M.B. mobile app
I can't help with the cooling problem but I did notice that you joined Friday and here it is Tuesday and you already have 65 posts. Don't you ever sleep?
Hahaha literally almost never on the weekends. I am gone all week and through the day I play with the kids so I try to be in the shop as late as possible lol. Sent from my SAMSUNG-SM-G900A using The H.A.M.B. mobile app
First thing you need to do is get a infared thermometer and see what side is getting hot,it has basicly two cooling systems in one with two temp sending units going to one gauge so you could just have one side not cooling good.
I'll have to defer to the flathead experts. Vinegar sounds right, but I'd rather hear from someone more experienced with this flush method. Is your radiator original too? That is, is it the correct size, and if it's old, is it plugged? If your flush doesn't work and it's the correct radiator, I'd recommend taking the radiator itself in to a shop to have it checked for sludge. To the experts: if Roys40 has it flushed, what are the chances cleaning it out will reveal leaks? Last thing - a fan shroud may help you out. Not sure a '40 Ford came factory with a shroud (I'm betting not), but it should help if you can find one that fits.
You also need to be sure the distributor is advancing properly and that the carb is not causing a lean condition. Both these things will cause overheating.
Will it do it when it’s just sitting there idling or only when driving? Like if it sat there idling in the driveway for 45 minutes does it over heat? Seeing as it only happens in the summer I’m going to say it doesn’t sound like your standard Weird/poor timing advance flathead problems. Get a temp gun and see which side is getting hot. Could be as simple as onebad water pump
Does any water shoot out of tail pipe when it has been sitting and you fire it up? Mine did and it was a cracked block.
Your 1940 Ford has been overheating every year that it has been driven in warm weather since 1940! That's what flathead Ford V8's do. Look at the design...the exhaust is routed from the top of the block exhaust valve ports and THROUGH the block (exhaust temps can be in excess of 1000* f) warming the 'coolant' as it p***es to the exhaust ports and into the manifolds. Oh, and then the now preheated water is supposed to also absorb the combustion heat from the cylinders and heads. I think you can see how this design can easily result in thermal overload. Ray
See? Just needed a flathead expert ( not me!) But I myself learn alot on this site. I'm hoping more folks will chime in. I think you got a lot of good responses so far.
Cooling of flat heads has been discussed to long ends for 80 years or so. Hot Rod magazine had an article ***led "keeping your 40 cool" or something of that nature so a search might turn up some useful info. I used a 296 flattie in my 40 and during the building stage I made a channel for a Chevy diesel truck radiator to slide in from the side before the right fender was bolted on. It nearly touched the head light buckets on each side but the ****er ran cool.
Define "overheating"... What you have to remember is there were no overflow tanks and 16 PSI systems in the 40's...least with a FHV8, so thing is if you're filling that radiator up to the top, the 4lb pressure cap opens, and coolant comes out the overflow tube...today in a "new car" we see the coolant on the ground and that's overheating. So, (***uming that's what's happening), let the coolant do it's thing, should be down in the top tank...at least...I dunno..1.5 inches of so...probably more...but just let it go out the over flow and seek it's level, then see what happens. Edit: Are thermostats installed in the upper hoses?
[QUOTE="Budget36, post: 12356815, member: 257791" Edit: Are thermostats installed in the upper hoses?[/QUOTE] I was wondering that too. Do flatties have thermostats?
General hot fixes. Yes running your engine with 100% vinegar daily for a week will clean your system. Do make sure your timing is advancing properly. Do away with your thermostats. They are limiting your volume. Install a new set of either Skips pumps or Mac Vanpelt’s. They have improved impellers. And finally install a 2-4 pound pressure relief valve on your overflow tube. It will pressurize your system. FYI 200-210 degrees is not hot.
With overheating flatheads, I like to start troubleshooting from the front. What condition is your radiator? If it's plugged or dirty, rebuilt water pumps or anything else will not make any noticeable improvements.
Lots of good information over on the Ford Barn about over heating flathead's. Big and small chunks of rust is making its way around the engine and radiator blocking the water p***ages, using rust 911 the same way your using the vinegar will clear some of the p***ages. The best way to clean out water p***ages is to pull the heads and clean out all the chunks of rust. If you decide to have the water pumps rebuilt, there are bolts in the center of the lower water outlet, they can be a bear to get out, usually there is not much left of the bolt head.
Do a compression test, check for blown head gaskets, check to see if your radiator hoses are collapsing, remove thermostats and see if they are working in a pan of boiling water on the stove, check timing and see if its running lean.
Once you make sure all the small parts (fan, water pumps, advance in the distributor, thermostats opening when they are supposed to) are working, the keys to keeping a cool flathead are two things: a clean block, and a clean radiator. As mentioned above there is probably a lot of rust in the block, and the vinegar might not dissolve it. Removing the heads and ramming stiff wires down into the p***ages and the bottom of the jackets will loosen rust and casting sand that has been there since new. Having the radiator boiled out and rodded is also required. But good luck finding a good radiator shop that can still do this operation. I don't remember if '40 radiators were pressurized from the factory. If not, have the radiator shop switch the neck for a new one that will hold pressure. Try a 4 pound cap. It will raise the boiling point.
So I guess I have to subscribe to even my own posts? I haven't been getting any notification if this one? https://www.jalopyjournal.com/forum/index.php?threads/1089728/
Lots of great information here as usual from 40 owners. I drove my 40 to Des Moines once when it was a 100 + degree weekend. The owners manual read that if its not boiling over, its ok. My gauge was on the H but the engine never boiled over so I kept going the whole weekend and the car made the trip alright. This is not a reason to not follow the suggestions as stated; as these suggestions need to be addressed also.
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