Hey Folks! By way of introduction, I'm Jim, and I am the proud owner of two "new to us" old Fords. For myself, I have a '50 Custom Tudor...and during the search for my car, my wife found a '51 F1 that she couldn't live without.

Since she is so understanding...and I am sure she will wander along here soon...getting her truck on the road is the top priority. The truck runs great, fires right up, idles down smoothly, but tends to run hot (according to the aftermarket guage the PO installed). No steam from the vents, no bubbles in the coolant, no water in the oil. Running a 4lb cap that looks old, but functioning.

So far, I have replaced the water pumps, thermostats (160), flushed the system, and replaced it with about a 30% glycol mix. If anything, she's running hotter. According to the guage (need to confirm with a thermometer), she is running around 190-200 when idling, but gets up to 230 when driving--although so far that has only been around the block a couple of times on country roads, up to about 35mph.

I'm looking for the most economical path from here. The radiator seems to be flowing well, but it is hard to tell what condition its really in. I know it has a couple of seeps in the upper tank, but that is it. I have vacuum timed at idle, but haven't checked the vacuum advance.

The truck has a non-original fan and no shroud. The fan is a 5-bladed, assymetric deal, and tends to slide back and forth on the shaft about 3/8 of inch (which can't be helping). Any good suggestions on a fan and shroud? How about estimated prices on a radiator rebuild versus the highway robbery that is a new on? Anything else I should be checking?

My wife would like to keep her flattie--but there is a cost break at some point. Any ideas would be much appreciated!

Jim

 

The two biggest things affecting flathead temps is 1. how much crud the system has in it and 2. timing.

I had my radiator re-cored when I started driving it and it solved all sorts of problems. It will sit and idle all day long without overheating, summer stop and go traffic doesn't even get it too warm. I found a local radiator shop that put in new cores - cost me about $280 six years ago. It was the best investment I've made.

Without seeing your fan its hard to tell what you have or what to replace it with. My preference is the 6 blade truck fans. They're noisy, but they pull a hugh amount of air. I can also tell you the shrouds are critical. Henry knew what he was doing when putting them there. You have to have the deflectors in the hood, beside the radiator and under the grill in order to get the air where it needs to be.

The block can also have left-over casting sand in the lower parts that don't help. If you ever have it out of the truck, dig around with a coat hanger and a hose. Bet you'll find some.

I'd put 180 deg thermostats back in. Flatheads aren't afraid of heat and as warm as it says it is, you're above the opening temp for the stats. Too cool and the combustion by-products in the crankcase don't evaporate - destroying things from the inside out.

I've run my 48 as a daily driver and I've learned to watch and listen to what the engine tells me. If there is no cracking and popping, no bubbles or foam in the rad, no discoloration, no steam, etc. sounds to me like you can just run it!

Flash of light!! Was the high temp on startup after changing the t-stats? I've had air pockets keep the stats from opening until the engine got really hot. My solution is drill two 1/8" holes in the flat rim of the t-stat to allow air in the head to percolate out.

Sorry this is so long. Tell your wife she's right about the flathead and the 51. I think it's the sharpest one of the bunch. I've got two 48's and a 52. Welcome to FTE and flatheads.

 

I agree with installing the 180 t-stats. I use my 51 F-6 to pull and have not had any heating problems since going with 180 degree thermostats. I also use 40 below additive from pro-blend. When the truck is at operating temp place your hand on diffrent parts of the radiator to see if there are any cool spots. A shroud is also very important I may have an extra one if you need.

 

Mt,
Can you tell me a bit more about the six bladed truck fans? I think the F1 came stock with a 4 blade. Another question, should there be forward and backward play in the fan pulley? It doesn't seem like it should. The fan was clearing the stock pulleys, but when I put it back on there was some interference with the Speedway pulley noses. I don't think they are any longer, but I may have missed something in reassembling the fan.

As for the thermostats, I will look at some 180's. The heat after installing was after the thermo's had opened...and I did drill a small hole in the apron to let the trapped air out. Looks like a recore or a new radiator--with a shroud, is in order.

Jim

 

take it to a rad place that has a diagnostic tool that measures the amout of combustible gases in the coolant, it could mean a cracked jacket/head/block. If you can find a place that can do this test it would tell for sure. Otherwise, maybe the jacket is full of crap and only lets some coolant flow through it. Try to flush it out with a strong stream of water mixed in with compressed air through a headbolt in order to break up any sludge that might be out there and flush it out the water pump. Ylou'll have to remove the thermostats to do this. maybe a 13lbs cap wouldnt hurt either. My fan is a 4 blade and not shrouded on my 239 and i can drive all day on highway and not over heat so i personally think your fan is good enough. Kinda of weird, i was listening in on a conversation with my flathead parts dealer and the guy he was talking to had the same/similar problem so im passing on what he said. Good luck!

 

Jim, there shouldn't be any play in the fan hub. Something isn't right with your fan. The speedway pumps should fit fine. I don't know too much about the 6 bladed fans except that all my trucks (F1, F2 and F6) have them. I've also heard that they were used on the larger work trucks so the F1's might not have had them. Watch ebay for 8BA fans and you'll see them once in awhile.

effieman, I doubt you can get enough pressure thru a head bolt to break any serious amount of sludge loose in either the block or the radiator - there are just too many 90 deg angles to keep the pressure up.

For the rad, pull it out and flush it. Do not use a 13 pound cap - you'll blow the top tank seam apart. Stock used 4-7 pound caps

 

The flathead is particularly sensitive to timing. It must be the cylinder head temp issue with early and late firing but I've seen a bunch of change in the temp by working on the timing. Flathead Jack in northern CA swears that most of the high temp issues come from improper timing. Its cheap to experiment with it.

 

Folks, thanks for all the suggestions. Obviously something is amiss with my fan pulley. Any thoughts on where to pick one up? I've checked the sites I know...and no one seems to carry them.

Jim

 

oldcarcenter.com its based in Langley B.C. Canada. Jim (his name is Jim too) should have it, theres a catalogue you can download and has all sorts of vehicles (mostly flatheads) so im sure if you look through there you could find something. Im canada shipping is free over $40 but not sure about the states you can email them and find out tho. They are pretty good. Check it out

 

Jim,

Where are you located in the Republic. I'm in the Houston area. I have a friend who travels frequently to Corpus and I make multiple to the the DFW every year. I'm have assembled quite a collection of broken flatheads. I have a few radiators as well. A fellow member (F6Guy - Matt B.) PM'd me suggesting I find out where you are in the event you are nearby and I might be able to help out.

Carl G.

 

You NEED a shroud. Period. I would idle fine, as soon as I drove it would overheat. Shroud fixed most of the problems.

 

i dont have this problem and i dont have a fan shroud on my 239

 

It's a tad warmer down here.

 

pffft just so you guys know we all dont live in igloos and it gets just as hot here in the summer as it does there, you just have it for longer periods of time

 

Effie,

I don't dispute it gets warm up there but 100* days up there are mighty rare and I suspect your flattie may run a bit warmer on those days perhpas making the shroud necessary.

BTW - we haad snow in Houston two years ago on Christmas eve and we were the northern edge of the storm. Admittidaly nothing like what you folks get but I wanted to pioint out that the weather thing goes both ways. That said, my dumb a$$ just got back from Portland and Spokane. I forgot to bring a jacket. It was 90*+ when I left here and it didn't occur to me that it might be a little chilly up there.