Haven't seen a flathead overheating thread in a least a week... My V8-60 powered Bantam has overheated since the day I got it running a couple years ago, before I put the blower on. I have played with timing, thermostats and all of the other flathead tricks that I'm aware of. I have as big a 3 core br*** radiator (about 15x19 core) as will fit, to my estimation should be large enough for a 136 cu. in. engine. Driven it with and without hood, fenders, etc.. New water pumps. Spal electric fan, mechanical won't fit. The engine is not fresh, smokes a bit with blow by, nothing terrible. Block has some scaling, I have run cleaner through it a couple of times but it is not a freshly hot tanked block. It overheats both freeway and around town. I've been using it for short errands mostly and living with it. A few weeks ago I took it to a party 25 miles away, had to stop halfway and let it cool, add water. Now here's the odd (at least to me) part. It will get to 240 on the gauge, but shooting a handheld laser temp gauge at the heads shows less, maybe 210-220. Still hot. I have a 14lb. radiator cap, it doesn't open, no water on the ground when I stop but upon cooling off it will be down 2 quarts of water. Where is it going? Doing some testing today. There are no bubbles in the water at the cap when running. No water in the oil. No discernible water coming out the exhaust pipes, unless it is burning beforehand. Right now I have a mighty vac cobbled on the cap opening sitting at 5lbs. vacuum. With the heads off I have inspected the areas around the valves closely for cracks. Changed heads and gaskets several times to no avail. V8-60s, I've heard, do not suffer cracking as much as the larger engines. Where would a flathead block crack in such a way that water would get used and not show anywhere? I have a new engine going in this winter but I would like to know that it is going to run cool.
It has to be scale build up in the water jackets. Head gasket corrosion or water pumps aren't cutting it.
Heads and gaskets are fresh but I wonder about those water pumps. I'm going to pop the upper hoses off, start it up, should pump a good amount of water out.
If it's an older build as you say and you have known scaling, there's a good chance you have impeller wear/loss. You also say you have a 14 lb cap. I don't know so much on 60's but I would guess it's the same as a standard flatty, it's not designed for ANY pressure.
They don't have core plugs like other engines. I have looked through the head gasket, water pump and lower hose openings. Nothing too alarming but who knows what lurks where I can't see. However, I have just done some testing. I have always just had one radiator cap on the p***enger side. I removed the driver's side top hose and connected a hose straight up out of the head about a foot and another up from the radiator connection and filled both up. Started it up and no water was being pumped or ****ed out of either hose. Even more alarming were small bubbles coming out of the hose attached to the head. Only ran it about 20 seconds, maybe they would have cleared up. Wish I knew exactly how water travels and is shared between the two sides and pumps (it is, isn't it, besides in the radiator?). Going to play with it a little more, looks at the pumps again, and if I can't find anything I"ll just live with it until this winter and swap the engine out for my new one. Thanks for the suggestions.
If you're not moving any water from one column and out of the other you either have a serious blockage or your impeller went bye bye. That is unless the pump is air bound but with two open columns the water should seek its own level at rest and displaced enough air to allow the pump to prime.
The 221, 239 size flatheads do not share water in the blocks. Each side is completely separate from the other, hence the two water pumps. The only place that the water can mix is in the radiator. I ***ume that the v8-60 is the same. You should have had water ****ed down through the radiator as the water is drawn in the bottom by the pumps and pushed up through the block and out the top of the head. You should have had a small geyser there. It looks to me like you need to replace the pumps.
Yep, 60s are separate also I just learned. OK, this morning's escapades. I disconnected the radiator and ran extensions up from the bottom hoses, two separate systems. Filled each side to the outlets atop the heads. OK in this video I have the water pumps still disconnected after pulling them and verifying they are in working order, which they were. As expected, the water pretty much sits there. I know it sounds like ****, my distributor, plugs and wires all covered in rusty water. Here it is with the pumps hooked back up. Surprisingly at idle the water still just sits there. Revved up it starts to move some water. Towards the end I had to refill the p***enger side, that's why nothing there for a moment. or two. The water in the long hoses sits even with the top of the heads, put more in and it just runs out the heads. I retorqued the driver's side head, still some minor small bubbles. Going to do more running like this and see what developed.
If your saying you see bubbles coming up through the water, that may indicate a possible cracked block or a head gasket leak. Both would let exhaust into the cooling system. Which in turn, would make the engine run hot. It doesnt seem to be pumping much water though.
Stock pumps, impellers in good shape, nothing out of the ordinary so I don't know why it would be moving any less water than designed. It may be that when all hoses are connected through radiator it changes the dynamics of the flow but yeah, I expected more. Didn't see the same bubbles after retorquing head but I need to run it some more. I'm on break right now..
Whose water pumps are you using??? How did you verify that they are "good"?Did you try to spin the pump by hand after installing?? Did you check and see if maybe the pulley shaft is spinning inside the impeller??
I pulled them both as I mentioned. Had them out many times, have several spares and rebuild kits. All have the same impellers. If the spring that holds the impeller to the shaft breaks it will look like it's working on the outside but the impeller won't be turning inside. They were fine and the impellers are spinning as evidenced in the water moving when revved up. I know on a small block chevy for example, the pushes a bunch of water, even at idle.
BUT,,,,,They were moving water BUT not near enough...Maybe the spring is slipping when trying to move water.. your video shows very little water movement..from the RPM you engine was turning
The impeller is keyed to the shaft, the spring only holds it up against the housing. If the spring breaks, the impeller can move out past the keyway and the whole plot falls apart. I am going to take the belt back off and spin the pumps one at a time with a drill motor and see what that does.
your photo above does not show the pulley ..How is it connected to the shaft? maybe slipping there something is definately wrong within the pump or it would be throwing water at the RPM in your video
Can it be the distance being to big between the impeller and the pump "house", so it just twirls the water instead of moving it? Is there a chance that it's the wrong pump?
Well I do believe I have identified the problem. Hold on to your underwear, this is a good one. First I ran the pumps with a drill motor, no difference. Then I came inside and ate a big sandwich. And thunk. Thunk about how the impeller moves the water. Then I removed the pumps for a look inside... Well, as you can see from this spare block I have, the water comes from the hole in the middle and exits through a slot on the side just visible at 1 o'clock in the photo. Back over my heap. It's block is an old Midget racer block, nicely ported and relieved. Also has holes above the pan rails for extra cooling lines. Bad photo, high noon sun, but you can see the area where the water enters is broken out, both sides. I can only surmise that some other type of pump was run on this engine, and this area removed to enhance flow or some such. Obviously not going to work with the stock pumps, which were installed when I bought it, but I don't think it was ever run in my truck. The pumps are just churning the water. So I'm sure that's the problem. Nice to know at least. Appears the only way to run this block would be with another (electric?) pump system. However, as I mentioned in my first post I have a fresh motor waiting to go in this winter so I can continue to do short trips around town like I have been. Come on rain! Thanks for all the replies.
Glad you found the problem....Do youy have an extra front cover thats in good shape???The cover that the pumps screw into.
I do on another motor but it looks to me like the broken off bit is part of the block not the cover. Here's the back side of a timing cover with pumps in place from the 'net.
There was a Chevy cross over conversion water pump mod that has been done. Maybe? Or you could try to mill off some sort of divider plate off the pump shaft? Guessing on that one. Electric looks like the way to go. Cool setup, very neat
Hmm that is an interesting thought. But by the time I re-engineered the motor mounts and pulleys I could just stuff my new block in. Thanks though, I love outside the flat thinking.
Funny what new thoughts the mornings bring. Before I put this back into one lump I might as well turn up a couple of washers the size of the missing pieces and epoxy them in there. Should be able to restore to original configuration and see how much it helps the cooling. Will report back results, how refreshing it would be to drive around for an hour and have the gauge stay under 200. I'll video the same tests after I get it together.
Bump. So to catch up, my washer and JB weld block repair didn't work. I suspect the washers did not provide the proper water pump vane clearance, or something. So I have moved on to my replacement engine, and today while I was giving it a bath tried the same test as before with an electric drill. Learned a couple of things: 1. Pumps a lot more water than my old ******ed up engine (still in running truck). 2. Obviously a lot more water gets circulated through the front of the block than the back. This is a known issue and race engines are usually modified in some way to get water circulating at the back of the block. Those engines though usually have crank driven water pumps and be plumbed anywhere you want to drill into the engine. With the stock pump, which I am pretty much forced to use due to clearance, I'm not sure how I can accomplish this.
The heating issue may also be in the mathematics since it has been hot since it was installed. All the efforts to resolve the heating issue may be impossible if the system cannot heat balance. Once the heat has soaked into the block then it could be too hot. All the work done may be chasing symptoms instead of perhaps the root cause. Possibly more heat in than heat out with an under sized radiator. It may be worth talking to a radiator manufacturer as to what the radiator surface size should be for the engine. (ie) The size of the rad that would be used with that engine in the original fords compared to the rad in the Bantam. You may even be able to calculate what is happening as an engine should create a btu value/hp and what the btu capacity would be for the radiator. High performance pump like Drake or Speedway may help as well. Heat exchange is best when the velocities of the fluid and air are p***ing one another very fast in opposite directions over the exchange surfaces. There was a flathead on this forum or Ford Barn that was mysteriously losing coolant. It eventual turned out to be a hairline crack in the block an an exhaust runner. A micro crack may need pressure to weep into the exhaust and when the engine cools it would **** air in with the engine/rad cooling down. A small weep with blow by & smoky exhaust may go unnoticed. They use vacuum breakers to protect an exchanger when all the valves are closed. The cooling down has enough vacuum to collapse an exchanger so the va***m breaker allows the system to inhale. A micro crack in a block would act like a vacuum break & allow the system to pull air into the engine's water jacket that could hide in the block until the engine is started. A fine crack may tighten with a cool block so that a leak would be a hidden weeper. Just a thought.
Thanks for mentioning this ^^, I have suspected something similar for a long time. Mine goes through water with no apparent leak as well. I'm just going to put the new engine in with stock cooling system and take it from there.
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