Hi guys hope I have this on the correct page? I have a freshly built 69ab I puchased already built and run in from and machisted from memory 20" over size piston other than that stock as a rock. I removed the cast heads ,replaced studs and fitted a new pair of Eddie Meyer repo heads Thickstun PM 7 and a new pair of 97,s also running a Harman Collins mag rebuild. Cooling system is a non pressure original 33 radiator and I'm not using thermostates. Engine starts and runs great, problem is when running down the high way she pumps a heap of coolant out the over flow. When I remove the cap it is aerated like a milkshake. Also when idling looking in radiator coolant seen fine once I step the rev up I can see a heap of bubbling. Before I remove the heads is there any thing else I should check? Or am I delaying the inevitable ? Thanks heaps in advance Fnjunk.
If it is bubbling then it is possible you have compression leaking into the water jacket somewhere. First thing I would do is retention the heads and drop some good quality seal up in it and see how that goes. I have just started my new flatty and it has taken a number of heat cycles and re-tensioning to get it right and keep the water in. Also in terms of non pressurised can you run say a 7lb cap so it has some pressure? And have you checked the temp with a temp gun - they are about $35 from Jaycar and worth their weight in gold
Thanks acme I just retentioned the heads there at 45ft Didn't really want to run crack sealant (may have too) Was considering ripping the heads off tomorrow and replacing gaskets and spraying them with Holmar. When you say keep the water in yours where was it leaking from?
Don't think I can run the pressure cap as the over file is in the centre of the radiator core not out of the neck.
Mine was weeping between the head and the block - gasket was not pulled down tight enough but also weeping / wicking up the head studs. I stopped the heads weeping but was unable to seal the head studs so I had to pull the heads - in the end I sealed the studs with the GM heads stud sealer not cheap but great stuff. I used hylomar with the first gaskets but not the second set.
Is the aerated milkshake stuff oil and water ? If so, you will have to renew both. I was told to torque heads down, put some miles on it, re torque, put more miles on it and torque for a third time. I did put them on and re torqued once. Hopefully others will comment on this.
Clem it was not oil was just aerated water, I was hoping someone would say water pumps can cause this? I also used GM sealer but didn't spray the gaskets as I have used copper coate with cast heads but as these are aluminium I was cautious not too.
Retorque, add thermostats, and see if there is a way to put a pressurized cap on that old radiator. Might require a new neck soldered on and rerouting the overflow. But adding a 7 pound cap should really help the situation. I used to have a '39 Chevy that had a stock unpressurized radiator hooked to a SBC. There was no way to keep it from bubbling a bit of coolant out the overflow in the summer whenever I shut it off. Do you know what the condition of the water jackets is? Many problems with a flathead are caused by rusty and plugged up water jackets in the block. My flathead had the water jackets sandblasted clean when rebuilt and the car goes down the highway at 170 degrees F. But I also use a nice new Walker radiator.
It does not sound good as to leaking head gasket however with the flathead having 2 water pumps it is too efficent at moving water. I know this will not make since but you are moving the water too fast and it cannot cool. I ran thermostats and trimmed the impellers some to cure my probelm. Tex,s Smith book on flat heads covers this. And I may say an electric fan for me.
I am running an original '35 radiator. Originally ran it non-pressurized as it too had the overflow at top center of top tank. Lot of coolant loss. Eventually, I had to cap off the original fill and put a new fill at top back of top tank with overflow. I had the original overflow at center top of tank sealed off. I am running a 4 lb. cap on it. They aren't too easy to find but it is now working out just great. The 7 lb. cap was a bit more than I was willing to use on such an old radiator. Flatty runs cool all day long even in blistering heat. Andy
Start with the simple suggestions! Retorque first. see what happens. If prob continues, yank off water pump belt and look in to see if problem remains, disappears, or lessens...THEN it's time to worry about other things. Remember that in an unpressurized system that is working normally, topping up produces a short period of overflow. The top 2 or 3 inches get blown out as car warms up, then the resulting level is stable. The space created takes care of expansion and contraction and you should see no more loss if system is tight. Do go to 180 thermostats, but not til this problem is solved. Early radiators can withstand only mild pressure, sat 4 pounds or so, due to the big tanks. Again, this is something to do LATER... I opine that it can be done, never tried it, via the overflow tube. I'd get tiny one way pressure valves like the ones sold for streetrod brake systems and screw 2 into a small brass T fitting...the OUT one chosen at 4 pounds, the IN one at 2...affix the T to a rubber hose extension of overflow and put it into a bottle. Pressure plus fluid retention! One of the main effects of pressure is to help reduce areas of cavitation and localized hotspots. The ability to run past 212 is an almost entirely illusory benefit.
Is a pressure pump on the Rad cap not an option to check for head gasket leaks? I would think with it not running it should hold 5 to 6 lbs of pressure. If not keep pushing it till water shows up in a cyl or pan then I'd go fix the issue. Bubbles in the coolant really don't bother me as long as it don't Perk up over the top. The Wizzard
The original impellers do not move the water too fast. In fact a lot of Flathead's you see running in hot parts of the country run improved impeller design with excellent results. As Bruce says, pressurizing the system can help tremendously. An easy fix with retaining the original cap neck is to attach a 2-4 pound pressure valve to your overflow hose. A residual brake valve works great for this.
I like Bruce's idea. My uncle was an engineer at modine and I asked him about the no thermostat thing years ago and about guys putting restrictors in and he said you should run restrictors if you take thermostats out.They actually cause more pressure in the block than radiator. He knew his shit he worked on the penske indy car stuff.lost him a few years ago. you have other issues now but just bringing this up.
According to Smokey Y... All engines have areas of cavitation, with water doing crazy flows, or very local overheating, where you have actual boiling in a tiny space while engine as a whole is fine. These phenomena push water away from the iron, obviously not good, and pressure helps. Pressure on overflow, back pressure from stats...
If you are certain that it is not a head gasket or crack problem, your problem is most likely water pump seals. Had the same problem with my 8ba, coolant foamed like warm beer. Spent most of one summer trying to find the problem. Finally talked to an old flathead racer from the 50's. He told me that the water pump seals were allowing air into the cooling system. This only happened when the engine was running, there was no leaks around the seals when the engine was not running. Have posted this before on H A M B and on Fordbarn and have been told that the condition is impossible . Long story short, rebuilt the water pumps and the problem was solved. If you want more info or want to discuss this further, e mail me at [email protected] or call me at 705 439 2567
Are you running anti-freeze? I had the same problem as you do, but when I switched to just water, the foaming went away.
Thank you for your input guys ,a mate is coming past later with a CO tester that way I can see if there's exhaust gasses in the radiator Hopefully there isn't,If this is the case I will try running it without the belt to see if this makes a difference as im not sure of the condition of water pumps. I have a pair of thermostats I can sit on top of the head outlets. I'm off to see the radiator shop today to see if he can convert the radiator to a pressure system,if not I will make up the overflow bottle as Bruce has described. yesterday I did flush the system and filled with coolent that made no differance. I am also running a termo fan that cuts in at 160. Thank you all once again for the input . Fnjunk
If you do end up pulling the heads try using VHT on the gaskets. I always use it and never have leaking gaskets, just remember to retorque the heads at least 3 times when cold.
Thanks C69A I do use that product but was under the impression it was a no no with aluminium heads. Did a CO test today looks to be no exhaust gases in the cooling system, must say I'm happy about that. Will fit up some thermostats tomorrow as it looks to me as the water is flowing too fast at high rpm. Spoke to a local radiator shop also they are going to build me a new radiator to run a pressurised system that a couple of weeks away. Cheers Fnjunk
Some place sells a pressure valve that goes inline in the overflow putting some pressure in the radiator and then just run the stock non vented cap. Might be Mac's
Are you going to have your stock radiator re-worked to make it a pressurized one? I don't know if your shop has done a lot of this, but you might consider talking to Brassworks - they make some really nice stuff. http://www.thebrassworks.net/shop/R....html?osCsid=c83fab5116ec942373a8d6cbe025a630
Well, I see the "water moving through the radiator too fast to cool" myth has surfaced here even though your complaint does not include overheating. That said, pumping water too fast can cause your problem. Removal of the restriction caused by the thermostats can result in greatly increased fluid flow. Just check out a handy pump curve to get an idea of what I mean. As a result of increased flow, water will "accumulate" in the radiator top tank as it can't flow through the core fast enough. Remember, gravity is the only force pushing water through a non-pressure radiator. Since your overflow is essentially a fluid level control, the engine begins to pump water out the overflow. In addition, the pump suction is now starved for fluid, resulting in a low net positive suction head. This condition may cause cavitation and/or introduction of air through the pump seals. Either condition may result in bubbles in the top tank. Try installing thermostats or restrictions to see if that doesn't reduce the fluid loss. A dirty core restricting flow may also be a culprit. A pressurized cooling system will raise boiling temperature of the coolant and, of course, reduce the tendency to pump coolant out of the overflow, but seems an expensive fix when you really need to run thermostats, IMO. Good luck Farmalldan
Something else I learned a long time ago about adding pressure to a Flat Head system. The genni Henry Ford pump will often start leaking past the seals with it when you didn't have any leak at all with just therm's in the hoses. The Wizzard
I would definitely rebuild the pumps before I spent a bundle of money trying to convert to a pressure system. Converting to a pressure system will not solve your problems. An overflow bottle will collect the coolant that is pushed out, but the foaming action will eventually push out enough coolant to cause the engine to over heat. As I said in my earlier post, I have been through the same problem that you are having. Pump rebuild kits are relatively inexpensive and it is not hard to install them. Another option is to have your pumps rebuilt by a rebuilder, your local parts supplier should be able to access this service for you . As for the theory that the pumps are moving the coolant too fast, I Believe this to be a bunch of B S. Ford built millions of flatheads that ran without cooling foaming problems
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