Still fighting cooling problems on the coupe - 8BA...new radiator, head/intake gaskets, 180' thermostats, and radiator cap... filled with 85% distilled water, 15% coolant, and a quart of Purple Ice...timing set at 6' adv at 800 rpm... electric fan. Took it around the block yesterday for the first time in a month or so... gauge said 200', but when I got back to the house it was puking water from the overflow. I know this thing can run cooler, so big question is 'Can water pumps go bad?'. My take on my drivers has always been that water pumps don't go bad unless/until they leak - these don't leak. Should I think about fixing/replacing the pumps, or am I missing something obvious?
If you radiator was full to the top when you started out, normal expansion would cause it to puke. It takes 212 degrees F to boil. If you have a 7lb cap it won't boil until over 220. If you're running an unpressurized system let it puke out the extra and then leave it down that much. Keep us posted an what else you find out.
AV8Paul may have your answer if it's un-pressurized. My Model A banger used to be the same way. Puked the top 3 inches out of the radiator when you filled it, but then ran fine all summer on what was left. It just didn't like a full radiator.
My Origian typ radiator is always 2-3" low on water...Otherwise it will puke it out. And works like a dream... A big cause of overheating on flatheads is Timing, so double check your timing first. Regarding water pumps, i guess once in a million the impeller can "fall of" the axle i guess, otherwise the leaking theory is a good one. Regarding the timing checkout what MR FlatheadJack says.
Skip Haney from Florida makes a high volume flathead pump that also uses the new style bearings. I haven't personally used these but Every who has installed them are more than happy with the results. I would first check the items mentioned above but also consider a head gasket or cracked block issue. A friend of mine installed a rebuilt engine with the same symptoms only to find a cracked block problem. I hope someone has Skips contact number here. Or you could go to Ford barn discussion board and request it there.
I've had my share of flathead water pump problems, but they were always either leaking or siezing up, never anything else. My guess is your pumps are fine. As for the coolant puking out the overflow, that's normal for a full radiator. As the coolant heats up, it expands and creates pressure and that pressure has to go somewhere. Also, when you shut your engine off, the temperature of the coolant actually spikes up, creating even more pressure. That's why they tend to puke more just after you shut them off. (you probably already knew all of that) If it runs hot while moving at speed, the problem could be the radiator (too small or maybe clogged). If it runs acceptably cool at speed, but heats up idling in traffic, the problem could be airflow (fan, shroud, sheet metal to duct air thruogh through radiator).
Flathead cooling problems are common it seams but I've found it often to be a gauge out of calibration. When heating problems show up on any motor but seems mild I alwayse use a Candy thermometer and stick it in the Rad. just to make sure. You wouldn't belive how many brand new gauges I've found that were as much as 20 degrees off. Another thing I do is time with a vac gauge. Set your carbs as best you can then watch the vac gauge while you advance the timing. once you have found max vac back off or retard it 2 inch pounds of vac. and lock it down. I've used this method for more than 40 years and it works for me, hope you have the same results. The Wizzard
Good stuff guys - thanks. This is the first I've heard about the 'not liking a full radiator' angle, but this may be a big part of it. I'm still tweaking on the timing to fix an off-idle stumble, so I'll continue to focus there. If I reach a breakthrough I'll post an update.
Try 2 deg at 450-500 rpm for the initial and then it should be 22-24 by 1500 for stock or mild. Can you measure the temp at each head? Besides initial timing the most common causes of flatty overheating are in no particular order. Wrong or weak advance springs Leaky dizzy diaphram Leaky head gasket Stuck thermostat (or none) Collapsing hose Radiator blockage, wrong cap Restricted water passages in block or head Slipping pump belts often due to scored bushing or bad bearings, dont want too tight either No hood Fan location, should be at least 4 blades That should be enough for now.
By the sounds of their past history, any temperature short of cracking the block and any temp above blowing a freezeplug. Mine runs between 170 and 185 degrees depending on the outside temp and the traffic pattern.
what is the recomended safe temp range for a flathead? I like to shoot for 180-200 with a 7 lb cap system. Too cool and you can develop sluge problems as the chemicals fall out of suspension. Short drives where the oil never gets to full temp is no good either.
286 merc just touched on it but I don't know how many guys have done this.....check the size of your radiator cap. Not the pressure but the length. most newer (post mid 50s) are .50 tall whereas the older ones were 3/4" to 1" tall. If you bought a new cap then the overflow res is always open and the system cant build pressure. just a thought, I made the mistake once a few years back when I was new to flatmotors and I'll bet I have had 5 guys ask me the same question and have had the same problem.
What distributor are you running? If it's a stocker, it's not easy to find out what it's actually doing--revving it up in neutral and checking tells you nothing. If it's a recent Mallory, it needs a complete checkout--they seem to come with way too much advance, and the lack of vac advance certainly isn't helping at cruise speeds. Advance is particularly important on a flatty, because besides killing power, running retarded greatly heats up the exhaust--which runs right through your water jacket for about a foot!
All this talk about the engine gets hot because of the timming...What should the timing be set at? Why don't you set the timmming at full advance? I've never worked on a flat head before, but I've always set my engines timming at full advance. What is full advance timming degree on a flatty?
Well, with 8BA type engines there are difficulties--the stock distributor full throttle curve depends on venturi depression, and so only functions at actual road load--revving it up in neutral doesn't tell you squat, and you can't eve figure out how much or when it's going to advance without some fairly elaborate trickery. Curren Mallory's have at least sometimes a small-block chevy curve, maybe 10 degrees more than is wanted, so if you set it to full advance without altering the curve, your initial advance will likely be after TDC! To start, you've got to either go through the drill of figuring out what the stocker is actually doing or get an aftermarket and figure out it is doing! Due to the bizarre design of the stock system and the abject collapse of Mallory design and quality, life is hard...it's not like a Chevy SB, with a good original setup and a huge aftermarket of decent choices. My choices here would be to use an ancient flattop Mallory and spend half my life hunting for tuneup parts or to investigate the new MSD--but in any case, I wouldn't assume anything to have a usable curve until checked out.
Is there a way to set up the distributor with a mechanical set up...that way eleminating the vacum portion. Then maybe a petronics set up for it? I've seen magnieto set ups for flattys that don't work on vacum. Sounds like that old vacum dist. is nothing but a crap shoot for timming.
One problem not often addressed is rust from a newly started engine. When an engine sits for a while and dried out, the rust gets flakey. When it is installed and run, the rust breaks loose and stops up the new radiator.You should always blow it out if possible. I have heard of panty hose in the return hoses to the radiator to trap the rust. Good luck
Sorry - forgot the dizzy in my original post - it's a Mallory dual-point with Uni-Lite conversion done before I bought it - no vacuum adv. In timing it, the initial is about 6' adv at 800 rpms (doesn't idle any lower) and hits 20' adv at about 2000 rpm. Also, it runs cooler at idle than at speed, and it won't really idle below 800 rpms... running 3-97s with direct linkage (non-progressive). If I advance the timing to 10' at 800 rpms it will idle better but loses much of it's off-idle torque and doesn't really help the cooling problem - it still doesn't detonate with this much advance, but it's not nearly as much fun to drive. Still think it's timing-related? Maybe Mallory issues?
Check your gauge. I just installed 2 stewart warners (one for each head) in my 51. The stock gauge, even with new senders, always read hot, but it would never boil over. I spent this fall chasing a problem that I just found out never existed. I even replaced the radiator. After the run-in test with the new gauges, one head runs at about 170 and the other runs at 175. Timing may be an issue, but start simple first. TDC
yeah, my guages are crap. I have to thump one to get it to work, mine goes to 180 and stays there regardless of outside temp.....
I went ot speedway. They were having a special on SW race gauges. The triple mount, water temp, oil pressure, and fuel pressure (not using this), for $60. (these are the deluxe ones, 2 5/8"). I then had to buy an individual water temp for the other side, to match the other gauge. This is where they whack you. $48 just for one gauge! But the results are WAY worth it! TDC
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