I have had a 1950 flathead for three years and have had no issues with it. However, I am learning about flatheads as I go and hope someone might be able to shed some light on my question. I searched the site and didn't find anything in the archives to answer my question. I was working on my truck today and started it up fine and let it warm up. There was some water vapor coming out of the exhaust, but nothing out of the ordinary. As warmed up, I did add some water to the radiator. It took about a half gallon. I didn't think anything about it...put the cap on and went for a little ride. I got it out on the road and drove for 20 to 30 minutes. It ran normal and temp was fine. Car ran fine. I notice some smoke in my side mirror at stop lights on way home but didn't think to much of it. When I got home I pulled into the garage and noticed water with some green colored coolant dripping out of the passenger side exhaust from some pin holes. It didn't have oil in it. I have never had this happen before and was wondering if this has something to do with bing overfilled or do I have more significant issues? I have had water come out of overflow before but not out of the exhaust. Engine runs like a sewing machine as usual at idle and running down the road. Any advice apprciated.
Could be a bad head gasket or a split from the cooling system at a head bolt into the combustion chamber. You can purchase a kit from NAPA to check for exhaust gases in your cooling system. I would check that first.
Mine did that after I first put it together. Retorqued the heads and it was fine. Posted from the TJJ App for iPhone & iPad
Coolant coming out of the exhaust is never good. It could be a blown head gasket(not too bad at all) or a cracked head(pretty bad) or a cracked block(real bad)
Crack, probably from valve seat into bore. That area of a flathead block is really thick (About 1/2 inch) They won't leak when they are cold but as soon as the engine gets up to operating temp the crack will open up and they will do exactly what you are describing. Its not too hard of a fix, any good machine shop can do it. Usually takes a few stitching pins and a cylinder sleeve. I've done a bunch of them. Good luck.
Id pull the plugs and spin it over … look for a super clean plug … the part that don’t sound good is that it runs good. A cracked exh. port would suck.
Well they don't heal so if the level is not going down any more I'd suspect the over filling situation. Many new guys are not used to the level of the coolant in a running flathead. If it overheats then you may have a leak. You can get the radiator pressure tested without removing it. If it holds pressure you are golden. If it won't hold pressure then you need to investigate further. My old sport coupe would use some water over time. If I noticed the temp running warmer than usual, I'd add water and let it seek it's own level until it's at operating temp and everything would be fine. 20 or 30 minutes of running time and no boil over makes me think you are probably OK but you need more tests to prove that. IMHO
Tommy, he wrote he has coolant coming out the exhaust pipe, probably not ok. as said hope for a head gasket problem but it sounds like a leak/crack after the combustion. bars-leak might be your friend.
I have used this stuff called Blue Devil ( http://www.gobluedevil.com/headgasketsealerproduct.html) with total sucess a few times, the stuff is about 65.00 at the local parts store But Damn! It actually works! Cheers! laz
Maybe but a pressure test will tell for sure. Other than that and we are just guessing. I've never been able to drive 20-30 minutes with a bad head gasket or cracked block.
Before you tear stuff apart a little diagnosis will help determine a plan of attack. First step is to pull the plugs from the the block before you do any maintenance, if you have a coolant leak one will be exceptionally clean. This will tell you where to look when you remove the head. Next question, do you have a pressurized cooling system? If you do ,remove the pressure cap, replace the plugs and start the engine to determine if a leak appears with no pressurization. If you have a pressurized system and there is no leak uncapped then you can expect a leaky head gasket when pressurized. If there is a leak with out pressure this would also indicate a bad head gasket or potential casting crack. Next test is to retorque the heads and repeat past test. If you noticed a head bolt with lesser toque than others near the leaking cylinder most likely head gasket issues. Unfortunately retorquing doesnt fix the issue it just delays service. A crack in the valve seat area would usually be indicated by a whisp of white steam out the exhaust that doesnt clear up or shows up after a short period of operation. Hopefully its just a head gasket, they do deteriorate. When replacing the gasket remember to give it a good coat of silver spray paint on both sides to promote a good seal and retorque as to specs.
mine was head bolt into water jacketit was comming from middle ports took our top bolt over the middle ports resealed and it quit
I used to owm a boat that had a flat head in that had problems. When I first started it, it read water pressure, then when it got hot, it jumped up and read steam pressure, after a while the water boiled off and read oil pressure! It wasen't long before it got replaced with a SB.
Leak at bolt/stud, loose torque, head gasket, crack in block. KW fiberbond ( or whatever ) works miracles. 27.00 on Amazon.
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