8BA block concern

3twinridges

3twinridges

Well-known member
Past couple of days Dad and I have noticed water drops in our newly rebuilt 8BA from the exhaust crossover pipe. We don’t think it’s coolant but I can’t rule it out. We started it two days ago to blow out whatever condensation might be in it. This morning it was weeping again so to rule out a gusher I took the drivers side exhaust manifold off. The inside of each exhaust port was damp with some moisture but no drops or a trickle or anything like that. We started it again and no white smoke or anything. Is it normal to be getting that much condensation?

JB
 
My ‘50 drips moisture from the exhaust frequently. If your not losing coolant and it doesn’t feel like antifreeze, I would think it’s just moisture...... Mark
 
It’s very humid here in Atlanta. We ran the engine today with the manifold off, no steam or any sign of issue. Ran it for maybe a minute. Came back an hour later and center port was wet. Concerned about it....hoping that if any port would have condensation it would be that one due to the design, but I also know that is the one more prone to crack.

JB
 
Combustion is formed during combustion, and shows up more prominently in times of high humidity. Mufflers used to have a small mole at the bottom to allow drainage. I always try to only start my cars if I can run them long enough to dry out the system. This condensation is the main source of sludge formation. Good grade detergent oils help to keep sludge in suspension so the oil filter can catch it.
 
Went back over to the the shop and checked it, it’s coolant coming out of the center exhaust port. I pulled the plugs on those cylinders on no sign of a flooded cylinder. I cannot think of any other reason other than a cracked block. I know the machinist repaired one or two head bolt holes but I wouldn’t think that would impact the exhaust chamber.

JB
 
did you use those exhaust dividers? sounds like it is weeping up a head bolt? I would retorque the head bolts, drain and refill with water only and put some sealer in the block and run it. I like the old fashioned barrs leak in the pellet form to stop these small leaks.
 
Alan, generally new to flatheads and this is my first v8 build. I retorqued recently the third time topping out at 60 lbs. How would a weeping headbolt in the middle bank get into the exhaust port and come out the exhaust manifold? I looked at that and didn’t think any headbolts went into the exhaust port.

JB
 
60 lbs is really a little high on the head bolt torque, could be contributing to the problem. If they are aluminum heads it is way to much torque IMO. Flatheads have fairly thin decks. If it was me I would try a stop leak product.
 
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Stop leak first . You didn't say if your running a pressurized cooling system . If you did sorry I missed it .
 
There are some folks that will tell others that cracks in the center bolt area are normal but they are a sign of past overheating that resulted in small deck cracks that start at the center bolt and spread to the coolant ports. They will sometimes not affect anything but like any crack, they have a tendency to keep on growing until the reach an opening somewhere. The center ports are siamese types so there is a lot of heat concentrated there and the cracks can extend down through the casting until the reach the exhaust port. There is no real way to get in there and make a repair so it effectively ruins the block if sodium silicate sealers won't fill the crack or cracks there.

It also could just be the head gasket. You can try sealer since it is the easiest way to approach a leak like this and results can be good in most cases. If it doesn't stop the leak than the head will have to come off to see what's going on there.
 
Try sealer as suggested, then as rotorwrench said you may need to pull the head. If you did not put a bit of silicone sealer on the head bolts when they you installed them I would do that next time. I would also use a new head gasket because this one was squashed a bit with 60# of torque. I would use 50# as the final torque after doing 35#, 45# then 50# sequential torque procedure.
I start sweating (compensating) when I hear Atlanta, I am just an old desert rat.
Just a learning experience, enjoy the adventure... Chap
 
The head gaskets are copper and have been a pain, so I wouldn’t be surprised if it was them. The torque sequences have been over a period of about two years so I could have disturbed the aviation sealer.

JB
 
I've used 2 sets of Copper head gaskets and I had an old timer tell me to coat them with a good quality aluminum spray paint. I did that and torqued them (Offenhauser heads) to 35 then 45 and had no leaks? Also used sealer on all the head studs then followed up with a good quality block sealer after break in.
 
I find that most old Ford engine have very minor coolant leaks.
I put a large bottle of Barrs stop leak in every one of my engines
along with 2 bottles of Purple Ice and whatever anti freeze you
like. The P.I. treats the inside of the block and cylinders so the
heat transfers into the coolant better. I use the Barrs with the
copper flakes. Run the engine up to 200 degrees and shut off,
DON'T remove the radiator cap. Let it sit over night before
removing the radiator cap. Sitting over night with whatever
pressure is in the system will force the sealer into any small
leaks. Under certain temperature conditions you will still get
condensation out the exhaust pipes. G.M.
 
Condense will burn right out within a minute or so. A leak will usually show up as steam coming from the exhaust at idle and may do that any time the engine is idling until the leak is stopped up. Most of the water glass manufacturers will give you instruction for their product. Most required the coolant to be drained before treatment. Water is used during the treatment then drained after several heat up and cool down cycles to get the unused sodium silicate out of the system. The drained coolant can then be reusded or new coolant can be used as appropriate.
 
Why don't you get it out & DRIVE it for a while every day for a month & see if it changes. I think you have condensation based on the short time you run it.
 
Thanks for the posts. It’s weeping coolant for sure out the center bank. Before I replace the head gasket or put a stop leak in it I am going to see if I can pinpoint the leak with a borescope. It should be here by Friday.

JB
 
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