Exhaust port leaking water

truck said:
Hi all,

The topic starter's, Finn Flatty's, car is in my garage and i am helping him to get the car rolling. However, this is my first flathead i've ever played with.

I tried to narrow down the possible leak source by unbolting a head bolt one by one around the cyl #8 and pouring water into the cooler. At least, next to exh #8 the bolt holes where bolt head paint-marked in white are thru to the water jacket (pic 'waterbolt'). There was no sealant on the bolt threads. Are these bolt holes normally drilled all the way to water?

Next removed the head (pic 'headoff'). Nothing wrong there that i can see. Can you point out which bolt holes might crack to exhaust #8 - to take a closer look?

The leak is in the exhaust port somewhere quite near the exhaust flange, since the water is not getting into the cylinder neither oil pan.

Any help is greatly appreciated.

Thanks.
Click to expand...
To answer one question, it is normal to apply sealer to all head bolt threads (something like non- hardening Permatex) Because the majority of them are wet holes.
 
If you look at the picture above posted by 51 Merc-ct post #17 the threads marked with arrows, as far as I could see from the pictures of the exhaust port on your engine, it looked like the bottom arrowed thread is the culprit.
The threads with yellow arrows should go to water. If they have been drilled out, it may be that the drill went too deep and ruptured the exhaust port. Remember I'm only looking at a picture though.
Have a good look in there, tell us what you find.
Martin.
 
As Martin says, take a good look down the three bolt holes that are over the exhaust passage. look to see if any have been accidentally drilled into the exhaust port.

You ought to be able to see the problem easier than we can guess what the problem is. It might not be an accidental overdrilling at all but a crack. Hard to say from here.

Good luck.

You may need to somehow pressurise the block to find the leak.

Mart.

Edit: Apologies for any auto added hot links, don't click on them.
 
Measure the depth of the (3) threaded holes adjacent to the #8 exh. port.
They should measure about .900" deep from the surface.
As measured at the most outboard hole it would take a hole about 1.875" deep to break into the exh. port. (At least on the block that I have)
 
Ok, a question. In both the original posting and the photo in #20 with the head off, it looks like water is leaking out of the lower water passage between the two rear cylinders. Looks to me like water strikes in both photos.
 
I believe the engine can still be pressure tested when re-assembled. Might save some guess and detective work.
 
Hmmmm . . . I've seen core plug wires inside the water jackets of every flathead I've ever taken apart, but have never seen them inside the actual port.

The port area itself had it's own core plug, so I find it hard to believe a wire was in there. Also, just from the picture, the 'wire' looking thing sure seems to have a bigger diameter than the wires I've pulled out of the water jackets.

BUT - as with all things flathead, there is a first time for everything!
 
Dale,
The "core wire" in the pic. These doodads that I've seen are about 3/32 diameter, I'm not comfortable calling them wires, that's why in my first response I refered to them as a left over from casting cores. You correct they arnt like the wires in the water jackets.
Oftentimes you can't see them as there out of sight deep in the port hiding around the side of the cylinderd, but you can feel them when having a poke about with a bent screwdriver. Granted the one in the pic is longer than most, normally about 1/4" tall.
I'm surprised you ain't seen them. There was a cut up 8BA block that was posted on a forum a few years ago, the exhaust port had one of these doings in it tucked around the manifold end of the port.
Martin.
 
scooder said:
Dale,
The "core wire" in the pic. These doodads that I've seen are about 3/32 diameter, I'm not comfortable calling them wires, that's why in my first response I refered to them as a left over from casting cores. You correct they arnt like the wires in the water jackets.
Oftentimes you can't see them as there out of sight deep in the port hiding around the side of the cylinderd, but you can feel them when having a poke about with a bent screwdriver. Granted the one in the pic is longer than most, normally about 1/4" tall.
I'm surprised you ain't seen them. There was a cut up 8BA block that was posted on a forum a few years ago, the exhaust port had one of these doings in it tucked around the manifold end of the port.
Martin.
Click to expand...

I've seen plenty of casting imperfections, but as you noted - not pieces of loose wire or rod hanging around in ports. This pictures seems to show a rod/bit/tap or something that has come from above and it does look like the port is cracked in that area. Hard to tell without having the block in hand, but it sure looks funny to me.
 
51 MERC-CT said:
Two head bolt holes (marked in yellow) go into the coolant core, the one marked in green is blind and if drilled too deep could break into the exhaust port but does not look like it would come close to any coolant core.
Click to expand...

Thanks for all helpful responses.

I tried to follow the #8 exhaust port, the best i could, to see holes or cracks. Visually and with a pick. All bolt holes on that end of the deck are helicoiled.

Only big enough suspicious opening (for the speed the water was escaping the exhaust pipe), is at the bottom of upper corner bolt hole (see pic). The green arrow at post #17 pic. Which, however, seems only to lead to the exhaust port - like 51Merc said. :confused:

Shooted compressed air into the port too. Suspect bolt hole bolted & exhaust valve closed, i could not recognize a leak enough. The cracked hole definately would be enough, but i can't see how it is connected to the water.

Views and ideas are very welcome.
Thanks.
 

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Update: The suspect found guilty.

Rethread drill obviously have hit the water jacket. At the end of bolt hole there is openings to water and exhaust at opposite sides.

Now the question is what chemical to use and what would be the procedure for good permanent fix.

Thanks.
 
Finn Flatty said:
Hi,
I have a freshly rebuilt 8ba. Started it today for the first time and
to my disappointment realized that the driver side exhaust is leaking
quite a lot of water, the leak comes from the last exhaust port, cylinder #8.

It's quite hard to look into the port, but when touching with fingers you can feel
a sharp corner, maybe something like a small cracked piece.
Pouring water does not help finding where the leak is.
There are repaired bolt holes with helicoils. I'm wondering if the bolts have been drilled too deep.

There is a strange "tap" in that port pointing upwards. Please look at the picture attached.
Would you have any idea about that piece in casting.

A well-known builder here in Finland put the motor together and I did not
suspect a problem like this would arise, but here I am with an issue...

-Pasi
Click to expand...
My situation was similar to yours,turned out to be drilled to far when repairing broken stud.
The result, drilled into the water jacket.
The repair involved tapping the hole and inserting a 1/8 inch NPT stainless plug. All the work was done through the head bolt hole. Search "water in exhaust port" on the forum.it has all the information you need if that is your problem.
 
Thanks for all helpful replies.
The leak is blocked now. Filled the bolt hole with high temp
silicone and bolted in head bolts while silicone wet. Seems to hold up.
 
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