8BA block leaking water from exhaust port ?

[dono50]

Installed an 8BA engine with new rings,bearing and valve job.
Added water and a stream of water exiting thru the header on the passenger side.
Loosened the bolts on the header and the water is coming from the center port. Any help appreciated

[ford38v8]

Sounds like at least one of your exhaust manifold bolts was too long and penetrated the water jacket. I haven't had the pleasure, but I'm told that it can be repaired with sealer on the bolt threads.

[Ol' Ron]

I had a cracked exhaust port in #5 cyl. The blind hole had a bad heli coil in it. When trying to replace it the bottom of the hole broke out and water cot into the cyl and oil?? tried to fix it with some cermac stuff, but no go. Good engine too.

[Roger/Sacramento]

I had water in the exhaust initially with my motor. Head gasket leak. Check your plugs.

[Bluebell]

You want to hope its the head gasket.

[dono50]

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I hope it's the headgasket but there is no water in the oil'

[Bluebell]

If you drop of the header, you''ll be able to see if it's from one of the stud holes or the exhaust port itself. If it's a port, you'll know which cylinder to look carefully at when you remove the head. Worst case is a crack at the valve seat to the bore.

[Mike51Merc]

Originally Posted by dono50

I hope it's the headgasket but there is no water in the oil'

There are no oil passages in a flathead head.
You may have a bad gasket that dumps coolant into the combustion chambers, but only the coolant that bypasses the pistons rings will get in the oil.

You say the port is leaking. Does that mean you eliminated the bolt holes as a possible source?

It could be a cracked block. Is it leaking from the center port? The center ports are more prone to crack than the others.

[Walt Dupont--Me.]

i'll tell you a little story about a new engine I had leaking out the center exh port. I pulled the head and noticed a crack between the top center bolt hole and the water hole about 1/2in below that bolt hole. You would think the gasket would seal that crack but with enough enspection I relized the bolt was to short and the water was leaking from the crack below the threads in to the exh port. I cleaned the threads on the block good and put a good sealer in the threads and used a longer bolt with sealer on it that extended in to the exh. port and it never leaked again. That's my story and I;m sticking to it. Walt

[Bluebell]

It's a good story Walt because all these little bits help us learners to build a knowledge base about these engines. Thanks.

[dono50]

Thanks for the possible causes. I have the header off and will refill with water and see if i can track it down.
Walt, a question for you. When you replaced the top bolt was it the stock size length or longer? If longer, about how much?

[dono50]

btt

[Jack E/NJ]

Walt #9>>>>>>crack between the top center bolt hole and the water hole >>>used a longer bolt with sealer on it that extended in to the exh. port>>>

Jack E/NJ

[GOSFAST]

Pay attention to Walt here, this is good call!

I'll place some shots below here that may help??

If there's a crack AND if it's not like the "Grand Canyon", you may have a good shot at an easy repair. It's going to all depend on how "lucky" your day is in the end!

Walt has it correct with the sealer and the longer bolt, we had one similar but did the repair from another angle. The head bolt hole needs to be through to the exhaust crossover for this repair to have a chance at working!

We cut a short stud (stainless steel), placed in the head bolt hole to leave most of the original threads still visible. The length of the stud is important, 1.062"/1.125", you have limited threads to work with and still accept the head bolt when you've finished. The 1.062" number is preferred. This stud dimension will leave about 1/2" exposed threads with a 1/4" of the stud threads doing the holding! A screwdriver slot in the end of the stud makes the installation easier. This is seen in the photo, not all that clear, but the slot is there.

Seal up the stud with some decent sealer, we use the hard setting Permatex. Try to get the sealer down INTO the thread area, don't put it on the stud and screw the stud in, this will "shear" the sealer off the stud. Install the stud until it bottoms against the exhaust passage.

It's really a long shot, and we did it only one time, but it worked in our case. The unit was on the engine stand with no head in place, which made all this much easier.

There is no guarantee this is even your issue, but it's worth a shot. It would probably be worth the time to R&R the one head. Get a closer look??

(Add) The distance between the deck surface and the heat-crossover is 1.562" (nominal).

(Add-2) All this info depends on (1) this type crack is the issue, (2) how bad/where the crack is, and (3) stated above, your luck!



Thanks, Gary in N.Y.

P.S. If you do the above procedure don't forget to double-check the head bolt length for reinstallation. It cannot come in contact with the top of the stud in the hole during torquing! Use the same sealer on the head bolt/stud. A stud would be better served here, this could hit/rest against the stud with no issue! Good luck, if you have any other questions just contact me. Below here the photos show the stud, the stud being installed, and the finished job!

[dono50]

Gary,
Thanks for the helpful info and photos.
A question: What is the advantage of using the 1.62 ss stud and headbolt as opposed to using a longer headbolt as Walt suggested. Does your method allow for a more accurate torque setting for that one headbolt?
At this point it's certainly worth a try but it's a big leak. When I filled the radiator the water was exiting the header like a slightly opened faucet .
The flatheads are always full of surprises!

[Walt Dupont--Me.]

Originally Posted by dono50

Gary,
Thanks for the helpful info and photos.
A question: What is the advantage of using the 1.62 ss stud and headbolt as opposed to using a longer headbolt as Walt suggested. Does your method allow for a more accurate torque setting for that one headbolt?
At this point it's certainly worth a try but it's a big leak. When I filled the radiator the water was exiting the header like a slightly opened faucet .
The flatheads are always full of surprises!

It sounds like you have a pretty good leak, you might even have a crack somewhere in the exh. channel down through the block. That stud hole goes right into the exh port so you I think you can use a 1/2 or 3/4 longer bolt. Walt

[Jack E/NJ]

Garry>>>you have limited threads to work with and still accept the head bolt when you've finished.>>>

I might add that, after plugging up that leaky hole, a flathead often doesn't care too much if a head stud or 3 are missing. 8^)

Jack E/NJ

[GOSFAST]

Originally Posted by dono50

Gary,
Thanks for the helpful info and photos.
A question: What is the advantage of using the 1.62 ss stud and headbolt as opposed to using a longer headbolt as Walt suggested. Does your method allow for a more accurate torque setting for that one headbolt?
At this point it's certainly worth a try but it's a big leak. When I filled the radiator the water was exiting the header like a slightly opened faucet .
The flatheads are always full of surprises!

Hi Don, it's difficult to diagnose some of these issues over the "web", it's much easier when the all the pieces are in front of us.

Judging by how fast the water is exiting I would still recommend R&R'ing the one head and maybe the intake. You would most likely have a better "picture" in front of you??

The repair I mentioned above is very similar to Walt's idea but uses a separate piece to block off the hole at the bottom of the thread. This allows the use of the original bolt or stud, possibly only by some shortening of a thread or two from the bottom. A stud would be more forgiving, just put it as deep as necessary.

The stainless material would be slower to "burn" away over time than conventional steel. It may never, actually, but what you are attempting to accomplish is buy some time for everything involved to basically "rust-closed" on it's own. Sounds wierd but it works. Sort of like a leaking stud or freeze plug, eventually they stop (99% of the time anyway).

In the end here, it's going to be your "judgement call", at this point you are closest to the issue!

(Add) Hi Jack, caught your post late, I calculated out the numbers and after the repair I mentioned the remaining thread depth works out to be .500"+, give or take few. This is still enough threads to hold a head bolt or stud. He does have a dilemma! If I were certain about the problem/outcome, I know it could be accomplished without ever removing the head. It's a tough one for sure!

Thanks, Gary in N.Y.

P.S. The explanation of the leak now sounds more serious than a "slight" crack, I just don't know from where I'm sitting here. I'd be happy for you to "nail" this one with little effort! Good luck in any event. Keep us all posted.

[russcc]

Prescription without diagnosis is malpractice. Was the block magna-fluxed after cleaning ? Were there any cracks ? Were they pinned ? Was the block pressure tested after those procedures ? If it was pressure tested before assembly, and no leaks, you may have a simple solution to the issue.

[Bluebell]

Ruscc, Do you mean the head gasket?
It sounds like too much water to be anything else?
Gofast, wouldn't it be better to make up a stud with a longer thread, and set that stud in there? or am I missing something?

[Jack E/NJ]

Bluebell>>>Gosfast, wouldn't it be better to make up a stud with a longer thread>>>

Yeah, after a couple hunnert thousand miles, I'd like to see how easy it'd be to replace that plug with a screw driver. 8^) Sorry, Gosfast, I couldn't help myself.

Jack E/NJ

[dono50]

Bluebell, I think your on to something with that much water. I took a compression test on the right bank and cylinders #2 and #3 have lower compression.
My next step is to have the head milled,new head gasket and longer bolt trick.

[dono50]

Bluebell, I think your on to something with that much water.
I took a compression test on the right bank and cylinders #2 and #3 have less compression. My next step is to have the head milled, new head gasket and longer center bolt. Will advise

[russcc]

Diagnosis is not assuming anything. If there were no leaks under pressure, then what could be the source ? The Fordbarnes are experts and can take the logic to the next level, stp by step. Cheers

[kendall]

it may be as simple as the wrong head gasket. pull the head.

[Mike in AZ]

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just curious....why have head milled??....Mike

[dono50]

I'll check the head first for straightness,if bad, replace or mill.
The exhaust valves on 2 and 3 cylinders have a water jacket between them and the exhaust exits thrust the center port.

[dono50]

Found the water leak in the exhaust port today. I removed the top center headbolt on the passenger head, added water so it would leak, and looked up the center exhaust port and the stream of water is exiting from a hole on the opposite side of the exhaust port in line with the head bolt I removed.
Any fix for this problem or is the block trash?

[itslow]

Originally Posted by kendall

it may be as simple as the wrong head gasket. pull the head.

That particular hole won't put water into the combustion chamber if left unsealed. If unsealed, it'll dump water all over the outside of the block.

[Mart]

Are you saying you removed the stud at the top of the exhaust port, and the water is coming in from the bottom side of the port, opposite of where the stud screws in from the top?

Do you think someone drilled out a broken stud and drilled straight through the bottom of the port into the water jacket??

This does sound pretty serious.

How hard would it be to get access to the leaking hole, drill and tap it and fit a npt pipe plug?

Mart.

[Mike51Merc]

Guys:

Isn't that the same hole that is used to bolt in aftermarket exhaust dividers?

I think Mart is right, or perhaps a longer bolt to pass through the port into the lower hole.

[Walt Dupont--Me.]

It is the bolt hole where you bolt down the deidviders. Can you see how big the hole is? Maybe some good block sealer will seal it. They do make some good block sealer, cain't remember the name, someone on here might know, It's worth a try. At least the water is not getting into the engine so you could try some sealers. Walt

[dono50]

Marty,
The extra hole is in line with the center head bolt that is near the temp. sensor.
The head bolt is 7/16, if I remember correctly, however the extra hole is about 1/4 in diameter with threads. I tried a 1/4 bolt with course, no good. It might be a pipe thread.
I don't know what an exhaust divider is but does it require drilling and tapping a hole in the port? The hole is only about a 1/4 inch deep. Too bad, would have been a nice engine!

[rotorwrench]

The dividers are an aftermarket add on that seperates the siamese port a bit more to prevent cross contamination between the two cylinders. It required a threaded fastener like a screw or a stud with a slot cut into it to hold it in place.

[Mart]

Could you drill it to 1/8 npt and tease a little pipe plug into it? The taper threads should tighten up and seal it all up. I have seen the plugs with a 3/16" hex key socket in them. They'd work well, I think.

I must say, though, it's a bit hard to tell exactly what needs doing without the parts right in front of me.

Mart.

[dono50]

Originally Posted by dono50

Installed an 8BA engine with new rings,bearing and valve job.
Added water and a stream of water exiting thru the header on the passenger side.
Loosened the bolts on the header and the water is coming from the center port. Any help appreciated

Here's what I have after cleaning the the extra hole in the exh port.
Someone drilled out a broken head bolt thru the exhaust port into the water jacket, hence the leak.
It is a hole within a hole. The larger hole is 9/64 with a smaller hole that is 9/64 in the center. No threads, I stand corrected.
Might be able to use the 2 piece headbolt as Gofast suggested or tap one of the extra holes and make a plug.
Any suggestions ?

[dono50]

Corection...Correction. The large hole is 7/32 and the small hole is 9/64

[Jack E/NJ]

Not being able to see exactly what you're up against, I assume the hole you're trying to plug is fairly small. How about trying to use a self-tapping screw slathered with hi-temp RTV?

Jack E/NJ

[Vergil]

This is a cut a way of the exhaust port, might help in describing which bolt

[GOSFAST]

Originally Posted by Mart

I must say, though, it's a bit hard to tell exactly what needs doing without the parts right in front of me.

Mart.

Couldn't have said it any better, it's much easier to come in with an idea when you're staring down at the parts.

Don, from the sound of the issue the separate stud idea may work?? Would help some if you could maybe draw a diagram, even by hand, or use the "cutaway" photo above and improvise on it?

The shorter stud I recommended above could have an end machined into/onto it to act as a "cork" so to speak. This is if I'm understanding where the hole is located?? Is the hole past the exhaust port, on the far side of it??

(Add) Hope Vergil doesn't mind, I'm using his photo to help show the issue. Is the hole located where the "black" circle is on his shot? Very nice cutaway by the way!

Thanks, Gary in N.Y.

P.S. To me this still has a "ring" of repairability to it. As I say, it is somewhat easier with pictures, even crude ones!

[Vergil]

The casting is .330" thick where the black dot is right under the bolt head, uphill is a little thinner, downhill a little thicker. Picture is to be used and marked up any way one wants to.

Vergil

Vergil

[dono50]

Yes, someone drilled thru a broken head bolt into the water jacket.

[dono50]

The head bolt is bolt #1 on the head tightening sequence. On the passenger head it is located between and below the 2 temp. sensors.
Yes, the extra hole(holes} is on the far side of the exhaust port. It is a hole within a hole. Large hole is 7/32 diameter and the small hole( in the center of the large hole) is 9/64 in diameter and it's about 1/2 inch deep.
Someone drilled out a broken head bolt starting with a 9/64 drill then a 7/32 drill thru the broken stud into the water jacket.
Any repair has to be worked thru the 7/16 head bolt hole so it has its limits. I never used an NPT tap but might be the way to go, space permitting

[Marv]

If it were mine i would clean up the small holes with the correct size drill bits to get rid of rust. Then i would use a 1/16 " nickle 99 welding rod and weld the small hole up and leave the 7/16 hole alone.

[Henry Floored]

I had this happen to an 8BA I was rebuilding for a friend. I drilled and tapped a hole right through the crack. I screwed a bolt in there with sealer then had the block decked a little. I was going to do that anyway. The trick was to place the hole (fairly large, 7/16 SAE if I recall correctly) so that it intersected the headbolt hole. That eliminates the crack. Of course I had to drill and retap the headbolt hole as well. Simple stuff really. Don't forget to get some Moroso ceramic block sealer and follow the instructions. It works wonders. Send me a PM and I'll give you my ph.# if you want to talk.

[Bluebell]

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If the hole is smaller than the stud hole and directly in line. Then what about selecting a suitable type of tap. ( assuming you can get in there)
Run a tapered thread onto a suitable steel rod, and wind it in (with a sealing compound) tightening it from the out side. then grind the stem in the port, away with a die grinder.(assuming you can get in there) (pulling the off cut out to refit the head stud)
If it is not central to the stud hole, can you make up a pilot that sits in the head stud thread?
You might have to weld a stem on your tap (nice and straight) Don't tap in too far, so that the taper is in the tapped hole.
Just trying to come up with helpful suggestions.

[trainguy]

Working thru the 7/16 thd hole I would drill the 9/64 holt with a #21 drill[.159] and tap with a #10-32 tap.I would the dip a # 10 machine screw in green locktite and screw it into the taped hole, cut the excess of in the ex port and grind flush.

[Mart]

Looking at the sizes, here's what I'd do. (very similar to above.)

Either drill out to the tapping size and fit a 1/8 npt taper plug,

See what grubscrews are available locally, say 1/4 UNC or 1/4 UNF and drill with the appropriate tapping drill not quite through. Then tap almost all the way through, and put a grub screw in the hole with plenty of sealant.

I think the term grubscrew might be a UK term, it's a headless screw with a pointed end, normally with a hex socket in the end so you can wind it in place with an allen key.

Run some sort of sealer in the block as a precaution and you should be good to go.

The npt plug would probably be best, but would probably mean the head stud thread would end up oversize and would have to be repaired with a helicoil.

I think the fix should be quite simple.

Mart.

[dono50]

I believe 1/16 NPT plugs with allen heads are available. If the depth of the hole is only about 1/4 inch deep might be tough to get enough thread. I never used NPT but willing to try if guys with expertise in this area think it's possible.

[Mike51Merc]

I guess the lesson learned here is knowing the bolt length before drilling it out. That guy went way too deep on that one.

Look at www.locknstitch.com and/or www.irontite.com

What about silver solder or brazing?

[rotorwrench]

The only draw back on NPT is that they are better done if a person has access to some tapered reamers of the correct size. Cast iron is brittle and a straight hole will cause a heck of a bite with a tapered tap. To install tapered plugs is more dificult that say a grub screw (or set screw here in the US) with some high temp pipe sealant or thread locker.

[Russ/40]

I may have missed the statement, but I will assume the hole into the jacket is note tapped. I would use a pipe tap to give the hole a tapered thread. Then take a bolt of the same size and thread count as the pipe thread. On that bolt, put it in a lathe and at 1/4" from the end, cut the shank down to minimal diameter. The concept is to create a breakaway bolt that will fill the hole, and as it tightens will shear leaving the plug in place. Use loctite on critical section. Experiment in determining the necessary diameter cut to allow the shear, on some 1/2" flat stock.

[Mike51Merc]

Originally Posted by Russ/40

I may have missed the statement, but I will assume the hole into the jacket is note tapped. I would use a pipe tap to give the hole a tapered thread. Then take a bolt of the same size and thread count as the pipe thread. On that bolt, put it in a lathe and at 1/4" from the end, cut the shank down to minimal diameter. The concept is to create a breakaway bolt that will fill the hole, and as it tightens will shear leaving the plug in place. Use loctite on critical section. Experiment in determining the necessary diameter cut to allow the shear, on some 1/2" flat stock.

It sounds (and looks) like he can get a saw blade or a dremel in there to cut off the excess.

[Fe26]

Originally Posted by Russ/40

I may have missed the statement, but I will assume the hole into the jacket is note tapped. I would use a pipe tap to give the hole a tapered thread. Then take a bolt of the same size and thread count as the pipe thread. On that bolt, put it in a lathe and at 1/4" from the end, cut the shank down to minimal diameter. The concept is to create a breakaway bolt that will fill the hole, and as it tightens will shear leaving the plug in place. Use loctite on critical section. Experiment in determining the necessary diameter cut to allow the shear, on some 1/2" flat stock.

A simple and elegant solution.

[dono50]

MY neighbor suggested a pin with an interference fit and locktite for the small hole.
Any comments ? I pretty much ruled out the NPT because I don't feel I have the expertise

[Jack E/NJ]

I guess I'm still not quite sure of what you're trying to deal with. But a self-tapping screw with a bunch of sealer still seems like it oughta work with minimal fuss.

Jack E/NJ

[Bluebell]

Dono50, Do you think you can get in there with a die grinder and smooth out a plug?
I'd be trying to keep the hole as small as I could. I suggested a taper tap, so that the insert bites when it's nearly home. You can run a thread on a piece of rod and cut it to suit, so that it goes tight on the taper at the end of the thread.
Any how, good luck with what ever you decide.

[Russ/40]

Originally Posted by dono50

MY neighbor suggested a pin with an interference fit and locktite for the small hole.
Any comments ? I pretty much ruled out the NPT because I don't feel I have the expertise

Since your exposing whatever you do to the environment of the exhaust gasses, your seal must be to pretty tight tolerances, or any sealer you use will burn away, and your back to a leak. The pin idea can work, if it will stay put. That's what is compelling about tapping the hole.

As to my solution posted above, if you don't have the lathe, you could pull it off with a drill press and a good corner file.

[dono50]

Bluebell,no, can't use a die grinder. Working thru a 7/16 head bolt hole.
My friend has a lathe and will try and make a tapered pin. Got to decide whether to use steel or brass?
After I pin it I'm planning to use Gosfast 2 piece head bolt to seal off the repaired area but will use a stud instead of a headbolt. I think it's worth a try.
Thanks to all for the great ideas. Will tackle the job in a few weeks and keep FB advised of the outcome

[dono50]

One other question....Is the Moroso ceramic block sealer a liquid that will flow or the consistency of epoxy?

[Bluebell]

Re the die grinder, I mean can you get at it through the exhaust port?
I hadn't heard of Moroso before this thread.
Cheers.

[JWL]

The Moroso sealer is poured into the radiator coolant.

I do not like the concept of a tapered plug without threads. Anything you use, such as a allen drive set screw will be much more reliable with a few threads scratched into the block material. The better solution is probably the 1/16 pipe plug but any threaded plug will work with sealer applied.

[GOSFAST]

Hi Bob, got some numbers for you.

The 1/16" pipe plug looks like the best method in the end. It looks as though it can be done ALL from above the deck surface!

The "bad" hole through the exh passage needs to be drilled with a letter "D" drill, I do believe here a 1/4" bit might serve better for final tapping. The "D" drill measures .246", the 1/4" only a couple thou more. Will help to avoid breaking the pipe tap. You don't need a bunch of "torque" on the pipe plug when finished, just seal it up good. If everything is "clean" I would use Loctite, if not, Permatex "hard-setting" (#1) sealer! Eventually this will "rust" itself closed (hopefully).

I have a few more shots below on a block I have here. My only real concern is running out of tap due to the length. The tap is 2.125" long and you only have .625" showing above the deck surface! It sounds like "no problem", but you need to tap the hole deep enough to get the 1/16" plug in by at least 3 threads. This means the tap usually needs to be somewhat deeper than it looks?

While you're chasing the correct depth with the tap, I would epoxy the pipe plug to an allen wrench so you can keep checking for the correct depth. Use it as a "measuring" tool. It will keep you from "losing" the plug in the passageway!

If you have any further questions or need any add'l dimensions just contact me.

Having access to all the necessary tools here, I would do every operation through some bushings to maintain "straightness". It can be done by hand, but very carefully.

Thanks, Gary in N.Y.

P.S. The nice part with this pipe plug repair, if you can accomplish it as described here, you will have "isolated" the entire area from the original head bolt hole, you can reuse a head bolt if necessary. The left photo here shows the tap "resting" on the exh passage, the center photo shows a broken bolt AND a broken tap in there. Customer attempt at repair! The end photo shows some of our "hole-repair" tooling (bushings) that comes in handy for sure!

[dono50]

Gary,
Thanks for the research on my problem.
This week I'll see what available in set screws or pins and figure out what is best way to go about it.
No question, an NPT plug is the best way to go but I would have to enlarge the existing hole which is 9/64. Never used an NPT tap and I hate to experiment and ruin the block.
Still leaning toward pinning, set screw or self tapping screw.
Too bad the engine is in the car(46 club coupe)

[Bluebell]

Dono50, JWL is very knowledgeable as are many others. I don't think you are heading in the right direction with pinning. With hot exhaust gases flowing through there, there is too much expansion and contraction going on. Your pin is likely to come out. Pinning (as far as I know) is not a recognised method of repair. If you use an ordinary fastener type thread, you have choices of size and tpi. As long as a deformed portion of the thread bites into the other thread (you could stake it through the stud hole)It will be good.

[dono50]

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Bluebell, I think your right, better to go with a threaded fix, #12-24 set screw might work out with locktite

[Walt Dupont--Me.]

Here is one more thought. You could drill out the headbolt hole in the block and tap it for a 1/2in. bolt. You would have to drill out the bolt hole in the head also. That would give you a little more room to work to plug that water leak. Walt

[GOSFAST]

Originally Posted by Walt Dupont--Me.

Here is one more thought. You could drill out the headbolt hole in the block and tap it for a 1/2in. bolt. You would have to drill out the bolt hole in the head also. That would give you a little more room to work to plug that water leak. Walt

Hi Walt, with respect to the 1/2"-13 head bolt hole, if he goes that route he would be better served just drilling ahead of time for a 7/16" heli-coil.

Two reasons for the heli-coil, first, you end up with an initial .454" hole, this is slightly larger than the one needed for a 1/2"-13 tap (.422" hole), if your talking about an access hole. And second, like I stated earlier, it allows the use of all the factory bolts again. Either the pipe tap, my preference at this point, or threaded machine screw size will isolate the repair. The pipe tap is definitely how I would approach it with the facts I have now.

The only other info I would be interested in is how "centered & straight" is the already drilled small hole. Working "through a small bushing" and having to open up that existing hole to .246" to work with the pipe tap would actually align everything perfectly and help avoid breaking the tap! It's very difficult to tap a "crooked" hole through an access hole. That's the last thing Bob would need now. If ANY tap breaks trying the repair, the odds will be good for pulling the unit!

(Add) Just an added tip, whatever tap size is chosen, make absolutely certain to begin with a brand new tap, don't choose a used one even if it's only tapped a single hole in it's life?? Most times a tap breaks it has been "fractured" previously.

Thanks, Gary in N.Y.

P.S. Again for Bob here, with respect to tapping ANY size in that repair area, it's really much easier to break a #12-24 tap using a .177" pilot hole than the 1/16"-27 NPT pipe using a .246" hole. Both are "breakable", but obviously the smaller size is easier.

[G.M.]

Walt they make threaded inserts like you described. I have some, I think McMaster-Carr has them. G.M.

[dono50]

I ruled out pinning, so I might go with the 1/16 NPT. If I drill with a .246 or 1/4 inch do I have to use a tapered reamer or just go from drill to 1/16 tap?
Good point, 12-24 tap is more apt to break.
Where can I buy a good USA NPT tap?

[trainguy]

10-32 is a fairly strong tap and I believe that your exiating hole is smaller than the tap drill size.,I would use a screw with a head on it to seat on the inside of the waterjacket..# 12 is a weak tap a better choice would be 1/4-28 if the hole is to big for a 10-32..Since the hole is already there I see no need to use a guide bushing the existing hole will act as its own guide.It appears to be a simple fix.It you don't feel you have the skill to do the job you may want to ask a machinest friend to do it for you.The tricky part is the tapping of the cast iron and tapping the hole straight,I would use kero as a tapping fluid to lube the tap.

[Bluebell]

The problem with using the NPT, is that it is tapered, and you may not have enough room to get a proper thread cut, before the leading end of the tap hots the other side water jacket. The same appplies to the appropriate reamer.
You can of course grind both away, but it might be tricky.

[GOSFAST]

Hi Bob, here's a shot of a very simple tool that can be made in about 5 minutes on a half-decent lathe. It is a 7/16"-14 x 1.000" bolt, and washer with the 1/4" drill bit in position!

This is to drill the 1/4" hole dead-centered, it cannot miss!

Thanks, Gary

P.S. Even now I still believe this pipe plug is the best and safest method to get it done. If you know any machinists/tool makers this is a huge plus. You can actually make a similar bushing to guide the tap as well. The tap diameter is exactly 5/16". Due to that 2.125" O/A tap length you will be limited on the travel with the tap handle/driver!

[Andy]

I desided to delete what I had written as it was goofy when thought over.
I would still be glad to make a drill bushing or anythink else that would help.
Gosfast and JWL are the ones to listen to.

[dono50]

Andy,
Thanks for your suggestion.Ii appreciate all the help that I have been getting from the Ford Barn members. Will let you know about the bushing...Bob

[dono50]

Gary,
The holes are not dead center in relation to the head bolt. Nice tool to keep the drill straight. Since the hole is not centered would it still work?

[zzlegend]

I read a lot of post here on the barn and have learned a lot. But this thread has me hooked. Been following this since day one. A lot of good info so far. Good luck on this dono. Cant wait to see how this turns out. Mark.

[JWL]

NO!! Do not use the centering bushing. The only thing you are interested in is plugging the existing hole. If you "center" the drilling and tapping off the deck threads it might not clean up the wayward hole someone punched through the water jacket. You could be left with half the hole sealed and half pouring water into the exhaust system. Any drilling and tapping you do must follow the mistake which has already been made.

Forgot to mention a EXTENSION tap can be purchased for the 1/16X27 pipe thread. That will get the shank well above the deck. Not cheap, but available and much less expensive than the 8BA block.

[GOSFAST]

Hi Bob, one more time.

If the job were to come in the door here it would leave with the pipe plug as a fix. It would either be the 1/16" NPT or the 1/8" NPT. I would need to evaluate where that bad hole is located. I have the same reservations doing this as a "home-repair" as John (JWL) above.

I'll give you one more "at-home" option. This should work with no problem. I am assuming the bad hole (at the bottom) is "targeted" somewhere inside the threaded portion of the head bolt hole??

If so, get a letter "U" bit and go directly through the upper head bolt threads. The drill will be a nice fit, the existing threads will act as the guide for this size bit. Drill through the bad hole area, make certain you don't drill past the first wall. You'll "feel" when the drill has broken through!

Take a 7/16"-14 tap through the existing head bolt threads and tap new threads below. There is enough room, and the tap is long enough to pull it off. You can go all the way through (on the new hole) or you can stop the threads "short". This will bottom-lock the 7/16" stud you can now use for the fix. This is one repair method I mentioned earlier in the post. You need no other taps or bushings to fix it with this method.

It would help also to have a photo of a longer bit "sticking" in the bad hole to possibly show the "angles" up at the deck surface. I also would NOT attempt using ANY "small" taps whether or not they reach/fit the existing hole?

Two add'l tips, when drilling, try not to "lean" sideways on the drill motor, and when tapping, use both hands on a dedicated tap handle, do not use a ratchet/socket setup to tap the hole. You want to feel the feel the tap cutting pressure with both hands. It will be somewhat difficult to break the 7/16" tap when using the head bolt threads as the guide!

There's a very high "nickel" content in these castings, be careful when drilling, there will be a tendency for the bit to "grab" the material. Use "light" pressure on the drill motor.

Thanks, Gary in N.Y.

P.S. As I stated earlier, if the job came in the door here it would have some size pipe plug in the repair and still maintain the correct head bolt or fastener! But it's easy when you have a full machine shop at hand and do this "stuff" every day.

[Jack E/NJ]

JWL>>>any threaded plug will work with sealer applied>>>

Bluebell>>>If you use an ordinary fastener type thread, you have choices of size and tpi.>>>

Ditto to both above. I wouldn't try to expand or fully tap the existing hole. Yes, clean it up a bit. But, no, don't try to mess with it too much more.

Fill the hole with good hi-temp sealant and on a metal screw whose diameter will easily screw and partially bite into the hole using modest torque. If this simple treatment doesn't stop the leak, you can always reverse course, and try one of the more involved though somewhat riskier options described previously.

Jack E/NJ

[dono50]

Gary,
My neighbor mad a plug that is very similar to your first suggestion. It threads into the head bolt hole and has a rounded plug end that rest on top of the hole.It leaves plenty of thread to insert a head stud. Same procedure that you used to fix a crack.
Will try and post a photo....Bob

[dono50]

Can't get a photo to post. If you want a photo send me your email address. My email is [email protected]

[Mike B]

Originally Posted by dono50

Can't get a photo to post. I[/EMAIL]

If you'd like, email a photo to me, and I will post it for you.

But all you have to do is look below your "post box"
and find the button "manage attachments"

Then "browse" on your computer to locate the pic (s) you want to post

Select Upload"

Then "submit reply"

[GOSFAST]

Originally Posted by dono50

Gary,
My neighbor mad a plug that is very similar to your first suggestion. It threads into the head bolt hole and has a rounded plug end that rest on top of the hole.It leaves plenty of thread to insert a head stud. Same procedure that you used to fix a crack.
Will try and post a photo....Bob

Hi Bob, at this point with all the info here I would be hesitant to try that fix. I assume your planning on that "plug" to simply have enough pressure on it to "seal" the hole??

I would say in that area you will see some very high temps, 1200+, and things will really be moving around.

The last method I mentioned I feel most comfortable doing (at home), drilling through the head bolt hole and lower hole and tapping it 7/16"-14 for the stud or short set-screw. This method puts the fastener directly in the bad hole and really has little chance of leaking regardless of the exhaust temps. A set screw would also eliminate the stud hanging in the exhaust passage.

I would attempt to stop the tap short in the bottom hole and have an inteference fit with the 7/16" threads.

Thanks, Gary in N.Y.

P.S. The nice part about tapping directly through the head bolt hole, using it as the tap guide, is the hole will be consistent all the way through. It will be an "uninterupted" thread across the exhaust passage. Again, Good Luck!

[Mike B]

Here's Bob's pics:
(kindy fuzzy)

[Russ/40]

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I don't understand how your going to implement that.

[dono50]

Originally Posted by Russ/40

I don't understand how your going to implement that.

The threaded end of the plug has a slot for a screw driver. It is installed first and the bullet shaped end rest against the 7/32 hole and seals it off.
The head stud is then installed and butts against the plug. There is enough threaded area to accept the plug and the head stud.

[dono50]

Originally Posted by GOSFAST

Hi Bob, at this point with all the info here I would be hesitant to try that fix. I assume your planning on that "plug" to simply have enough pressure on it to "seal" the hole??

I would say in that area you will see some very high temps, 1200+, and things will really be moving around.

The last method I mentioned I feel most comfortable doing (at home), drilling through the head bolt hole and lower hole and tapping it 7/16"-14 for the stud or short set-screw. This method puts the fastener directly in the bad hole and really has little chance of leaking regardless of the exhaust temps. A set screw would also eliminate the stud hanging in the exhaust passage.

I would attempt to stop the tap short in the bottom hole and have an inteference fit with the 7/16" threads.

Thanks, Gary in N.Y.

P.S. The nice part about tapping directly through the head bolt hole, using it as the tap guide, is the hole will be consistent all the way through. It will be an "uninterupted" thread across the exhaust passage. Again, Good Luck!

Gary,
If I understand correctly, I would not disturb the existing threads in the block. I would enlarge the hole in the exhaust passage with the appropriate drill size and run the tap thru the head bolt hole across the exhaust passage. If the hole is not dead center would I run the risk of breaking the tap?
Please explain how I get an interference fit.(not drilling completely through?)
I ordered a 1/16 NPT tap and plugs. I know it's the best solution if I am able to do it.
I also was thinking of tapping the small hole and using a 10-24 set screw in conjuction with the plug for the larger hole. Do you think that will work?
Bob

[GOSFAST]

Originally Posted by dono50

Gary,
If I understand correctly, I would not disturb the existing threads in the block. I would enlarge the hole in the exhaust passage with the appropriate drill size and run the tap thru the head bolt hole across the exhaust passage. If the hole is not dead center would I run the risk of breaking the tap?
Please explain how I get an interference fit.(not drilling completely through?)
I ordered a 1/16 NPT tap and plugs. I know it's the best solution if I am able to do it.
I also was thinking of tapping the small hole and using a 10-24 set screw in conjuction with the plug for the larger hole. Do you think that will work?
Bob

Hi Bob, this is an important step here. If you try the 1/16" pipe tap option first, with the 1/4" pilot hole, and for any reason it fails, short of breaking the tap in the bottom hole, you still have the 7/16"-14 bolt thread repair option. This is good. When you drill the 1/4" hole for the pipe tap you will see immediatley how the bottom hole looks. If it's not a "clean, solid, straight hole" I would not attempt this method. If the hole isn't "clean" it will make tapping new threads very difficult. It isn't mandatory to use a tapered reamer for the pipe tap, it will be fine, especially with the .250" hole.

I would also still recommend using that bushing, setting in the original head bolt hole I showed earlier, to drill the 1/4" pilot hole for the 1/16" pipe tap.

If this method fails due to the lower hole location/shape, just go to plan "B", the 7/16"-14 repair.

I'm sure hoping Vergil's measurements are "on-the-money" about the wall thicknesses?? If you have .330" (nominal) you will be good to go. The pipe plugs will be .300" long and fit nicely in the thickness of the casting if tapped to the correct depth! For this reason the pipe tap would be the better choice having more threads available, with the 7/16"-14 there would be limited threads. I believe it would still work but the smaller pipe thread would be better under these conditions. And now the entire repair is totally isolated, also very good.

As I stated earlier in the thread, I'm against using any smaller conventional machine thread (10-24, 12-24, etc.) tap sizes, these are very easily broken. Working "blind" at that depth through the OEM head bolt hole just raises the risks that much higher.

Also need to remember, the "driver" for the pipe tap will be very close to deck surface when the depth is reached for the plug??

Thanks, Gary in N.Y.

P.S. Just a couple tips for any hand tapping. First, when using the smaller pipe tap, go about an 1/8 of a turn at a time and back the tap up, go another 1/8 and back it up again. Stay with this procedure until the correct depth is reached for the pipe plug, this will help clear the chips and avoid breaking the tap, and second, cast iron gets tapped dry, no lubricant. Also, there appears to be some high nickel in these castings, this will have an effect on how the tapping "feels" when cutting threads. Just be careful!

[dono50]

Today, with following tools I repaired the hole in exhaust port/water jacket.
I used the method that Gosfast recommended and it worked out well.
Drilled the hole to 1/4 inch, tapped with a 1/16-27 NPT tap and used a 1/16 NPT plug with an allen wrench head.
Instead of sealer I used JB weld on the threads/hole and tightened the plug flush with the surface.
I used the 1/16 plug because all the work was performed thru the 7/16 head bolt hole with little clearance to spare.
Thanks to all that offered advice.This was a unique problem and the fix saved another flathead.

[Mart]

That's great - well done.

Mart.

[BILL WZOREK]

This has been a intresting thread / it shows what can be done / 1 Question with many answers.
With the care taker of another Flathead being able to pick & choose the best solution
For his ( OR HER ) Problem.

[GOSFAST]

Originally Posted by dono50

Today, with following tools I repaired the hole in exhaust port/water jacket.
I used the method that Gosfast recommended and it worked out well.
Drilled the hole to 1/4 inch, tapped with a 1/16-27 NPT tap and used a 1/16 NPT plug with an allen wrench head.
Instead of sealer I used JB weld on the threads/hole and tightened the plug flush with the surface.
I used the 1/16 plug because all the work was performed thru the 7/16 head bolt hole with little clearance to spare.
Thanks to all that offered advice.This was a unique problem and the fix saved another flathead.

Hi Bob, nice going, really.

After following you here, I knew you were capable and would get it fixed! There was never any doubt in my mind.

(Add) This post raises an extremely important point when beginning a build with an "unknown" block (or even a known one) with respect to magnafluxing vs. pressure testing. "Magging" this block alone would have NEVER revealed this issue, I realize it's an "odd" one, but it does raise a point. It would have "passed" fluxing but would certainly NOT have "passed' the pressure test. Don't let anyone try to convince you otherwise. To do both is OK, but the pressure test is "mandatory".

Thanks, Gary in N.Y.

P.S. You'll end up sleeping a lot better now! Enjoy the ride.

[john in illinois]

Dono glad you got it fixed. Very interesting thread.

John

[zzlegend]

Great. Good going dono. Glad it turned out. I have an 8BA sitting on an engine stand that I am going to get to one day. This will be one thing to remember when rebuilding gets closer. Mark.

[Russ/40]

Originally Posted by GOSFAST

(Add) This post raises an extremely important point when beginning a build with an "unknown" block (or even a known one) with respect to magnafluxing vs. pressure testing. "Magging" this block alone would have NEVER revealed this issue, I realize it's an "odd" one, but it does raise a point. It would have "passed" fluxing but would certainly NOT have "passed' the pressure test. Don't let anyone try to convince you otherwise. To do both is OK, but the pressure test is "mandatory".

Thanks, Gary in N.Y.

P.S. You'll end up sleeping a lot better now! Enjoy the ride.

I'll second that. I have an example on my run in stand. Passed mag, but later found a crack in the roof of the intake runner just below the valve. Block was never pressure tested.

[Russ/40]

Originally Posted by dono50

Today, with following tools I repaired the hole in exhaust port/water jacket.
I used the method that Gosfast recommended and it worked out well.
Drilled the hole to 1/4 inch, tapped with a 1/16-27 NPT tap and used a 1/16 NPT plug with an allen wrench head.
Instead of sealer I used JB weld on the threads/hole and tightened the plug flush with the surface.
I used the 1/16 plug because all the work was performed thru the 7/16 head bolt hole with little clearance to spare.
Thanks to all that offered advice.This was a unique problem and the fix saved another flathead.

Congratulations man! That is great. This has been very educational and interesting.

[El Rat]

It really is a simple fix. Since you seem to be reluctant to use a pipe tap ask a friend who may have some experience, or go to a local machine shop and ask to have someone come over after work and assist. Maybe it costs you 50.00 + parts but it won't take long. Need a 1/16 npt "tap" and an extension. Drill the hole to the correct size (easy to find that number). Screw an aftermarket 1/16" pipe plug (allen head) into the newly tapped hole with Permatex! Piece of cake...

[woodypecker]

Thanks to all for the education. I enjoyed reading every post. Most os all I am glad the block was saved.

[zzlegend]

dono50. Just curious if you are back up and running?

[dono50]

Originally Posted by zzlegend

dono50. Just curious if you are back up and running?

Finally got the engine started today and no leaks, I'm elated!

[GOSFAST]

Originally Posted by dono50

Finally got the engine started today and no leaks, I'm elated!

Hi Bob, you had doubts???

Thanks, Gary in N.Y.

P.S. Never a single doubt here, like I stated earlier, "excellent job"!!

[dono50]

Hi Gary,
Thanks for you technical and moral support.
I had some head alignment problems last week but redrilled 2 head bolt holes and used helicoils.
Would not start last week and a compression test showed 2 adjoining cylinders with low compression because 2 head bolts were off center.
After resolving that issue, it started, no problem, and sounds good.
Back to body work which is a lot less stressful.......Bob

[Vergil]

Thanks for the update Bob ......

Vergil

[Binx]

Originally Posted by dono50

I had some head alignment problems last week but redrilled 2 head bolt holes and used helicoils.
Would not start last week and a compression test showed 2 adjoining cylinders with low compression because 2 head bolts were off center.
After resolving that issue, it started, no problem, and sounds good.
Back to body work which is a lot less stressful.......Bob

Could you elaborate a little more on this issue? Are you saying you re-drilled holes in the head to align the gasket? What type of head?

Lonnie

[dono50]

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Lonnie,
I had 2 head bolts (#1 and #3) broken studs that were drilled off center and the head would not seat properly resulting in low compression on 2 cylinders
I redrilled and installed helicoils, not perfect, but close enough to get the job done....

[dono50]

Vergil,
Your cutaway was very helpful.
Thanks, Bob

[zzlegend]

Nice going dono. Glad to hear this. Mark.