8N - Cracked block - fixable

[SebTX]

Hello All,

My 1950s 8n is in trouble. I didn't notice a leak in the radiator and left the tractor running for 20 mins - It was still running when I came back but water vapor was coming out of the engine. It
obviously overheated and I now have a crack in the block behind the oil filter plate (pics attached). As far as I can tell oil is not mixing with water. Is this fixable? The crack seems to expand close
to the head gasket - not sure if I should pull the head. I've read in a few places that JB weld could do the trick. I appreciate any advice/feedback.

 

[Jim L WA]

I used JB Weld on my 2N and it is working will. But the crack on mine didn't have a gap as large as yours and was further down and to the rear of where yours is and was longer.
Yours looks nasty sorry to say. You will also need to have the head checked. It probably warped.
Let's see what others have to say.

 

[wore out]

I can't imagine it breaking like that from overheating, but not getting so hot that it seized up.

I wonder if it getting hot possibly opened up an old crack from freezing?

Hopefully, the cracks don't extend into the bore area.

At this point I would try some block sealer, following the directions closely.

I can't see anything to be gained by removing the head.

Hopefully, block sealer will hold for a long time, if nothing else to buy you some time to find another block or engine.

 

[HarryVanderpool]

Going by one of my favorite rules. "You can always afford to do things right THE SECOND time around", I would pull the head.
Pull the head and examine the deck to make sure of the total extent of damage. Then make the best repair possible. Check the head for flat. Drain and refill oil and coolant. My worst N buying mistake, "The Junk Pile" has a repaired crack that has worked since 2008, no problem.

 

[mhb@ufe]

That crack is right where a head bolt goes in so I would be concerned if any repair would allow you to retorque that head bolt without opening the crack again.

Mark

 

[wore out]

(quoted from post at 11:37:30 02/20/23) That crack is right where a head bolt goes in so I would be concerned if any repair would allow you to retorque that head bolt without opening the crack again.

Mark

''That crack is right where a head bolt goes in so I would be concerned if any repair would allow you to retorque that head bolt without opening the crack again.''

EXACTLY.

That's why I suggested leaving it alone and trying to get by with block sealer for a while.

IMHO, due to the location of the crack and possibly others under the head welding or otherwise repairing the block properly/permanently would cost more than finding a good replacement block or complete engine.

 

[HarryVanderpool]

Post a picture of the deck when the head is off.

 

[560Dennis]

Id sure give it a try .
Also recommend the your get your radiator flushed and pressure/flow tested .

 

[SebTX]

That is exactly what I was thinking - its a massive crack but somehow the engine was running fine when I stopped it. It might have been an old crack that I didn't notice before.

 

[SebTX]

Yeah - thats why I was asking if I should touch the head or leave it alone. I would love to pull the head and understand the extent of the damage but in this particular case it might be better to just try
block sealer. Thanks.

 

[SebTX]

Thanks to all for your comments - I'll keep you updated on my progress. Really hope to be able to fix my 8n - took me 2 years to bring it back to life (barn find) and now this.....

 

[Abbby]

Not much to loose by trying the block sealer

 

[Den N Ms]

SebTX I would try some Bars in it before doing anything else.


https://barsleaks.com/product/liquid-copper-1109/

 

[Tim PloughNman Daley RIP]

OOOoooh. Nasty. You can pull the head and see what what the heck hit, I'd want to know what caused it and if there is more damage than you think. You could, take the tractor or block to a shop and have them inspect and advise, and if cost prohibitive, opt to get another engine and swap out. I see a few N blocks on fleabay now for $350. I've never had luck with a large crack using JB Weld but a shop can braize it if not too bad.


Tim Daley(MI)

 

[SebTX]

Interesting - I've never used this stuff...I might give it a try. Thanks.

 

[Dave G9N]

(quoted from post at 10:26:10 02/20/23) Hello All,

My 1950s 8n is in trouble. I didn't notice a leak in the radiator and left the tractor running for 20 mins - It was still running when I came back but water vapor was coming out of the engine. It
obviously overheated and I now have a crack in the block behind the oil filter plate (pics attached). As far as I can tell oil is not mixing with water. Is this fixable? The crack seems to expand close
to the head gasket - not sure if I should pull the head. I've read in a few places that JB weld could do the trick. I appreciate any advice/feedback.



<img src=https://www.yesterdaystractors.com/cvphotos/cvphoto147957.jpg>

<img src=https://www.yesterdaystractors.com/cvphotos/cvphoto147958.jpg>

have only seen the picture and there is a lot that I can't determine from just a picture. It is a good picture. I have seen (and taken) a lot worse.

The crack doesn't look like the sort of failure that I would expect. I would clean the area of thick paint and goo and make sure that the crack is in the casting, not the paint. The paint crack to the right in the picture lines up with the break and looks old. The crud also looks old. Hopefully it's just a head gasket and the line of glop is from the bottom edge of the filter support, not the outline of a crack. That area should also be loaded in compression unless the crack angles down into the block.

If it is a crack, and the crack is shallow so the metal around the bolt hole is not very thick, I would remove any screw threads from the chunk and count on the bolt load to clamp it shut. JB Weld might work in this case. It might be best to apply the epoxy and snug the head down with a wax paper 'gasket' to line it up until the epoxy cures.

If the break is deep, we can have an endless discussion of all the ways that cast iron is such a bear to weld. The torque on the bolt is 65-70 ft-lb, so the load is only around 5000 lb, which isn't all that much as long as you have enough thread engagement below the crack. For a 7/16 bolt, maybe 3/4" is enough?

 

[Nyquil Junkie]

Copper block seal is good stuff... I've used it on several engines. it might have to leak for a few hours with it in there but eventually it'll clog it up and seal. I've sealed up worse leaks than that before with it.

 

[lha]

I have had to pressurewash tons of sealer that has at least partially blocked coolant passages in the block
and heads. The sealer becomes a gooey mess that is very difficult to remove. There is no oil pressure in the
area,only slight coolant pressure. Before I was told that cast iron couldn't be welded,I successfuly welded
an axle housing on an old Case tractor,and as far as I know,it is still holding 30+ years old.