Repairing Drilled Engine Block

[Husaberger]

I’m curious about the whole transaction. Isn’t that an older tractor?

It was out of warranty

I’m assuming old enough it wasn’t still under a new warranty, so why was a complete new engine issued for a spun bearing?

They would not rebuild. It was the only option my dealer gave me

Was it a special circumstance free replacement?

I wish. Cost me like $8k at the time

I’m trying to figure why the manufacturer required the block destroyed.

You'll have to ask Kubota but my current mechanic says they now make a big window into the block preventing what I am trying to do

 

[Husaberger]

As mentioned, the depth of hole is important as well as what it hit. That doesn't look too different from the freeze plug just below it. So if it looks to only be in the water jacket, perhaps just pound in a new freeze plug the size of the hole.

Drill hole location is purposeful. Fortunately misses the water jacket but goes straight into cylinder 2

 

[Husaberger]

Can you weld it?

willy

The issue is it goes into cylinder 2

 

[Husaberger]

From the pics, it looks like that red depth probe goes all the way into a cylinder, which would make repairs pretty difficult. If it's a sleeved engine, you might be able to punch out the outside hole a bit bigger so you can tap the inner one for a plug, seal it good with JB or braze, smooth it down with a die grinder, then tap the outer one or size it for a drive in frost plug. Seems like a lot of work for an iffy repair at best.

Looking into cost of sleeving it

 

[Jstpssng]

I've had one Stanley thermos; a wide mouth which for some reason, would never hold a stopper. I would barely get it turned in when the darned thing would strip. I never thought about returning it. I am not sure that the newer ones have the lifetime warranty.

The new ones are substantially thinner and lighter than the old ones, but actually outperform the old ones, in terms of keeping your liquids hot and avoiding corrosion at the welds. Just one of a million examples where the heavier/older tech wasn't necessarily better.

This is good to know. I've picked up a new one, noticed how light it was and opted not to buy it.

 

[WinterDeere]

I've had one Stanley thermos; a wide mouth which for some reason, would never hold a stopper. I would barely get it turned in when the darned thing would strip. I never thought about returning it. I am not sure that the newer ones have the lifetime warranty.


This is good to know. I've picked up a new one, noticed how light it was and opted not to buy it.

They've always had a lifetime warranty, so far as I know. So, I'd email their customer service about getting a replacement for your old one, before buying another.

But you might be right about them dropping the lifetime warranty, so many other great old American brands have, for various reasons.

 

[RayIN]

I believe that! Given half a chance, some people will screw up every good thing available.

I sent Stanley a letter in the mid 70's explaining the luke warm milk in my new thermos and they sent me a replacement.

I still have that one. I should take a pic and sent them a thank-you letter.

Off-topic; A mountain man decided to get a job in the city. He was hired to work on high steel erecting a building.
At noon his first day he noticed everyone had a box that contained their lunch, and a bottle of hot coffee. He asked what it was and was told it's a thermos-bottle.
He asked what it did and was told it keeps hot thing hot and cold things cold.
Next day he showed up with a new lunch box and inside was s thermos-bottle.
One man asked what he had in the bottle. The mountain man said,
Chicken soup and iced tea___.

Thank you, thank you, thank you very much!

As to the drilled engine block; Since i'm a retired toolmaker I'd tap the hole and insert a cap screw sealed in with red LocTite.
LocTite says the red must be heated with a torch to 500° before it will loosen.

 

[flyerdan]

As others have noted, it appears that it is a lined block, so pulling the liner should give access to the inside of the hole. Since it missed the water jacket, it would be able to be threaded, if a tap size is available, or if not a rod could be sized to be pressed it with some sealant. In either case, I'd leave a recess on the outside so that it could be brazed in to keep it from moving. What I'm unsure about is how the block would react to heat/cool cycles with a dissimilar metal introduced into what should be an unbroken field, with regards to stress cracks, warpage and other factors. If someone could opine on that it would be quite interesting.

 

[gstrom99]

The issue is it goes into cylinder 2

Why are to trying to save this old block? Even if a reliable fix were found, you'd still have the original spun bearing issue to fix. Cost prohibitive, IMHO.

 

[etpm]

So the drilled hole goes through solid cast iron all the way to the cylinder? If this is the case then this old machinist thinks it could for sure be tapped and plugged. If it was mine I would tap the hole for a tapered pipe plug from inside the cylinder. Use a steel or cast pipe plug so that it has a similar amount of expansion as the block heats up. Install the pipe plug with red Loctite. The hard part will be grinding down the part of the plug that extends into the cylinder so that it is flush without damaging the cylinder. Any competent engine shop could do the work for you and then use a boring bar to remove excess plug material. I would then have a shop turn a piece of cast iron or steel just a few thousandths smaller than the hole and install this with green Loctite. I think the correct number is 609. 635 looks to be an even better choice. Cut the plug so that it is just slightly longer than the depth of the hole so that you can use a punch and hammer to swage the end of the plug so that it cannot possibly come out if the Loctite ever fails, which it won't if used properly. Use Chlorinated brake cleaner, if you can get it, to clean the hole before applying the Loctite. Make sure the cleaner is completely evaporated before applying the Loctite.
Eric

 

[5030]

Interesting thread with a lot of good fixes, however, something isn't Kosher.

I work part time at an authorized Kubota dealer and I know for a fact that if you buy a reman engine from Kubota, for any reason or even a short or long unused engine, Kubota has to have documented proof the original engine was destroyed and rendered not useable or rebuildable. Documented proof for Kubota is detailed pictures of the destruction and or valid receipts from a scrap company.

I've destroyed more than one failed engine and in my dealer's case, that involves using a sledge hammer or torches and destroying it, not drilling a hole in the block that can be repaired. Like I said, Kubota requires documented proof as in pictures or scrap dealer receipts that the engine was rendered not useable or repairable, except for scrap value. Corporate policy. I have no idea about an independent non Kubota rebuilder or shop, only a Kubota authorized dealer.

The OP in his first post states a Kubota dealer drilled the hole and I'm very suspect of that.

Kubota revised and adopted that policy when the emissions engines came on the scene to prevent an owner of a failed engine replacing it with a non emissions engine.

Give me no pleasure in destroying a rebuildable engine but corporate policy is corporate policy anyway and at least the dealer I work for don't want to loose his franchise over an engine.

I will say, using a 15 pound sledge on one renders it junk real fast. That and using it for target practice with a high velocity round.

If you buy a long block from Kubota you cannot remove anything, a short block, you can. Not sure about other brands, just Kubota.

 

[ruffdog]

So the drilled hole goes through solid cast iron all the way to the cylinder? If this is the case then this old machinist thinks it could for sure be tapped and plugged. If it was mine I would tap the hole for a tapered pipe plug from inside the cylinder. Use a steel or cast pipe plug so that it has a similar amount of expansion as the block heats up. Install the pipe plug with red Loctite. The hard part will be grinding down the part of the plug that extends into the cylinder so that it is flush without damaging the cylinder. Any competent engine shop could do the work for you and then use a boring bar to remove excess plug material. I would then have a shop turn a piece of cast iron or steel just a few thousandths smaller than the hole and install this with green Loctite. I think the correct number is 609. 635 looks to be an even better choice. Cut the plug so that it is just slightly longer than the depth of the hole so that you can use a punch and hammer to swage the end of the plug so that it cannot possibly come out if the Loctite ever fails, which it won't if used properly. Use Chlorinated brake cleaner, if you can get it, to clean the hole before applying the Loctite. Make sure the cleaner is completely evaporated before applying the Loctite.
Eric

Agree but loctite 620 is more high temp.

 

[etpm]

Agree but loctite 620 is more high temp.

Your post is why interaction is great. High temperature resistance is probably most important rather than the highest strength. Especially since I suggested swaging the rod in the block. Belt and suspenders and all that. If I had that block I would be sorely tempted to repair it and then use it for something.
Eric

 

[f2000ez]

When you go to get parts for the rebuild and give the engine serial number, it’s going to raise a red flag showing the engine was “destroyed”. Kubota could come back to the dealer and give them a very hard time.

 

[DigDoug]

I had the dealer install a new engine in my Kubota L4740 when it spun a bearing

In order to get the new engine from Kubota, they required the dealer to drill the block

Now I would like to rebuild this engine and am wondering what it would take to repair the drill hole

See pics

Are you friendly with the mechanic at the dealership? Just ask him exactly what was done to the engine. Take some of the guess work out your project. I can’t imagine they would have a problem with you wanting to rebuild the engine…….

 

[Massey convert]

Why are to trying to save this old block? Even if a reliable fix were found, you'd still have the original spun bearing issue to fix. Cost prohibitive, IMHO.

I would agree. After you repair the drilled hole, you still have the same issue with the spun bearing, which would be more of a challenge.

 

[Cycledude]

Seems like a lot of time and money wasted

 

[Fueler]

Engine machinist/builder here.
The first move is to get it apart to assess if the rest of it can be machined and rebuilt.
The outside wall hole is not critical to operation or engine life if tapped and plugged. Don't over think it.
If concerned about the serial number when acquiring parts the aftermarket does not care.

It used to break my heart when Chevy would sledge hammer a perfectly good 427 vette block.

 

[boatmoter]

I had the dealer install a new engine in my Kubota L4740 when it spun a bearing

In order to get the new engine from Kubota, they required the dealer to drill the block

Now I would like to rebuild this engine and am wondering what it would take to repair the drill hole

See pics

I would tap some threads into it and install a pipe plug with Teflon tape

 

[WinterDeere]

I would tap some threads into it and install a pipe plug with Teflon tape

Oh no... now you've started a whole "tape vs dope" debate, that'll take us through the next 3 pages.