Frozen coolant

[alexanderfoti]

Hi all

Finally have some time to get my bike up and running.

It has the new 0 hour engine fitted but I did something stupid. When test running it, I ran a hose through the block to keep it cool.
I drained the block, but obviously not well enough. Over last winter we had temperatures below -7c and it must have frozen in the bottom of the block as it blew one core plug out.

I have run it since and it seems fine, oil is still clear. Seeing as its a big lump of an engine I am hoping that its still ok.

Thoughts?

[alexanderfoti]

Ran the engine up today, ran well, but thermostat housing was cracked.

Had to take the head off and found a cracked liner opposite the side that the core plug came out of (not surprising!)



This mark is slightly above the core plug that popped out:

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Am hoping liners can be removed and replaced and no other engine damage present. Possibly wishful thinking.

[mark_in_manchester]

Bad luck!

I don't understand why if there was only a bit of water in it, ice did not expand into the air spaces in the water jacket. Seems odd that enough pressure developed to blow a core plug. When you ran it - did the water jacket pressurise - is that liner crack an issue yet?

[alexanderfoti]

Yeah it is a bit odd. Lots of damage up top but none down below.

I phoned kubotaman today and sent them the pictures. They said they have never seen damage like that before. Their theory is that is where the gudgeon pin was stationary when it froze. Makes sense to me, the other 2 bores probabLy deformed then went back after it thawed.

Initially, I couldnt feel that mark but after having a play today, I can catch it with my nail at a certain point so this engine is scrap!

[mark_in_manchester]

If it's scrap, why not run it while you look for another one? I it didn't pressurise, well, maybe it'll work OK for a bit...

[alexanderfoti]

I Agree. Whilst it is not ideal, it runs and idles fine.

I am going to bolt it back together and finish the rest of the bike around it whilst I search for another.

[alexanderfoti]

Well, I bolted it back together, with a new headgasket. It runs fine.

Did a compression test for fun and 450/450/460.

Compression is good at lest! Going to run it for a while and see if it dies or not.

[gilburton]

Can I ask why you don't just replace the liner if it does start leaking?

[alexanderfoti]

Can I ask why you don't just replace the liner if it does start leaking?

Even though Kubota mention liner thickness and ease of replacement in their service manuals, the liners are actually embedded. So to put new liners in, I would have to have them bored out and new liners pressed in. Doable, but at the cost approaching that of a replacement engine.

[mark_in_manchester]

hey Alexander -

This is a nice series of youtube videos - this one in particular might appeal to you

https://www.youtube.com/watch?v=3l2t_-_k13U&t=495s

There's another where the guy puts a sleeve in with heat - it's all rather tense wondering if it will nip up part way down!

cheers
Mark