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Big hole in crank casing-new engine needed or repair?

staszekimogen
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staszekimogen Gongoozler

staszekimogen

Posted
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Hi,

 

Anyone with experience of working with boat engines please can we have some advice?!

 

Have just bought a narrowboat and trying to work out if we need to replace the engine or if its repairable- I've attached a photo below of the problem- it has a hole in the crank casing.

 

If it needs replacing does anyone know where we can source a suitable engine for a 57' on a tight budget. Seen calcutt prices and theyre way out of our league.

 

Thanks for your help, Imogen and Staszek

 

 

 

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Guest

Guest

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It's not just the hole .... the shiny journal you can see through the hole should have a connecting rod attached to it with a piston on the end ..... IMO.

I am no marine engine expert, but from bike engine days I agree with your prognosis. We used to call that a "thrown rod," or sometimes "a leg out of bed."

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MtB Veteran II

MtBDonate to Canal World

Posted
Posted (edited)

It's not just the hole .... the shiny journal you can see through the hole should have a connecting rod attached to it with a piston on the end ..... IMO.

 

Yes I'd say the big end bolts snapped and the piston is stuck at the top of the bore with a well mangled con rod hanging from it.

 

One might have thought the OP's surveyor would have noticed this, and perhaps mentioned it...

 

ninja.gif

Edited by Mike the Boilerman
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MtB Veteran II

MtBDonate to Canal World

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As said earlier its thrown a rod. The block is only good for scrap. At the bare minimum you'll need a short engine.

 

Given the big end is likely to have clattered the piston good and hard up against the head on each of the next few rotations after 'letting go', I'd imagine pretty much everything in this engine will be scrap...

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Naughty Cal Veteran II

Naughty Cal

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Yes I'd say the big end bolts snapped and the piston is stuck at the top of the bore with a well mangled con rod hanging from it.

 

One might have thought the OP's surveyor would have noticed this, and perhaps mentioned it...

 

ninja.gif

Hmm.

 

Or even the purchaser might have used their own eyes and seen it!

Edited by Naughty Cal
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Guest

Guest

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Posted (edited)

Hmm.

 

Or even the purchaser might have used their own eyes and seen it!

To be fair the OP may have been aware of the damage, and are just asking the best course of action; repair or replace? I bought my first NB about 13 or14 years ago with many known faults, asked loads of questions on here and elsewhere, and with the excellent advice of DOR, Martin Shorthose and a few other members, restored it to good health.

Edited by Guest
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Chalky Experienced

Chalky

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Given the big end is likely to have clattered the piston good and hard up against the head on each of the next few rotations after 'letting go', I'd imagine pretty much everything in this engine will be scrap...

 

I was being optimistic. I've seen this happen on a turbo charged engine (on a test track about 10 years ago) where the rod was followed by the contents of the sump, all over the hot exhausts. By the time the fire brigade arrived there wasn't much left.

 

At work we have the "piston broke" award for such events. Consists of a burned and holed piston attached to a bent rod screwed to the top of an engine management unit.

Edited by Chalky
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MtB Veteran II

MtBDonate to Canal World

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Hmm.

 

Or even the purchaser might have used their own eyes and seen it!

 

 

Indeed. And I'm wondering if the OP has a mooring, or if this is the third CCer popping up on this board moored on the towpath indefinitely while their repair "takes as long as it takes".

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Geoff Taylor Collaborator

Geoff Taylor

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Hi, the engine block and sump are repairable but unfortunately judging by the look of the crankshafts big end journal the failure was caused by either piston seizure, lack of oil or oil pump failure that caused a seizure of the big end, snapping the conrod and throwing it out of the side.

The engine will require a total strip down, crank regrind (assuming that it has not already at max tolerance so may need replacing), either way I guess nothing less than a total rebuild would suffice. Goodness knows what the top end may need as the cylinder head may be scrap.

Hopefully some other members will know where to find a good second hand replacement for you which costs less than a full recon unit.

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Guest

Guest

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I'm no expert but if I'd seen a hole in the casing of a boat I was buying you wouldn't be able to see me for dust.

Bled my water tank mike and got hot water .cheers for the advice.

That's fair enough, but it does depend on many other factors, and ones own capability, willingness to learn etc. Perhaps my views are distorted by the past, but such practices were once the norm with canal boats, people often restoring such items themselves.

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matty40s Veteran II

matty40s

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It does seem that the OP likes to post and never reply.

We don't know whether this is a boat they have bought with a survey or not, they never responded to the previous thread.

If it had a survey, was it just a hull survey or a full survey with engine test.

We don't know an awful lot.

The engine looks fecked to me , I would hope the boat is on hard standing and not on a 48 hour mooring with a "no Home mooring " declared licence.

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Guest

Guest

Posted
Posted (edited)

It does seem that the OP likes to post and never reply.

We don't know whether this is a boat they have bought with a survey or not, they never responded to the previous thread.

If it had a survey, was it just a hull survey or a full survey with engine test.

We don't know an awful lot.

The engine looks fecked to me , I would hope the boat is on hard standing and not on a 48 hour mooring with a "no Home mooring " declared licence.

I have no knowledge of the OP sorry. I just tried to help with their dilemma in what small way I could. I wish them well with their engine rebuild/replacement.

I do agree that more info might help, if indeed there is any more info to offer.

Edited by Guest
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Guest

Guest

Posted
Posted

We don't know what type of engine it is either.

 

That one is terminalI

 

Richard

It is a knackered engine ;) I agree a type would be useful, as it might help those more knowledgeable than I to ponder the cost effectiveness of rebuilding, or replacing. From my limited experience, Japanese stuff can be prohibitively expensive to rebuild. I learned that with an ancient and tired Yanmar.

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RLWP Veteran II

RLWP

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That diamond logo on the side looks terribly familiar.

 

I imagined it was a BMC 1.5/1.8 given the OP's comment about not being about to afford Calcutt's very reasonable prices...

AND it's MOWOG green!

 

The cast four hole mount doesn't seem familiar (bottom left)

 

Richard

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