Engine replacement - ideas?

[cheesegas]

 Hi all. I currently have a ~30 year old, unknown hours Isuzu 3KC1 in my 45' cruiser stern narrowboat. Rated at 30hp, keel cooled, dry exhaust. Runs very well and has been perfectly reliable other than consumable service parts, starts almost instantly even in the depths of winter. However, it turns out those parts are very very difficult to get hold of, and expensive too - the lift pump diaphragm recently went, Engines Plus wanted £800 for a new lift pump assembly. Fitted an electric one instead, damn thing keeps on leaking but that's another story...

 

I'm getting a bit antsy as service parts like the water pump are just over £1k, or there's pattern parts of unknown quality for about half that. Even finding new glowplugs took hours of calling around and not much change from £200 for a set of three as the cheaper ones marked as compatible actually weren't.

 

When the next expensive thing goes I'm tempted to swap it out, I'd also like a little more power for the tidal Thames too. Availability aside, it would be straightforward to drop in something like a Nanni or Beta 43 with a new PRM, especially as it can be supplied to suit the bearers...

 

However, because I seem to like a challenge, I'd like to put in something a little different. It's an old Liverpool boat so nothing special, but I'm toying with the idea of a low speed engine, something less sought after like a STW3 or Sabb. Seen a few old Rustons in boats which sound nice but apparently parts are impossible.

 

Any other suggestions of similar engines but with good parts availability? Around 40hp ideally, able to cope with a running at low load to charge batteries as I liveaboard year round. Lithium though so I'd be putting a polyvee around the flywheel and a big alternator on it.

 

I've done engine swaps on cars and would be buying a second hand engine properly checked/warranteed from somewhere like Marine Enterprise, complete with gearbox. Just replaced the engine control panel with one I've built so modifying it to work with a new engine would be straightforward, and the single lever Morse the same. Plenty of space in the engine bay, and the bearers are wide so any modifications shouldn't be too bad.

 

Thanks!

[LadyG]

I'm not an expert, but my Isuzu 33LB is fitted in my 57ft NB, it seems very simple, and that particular engine was used by some hire fleets.

Mine has a prm120.

I don't know about spares, never needed any.

I believd it has had a new propshaft, its over 20 years old. No smoke. Never need to top up the oil.

Others will know more about it 

Edited August 19, 2023 by LadyG

[Bee]

Engines in boats tend to last a long time and there are many of us with engines that are considered 'obsolete' and have not been manufactured for years. My own Beta 43 is getting on a bit and a brand new version could well have slight differences. I would stick with what you have got, changing engines can be a bigger job than you think. As for more power, the shove comes from the prop so if the Isuzu is happy with that prop a more powerful engine will need a different prop to make any difference. In my case the engine and prop will push the boat along at approx. its theoretical maximum hull speed so even if I stuck a bigger engine and prop in it the thing wouldn't go any faster, I suspect it would be much the same with many boats. Give the Isuzu a polish and talk to it nicely, it will probably last for years.

[Tony Brooks]

Also, try to find an Isuzu agricultural/industrial engine dealer. You are likely to find things like the water pump cost less there than from a marine dealer.

[cheesegas]

36 minutes ago, Bee said:

Engines in boats tend to last a long time and there are many of us with engines that are considered 'obsolete' and have not been manufactured for years. My own Beta 43 is getting on a bit and a brand new version could well have slight differences. I would stick with what you have got, changing engines can be a bigger job than you think. As for more power, the shove comes from the prop so if the Isuzu is happy with that prop a more powerful engine will need a different prop to make any difference. In my case the engine and prop will push the boat along at approx. its theoretical maximum hull speed so even if I stuck a bigger engine and prop in it the thing wouldn't go any faster, I suspect it would be much the same with many boats. Give the Isuzu a polish and talk to it nicely, it will probably last for years.

Thanks for the reply. Yep, it’s well looked after and runs very nicely, plenty of hours left on the block but it’s the service items which wear on every engine that I’m concerned about. A water pump and a set of glow plugs is almost half way to the cost of a reconditioned engine! It’s in need of a new exhaust manifold soon too which is totally unobtainable, quotes for a custom one are in the £1k range. 
 

I do put a lot of hours on it too.  
 

It’s slightly over propped as it is, like most boats - wide open throttle gives black smoke from over fuelling rather than sitting on the governor. I agree that a more powerful engine would need re propping. Fine for the canals but punching the tide is slow going compared to other similar length narrowboats. 

[MtB]

10 hours ago, cheesegas said:

Any other suggestions of similar engines but with good parts availability? Around 40hp ideally, able to cope with a running at low load to charge batteries as I liveaboard year round.

 

Point of order...

 

Tracey just pointed out in another thread the Lister STW runs the alternator pulley at half-engine speed so is not suitable for low-engine-speed charging.

[Troyboy]

For a simple engine the BMC 1.5 diesel is hard to beat . Parts availability is good and from current Ebay listings you could get a waterpump for £45, 4 glow plugs for £21, Lift pump for £27 and a head gasket set for £22. and be able to fit those yourself as you state you have swopped engines in cars before. 

[MtB]

 

 

 

 

44 minutes ago, Bee said:

Give the Isuzu a polish and talk to it nicely, it will probably last for years.

 

Also make detailed plans for an engine change anyway, and then show them to the Isuzu. It will probably shape up and run perfectly reliably for years, once it understands your intentions.

 

 

 

[cheesegas]

Just now, Tony Brooks said:

Also, try to find an Isuzu agricultural/industrial engine dealer. You are likely to find things like the water pump cost less there than from a marine dealer.

Thanks, yep I’ve called around every plant dealer who sells Hitachi machines - the same engine was fitted to some Hitachi EX range mini excavators. However, that was in the 90s and no luck…

8 minutes ago, MtB said:

Tracey just pointed out in another thread the Lister STW runs the alternator pulley at half-engine speed so is not suitable for low-engine-speed charging.

Indeed, SR/STs and a few other Listers drive the alternator from the end of the camshaft which runs at half engine speed. However, the usual trick is to install a 10" or larger pulley on the shaft (something I've done before on other boats as I do a bit of marine electrics) to give you the required ratio. 

 

8 minutes ago, Troyboy said:

For a simple engine the BMC 1.5 diesel is hard to beat . Parts availability is good and from current Ebay listings you could get a waterpump for £45, 4 glow plugs for £21, Lift pump for £27 and a head gasket set for £22. and be able to fit those yourself as you state you have swopped engines in cars before. 

Yep, a refurb'd low hours BMC is a good choice, plenty around as well. 

[magnetman]

BMC 1.5 is great. I have two. 

 

I also have a Perkins P4 which is a bit of a beast very well made. 

 

Sometimes these (P4) turn up as crated ex admiralty units but would need marinising and its quite large. 

 

Measure very carefully how much room you have. 

Height will be an interesting measurement if it is a cruiser stern. A lot of older engines can be quite tall and also have deep sumps. 

[BWM]

I had an Isuzu 3kr1 in my last boat and it too was ludicrously expensive for parts, along with poor spares back up. After numerous conversations with suppliers of all types, I came to the conclusion that these engines were generally fitted in small plant machines, and therefore weren't usually repaired during the relatively short working lifespan. 

  Keep the antifreeze fresh, as the head gasket is something of weakness if not looked after. 

[MtB]

1 hour ago, magnetman said:

A lot of older engines can be quite tall and also have deep sumps.

 

When I bought my Kelvin K1 on a pallet, it was about the same height as me.

 

Once installed in the boat, this went down to a more reasonable shoulder height.

 

 

[system 4-50]

A Beta is a better buy.

[Lily Rose]

36 minutes ago, system 4-50 said:

A Beta is a better buy.

 

Make sure it's not a Beta Max though.

[magnetman]

Beta Marine arrr good and they will do 'special feet' to get the engine to match the existing beds. Presumably there are occasions when things won't fit if the beds are too narrow but they do offer this which is quite wise of them. 

 

 

[Tracy D'arth]

Canaline  are a good alternative, will arrange mountings to suit and to fit the existing gearbox if requested.

[Jen-in-Wellies]

Beta have detailed dimensioned drawings of their engine/gearbox packages on their web site, so you can assess the practicality and what engine bed modifications may be needed before making a decision.

[Bee]

4 hours ago, magnetman said:

Beta Marine arrr good and they will do 'special feet' to get the engine to match the existing beds. Presumably there are occasions when things won't fit if the beds are too narrow but they do offer this which is quite wise of them. 

 

 

I didn't know that, clever and very useful.

7 hours ago, cheesegas said:

Thanks for the reply. Yep, it’s well looked after and runs very nicely, plenty of hours left on the block but it’s the service items which wear on every engine that I’m concerned about. A water pump and a set of glow plugs is almost half way to the cost of a reconditioned engine! It’s in need of a new exhaust manifold soon too which is totally unobtainable, quotes for a custom one are in the £1k range. 
 

I do put a lot of hours on it too.  
 

It’s slightly over propped as it is, like most boats - wide open throttle gives black smoke from over fuelling rather than sitting on the governor. I agree that a more powerful engine would need re propping. Fine for the canals but punching the tide is slow going compared to other similar length narrowboats. 

I see what you mean, a quick glance at E bay shows just a few expensive bits and pieces and nothing resembling a whole engine for spares or an exhaust manifold. Could be a good plan to keep an eye out for something similar with a bit more power that could handle the present prop.

[roland elsdon]

Saw a proudly proclaimed cruiser thingy saying “powered by electricity’.

Strangely in the same spot as 3 weeks ago ( 48 hr mooring).

Maybe I should sign write moved by diesel on the old nail.

Probably waiting for electron delivery as it had less panels than many. 

[magnetman]

Diesel is solar power just a bit noisy. 

 

 

 

 

The reason people write 'electric' on boats is because they are very quiet and passers by always ask 'is it electric?'

 

I'm out on the floating electric beer drinking platform currently avoiding close interaction with humans. 

 

Next time I will say it is nuclear powered. 

 

 

 

Everything everywhere is solar powered. 

[ditchcrawler]

On Facebook this evening 

[cheesegas]

9 hours ago, system 4-50 said:

A Beta is a better buy.

Yep...albeit with an 8 month lead time at the moment! You can't get it to match your current engine without getting a cancelled order engine and having someone else do it. Fully aware that a Beta/Canaline/Nanni etc is a nice, reliable, sensible option which would add value to the boat but I'm putting the feelers out for something a little more interesting.

 

 

11 hours ago, magnetman said:

I also have a Perkins P4 which is a bit of a beast very well made. 

 

Sometimes these (P4) turn up as crated ex admiralty units but would need marinising and its quite large. 

 

Measure very carefully how much room you have. 

Height will be an interesting measurement if it is a cruiser stern. A lot of older engines can be quite tall and also have deep sumps. 

Looked at this option and I've got space for a 4107/4108 but one of the bearers needs a chunk taken out of it - the current engine has a massive air cleaner on top so the deck appears to have been built higher than similar Liverpool boats of this era.

 

 

3 hours ago, roland elsdon said:

Saw a proudly proclaimed cruiser thingy saying “powered by electricity’.

Strangely in the same spot as 3 weeks ago ( 48 hr mooring).

Maybe I should sign write moved by diesel on the old nail.

Probably waiting for electron delivery as it had less panels than many. 

In an ideal - albeit boring - world, I'd have a 2000ah lifepo4 bank shared between house and propulsion, a 15kw motor and a 15kva capsule generator. Silent recharging in winter (cc'er with no shore power), quiet cruising all year round and the range boosted by solar in summer. Perfect for cc'ing but few advantages for your average non liveaboard who goes on long summer cruises, moving every day and the boat sits on shore power all winter.

[john.k]

A P4 is a very much larger engine than a 4/108.........if you have room for a P4 ,then a more modern 4/236 will also fit the same space.....  there is a smaller capacity on the same block called a 4/212   same motor with a shorter stroke.........one of my boats had a 3/152 direct injection......this is a very common motor in Lincoln Welders,also in Massey Ferguson small tractors ..MF135..?.............Perkins parts are cheap as dirt ,and readily available.

[magnetman]

P3.152 is a very nice engine. Very powerful units these are easily capable of shifting a heavy full length narrow boat. 

 

 

My P4 is in a 9 foot wide inspection launch so it sort of looks smaller in the engine hole. Ex admiralty engine marinised by the boat builder. 

 

It is probably too large for a narrow boat engine fitted right at the back.