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Replacement engine HP size - advice pls!


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Hello, my first ever post... here goes!

 

I have a 45ft Narrowboat with a 2.1 gearbox and 17” prop that has a very smokey and very leaky Petter PJ2W (22.5hp at 2000 rpm) which I want to replace with a newer engine, as I no longer want to keep throwing money at something that isn’t improving.

 

Ive been looking at the 30hp - 35hp size range for the replacement engine, but my skin tank would need extending for this, and this adds to the cost significantly due to the boat needing to be out of the water and the welding work done (an additional £2.5k) The sq ft of the current skin tank is 5.65 sq ft (tank measures 16” x 51” x 2”)

 

Canal contracting - who I will be buying a refurbished engine from - have suggested a Vetus M3.10 which is 22hp, as an alternative option which keeps the existing skin tank only.

 

Will this be enough power for my 45ft? I’ve seen that Canaline state that their 25 (22hp) is suitable for up to 45ft. But does this low go limit me from rivers and the Thames for example? I cruised last weekend to Rickmansworth from Cowley, and had trouble getting through a strong weir before Copper Mill lock. This could have been due to my engine being old, smokey and riddled with problems, but doesn’t make me feel confident about navigating a river with only 22hp.
 

It’s  worth bearing in mind that this isn’t my forever boat - I plan on upgrading to a newer and larger boat in the next few years, so saving £2.5k would be very useful.

 

Thoughts please :)

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No, multiple independent engineers have written the current engine off, and I found a survey from 1999 (boat is 1978) that said the exhaust has emitted a blue smoke ever since the engine was first put it the boat. It has caused me multiple problems despite refurbished injectors and fuel line replacements and so on, and so I think it’s time it went.

Edited by Vixen2021
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I think the PJ2W is an uprated version of the PH2W which were well regarded engines in their time. For the cost of a new engine, and all the disruption etc. that this will involve, I would have thought you could get this engine rebuilt. Have you spoken to a 'proper' engine restorer rather than someone who makes money out of selling you a new engine?

 

Edited to add:

Just seen your latest post. By properly rebuilt I mean engine out of boat, cylinders rebored, new pistons and rings, crankshaft reground with new bearing shells, valves reground etc.

Edited by David Mack
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20 minutes ago, Vixen2021 said:

 

It’s  worth bearing in mind that this isn’t my forever boat - I plan on upgrading to a newer and larger boat in the next few years, so saving £2.5k would be very useful

Where are you getting a new engine supplied and fitted, including whatever changes are needed to engine beds, water cooling, exhaust, engine controls, etc. for £2.5k??

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I don’t understand this, as an engine restorer will also be making money off of restoring the engine..?

 

I have spoken to a highly praised and reputable mechanic who offered the option of doing a full refurbishment, but the cost would be the same as getting a more modern refurbished engine. As well as this, the parts for the PJ are getting harder to come by.

 

And you misunderstand me - my original question was whether 22hp is appropriate for a 45ft boat. If it is appropriate, I save the added cost of the £2.5k it would cost to have the additional skin tank welding to suit an engine with a higher HP.

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22 minutes ago, David Mack said:

I think the PJ2W is an uprated version of the PH2W which were well regarded engines in their time. For the cost of a new engine, and all the disruption etc. that this will involve, I would have thought you could get this engine rebuilt. Have you spoken to a 'proper' engine restorer rather than someone who makes money out of selling you a new engine?

 

Edited to add:

Just seen your latest post. By properly rebuilt I mean engine out of boat, cylinders rebored, new pistons and rings, crankshaft reground with new bearing shells, valves reground etc.

It may well be more economical to have your old engine overhauled completely as David Mack says.

Not necessarily using boat yards,but a diesel engine specialist who overhauls truck,plant,and industrial engines.

I think 22HP is more than adequate for canal use and non tidal rivers.On tidal rivers,I thought most sensible boaters cruise with the tide and ebb unless circumstances dictate otherwise.

Edited by Mad Harold
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7 minutes ago, Vixen2021 said:

I don’t understand this, as an engine restorer will also be making money off of restoring the engine..?

 

I have spoken to a highly praised and reputable mechanic who offered the option of doing a full refurbishment, but the cost would be the same as getting a more modern refurbished engine. As well as this, the parts for the PJ are getting harder to come by.

 

And you misunderstand me - my original question was whether 22hp is appropriate for a 45ft boat. If it is appropriate, I save the added cost of the £2.5k it would cost to have the additional skin tank welding to suit an engine with a higher HP.

£2.5K to stick a skin tank on is extortionate, perhaps there is more work required to fit a different engine? I would get estimates for rebuilding the original properly.

Better the devil you know ...........

 

I would go for the Canaline, the Vetus will cost you a king's ransom for spares.

Edited by Tracy D'arth
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Just remember what @Tracy D'arth says about spay gun refurbs. Before you buy such an engine I would insist on having a complete report containing all the pre and post machining measurements, list of new parts fitted, list of parts sent for checking/overhaul. You may not understand it but if you then posted it here we could suggest if it looked as if it was likely to be a long-lasting refurb.

 

Absolute engine power is not the be all and end all it. Your ability to read water and handle the boat (knowing when to tie up) is just as important. What does concern me is the torque your engine produces compared with the new one. That tends to determine prop size and I fear despite the quoted HP the new engine may develop less torque and thus need a smaller prop. Even if the old prop works the stopping power may be lacking.

 

I think 22hp will be usable on canals but may not stop the boat so well.

 

 

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Your PJ2W produces (or should produce) 22hp at 2200 rpm. A Vetus M3.10 produces 22hp at 3000 rpm. So to get the same power as your current engine you will need to run at a higher engine speed i.e. noisier. You don't say what ratio gearbox comes with the Vetus, but if it is around 2:1 you will need a smaller prop to match the higher engine speed. In general that means lower efficiency, slower acceleration and poorer stopping ability. None of that will make for easier boating, or help on rivers.

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4 minutes ago, David Mack said:

Your PJ2W produces (or should produce) 22hp at 2200 rpm. A Vetus M3.10 produces 22hp at 3000 rpm. So to get the same power as your current engine you will need to run at a higher engine speed i.e. noisier. You don't say what ratio gearbox comes with the Vetus, but if it is around 2:1 you will need a smaller prop to match the higher engine speed. In general that means lower efficiency, slower acceleration and poorer stopping ability. None of that will make for easier boating, or help on rivers.

Makes sense. Thanks!

6 minutes ago, ditchcrawler said:

There are people out there who would return that engine to you us new with a guarantee as opposed to something that the apprentices have practiced on 

Where do I find these ‘people’ ?

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Please understand that there are TWO important properties  of an internal combustion engine that must be considered when sizing an engine for a particular job, horse power and torque. For boat propulsion torque is argueably more important than horsepower.

 

Thus engines such as the National and Russell Newbery were expected and did power a 70 ft. motor and butty fully loaded. At best these engines produced a miserly 18/20HP but what they did have was "GRUNT", in other words lots of torque.

 

Whilst I tend to agree with  previous posters that a rebuild by a 'proper' rebuilder will in the long run be the most economic  if you must have a new engine insist on seeing if the engine has nice flat torque charastics. Remember that even the lunatic fringe do not cruise at 2,500rpm, well, not 'fer long anyways.

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But buying a recondition engine is just a big of an unknown as having your on reconditioned, more so because you can specify to what stranded your engine is rebuilt to, all you actually know about the one you buy is the paint finish

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It sounds like one of your proposed replacement engines is actually a smaller engine than can rev higher, and so maybe you are getting bad advice from the people trying to sell you a new engine, which is what others have alluded too.

 

As to a bigger engine and skin tanks, don't worry about it. Many many canal boats have undersized skin tanks and overheat if driven hard.

So, it takes about 3Hp to push your boat along the canal and so the amount of waste heat produced (to the skin tank) will be similar regardless of if this is coming from a small or bigger engine. With a big engine then you will get over heating if you run it flat out for a long time, but it will be fine for short blasts like emergency stops, just don't go thrashing up the Thames on red boards.

 

Note that if you fit the "new" 22HP engine and end up with a smaller prop and higher revs then that will also produce more waste heat.

 

.............Dave

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Ok, thanks everyone for your thoughts so far.

 

I’ll ditch the Vetus option, and then it seems like I have 2 routes to go down:

 

1) Get my current PJ2W refurbished at a ‘proper’ Diesel engine refurbishment place (or perhaps swap with an already refurbished same model from Real Diesels or similar?) This route means I don’t have to worry about the change in torque or hp or cooling.

 

Or

 

2) Replace the Petter with a refurbished engine that has a good ‘flat torque’ and insist on a breakdown of its history that I can share here for additional thoughts, as you don’t know what you’re getting from a second hand refurbishment. I need to be aware of the increased rpm of more modern engines with my propellor size and gearbox. But I don’t have to be too fussed about the skin tank extension as many boats are undersized in this regard.

 

There’s also a Beta Marine 30 being offered, which is 30hp @ 3600 rpm. Looking at the data sheet it looks like at 22hp it is 2000 rpm, so not too dissimilar from my current set up if I’m mainly cruising at 3 or 4 hp - have I got that right?!

 

Although do the higher revs of the Beta mean I need to be more cautious about the skin tank size?

 

I will look into the Petter refurbishment for cost quotes and see how it fairs.

 

Thanks all!

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5 minutes ago, Vixen2021 said:

There’s also a Beta Marine 30 being offered, which is 30hp @ 3600 rpm. Looking at the data sheet it looks like at 22hp it is 2000 rpm, so not too dissimilar from my current set up if I’m mainly cruising at 3 or 4 hp - have I got that right?!

You will probably have to change the prop to use the Beta.

 

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I know what its like having a smokey, clattering old heap of unbalanced cast iron but I would at least get a price on reconditioning your engine as Loddon says. A brand new engine is a dear thing, getting it to fit the existing beds, plumbing, electrics, exhaust and alignment is a lot of money too.  Add to that the nagging doubt of overheating and also, nearly forgot, a propeller to match the new engine and the bill gets even bigger. Just think, If you go ahead and replace the Petter you might just put it on E Bay for a knock down price, I might then buy it, recondition it for a lockdown/winter project and happily flog it for a nice profit. If the yard offers to get rid of it for you then that is what they'll do.  

Edited by Bee
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I can't remember who it was but there is an organised bunch going around telling people their engines are nackered, they can sell you a recon engine to replace it, charge you good money to do so then sell your engine on to the next person as a recon unit. 

 

I can't help thinking the warehouse to store the engines must be quite large. 

 

Get the Petter sorted out is the answer in this case, or shell out for a NEW engine. 

 

Any other option leaves you wide open to unscrupulous people with large warehouses full of "broken" engines which suddenly work fine and have new paint jobs. 

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1 hour ago, Vixen2021 said:

Ok, thanks everyone for your thoughts so far.

 

I’ll ditch the Vetus option, and then it seems like I have 2 routes to go down:

 

1) Get my current PJ2W refurbished at a ‘proper’ Diesel engine refurbishment place (or perhaps swap with an already refurbished same model from Real Diesels or similar?) This route means I don’t have to worry about the change in torque or hp or cooling.

 

Or

 

2) Replace the Petter with a refurbished engine that has a good ‘flat torque’ and insist on a breakdown of its history that I can share here for additional thoughts, as you don’t know what you’re getting from a second hand refurbishment. I need to be aware of the increased rpm of more modern engines with my propellor size and gearbox. But I don’t have to be too fussed about the skin tank extension as many boats are undersized in this regard.

 

There’s also a Beta Marine 30 being offered, which is 30hp @ 3600 rpm. Looking at the data sheet it looks like at 22hp it is 2000 rpm, so not too dissimilar from my current set up if I’m mainly cruising at 3 or 4 hp - have I got that right?!

 

Although do the higher revs of the Beta mean I need to be more cautious about the skin tank size?

 

I will look into the Petter refurbishment for cost quotes and see how it fairs.

 

Thanks all!

 

Getting your own engine rebuilt is an option, especially if its a good engine that you like, but proper rebuilds are costly so get a good estimate and see how that compares with a brand new engine.

 

You are correct that if the Beta is 22@2000 and this is the same as your engine then you should be ok with the same prop, you will not be able to use the higher revs but thats probably not a big issue, lots of boats never get to full revs. A good thing to compare is the engine capacity, if both engines make 22@2000 then I would expect very similar cc';s. Best not replace your current engine with a smaller one.

 

As you want to do this quite cheaply then an "off the shelf" recon is likely to be the cheapest way to go but there is a significant risk that you will just get another old engine with a clean up and maybe a paint job..

 

............Dave

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How about an ex ships lifeboat Bukh DV20 or DV24. They tend to be low hours and heat exchanger units are available but direct cooled ones convert to skin tank easily enough. Usually low hours. The downside is that work will be required to fit it but I doubt any more than for the Vetus and like many direct injection engines my DV36 tended to smoke on idle and under low speed light loads.   I suspect the Petter is also direct injection so may also tend to smoke at low speed and power in good condition.

 

I you used @RLWP (MES Midlands) to overhaul your engine he may well do the measurements and then advise/discuss with you what needs to be done and this may make a perfectly adequate job less costly. As long as your engine starts well from cold and has good hot at idle oil pressure I have seen nothing in your first post that suggests it needs and overhaul. Of course, we don't have all the advice you may have been given by "experts" but we don't know how good that advice is.

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10 hours ago, Vixen2021 said:

Makes sense. Thanks!

Where do I find these ‘people’ ?

As Tony Brooks has mentioned, RLWP, who is a member of this forum, is a professional specialist in older Lister and Petter engines. You could do worse than contact him.

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@Vixen2021 - are you aware that injectors in poor condition will cause smoke and make diesel knock worse, the diagnosis of your engine will really need a lot of input from you explaining what has been done in the past and such like. Then it will need some tests like checking the oil pressure cold, hot at speed and idle, compression test and ensuring the crankcase breather system is clean and free of blockage. In fact the oil leaks might be cured by simply replacing a hose, but I doubt it on a Petter.  It may also need the odd adjustment done before one could advise an overhaul with any certainty.

 

It's a lot easier just to tell you that you need the engine overhauled.

Edited by Tony Brooks
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