Choosing an engine

[Hairyloon]

Obviously there are a whole lot of different factors, but how do you go about deciding what size engine to put in a boat?

[carlt]

You find a nice, big, slow revving vintage engine with loads of torque, that can throw a big prop.

 

Then listen to the wonderful beat.

 

 

 

Alternatively...................

[Yoda]

No, I agree with Carlt.

 

However some find their favor in small, revy new diesels that don't need so much looking after.

[Chertsey]

Wasn't there recently another thread about this question?

[churchward]

Wasn't there recently another thread about this question?

Yup all things go in circles!

 

Now, if i was to fit a GI do you think I should earth bond my hull?

 

I'll get me coat.....

 

More seriously, some of it comes down to your own likes and dislikes. A slow RPM older engine is great fun if you're an enthusiast for those things and they do sound great. They are best placed though in a more traditional engine hole often due to the height and general physical size of the engine as much as anything plus useful to have all round access.

 

A modern high RPM diesel is fine and treated well will last you as long as the boat and is more suited to being put in a smaller space at the back of the boat. Here there is not much to choose between types the Kubota based ones are popular (Nanni and Beta variants) there is also Isuzu and Mitsubishi based engines that work well. Personally out of the modern engines I favour the Beta as I think the marinisation is good and the base engine excellent. However, as I say there is not much in it and some would say just choose the colour you want and by the manufacturer that produces it rather than worry about actual engine type.

 

In terms of size it depends on the size and weight of your boat. something around 35-40BHP (you won't actually use all this power but rather use about 20HP or less at cruising speed)in a modern engine spec will be fine for most boats bar the largest and heaviest of narrowboats. For old engines anything around 20HP or so is fine. You may want to up this a bit if you were going to spend all your time cruising on faster flowing rivers but even there the HP quoted should be OK.

 

There seems though to be a trend in new boat builds to increasingly go for larger engines but I think tis is more to do with customer demand and fashion than actual need.

Edited July 25, 2009 by churchward

[david and julie]

If by size you mean HP, then Beta give some guidance on their site - but obviously these figures would be practically meaningless if you want a traditional engine.

http://www.betamarine.co.uk/Templates/guidelines-inland.html

 

If I was thinking modern engine I would also consider the alternator set-up and for me Beta seem pretty good in this respect. My Beta 38 came as standard with a 95amp domestic(I think the bigger ones have 150 amp) pulley'd up at 3 to 1, with a very good belt arrangement - neither of mine have even needed adjusting in 1200 hours. Only downside is the domestic is mounted quite high which may matter with a trad.

[NB Willawaw]

Normally talk to a few engine suppliers to get an idea, then talk to a few owners with similar set-up's to see how they perform.

 

Bear in mind that different usages and loads like hydraulic bow thrusters, large alternators, TravelPowers etc will sap power away from the prop.

 

What size/type of boat have you got ?

[Hairyloon]

What size/type of boat have you got ?

None yet.

Have looked at a couple of projects that need engines, and before I get too serious, I need an idea of what sort of money I'd need for an engine... Or if I can marinate the one out of my landrover.

[churchward]

None yet.

Have looked at a couple of projects that need engines, and before I get too serious, I need an idea of what sort of money I'd need for an engine... Or if I can marinate the one out of my landrover.

If it is an old landrover and it is a non-turbo 2.2 or 2.5 diesel it is possible to marinise and there are some narrowboats with this engine out there. if it is a more modern turbo version then forget it. These engines are a bit big for a boat and it is more normal to see a BMC 1.5 or 1.8 diesel unit used. Also do not underestimate the cost and time it would take to marinise such a lump. a boat installation and cooling etc is very different to a car

 

Costs of new engines vary but it can range from £4000 to £6000 or so plus the cost of fitting. You will need to do your own research with main agents and engine suppliers for fitting costs and specific costs of engines. Many have websites with costs of base engines and options.

 

.

Edited July 26, 2009 by churchward

[Hairyloon]

If it is an old landrover and it is a non-turbo 2.2 or 2.5 diesel it is possible to marinise and there are some narrowboats with this engine out there.

Perkins 3.3, but the boat at top of my list is not a narrowboat.

That does mean that this forum is largely the wrong place to be asking, but the answers are still useful and appreciated, and besides, I don't know of a more appropriate one.

[carlt]

Perkins 3.3, but the boat at top of my list is not a narrowboat.

That does mean that this forum is largely the wrong place to be asking, but the answers are still useful and appreciated, and besides, I don't know of a more appropriate one.

What boat is it?

 

Not everyone here has a tin tube.

[churchward]

Perkins 3.3, but the boat at top of my list is not a narrowboat.

That does mean that this forum is largely the wrong place to be asking, but the answers are still useful and appreciated, and besides, I don't know of a more appropriate one.

Well, perhaps you could be a little more specific about what you do want and the responses would be more useful to you!!

[Hairyloon]

Well, perhaps you could be a little more specific about what you do want and the responses would be more useful to you!!

I'm back to thinking about this one...

[Hairyloon]

Hmm. Well that killed that line of conversation. Did I offend again?

[Arnot]

I'm back to thinking about this one...

Pehaps a Petter air cooled? I hear they were popular in concrete mixers.

 

 

Seriously though, I have only worked on a couple of cencrete boats in my time and both had Lister twins. Both owners seemed reasonably happy with them.

 

I have to say though I just don't get concrete boats. I know they were once more common and possibly even popular but maybe concrete cars would have been.

 

I guess that they were probably reasonbly cheap to make once you had the moulds but I would have thought that they would be an absolute liability when older.

 

Regards

 

Arnot

[Hairyloon]

I have to say though I just don't get concrete boats. I know they were once more common and possibly even popular but maybe concrete cars would have been.

It does not matter so much if a boat is heavy as it does for a car. Concrete cars not a winner I think.

I guess that they were probably reasonbly cheap to make once you had the moulds but I would have thought that they would be an absolute liability when older.

I think you do not use a mould. A steel frame is made, and the concrete smeared onto that. And I think I heard there are some pretty old concrete boats still afloat.

[ChrisPy]

because most of them are home-made there are a lot of bodged up hulls around with bulges, flats and generally unfair lines, which gives them a bad name.

they are useful in remote areas where repairing GRP or timber might be difficult; most coastal villages have a builder who can make a concrete patch repair to get you home.

 

they do not seem very relevant to inland waterways.

 

this link is interesting:

 

http://www.hartley-boats.com/

[WotEver]

I have only worked on a couple of cencrete boats in my time and both had Lister twins. Both owners seemed reasonably happy with them.

 

Yesterday as I stepped onto our boat and started the Vetus with a quick push of the button I joked with the owner of a beautiful Gardner-engined 60-odd ft trad who'd just finishing polishing all his engine's shiny bits "I don't have to spend all morning polishing mine prior to setting off."

 

His response was perfect: "If I didn't have to I wouldn't want one!".

 

With that he started it up and it made the most lovely chug-chug as I revved my way out of the marina feeling truly jealous.

 

T

[dor]

If you are looking at a modern engine, theya re all much of a muchness. However you may want to avoid anything painted bright yellow as it seems it is well known that they have crap gearboxes.