Lister ST2 Twin Air Cooling System & Matching Prop Query

[Pete Argent]

Hello everyone, we are new to this forum and are hoping that someone out there with knowledge of Lister engines will be able to assist us. We have a Twin cylinder air cooled diesel 17.5HP engine in our 50 foot narrowboat, which I am told it is an ST2? At one time, in the engine compartment it had some sort of canvas tube attached to a frame which linked the air intakes to the engine to assist in cooling it. This frame isn't there any more and so the engine runs hot all the time. We have taken to lifting the engine cover to allow more air in whilst we are travelling but this is far from ideal due to the smoke and noise from the engine. The engine runs ok but does tend to cut out at really unfortunate times, like as you enter locks etc. we are told this is because of her running hot? Anyone out there with a knowledge of this air cooling system that could point us in the direction of plans, photo's of someone who could help us make one?

 

In addition, I'm told my prop isn't suitable and is a sea going prop with much smaller blades than a still water prop? Is there a prop that matches my engine? Someone mentioned a company called Crowthers, anyone know them and what they do?

 

Thank you.

 

Pete

[Keeping Up]

The canvas "tube" isn't there as an air inlet, it's supposed to be there as an outlet for the hot air. As such there should be a large rectangular-shaped face across the whole side of the engine, and the duct to the vents in the side of the hull (or the roof) can be canvas, wood, plastic, or anything else - ours was made of aluminium and was just pop-riveted together. The big fan on the front of the engine, inside a wire cage, sucks cool air and blows it across the engine towards the ducting; if the mesh is blocked it won't work very well, and if there is no ducting the engine will definitely run very hot and will be prone to stalling when you throttle back.

 

I expect someone here will advise you on the best size of prop for your engine. Crowthers are able to calculate the ideal prop for you, then make it and sell it to you. Their props are slightly more expensive than others but are definitely the best. Either way you will need to know the ratio of your gearbox &/or reduction gear - there should be labels telling you the details somewhere on the side of the box.

 

 

Edited for tryping errrs

Edited May 18, 2014 by Keeping Up

[Leo No2]

I think maybe it should look a bit like this photo. It is in Sculptor and I know it is not the right fitting because Sculptor has a Lister HA3 but it is what we have at the moment. And yes, having had the cooling explained to me yesterday, the air comes in at the front of the engine and makes its way out through the 'elephant's' trunking. I would have thought keeping the engine room doors open, if you can, would help.

 

Edited May 18, 2014 by Leo No2

[bizzard]

Apart from the important and appropriate hot air outlet trunking being in place as described already;--These engines are not designed to be boxed in too closely or too much especially around the stern end where the fan intake is. If the engine is under a cruiser stern deck then it should have plenty of space around it plus cool air intakes on the hull side. If say in the stern end of a trad style boat under a box or floor perhaps on which you stand to steer, the same applies, keep the box fully open at the stern end where its flywheel fan is. If your engine box or floor is like this I recommend for boating in hot weather a hinged flap on the top of the box say 1' square be made sited directly above the engines two cylinders which can be propped open a few inches or so to allow engine top heat to escape, this is what I've done on mine.

Edited May 18, 2014 by bizzard

[Pete Argent]

Keeping Up, Leo No2 & bizzard, thank you for your advice regarding the engine cooling system, the hole in the cruiser stern decking seems the simplest solution to our problem but I'm open to any other advice. Regarding our prop, what kind of price are we talking? Hundreds of pounds or more? Thank you. Pete

[BEngo]

Budget for £300-400 for a 3-blade bronze prop about 16 in diameter. Smaller diameters will be a bit cheaper.

 

I'm not sure what your ST will actually need as that depends on at what engine speed it produces the 17.5 hp and whether it has a reduction gearbox ( probably but not invariably) and if so what it's ratio is.

 

Your chosen prop supplier will (or should) ask you this too so it would be worth finding out if you don't already know. They will also want to know the distance between the underside of the counter and the skeg which supports the bottom of the rudder, and the diameter and taper of the prop-shaft.

 

N

[springy]

You also mentioned "Smoke" associated with running hot - Air cooled listers can get the cooling fins on the cylinders clogged with

a "layer" of crud - a small amount of spilled/leaked oil or diesel running down the outside of the cylinder attracts dust/fibres etc

and this will form a nice insulating layer promoting overheating.

 

see http://www.canalworld.net/forums/index.php?showtopic=41636

 

springy

[BEngo]

And if it doesn't get too hot the dust, hairs etc. retain moisture which come of as oily smelling steam when the engine warms up.

 

N

[J R ALSOP]

Never mind the engine, can we have a close up of the Loo!.

[biltri]

I have an ST2 which also runs hot. I have stainless steel flexible flue linings taking the cooling air exhaust to a grille in the side of the engine compartment (cruiser stern). The engine only runs too hot when I push it, even though the previous owner had the lack of foresight to shove a 2" plastic tube through the cooling air intake reducing the capacity by about 20% ! I went on a long cruise of 2 weeks last year during that hot period we had and found that lifting one of the deck boards did indeed help, although far from ideal. We are going away again this year and my plans to tackle the cooling problem are currently in motion. I am cutting a couple of new holes in the side of the boat, one for the combustion air intake (which will give me back some of the original grille area, and another 12"x4" grille to provide more air. I have even considered fitting an automatic cooling fan from a car if this doesn't solve the problem. For now, I just keep the speed down to 3-3.5mph.

By the way, I have an old Lister ST2 manual which describes how to "box-in" the engine for sound proofing purposes, taking account of the cooling air required. Believe me, my engine is in desperate need of sound proofing! What? Eh?

[listerst2 lt]

Most Listers will run hot. I know a few people who have fitted fans to help engine cooling mine used to overheat too. Till I put a pipe on the air intake sonit sucked cold air in and modified my exhaust system. I ran up the river Trent after making these moddifications with bit of a flow on at 3 quater throttle all the way and it never overheated

No need for fans really.

Liam

Nottingham Narrow Boat Mechanic

[Tony Dunkley]

I think maybe it should look a bit like this photo. It is in Sculptor and I know it is not the right fitting because Sculptor has a Lister HA3 but it is what we have at the moment. And yes, having had the cooling explained to me yesterday, the air comes in at the front of the engine and makes its way out through the 'elephant's' trunking. I would have thought keeping the engine room doors open, if you can, would help.

 

 

I don't want to worry you, but if that's an HA3, then somebody's pinched about a third of it.

[RLWP]

 

I don't want to worry you, but if that's an HA3, then somebody's pinched about a third of it.

 

And if the plaque is correct, it's an HB

 

Richard

[Liam]

Tony Dunkley, beat me to it!

[Dave Clinton]

Keeping Up, Leo No2 & bizzard, thank you for your advice regarding the engine cooling system, the hole in the cruiser stern decking seems the simplest solution to our problem but I'm open to any other advice. Regarding our prop, what kind of price are we talking? Hundreds of pounds or more? Thank you. Pete

I have a 19" x 13" LH prop for a 1.5" shaft ( ie suitable for a Lister ST2 ) for around £150 plus carriage.

[kingswood]

I have a water cooled lister stw2 it also gets warm in the summer I have I 12 v blower that draws air in to assist with cooling as it inside on a trad stern only time it over heated was when the rubber impellor broke