lister overheated - what now

[robby09]

Hi all I am new here but my question is on topic! I have recently purchased a lovely 42ft Harborough Marine NB with a Lister LR2 engine. She decided to overheat coming out of the Saltesford tunnel near Barnton which then prompted my research into all things Lister

 

The engine lives under the stern deck with what I can only describe as a wooden outlet air duct connected upto the external air vent on the port side. So far so good. My concern is there appears to be no way nice fresh air can enter the air intake. The previous owner clearly had the same concerns as he fitted a huge electric fan above the engine blowing air onto the engine in an effort to rectify the lack of air being sucked into the duct on the engine. I would like to improve this for a couple of reasons.

 

1. The fan consumes a great deal of battery current and the fitted alternator is struggling to keep the batteries charged unless at higher revs.

2. The fan is nearly as noisy as the engine!

 

Is there any benefit to having an external air vent on the rear of the hull and ducting leading to the air intake to help matters?

 

Thank you for any advice in advance!

Edited May 9, 2016 by robby09

[RLWP]

Is there any benefit to having an external air vent on the rear of the hull and ducting leading to the air intake to help matters?

 

Thank you for any advice in advance!

 

the short answer is yes - sort of

 

The engine takes in air from between the flywheel and the gearbox. It is unusual to have a duct leading to that point. On the other hand, you do need a big hole somewhere to let air under the boards for the cooling air

 

Now, many engines seem to have poor arrangements for air both in and out, and they don't overheat, so you may have something else going on

 

Richard

 

MORE: I can't imagine the fan is helping much

Edited May 9, 2016 by RLWP

[bizzard]

Are you certain it is an LR2 and not an SR2 ? The LR2 is only 10 and a bit hp which might struggle a bit with a 42ft boat although Harborough marine hulls were a nice shape that cut through the water easily.

[robby09]

Hi guys and thanks for the replies. Richard yes there is something else going on a small oil leak that hopefully is now cured and the engine has just been steam cleaned to remove the muck that has been there for a number of years. I would agree there should be a 'hole' somewhere to let fresh air in but there isnt but I struggle to imagine the setup has been like this for 40 years and not overheated before or perhaps the electric fan just about helps but is far from ideal.

 

Bizzard its the LR2 with hydraulic LH150 box and according to the engine plate 9hp. I am considering an upgrade but what to?

[RLWP]

I struggle to imagine the setup has been like this for 40 years

 

And so do I. It isn't unusual for boats to change quite a bit in that time, maybe the deck boards have changed

 

Simple upgrades would be a bigger Lister - an SR or ST for instance

 

Richard

 

MORE: This is what I would expect for a Harborough:

 

 

A large rectangular air inlet in the side, often below the gunwale and above the deck height, maybe at the back of the battery box

Edited May 9, 2016 by RLWP

[robby09]

Hi Richard, I wish it did look like that ..... there is a small 6" x 4" on the port side where the hot air is expelled.

[robby09]

I am trying to upload images but get an error

 

You are not allowed to use that image extension on this community

 

 

Any ideas?

Edited May 9, 2016 by robby09

[RLWP]

I am trying to upload images but get an error

 

You are not allowed to use that image extension on this community

 

 

Any ideas?

 

jpg usually works

 

Richard

[robby09]

Nope that failed is it because I am trying to cut and paste the image?

[RLWP]

If you use the full editor on a PC there is an attach image button

 

Richard

[gazza]

 

Screenshot of the full editor on a mobile.

 

Click full version.

Click reply.

Click more options.

The use the image attachment dohdah thing.

 

I'm crap at IT but can manage this

[robby09]

 

Uploaded image hopefully

Thank you guys for your assistance pictures attached of the engine, stern deck and starboard side.

[bizzard]

$_12.JPG

 

Uploaded image hopefully

Thank you guys for your assistance pictures attached of the engine, stern deck and starboard side.

A vent could be cut in that floor board, as big as possible as near the rudder stock as poss so it won't be in the way. A cowl with a louvre intake grill would need to be made (easy with plywood) to stop rain getting in. I have seen this done on a couple of older boats with a/c Listers, but not Harborough Marine boats which always had the hull side intake vent, even their 1960's wooden hulled narrow boats had them. The floor board vent cowl will let more noise escape though. It wouldn't be difficult to cut a vent in the steel hull side with an angle grinder and cutting disc, perhaps above or astern of the starboard fuel tank.

[RLWP]

Definitely not the original boards. I wouldn't be surprised if she hasn't had some steelwork done at the back as well to make the semi trad stern

 

Richard

[bizzard]

Definitely not the original boards. I wouldn't be surprised if she hasn't had some steelwork done at the back as well to make the semi trad stern

 

Richard

Yes, and that tiller swans neck is unusual too, done to accommodate the wind dodger I expect. It might even have been a cruiser stern boat originally, the gas cylinders would have been in those two segment shaped lockers at the back.

[robby09]

Thanks again so I've got an alien ?. She has certainly been reworked at the back as some of the steel is clearly newer than the original build. I prefer the idea of a starboard vent it will be quieter if nothing else! The tiller looked wrong to me also but at least the stern tube greaser is above deck ?

[RLWP]

Yes, and that tiller swans neck is unusual too, done to accommodate the wind dodger I expect. It might even have been a cruiser stern boat originally, the gas cylinders would have been in those two segment shaped lockers at the back.

Well spotted

 

Richard

Thanks again so I've got an alien . She has certainly been reworked at the back as some of the steel is clearly newer than the original build. I prefer the idea of a starboard vent it will be quieter if nothing else! The tiller looked wrong to me also but at least the stern tube greaser is above deck

I bet if you inspect the hull you'll find a plate welded in where the original vent was

 

Richard

[bizzard]

The original hull side steel thickness should-would, have originally been 3/16''

[robby09]

Cheers Richard I will take a look.
Oops sorry the image rotated

Edited May 10, 2016 by robby09

[FadeToScarlet]

No wonder it's overheated, it's upside down.....

[robby09]

Very good

[FORTUNATA]

These SR2's are now getting on in years as they were very popular and reliable back in the Seventies. I can't help but think maybe too much is expected from them as if they will go on forever without the recommended maintenance. This is outlined in the service manual and it is indeed an engine that was built with a view to hands-on maintenance.

A Lister air-cooled engine will certainly get hot if it's getting on in years and is being run hard. So, have you cleaned the cooling fins and blades. There was a special tool sold by Lister for this purpose but I guess you'll have to improvise. From experience I can tell you it's a horrendously mucky job. These cooling blades get coated in thick muck and grease and then provide little cooling air when needed.

Also a decent set of air ducts helps.

As others have said, diesel has been known to leak into the sump which can in rare cases create a runaway nightmare. Fortunately access to fuel pumps is fairly routine via the housing doors on the block.

[robby09]

Hi just an update, Muck cleaned off fins and she is running cooler but I am still considering an upgrade as 9hp on this 42ft boat seems under powered. Any suggestions as to what to consider?

[magnetman]

Look for an Lister SR2 or ST2? I think this has already been suggested.

 

If you went for a water cooled engine you would need to have modifications done to the engine beds for mounting it and either a skin tank/keel cooler or some sort of mud box installed for raw water cooling (not ideal on canals). It would be a lot easier to put another Lister in there.

 

I would suggest a new thread to discuss a replacement for a Lister LR2 in a 42ft narrow boat

Edited May 11, 2016 by magnetman

[RLWP]

Well, this would explain the OP's problem:

 

 

Richard