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Where to buy lister alternator pulley?


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Hi All,

 

My Lister SR3 alternator doesn't produce any current at low revs so I would like to upgrade the pulley to get it spinning faster. I think a 12" will just fit on the end of the shaft. The alternator will then have to be mounted forward of its current position. Is this a good plan?

 

Where can I source pulleys (12, 11 inch) for this? the shaft is 1.5"

 

Thanks

 

IMG_20190720_140341.jpg.918b80064ee94bbebadaa256f3c59c5e.jpg

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3 hours ago, Alan de Enfield said:

Would it not just be simpler to increase your revs a little ?

 

No engine / alternator is putting out 'much' at tick-over. It is the norm to increase your revs to (say) 1200rpm when starting to charge and then reduce them as the battery becomes charged.


It is actually a very standard fix to put a big pulley on air-cooled Listers.

 

They are slow revving engines anyway, and if, as David explains, the drive is from the camshaft not the crankshaft, the maximum RPM Is halved.

They  really do need a very big step up ratio between engine and alternator if an alternator is o produce a reasonable output.

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19 hours ago, Keith M said:

Fenner Power transmissions 

Will be able to supply the pulley and taper lock.

 

16 hours ago, gabble said:

Have a look here http://www.bearingshopuk.co.uk/belts/v-belt-pulleys/

 

Pulleys of almost any size and separate bushings to fit your shaft

 

14 hours ago, matty40s said:

I'm quite sure Richard and Sue will have something suitable.

http://www.primrose-engineering.co.uk/

 

Thanks looks like some good options there

17 hours ago, alan_fincher said:


It is actually a very standard fix to put a big pulley on air-cooled Listers.

 

They are slow revving engines anyway, and if, as David explains, the drive is from the camshaft not the crankshaft, the maximum RPM Is halved.

They  really do need a very big step up ratio between engine and alternator if an alternator is o produce a reasonable output.

Do you think this will be a big enough of a step up? or would I need to go further with another set of pulleys? or a more suitable alternator if there is such a thing

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6 hours ago, davivid said:

 

 

 

Thanks looks like some good options there

Do you think this will be a big enough of a step up? or would I need to go further with another set of pulleys? or a more suitable alternator if there is such a thing

What is the maximum engine revs of your Lister? What is the diameter of the engine pulley? What is the diameter of the alternator pulley. You don't want the alternator going over speed at max engine revs, so take the ratio of the two pulley diameters and multiply it by max engine revs. Divide that by two if the engine pulley is on the camshaft pulley, rather than the engine pulley. As long as that number isn't greater than the maximum safe speed for the alternator, then all is OK. An older style Lucas alternator, like the one that appears to be fitted to your engine, is probably good up to around 12,000rpm. Modern alternators can go a lot higher. This should give you an idea of how big a step up is OK.

 

Jen

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6 minutes ago, Jen-in-Wellies said:

What is the maximum engine revs of your Lister? What is the diameter of the engine pulley? What is the diameter of the alternator pulley. You don't want the alternator going over speed at max engine revs, so take the ratio of the two pulley diameters and multiply it by max engine revs. Divide that by two if the engine pulley is on the camshaft pulley, rather than the engine pulley. As long as that number isn't greater than the maximum safe speed for the alternator, then all is OK. An older style Lucas alternator, like the one that appears to be fitted to your engine, is probably good up to around 12,000rpm. Modern alternators can go a lot higher. This should give you an idea of how big a step up is OK.

 

Jen

Maximum RPM for a Lister SR3 is usually quoted at 2000RPM

 

So the camshaft maximum is 1000RPM

So unless a pulley is fitted that gives a step up of a full 12:1, your maximum suggested alternator speed is hardly likely to be exceeded.

For all practical purposes with old air cooled Listers the best pulley is probably the largest you can realistically fit.

Something like my HA engines drive off the crankshaft, not the camshaft, but only have a maximum of 1,800RPM, so even there a ratio of well in excess of 6:1 would still not cause the alternator to exceed 12,000 RPM

  • Greenie 1
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Providing the boats electrics are relatively simple without massive inverters, huge battery banks and and all that stuff, that existing alternator with that pulley it has on it, plus the large diameter camshaft pulley 12'' if poss and it should charge well enough.  No need to torcher the drive belt with a tiny diameter alternator pulley.

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2 hours ago, bizzard said:

No need to torcher the drive belt with a tiny diameter alternator pulley.

Definitely go for a larger engine pulley, rather than a smaller alternator pulley if at all possible. The smaller the alternator pulley, the less surface area is available for the belt to grip and the more chance of slip under high loads when charging empty batteries. Also, the wear on the belt will be worse.

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6 minutes ago, Jen-in-Wellies said:

Definitely go for a larger engine pulley, rather than a smaller alternator pulley if at all possible. The smaller the alternator pulley, the less surface area is available for the belt to grip and the more chance of slip under high loads when charging empty batteries. Also, the wear on the belt will be worse.

Yes indeed. Although being only the camshaft pulley and alternator pulley involved, ''no water pump'' on those engines, the wrap around is good. But I don't like the very small alternator pulley's at all.

Edited by bizzard
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1000 rpm at the alternator is not going to produce much output.  There are things you can do to improve this, by modifying the alternator.  Sir Nibble of this forum is your man for the details.  Or you can buy specialist low speed alternators  though I woud not expect them to be cheap.

If fitting modified pulleys go for  a multi ribbed belt rather than a V or wedge belt.  Ribbed belts cope better with small pulleys and limited wrap round which are inherent in high step up ratio drives.The Automotive standard is size J and you will need at least 4 ribs.  6 better.

 

N

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1 hour ago, davivid said:

The alternator pulley is 2.5" so that will give me a ratio of approx 1:4.7 using a 12" drive pulley.

 

I have no idea what RPM I usually cruise at but it will be low. 400rpm? so 200 at the camshaft will give approx 938 at the alternator.

I very much doubt your cruising RPM is anything like that low - I'm not even convinced it would idle well at that speed.

I feel sure that unless you only go everywhere very very slowly your cruising RPM will be at least double that number.

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From the photo it appaers to me that there is littlie room to fit a larger engine pully.

Therefore, how's about making a layshaft type arrangement with an additioan set of pulleys which will give you a much better 'gearing' ratio?

 

 

 

 

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The thing is that not all that long ago probably a great many leisure and hire narrow boats used the Lister LR, SR, ST, 2 or 3 cylinder versions with only one alternator, early boats, dynamo and control box, 10 or 12'' camshaft pulley, a start battery and often just one or two 110amp cabin batteries with a diode or split charge relay. Usually fitted out with lots of 10 and 20watt incandecent light bulbs the usual water pumps, often a shaver socket, radio, often a little telly. Ok hire boats cruised all day long to get their money's worth, Leisure boaters carried candles and oil lamps, sometimes bracket gas lamps. And then along came ''The mobile phone'' which needed charging now and again, up went the cabin battery use a little, then along came the internet and the power needed shot up, ,Boaters now had to cruise 24/7 to keep up with the battery charging or buy a stinky noisy generator. The rot had set in, another cabin battery needed and another and another, then bigger more powerful engines to cope with bigger more powerful alternators, inverters and so on. And of course power usage has escalated hugely ever since, giving many folk nightmares, problems, anguish, astronomical expense, constant worry and electric shocks. :)

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2 hours ago, alan_fincher said:

I very much doubt your cruising RPM is anything like that low - I'm not even convinced it would idle well at that speed.

I feel sure that unless you only go everywhere very very slowly your cruising RPM will be at least double that number.

To find the real cruising rpm there are various frequency analyser apps available for Android and Iphone mobiles and tablets. They use the microphone and give a sound frequency indication from the engine sound they pick up, which can be converted to an engine speed. Needs a bit of interpretation to get the right value, but useful. If there is a tachometer on the control panel its accuracy will depend on if it was set up properly in the first place. Not something that can be totally trusted.

Jen

Edited by Jen-in-Wellies
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39 minutes ago, bizzard said:

The thing is that not all that long ago probably a great many leisure and hire narrow boats used the Lister LR, SR, ST, 2 or 3 cylinder versions with only one alternator, early boats, dynamo and control box, 10 or 12'' camshaft pulley, a start battery and often just one or two 110amp cabin batteries with a diode or split charge relay. Usually fitted out with lots of 10 and 20watt incandecent light bulbs the usual water pumps, often a shaver socket, radio, often a little telly. Ok hire boats cruised all day long to get their money's worth, Leisure boaters carried candles and oil lamps, sometimes bracket gas lamps. And then along came ''The mobile phone'' which needed charging now and again, up went the cabin battery use a little, then along came the internet and the power needed shot up, ,Boaters now had to cruise 24/7 to keep up with the battery charging or buy a stinky noisy generator. The rot had set in, another cabin battery needed and another and another, then bigger more powerful engines to cope with bigger more powerful alternators, inverters and so on. And of course power usage has escalated hugely ever since, giving many folk nightmares, problems, anguish, astronomical expense, constant worry and electric shocks. :)

Ferzakerly.

Folks expectations nowadays are much higher nowadays as you say / imply and providing / suggesting workable solutions is more and more difficult.

I have an SR2 genset here that runs at 1500 rpm and it's very noisy, perhaps running the OP's engine at 1200 rpm or less ought to be his tagget. That means some large pulleys are needed. These can be heavy and expensive. Perhaps a small onboard water cooled diesel genset might be the least cost / least disruption solution...

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15 minutes ago, OldGoat said:

Ferzakerly.

Folks expectations nowadays are much higher nowadays as you say / imply and providing / suggesting workable solutions is more and more difficult.

I have an SR2 genset here that runs at 1500 rpm and it's very noisy, perhaps running the OP's engine at 1200 rpm or less ought to be his tagget. That means some large pulleys are needed. These can be heavy and expensive. Perhaps a small onboard water cooled diesel genset might be the least cost / least disruption solution...

We-they played a lot of Ludo, Snakes and Ladders, Happy Families and unhappy families in those days, not to mention Meccano.

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4 hours ago, bizzard said:

The thing is that not all that long ago probably a great many leisure and hire narrow boats used the Lister LR, SR, ST, 2 or 3 cylinder versions with only one alternator, early boats, dynamo and control box, 10 or 12'' camshaft pulley, a start battery and often just one or two 110amp cabin batteries with a diode or split charge relay. Usually fitted out with lots of 10 and 20watt incandecent light bulbs the usual water pumps, often a shaver socket, radio, often a little telly.

Er - No - when we started (70's?) I think fluorescent lights were in vogue, water pump was a rubber bulb on the floor that you stood on (or a little lever at the side of the tap). Shaver*, telly and radio - definitely not.

 

[ * - on a subsequent trip a friend from school (we were then both in our early 20's) observed that the allegedly 230v shaver point on our hire boat changed his "shaver" into an "electric plucker" ]

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