Lister ST3 alternator

[Nathan 0121]

Hay guys can anyone help I need to get a alternator. For my engine can anyone tell me witch one fits. That I could just pick up from the shop. I'm thinking the

Lucus A127 might be the one but I honestly don't know

 

Thanks 

[BEngo]

Have you any pictures of the one that was there, or pictures of the bracketry and the drive pulley?

An A127 may well fit, but without seeing the engine it is impossible to tell what should be there/will fit.

N

 

[Nathan 0121]

Hi buddy thanks for the reply.

There's no alternator on it. I was given one with the boat but it don't fit.

The engine apparently had been run in around 4 years. So my friend got that sorted and she fired up first time but ideal want to get alt on her asap so not to kill the battery when we need to start her up 

[bizzard]

33 minutes ago, Nathan 0121 said:

Hi buddy thanks for the reply.

There's no alternator on it. I was given one with the boat but it don't fit.

The engine apparently had been run in around 4 years. So my friend got that sorted and she fired up first time but ideal want to get alt on her asap so not to kill the battery when we need to start her up 

They use a lefthanded alternator as depicted, although it is an old ACR one, a left A127 is a direct swap. There is a lot of room on those engines to fit most alternators with the use of nuts bolts, spacers, washers ect, and slotted adjusting bracket where there are selctions of them,( straight, curved, angled ect) on Ebay.   Do you have the large diameter alternator  drive pulley on the camshaft 9, 10 or 12'' ?.

Lefthand Alt.

[Boater Sam]

A universal mounting alternator is the easy way, fits anything.

 

Try https://www.ebay.co.uk/itm/Alternator-MARINE-MULTI-FIT-UNIVERSAL-UPGRADE-12-VOLT-90-amp-high-output/312692449828?hash=item48cdec2224:g:DA4AAOSwLo9dJKGT

[Nathan 0121]

Hi guys thanks for the help I ended up getting one from a local place.

[Tony Brooks]

Not sure if this is relevant but with older Listers and alternators I feel you need to be wary. Some drive the alternator the opposite way to what is usual and if this is the case on an ST you need to ensure the alternator fan is either a duel rotation one or the vanes are bent correctly for the direction yours goes in. The alternator itself could not care less which way it is rotated but if the fan is incorrect it is likely to cause overheating and a short life.

 

I think a universal fan has the blades set on the radius where as handed fans have them at an angle to the radius. I think (because I can never remember) the angled blades need to have the outside tip trailing when running on the engine. Someone will soon correct me if I am wrong.

[Boater Sam]

1 minute ago, Tony Brooks said:

Not sure if this is relevant but with older Listers and alternators I feel you need to be wary. Some drive the alternator the opposite way to what is usual and if this is the case on an ST you need to ensure the alternator fan is either a duel rotation one or the vanes are bent correctly for the direction yours goes in. The alternator itself could not care less which way it is rotated but if the fan is incorrect it is likely to cause overheating and a short life.

 

I think a universal fan has the blades set on the radius where as handed fans have them at an angle to the radius. I think (because I can never remember) the angled blades need to have the outside tip trailing when running on the engine. Someone will soon correct me if I am wrong.

You are correct Tony.

The fan pulls air through from the rear of the alternator to exit from the fan. 

[Nathan 0121]

Yea I did ask that question as my engine runs anticlockwise. The guy was adamant that the blades would pull the air in to cool it regardless witch direction it was running. 

So I hope he was right and not just thobing me off

[Tony Brooks]

Actually the fan pulls the air out of the alternator, not pulls it in. Now, after that I would advise you to look at the blades yourself. You will see a flat disk like behind the pulley that may or may not have cut outs in it from which the blades were formed. You need to look at the bits that stick backwards away from the disk towards the alternator. If they are All set on radii/diameter lines then they are OK, they will pull the air out equally efficiently in ether direction but if the blades are at an angle to the radii/diameter lines then you need to see which end of the blade trails when running. if its the inside end then it is the wrong fan, if its the outside end then its fine (Subject to me being right about the angles and Sam implies I am).

[Boater Sam]

1 hour ago, Tony Brooks said:

Actually the fan pulls the air out of the alternator, not pulls it in. Now, after that I would advise you to look at the blades yourself. You will see a flat disk like behind the pulley that may or may not have cut outs in it from which the blades were formed. You need to look at the bits that stick backwards away from the disk towards the alternator. If they are All set on radii/diameter lines then they are OK, they will pull the air out equally efficiently in ether direction but if the blades are at an angle to the radii/diameter lines then you need to see which end of the blade trails when running. if its the inside end then it is the wrong fan, if its the outside end then its fine (Subject to me being right about the angles and Sam implies I am).

The idea is that the cooler air enters the rear to cool the electronics first, passes through the stator and exits tangentially from the fan.

[bizzard]

The fan on the alternator picture in my post 4 is for clockwise rotation looking at it face on to the pulley.

[Tony Brooks]

50 minutes ago, bizzard said:

The fan on the alternator picture in my post 4 is for clockwise rotation looking at it face on to the pulley.

 

Yes, as indicated by the trailing edge of the blades.

1 hour ago, Boater Sam said:

The idea is that the cooler air enters the rear to cool the electronics first, passes through the stator and exits tangentially from the fan.

And if you drive a clockwise fan in an anticlockwise direction the angle on the blades would tend to try to scoop air towards the centre thereby acting against the required air flow.

[Sir Nibble]

1 hour ago, Tony Brooks said:

 

Yes, as indicated by the trailing edge of the blades.

And if you drive a clockwise fan in an anticlockwise direction the angle on the blades would tend to try to scoop air towards the centre thereby acting against the required air flow.

Whilst also setting up a centrifugal effect in the correct direction. Ends up effectively cooling the drive end bracket.

[Nathan 0121]

I'll try to get a picture guys thanks for the help ?.

 

I'm coming out the water next week I'm hoping to the god of boat's that it's not really bad. 

 

And then I can get on with the refit.

Out with the commercial hire boat layout.

And in with my own

Edited August 8, 2019 by Nathan 0121