Second alternator on Thornycroft T90

[Dutchie]

Hello All

For the wintertime i will replace my batteries for bigger ones , i thinking about 4 Trojan T105 batteries in Serie/parallel 12 volt, but i,m sure that i need more load cap. from my alternator , now the original Lucas ACR is mounted which is only 25 amp.

i,m thinking of two options : 1: replace the original alternator for an Alternator of 55 amp. from a Ford Escort/Orion.

2: To build in the 55amp alternator together with the original Lucas alternator and mount another second pulley on the lucas alternator to drive the second one . both circuits separated , the original for the starter batteries , and the second for light and other services.

did anybody have some suggetions for this job ?

Edited October 21, 2014 by Dutchie

[jake_crew]

You seem to use the words dynamo and alternator.

 

Assuming you mean alternator, I've seen three fitted to an engine once, each on a separate belt and engine pulley groove.

 

So if thats what you want to do ... go ahead.

 

As you say, each should feed separate batteries.

[Arthur Brown]

Usually 12v 70a is about the limit for a vee belt driving an alternator. So for more than that you will need to consider the pulley on the engine. You may get a suitable pulley with two Vee grooves or a wide notched belt or a polyvee belt will be needed to extract more power from the engine. It doesn't matter how many alternators if the belt will not transfer the power.

[Tony Brooks]

I am not at all sure about how large loads on the engine pulley will affect the torsional oscillation damper used on 1.5s. I would suggest that you take great care and take advice from Calcutt. I would hate your crankshaft to snap.

[Dutchie]

Thanks all for the Advice !

i,m sending an E mail to Calcutt , if there is an risk for the crankshaft i,m thinking to use only te 55 amp alternator , i read in some topics here that more owners done this job with succes , but first wait for the answer of calcutt.

[Tony Brooks]

Very wise, better safe than sorry. To a degree it depends upon exactly how and where any extra pulley is mounted.

Edited October 23, 2014 by Tony Brooks