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#1 Alternator Upgrade Pully
Posted: Mon Nov 09, 2015 3:59 pm
by 2010paul
Hello,
I wish to buy an Alternator Pulley for a ' Double V ' belt
I have upgraded my Series 1 to Alternator .
Please advise,
Kind Regards,
#2
Posted: Mon Nov 09, 2015 4:20 pm
by Heuer
It is known as a 'Duplex' pulley and SNGB sell them as part C24392 for the standard D11/AC alternator. It may not fit depending on the shaft diameter of your alternator though which could be 15mm or 17mm. What alternator are you fitting?
#3
Posted: Mon Nov 09, 2015 4:48 pm
by 2010paul
Hello,
Thank you, I already fitted the Duplex pulley from a dynamo but the output is not sufficient, so I guess the SNGB one should fit OK
Kind Regards,
#4
Posted: Mon Nov 09, 2015 4:54 pm
by Heuer
The 11AC pulley is 2.5" diameter if I recall correctly. The alternator needs to be producing maximum voltage at reasonable engine rpm which is regarded as being about 2,000rpm for a road car. Therefore a pulley ratio of between 2:1 and 3:1 is normally specified.
#5
Posted: Tue Nov 10, 2015 9:00 pm
by ALAN COCHRANE
Paul
Another option is to keep the original single V belt and fit a pulley of the right diameter from another scrap Lucas Alternator. This is what I did and in the process discovered that there are many Lucas alternators of the period with identical shaft sizes. This means you will have plenty to choose from.
In addition it's probably cheaper than buying the Duplex pulley.
Cheers
Alan