[Healeys] Generator pulley dimensions

[Harold Manifold]

Mark,
 
This may be more information about v-belt pulleys than you ever wanted to
know but my Healey engine is in pieces and the measurements are easy to get.
All this information is based on Healey 3000 29D series engine built in
approximately October 1960. The Mk2 engines were 29E series but as long as
your car was equipped with a Lucas C45 Dynamo the information should be the
same for both engines.
 
Driving pulley diameter (crankshaft) is 157mm.
Driven pulley diameter (Dynamo) is 99mm.
 
Speed of driven pulley = Engine RPM x 157 / 99. If the engine RPM is 2500
then the Dynamo RPM is 3,965
 
With the 110mm driven pulley if the engine RPM is 2500 then the Dynamo RPM
is 3,568.
 
The Dynamo will be 10% slower with the 110mm pulley but I suspect the real
issue is the Dynamo output at low engine RPM's. I don't have any information
on the size of the crankshaft pulley on the 100/6 but if it was the same
157mm pulley used on the 29D series and later engines then the switch to the
smaller 99mm pulley was to improve the output of the Dynamo at low engine
speeds. The only adverse effect will likely be your headlights will be
dimmer at low engine RPM.
 
I trust this helps.....Harold


  _____  

From: Healeys [mailto:healeys-bounces at autox.team.net] On Behalf Of Mark
Donaldson
Sent: Saturday, June 10, 2017 7:22 PM
To: healeys at autox.team.net
Subject: [Healeys] Generator pulley dimensions



Listers,

 

Until now I'd never noticed the small differences in generator pulley
diameters.

 

What is the diameter of the pulley fitted to a Mk II tri-carb - part number
AEC 910 ?

The one presently fitted to mine is 100mm.  It does not have a part number
on it.

 

I have a 100/6 pulley with part number AEC 291 sitting on my shelf.  

It shows the part number on the casting and has a diameter of 110 mm.  (see
photo attached.)

 

As a matter of interest - could the 100/6 pulley be used on a later model
without adverse effect - bearing in mind the generator speed would be only
marginally reduced.

 

Mark

 

Ardmore

NZ

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