[Healeys] Dynalite or which alternator to C42 Generator

Roger Grace roggrace at telus.net
Mon May 1 23:34:47 MDT 2017

Given the endless discussions on this topic, thought it would be useful to remind myself and any others who are interested in the major differences between alternators and generators

In a gen. the heat generated is in the rotating armature that is on the inside of the enclosure and this is why cooling is important/difficult and the fan on the pulley provides this through the enclosure. The brushes on a gen work hard and switch full current several times per rev. hence the wear and sparking. Gen usually has an oilite bearing at the rear that also wears. This is a critical component as wear (dry no oil) could eventually lead to scraping of the armature on the field poles and throwing of lead at comm. Take care of your brushes, bronze bush and bearings and you will have a reliable gen.

An alt. is inverted with the main winding on the outside (easier to cool hence more output) and the field  on the inside; hence the shape - larger diameter and shorter. No mechanical commutator switching needed as this is done by diodes. Slip ring brushes feed low dc amps to the internal rotating field - that last almost forever. Alt usually have more reliable front and rear rotor bearings and less rotational weight as the main windings are on the stator and thus more mechanically robust than a gen.

The discussions here also confuse me about the amps needed for our cars. I am with Chris on this one and wonder why you would need an 80 amp alt ?? !! Unless you run an extra 2 spots for long periods you likely don’t need the hi output of an alternator rather the mechanical reliability and the improvement of eliminating the mechanical regulator.
Lets say headlights at 55W each; 5 amps for ignition and auxiliaries; 3 amps for side lights (convert these plus brake lights to LED’s to lighten your load); blower at 3 amps; wiper at 5 amps; OD 1 amp as worst case continuous. This gives a total of around 26 amps full house driving at night in the Winter and raining !  Intermittent loads are horn, brake lights, indicators. etc. 

No doubt one day will convert to an alt but it would likely be to eliminate the awful cheap non adjustable regulator that I had to purchase after my 50 year old Lucas one failed.

From: Chris Dimmock 
Sent: Monday, May 1, 2017 6:42 AM
To: Simon Lachlan 
Cc: Healey List 
Subject: Re: [Healeys] Dynalite or which alternator to C42 Generator

The funniest thing I find about the "alternator inside a generator" conversions is the bloody pulley. It might look like a generator body - but you have to run a tiny pulley, because it needs a bucket load of revs to generate didly squat, more than a generator. 
Any good Lucas generator runs a Larger pulley - because it generates enough amps and stuff at low revs. Seriously men. Who revs their car past 5,000 rpm on the road? 
I run a C42 with a bigger DWR Pulley. 
That means I'm slowing down the old Lucas C42. Because it already generates enough power. 
Ok. I'm not running a 1,000 watt sound system or 4 IPods, and a grille full of spotlights. FFS - it's a Healey!!
So if you run one of these alternator inside a generator silly things, it's a joke. You've got a fake, compromised alternator. Immediately identified by the pulley. An alternator needs air for cooling. A generator casing doesn't provide that. 
Run one or the other. Generator or alternator. I've got no issue if you run an alternator. Run a good, sensible, reliable one. 
Nearly as stupid as putting a disc brake inside a brake drum. Same issue. 
Innovative- but it doesn't work unless all you do is drive to a coffee shop. 
Simon. Just get a C42 and return the core when you get back. 
Best Chris
Being Grumpy about modern shit. 

Sent from my iPhone
On 1 May 2017, at 3:54 am, Simon Lachlan <simon.lachlan at homecall.co.uk> wrote:

  My nephew’s generator issues may resolve themselves soon. May…….

  We may look at replacing the C42 in his BJ8 with an alternator, one of the generator lookalikes.

  Dynalite is one of the names I’ve come across, as sold by Holden’s. The Usual Suspects don’t seem to give their lookalikes their brand names.

  Anyhow, I know this topic came up a few months back, but I wasn’t interested then! So:-

  Does anyone have experience of these things?

  Is any brand better than another??


  Holden’s claim 45amps for theirs. AHSpares claim 50amps. A BJ8’s C42 generator kicks out 30amps max. It seems that one does need the BIG fuse in the Dummy Control Box. When I put in my alternator, a Lucas ACR, I put in an extra cable to carry the extra amps…….apparently if the alternator is really belting out the amps, the old wiring is a bit marginal.


  Any other thoughts? 

  Kind advice to the effect that putting more modern electrics in our old bangers is streng verboten is unnecessary at this time.




  Support Team.Net http://www.team.net/donate.html
  Suggested annual donation  $12.75
  Archive: http://www.team.net/archive
  Forums: http://www.team.net/forums

  Healeys at autox.team.net

  Unsubscribe/Manage: http://autox.team.net/mailman/options/healeys/austin.healey@gmail.com

     Virus-free. www.avg.com  

Support Team.Net http://www.team.net/donate.html
Suggested annual donation  $12.75
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums

Healeys at autox.team.net

Unsubscribe/Manage: http://autox.team.net/mailman/options/healeys/roggrace@telus.net

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/healeys/attachments/20170501/9ba4c224/attachment.html>

More information about the Healeys mailing list