6V Dynamator - first hand experiences...

[Roland Alcock]

Sounds like a sensible decision - the two I have are working as they should since I replaced the new gears with originals.  Roly, I think, has a similarly positive experience after doing the same.

Correct. 600 miles so far and no deterioration in any gears - as expected. 

Similarly for Ron Sadler, although he did not need to change the distributor drive gear as it IS hardened. 

Roly

[Nigel was in Brittany]

Well that shows the quality control at Accuspark , some gears have been hardened, most have not.

[Nigel was in Brittany]

Congratulations to Accuspark for attaining the dizzy heights of 10,000 page views and 101 comments about their Dynomator , and they to Quote their managing director Tony Ibbertson "We are absolutely not accepting liability" , strange how over 20 engines have had problems since fitting the Dynomator. Nothing has been heard here from Accuspark here since 21/5 and since then another problem has occurred with the distributor drive end of this product.

[Ruairidh Dunford]

1500 miles into using the Dynamator (with original Austin gears fitted) - all working well and as it should.  We have experienced extremely high temperatures the last two days topping out at 39c briefly yesterday afternoon, the unit appears to cope with this without issue.

I am running the unit in conjunction with an Accuspark electronic distributor fitted, with it’s original Accuspark gear, this unit is also providing great service, so far, after 2500 miles of use.


   

[Roland Alcock]

   
Same for me. Austin gears and no problems. The Dynamator performed consistently. 800 miles up to the north and back. Another 300 miles locally. All in this heat wave. One bout of overheating ascending Buttertubbs Pass, mainly due to the lead car going so slowly because of fuel evaporation. I asked one of my friends while he was at Beaulieu to pick up some timing gears for me, to replace the ones I had consumed. He looked at the matched pairs on offer, as he wouldn’t have used any of them in his engines due to condition and damage he didn’t buy any for me.

[Nigel was in Brittany]

I understand that Accspark has asked for and been provided with a set of Austin timing gears and a distributor drive gear to see if they can get it right.

[Ruairidh Dunford]

They have been loaned a complete NOS set by a Forum member (not me) but I think swapping out for original is the way to go just now, if you want to use this unit.

[Nigel was in Brittany]

Yes, I agree. They must now have 2 sets of gears as I know another set has been loaned/donated by a non forum member.

[Bob Culver]

This whole topic has been interesting.
 
For a start , based on a very small sample, I understood the distributor drive pair of gears to be not hardened originally. The loading is very low, intermittent and the rubbing speed modest. The original gears in my car failed at about 70,000 so cannot be many original left, but does anyone know for sure what was used?
 
I am staggered by the degree of wear experienced with the dynamator drive gear. I wasted a couple of hours burrowing through various ancient tomes acquired from 2nd hand shops over the decades. It seems the term skew gears is a misnomer. Screw gears correct. Of possible interest, if of no practical help, but one book had this to say abbreviated, ”Because of the point contact of screw gears, even light tooth loads set up very high stresses at the point of contact. ...Wear can be considerably reduced ...if the gears are first broken in by operating under light load...and if extensively broken in load capacity can be very considerably increased.” Soft steel on self was given a very low load rating, medium steel on medium steel or on cast iron about 3 plus x better, and ci on ci 4x better! No figs for soft steel on ci.
“In general to avoid scuffing soft steel and ci should not be used (paired or together?) if the pitch line velocity of either(?) gear is considerably over 1,000 fpm “(which with Seven  it is) “Screw gears for significant powers  should run in oil.”
Starting out with high watts load dubious.
Has it been established what the dynamator drive gear was cut from?
What would be the likely worst material? Free machining m.s? Or ordinary m.s, or tough steel?
I was surprised at the damage. Would reasonably expect a wide tarck to develop and wear then slow.
The life of  ci  gears remarkable, esp as many bedded in on other cars and at slightly different mount angles.
Can any gear experts comment?

[Nigel was in Brittany]

The problem is Bob Accuspark do not reply about things that have concerning the damage caused by the faulty gears apart from "we are absolutely not accepting liability", and do not reply to an invoice for repayment due to the damage caused to a newly rebuilt engine etc. My claim is now going to another level if payment is not received within 28 days.