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Small denso alternator
Shooter63 - 28/5/17 at 04:20 PM

Before I go mooching around the interweb, has anybody got one of the above laying around they don't need it's the little 35amp job I want/ need as small as possible.

Shooter


femster87 - 28/5/17 at 05:17 PM

Got one with no pulley. Never used d so don't know condition.


big_wasa - 28/5/17 at 06:17 PM

Some Suzuki bandits where fitted with the Denso 40a alternator. They have three mounting points and a tapered pulley shaft but if your mounting it yourself it can be a cheap genuine denso that is designed to rev higher than the tractor copies.


http://www.locostbuilders.co.uk/viewthread.php?tid=195716&page=1

And this guy put one on a Duratec.

http://www.locostbuilders.co.uk/viewthread.php?tid=195884

[Edited on 28/5/17 by big_wasa]


starterman - 28/5/17 at 08:16 PM

quote:
Originally posted by big_wasa
Some Suzuki bandits where fitted with the Denso 40a alternator. They have three mounting points and a tapered pulley shaft but if your mounting it yourself it can be a cheap genuine denso that is designed to rev higher than the tractor copies.


http://www.locostbuilders.co.uk/viewthread.php?tid=195716&page=1

And this guy put one on a Duratec.

http://www.locostbuilders.co.uk/viewthread.php?tid=195884

[Edited on 28/5/17 by big_wasa]


Can I ask where you got the information from that they are designed to rev higher than the tractor copies?


big_wasa - 28/5/17 at 10:31 PM

Look around the net for failures of the kybota / denso copies from kitcars to tractors. I am not saying they offer any advantage over a genuine Denso. They are just a cheap alternative source of Oem alternators.


spiderman - 28/5/17 at 11:35 PM

I suspect that a smaller pulley is used on the tractor ones as they don't rev like a car. When put into a car without increasing the pulley size they will be over revving the alternator.


big_wasa - 29/5/17 at 05:37 AM

Most come with a single v so are changed to multi rib anyway.

Lots of posts being the bearings that fail. At a guess the little tractors have a power band of a couple of thousand rpm, a Zetec maybe 7000 and a bike will be near double that.

[Edited on 29/5/17 by big_wasa]


starterman - 29/5/17 at 07:27 AM

Some of the posts are quite interesting to read if not a little amusing.
I play with starters and alternators for a living and my professional opinion
is that you're not totally correct, to put it politely.


tims31 - 29/5/17 at 08:55 AM

quote:
Originally posted by starterman
Some of the posts are quite interesting to read if not a little amusing.
I play with starters and alternators for a living and my professional opinion
is that you're not totally correct, to put it politely.


listening.....


big_wasa - 29/5/17 at 11:06 AM

quote:
Originally posted by starterman
Some of the posts are quite interesting to read if not a little amusing.
I play with starters and alternators for a living and my professional opinion
is that you're not totally correct, to put it politely.



Then educate me. I am always willing and wanting to learn.

Why are there a lot of reported failures of the Denso style copies when spun well over that of its intended home of a tractor / forklift ect ?


PumaWestie - 30/5/17 at 06:31 PM

The maximum recommended rpm of the small Denso alternators is 18000rpm. Therefore you need to gear the pulley size on the alternator so that with your maximum engine revs you don't exceed this based upon your engines crank pulley diameter.

Standard road car alternators are geared nearer to 15000rpm

Therefore there is some truth in what has been posted regarding pulley sizes but without knowing the full reason