What motorcycle alternator Amp`s ???

[W.olly]

Hi all, i am looking at an idea for an alternator for my kit car, i need one small enough to get in the engine bay, i have fitted a bigger engine in which is a 2.9i V6 Cologne, the car doesnt have loads of electrics just lights but the original alternator gave out 90 amps, but as there is no electrics like in the original sierra 4x4 i wont need that much amp output???

So i was thinking on a motorbike alternator like a Goldwing etc etc

does anyone know a good one to look at without spending hundreds of pounds, dont want a new one a si will be happy to get one and reconditoin it.

cheers

wolly

 

[rtbcomp]

Strictly speaking the alternator does "give out amps" it supplies 12v and allows the circuits to take upto 90 amps, so if space isn't a problem you may as well keep it.

 

[W.olly]

Strictly speaking the alternator does "give out amps" it supplies 12v and allows the circuits to take upto 90 amps, so if space isn't a problem you may as well keep it.

Thats just it, i dont have the room for the original alternator so the reason for a bike one as they are smaller in size.

cheeers

 

[BrokenBiker]

yeah the 90 amps is just max rating. 12v is the constant. Easiest way is to work out how much current your lights etc need at 12v, how much is needed to keep the battery topped up and then add about 20% on that to get the max current output you would need.

although that said, if you can keep an original then i would. Makes everything a lot easier

 

[711jrp]

Not a bike one but these are used quit a lot when space is tight, Diahatsu Alternator (35 amp) 27060-87201 or DENSO:1002111610

 

[BrokenBiker]

i was about to say don't the little jap cars use small alternators. The one on my mother swift was tiny

 

[W.olly]

I will add the amps up and see, i found this one on `the bay of all evil`
http://www.ebay.co.uk/itm/251573250333?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

perfect size, Amps 40, just thought it has the same electrics as a MK1/2 frod escort so i will have a look at what the spec is on them alternators, well dynomo


found that the priginal escort dynomo gave out max 22amp

 

[CompoSimmonite]

You could always add a pulley to the prop flange and run an alternator from there. Not a silly idea as used on classic vehicles etc where owner want it to look original under the bonnet and hot rods where they want an uncluttered engine bay.
Google prop shaft driven alternator for further info.
I believe Suzuki Bandit alternators are easy to adapt for car use if you want to go the motorbike unit route

Paul H

 

[W.olly]

Hi Paul. i have done that in the past aswell as a compressor when building off roader 4x4s, so not daft idea, but on this car its more hard work as there is SOoooo little room under the car its unbelieveable, only just get an exhaust under lol

 

[Normsthename]

The only problem I can see is the majority of Bike Alternators are fixed on the end of the crankshaft on a Woodruff key.
There are a few bikes that use a Belt driven alternator like BMW, Moto Guzzi etc.
I would go with a BMW motorcycle alternator myself.....

Andy

 

[pedrobedro]

Bikes don't have alternators they have generators which give out an AC current which is then regulated and rectified down to about 14v DC by the regulator rectifier. The little Denso alternators used on most Japanese cars are favourite if you are tight on space. Alternators usually give out between 13.8v and 14.4v to keep a battery topped up. If a battery reads 12v it is shot, they should hold about 12.6v if they are healthy.

 

[octo0072000]

re position it put it up top as it's on a V6

 

[W.olly]

I am lookig at the Daihatsu ones now, look small enouhg, i just need to get the body back on and do a few measurments then to the breakers to look at some.

re position it put it up top as it's on a V6

not much room but it will be going on top anyway, this is the space i have, and the air filters will be off side top. so the alternator will be going where the power steering res was, the braid hose have been removed as not needed there as they are from when the Pinto was in

 

[octo0072000]

as your using a efi you could use the older manifold and revert back to carbs also a lot less messing with wiring too also gives you a bit more room as well

 

[W.olly]

Staying as is mate, better allround than carbs, better fuel which will be needed lol. cost to much to conveet aswell, only paid £90 for the complete lot, all i could afford but no complaints. only need to get the alt in and it done really, well on the engine bay side. wiring isnt all to bad and got a few mates to help me out there as i am crap with wiring.

 

[CompoSimmonite]

Have you thought about a "jack shaft" so the alternator could then be mounted elsewhere - say behind the engine or infront of the rad ?
This sort of give the idea of what I mean -

Paul H

 

[AndyStobbs]

bikes typically have the alternator as a part of the engine rather than a bolt on piece. Look at the alternators on small gensets with e-start etc.

 

[the snooper]

Bikes don't have alternators they have generators which give out an AC current which is then regulated and rectified down to about 14v DC by the regulator rectifier. The little Denso alternators used on most Japanese cars are favourite if you are tight on space. Alternators usually give out between 13.8v and 14.4v to keep a battery topped up. If a battery reads 12v it is shot, they should hold about 12.6v if they are healthy.

anything that generates AC (alternating current ) is an alternator hence the name

 

[graffian]

bikes typically have the alternator as a part of the engine rather than a bolt on piece. Look at the alternators on small gensets with e-start etc.

The piggy back alternators are sometimes belt driven, Kwacker ZXR comes to mind, sometimes geared like
a GSXR/Exup; not that there would be any problem replacing the gear with a pulley, but geared ones
are flange mounted.

They are not all that small, small car alternators are pretty similar, I can dig out a GSXR one and measure
it if you want.
I would guess the output would be a bit low for you. Just had a look in a bandit manual, 550W max @ 5000 that seems a lot!

 

[Wallace]

My Triumph Speed Triple has a 25A external alternator, I think you would be running it flat out on a car with the lights, wipers and ignition on and be better off with something 40A+ for normal reliable road use.