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who else has had a Brise alternator fail ?


Jason Plato

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People who spin 'em up too fast? Which one do you have? Ther small 40 amp one seems to be more prone to mishaps than the 50 amp one although even these have been known to go. I have run a bigger alternator pulley on mine since new and have had no issues. With the small 40 amp alternator and the big 80mm pulley you can have charging issues at tickover that I don't seem to have experienced with the 50 amp alternator and same pulley on the road. If you are giving the engine loads of revs then over-revving of the alternator can be an issue.

 

At 75000 rpm the alternator is turning over 12,000 rpm which seems to be OK. The 50 mm pulley gives 19500 rpm which is too much in my opinion. People disagree with me but then my alternator is still working 😬

 

AMMO

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Dave,

 

I've run Brise alternators since 2000. Same as Ammo, I have it geared so it doesn't do much at idle. The mode of failure can tell you a lot. If the windings have gone, then you have to wonder where and how it was wound. Regulator failures are "user serviceable" and a good motor factor should be able to supply new regulator packs.

 

As a point of interest, I have found out a fair bit about the supply chain for Brise uprated alternators. They go via several suppliers for winding/assembly etc. including the guy that I use to rebuild my alternators...

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as you know I've had 2 fail this year, first was the windings went on the first one, the 2nd only managed 1 trackday and I'm yet to find out what the problem was with that one.

 

R400 Duratec Build and Modification Pictures

here

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Dave,

 

I would be surprised if it were revs that killed it, with the 64 mm alt pulley the max the alt will see on your car is 14,500 rpm. Heat should also not be a problem as its mounted on the induction side. If its the electronic regulator or rectifer thats failed within the alt I would look at the wiring harness and the FIA battery cut off switch for a bad connection causing a spike.

 

Rob

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As long as it fits and spins, that's an alternator that is up to the job. *wink* I bought an alternative from a cheapie source and now can't remember which one was Brise and which one wasn't. Word of warning though... it was inattention to pulley alignment when swapping between two alternators which lunched my engine (I might have been trying to gear down the replacement having overheated the first and I certainly possess two pulleys with different alignment, both sourced from Brise).
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Mine's on its way out......need to whip it off and see if it can be salvaged.

I rev the nuts off my car so tending to agree with Ammo that it needs a larger pulley.

 

I'm also going to move it to the induction side of the engine over the winter.......I don't think the heat is doing it any good either.

 

Simon Bell - Caterham 7 Duratec R

I`ve seen the future.....and it`s powered by duratec Check out the website here

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it was inattention to pulley alignment when swapping between two alternators which lunched my engine

 

you need a duratec Peter *wink*, external aux drive belt *cool* and no alt belt in cam cover incidents.

 

Dobuy - let me buy one and check it before I post details to save wasting everyones time if its a duffer. *wink*

 

but I will post if its a *thumbup*

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Just found the graph that came with my 50 Amp alternator. It shows that it reaches maximum output at 6,000 alternator rpm. After that the output levels off. My alternator supplier is going to get me the graph for the 40 A version as well but he says that is pretty much the same. No increase in output over 6,000 alternator rpm.

 

The problem is tickover where the alternator is not spinning that fast and the output is low. Looking at the graph I have approximately 10 Amps at 1,500 rpm alternator rpm and 20 Amps at 2,000 rpm. So you have to play a juggling act to make sure the alternator is spinning fast enough to give you some charge at tickover.

 

With the 63 mm pulley you have 2.07:1 ratio

With the 80 mm pulley it is 1.63:1. This is working with a 131 mm crank pulley.

 

Just a bit more information to help you make an educated decision.

 

 

 

AMMO

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Dobuy

 

the alternators on the exhaust side are different to mine on the inlet side .

 

When I broke down the other week MikeE brought his alternator (exhaust side) over and it wouldnt fit.

 

The one I'm looking at is from a Suzuki car.

 

I'll post once I have more info etc *smile*

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Dave,

 

If you are convinced by the blurb on www.brise.co.uk it states that ALL their alternators have heavy duty regulators and uprated bearings. I also read the spec sheet when I collected my alt from Steve Hurst which read much the same, max safe revs 15,500 rpm.

 

Brise certainly have them apart rotate the field windings, perhaps they fit the uprated bearings whilst its ijn bits. don`t know any more sorry.

 

Do you have a diagnosis yet ?????

 

Rob

 

 

Edited by - Rob Walker on 17 Jul 2007 11:00:37

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Brise fit a grub screw to prevent the field windings vibrating in the case, they also fit a diode to prevent damage to the regulator should the alternator loose its 12v supply, such as when an engine is stopped using the cut off switch, I have spoken to them about max speed in the past and have been told 17500 rpm should be OK.

 

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