Thread: Biggest Amp Alternator for a Rover V8 V belt engine?

Yep, I would love to hear the answer to that as well. I have an 85A alternator only because it was cheap, just an AU V8 alternator and bolts straight in but it is not big enough, especially if doing a lot of winching.

I know a couple of people running 120A alternators on 3.9l motors but that is the biggest I have seen.

I have a 120 on my 3.5. Don't know any details though

Now trying to work out where i can put the 80A 24V alt

Dave

I fitted a Bosch 120 amp to my 3.5 and it generates plenty of power for my use (no winch, plenty of lights). But it is currently off the vehicle to chase gremlins. Since fitting the alternator I have had rough running issues (EFI). The more electrical load I put on the system, the lower the amount of revs I can use.

IE: No electrical load apart from engine running, full rev range available.
Full load (400 watts of additional lights, A/C, stereo,etc) and it will only run smoothly to about 2000 rpm.

This is a very odd and frustrating fault. All relevant power supplies and earths have been checked. Extra, larger power and earth cables have been fitted.

I suspect the alternator has a fault which is causing a "dirty" power supply which then interferes with the engine management.

what car is the Bosch 120amp alternator from?

what about the pulley size? - I want the rev counter to be accurate.

LRH

The bosch alternator was selected from a cattledog. Any decent auto sparky should be able to source one, and get a pulley to suit. There was a little bit of mucking around with the brackets and belt size, but nothing too serious.

I have a 100 amp unit. I have found that the more the alternator has to work the shorter the belt life. (3.5 ex efi) When I had the ford fans fitted they were drawing just under 40 amps and I was replacing the altenator belt ever 5-6 months. Since removing the fans (and less constant load on the altenator) the belt shows no sign of wear at all after 6 month.

rehashing this old thread as I am about to have a mitsubishi 100amp alt fitted to my v belt 3.9

I have had the same problems with the bosch 120 as mentioned earlier in this thread.

Will report on the mitsubishi unit once its fitted.

I fitted a Bosch 120 amp to my 3.5 and it generates plenty of power for my use (no winch, plenty of lights). But it is currently off the vehicle to chase gremlins. Since fitting the alternator I have had rough running issues (EFI). The more electrical load I put on the system, the lower the amount of revs I can use.

This has been discussed many times, and the info I gave was to shield and reroute the wires from the Dizzy to the coil, away from the alternator. A member in Tassie? did this a while ago and reported that it fixed the problem.

One cheaper alternative to a big alternator on a V belt car is to fit a second alternator mounted to the Sanden compressor. I have a Bosch 85 amp in the normal LH position and an Ingram 85 amp next to the compressor.
Works well. I wrote it up several years ago.
Attachment 11822
Regards Philip A