B30 alternator upgrade.

Rob

The alternator on my 164 is ~~fucked~~ no longer serviceable. I would like to replace it with something else.

Before I go measuring and trying to find something that will work, can anyone tell me if later redblock stuff has the same mounting points/belt alignment as the early stuff.

Hoping to sneak an easy upgrade.

Philia_Bear

Iirc a pile of gm stuff fits

Major Ledfoot

Rob wrote Before I go measuring and trying to find something that will work, can anyone tell me if later redblock stuff has the same mounting points/belt alignment as the early stuff.

I'll compare the B30 one I have to a later one. Let you know later tonight or tomorrow.

Rob

bgpzfm142;43902 wrote
Rob wrote Before I go measuring and trying to find something that will work, can anyone tell me if later redblock stuff has the same mounting points/belt alignment as the early stuff.
I'll compare the B30 one I have to a later one. Let you know later tonight or tomorrow.

that would be excellent... thanks

Angus242164

If it's a Bosch one then you can actually transplant the guts from similar later Bosch units into the original casing, to give you a higher output.

I did this with my 242, I used the front casing, fan and pulley from the original 55A unit, and fitted the rotor, stator, rear casing and regulator from a VN Commodore alternator, turning it into an 85A unit. The only mod needed was grinding four small slots into the outside of the cast iron stator to give clearance for the casing bolts.

Another advantage of doing this, is that it allows you to use a common later model internal voltage regulator, which can be easily replaced if need be. One extra wire has to be added, from the regulator to the positive battery terminal.

Philia_Bear

Needs more 250amp gm firetruck unit

egads (she/her)

There are bolt on Mitsubishi options also. This one is on a b20.

Rob

interesting... but that is on the wrong side.

egads (she/her)

Should work on either side.

Rob

yes it should... thanks

Major Ledfoot

@Rob - At a cursory glance, they're of similar dimensions. Light was running out, so I'll get measurements tomorrow and grab photos.

Rob

Thanks @bgpzfm142

Major Ledfoot

@Rob - sorry for the delay, just did some further checking.

Unfortunately my spare B234 didn't have an alternator fitted, but it still has the bracket on the engine.

Since I still had a B30 alternator, I tried to see if things would fit the other way around. If it works one way, it ought to work the other way, right? Well... maybe.

The B30 alternator takes a larger bolt than the B234 alloy bracket is prepared to take. As you can see, the two mounting holes take fairly small bolts.

The B30 alternator's mounting bolt is significantly larger, although the spacing seems about right.

It appears that if you drilled out the mounting hole in a later model alternator, the pulleys would line up - or at least, if you placed a sleeve in the B30 alternator's mounting hole, it would allow the pulleys to line up on the B234 - see below picture.

But without a late-model alternator at hand, it's impossible to say if it has enough meat around the mounting to be okay with a bigger hole. So IMHO Angus' suggestion (swapping the dead B30 unit's front casing etc onto a Commodore unit) to be the most cost effective and reliable.