alternator V-belt

[Dion]

20230516_170511.jpg (285.62 KiB) Viewed 473 times

My Interceptor has the Mitsubishi alternator, and currently wears a "Pirelli SPZ 1147 LP 1160 LA" belt.
1147 would be the length but why 1160? And what would AP and LA mean?

When I googled this I came across this webshop: vbeltshop.com. My belt probably is under Metric V Belts / Metric SPZ Belts.

What replacement belt would be good? I guess the Mitsubishi alternator may have a metric pulley/groove whereas the Chrysler V8 probably has a "Classic V Belt".

What belt width would be best for the engine pulley?

[slotcarone]

That fan pulley is designed for a wider belt but the narrow belt should also work. I would take that one off and go to any auto parts store and have them match it up. Simple.

[Grant]

I've been down this road Dion, if you find a good anorak Alternator man you should be able to find a single pulley with a wide belt groove for it..I managed to find one at an Alternator rebuild place
Or take your old pulley from you old Alternator and modify it to fit you Mitsu one, then it will be as it should be

[Steve Payne]

It looks like you have a 383 and these originally had a 13mm belt. The 13mm belt does sit a bit high in a Mitsubishi Alternator pulley but if a lot of tension is put on the belt it is usually OK. The problem is if you have working AC as this puts extra load on one belt and they can slip.
Part of the problem is an Alternator needs 1hp for every 10amps generated approx, if you put a high demand on the system potentialy you are asking the belt to drive 9hp and another 3hp with AC.
There is no exact belt to use as they can be anything from 1475mm ro 1550.

Steve

[slotcarone]

Pretty sure the car in the pics does not have AC. The belt will be fine as is.

[jvcarrier]

To me, it looks as though the alternator is not correctly aligned with the water pump, it seems to be set tooo far back, which will not be helping.

[Dion]

No AC indeed (car is a Mk1).
The belt is fairly tight or it would shreeek.
Did not think of replacing the pulley with the one from the original alternator!
Thanks for all suggestions and tips.

[slotcarone]

Alternator pulleys typically do not interchange from one manufacturer to another. You are trying to fix something that is not broken here. Like I said in my original post if you just replace the current belt with a new one you should have no problems as that size single belt is adequate to drive the alternator and the water pump.

[Grant]

Alternator pulleys typically do not interchange from one manufacturer to another. You are trying to fix something that is not broken here. Like I said in my original post if you just replace the current belt with a new one you should have no problems as that size single belt is adequate to drive the alternator and the water pump.

But it's correct to have the same size "V" pulleys on the ancillaries Mike, the narrow belt on the wide pulley isn't correct really

[slotcarone]

That wide pulley on the water pump is a v shape and the narrow belt will work as well just sitting lower in the v groove. The angle of the v is the same either way.

[thomaslk]

My Interceptor has the Mitsubishi alternator, and currently wears a "Pirelli SPZ 1147 LP 1160 LA" belt.
1147 would be the length but why 1160? And what would AP and LA mean?

To give you a concrete answer - LP means „length on pitch“ and is a kind of „effective length“. This length can not be measured on the sample belt but calculated knowing the inner and outer circumference as well as the belt profile.
LA means outer lenght („Länge Aussen“ in German) and can be measured on the outer circumference of the belt.
rgds
Thomas

[DPP]

To me, it looks as though the alternator is not correctly aligned with the water pump, it seems to be set tooo far back, which will not be helping.

John has pointed you in the right direction, sort this first then see where you are.