V belt size to bypass Air Con compressor

[DMitch16]

Issue
The air con compressor pulley shaft has cracked so I
need to fit a new compressor as the shaft is part of the end casing. I can't do this until next weekend and need the car for work.

The damage
Pulley bearing has failed, circlip has been forced out of its groove on the shaft and the spring clutch has broken away (all 3 spring pieces).
Cracking will soon lead to a sizeable piece of the shaft breaking off at which point the pulley would have come off and a bigger mess would have ensued. Caught it in time to avoid that and I have a good used identical compressor waiting to go on next weekend (have to degas AC system first though).

Meanwhile the QUESTION
Can I temporarily bypass the AC compressor by fitting a smaller V belt between the crank and alternator and if so what size does it have to be (part numbers of decent brands would be useful) and would I still be able to use the tensioner or do I have to remove it e.g. if a stretch belt can be used like those on non AC common rails? Mine is a PD of course.

All help greatly appreciated.

[rowdy-999]

Run a piece of string around to get a rough size.

[DMitch16]

Run a piece of string around to get a rough size.

Thanks but I was looking for a more off the shelf kind of solution. I have the rough measurements by running a garden wire around the circuit but the tensioner pressure is based on the longer belt fed over the ALT then down to the AC compressor. Shortening the circuit might put more strain on the alternator pulley if the existing tensioner is used on too short a length belt. I have seen ETKA diagrams with a belt from crank to alternator (overlaid on the diagram for the normal AC incorporated circuit) but could not find any more info on it.

Solved: Mate of mine just rang and said the PK950 belt is the one I need specifically for a BMR without AC as there is no layout difference. Have one at ECP for a tenner so off there at the crack of dawn tomorrow.

[ade555]

Thanks but I was looking for a more off the shelf kind of solution. I have the rough measurements by running a garden wire around the circuit but the tensioner pressure is based on the longer belt fed over the ALT then down to the AC compressor. Shortening the circuit might put more strain on the alternator pulley if the existing tensioner is used on too short a length belt. I have seen ETKA diagrams with a belt from crank to alternator (overlaid on the diagram for the normal AC incorporated circuit) but could not find any more info on it.

Solved: Mate of mine just rang and said the PK950 belt is the one I need specifically for a BMR without AC as there is no layout difference. Have one at ECP for a tenner so off there at the crack of dawn tomorrow.

Handy to know, will get one my self just in case I have that problem for a £10 is worth having as spares

[DMitch16]

The one they gave me was PK948 but 2mm won't make any difference with the tensioner there. Working a treat and still have the ECON air flow inside just no AC.