Replacing W-pulley with V-pulley

[Mikael B]

I would like to replace my W-pulley on the crankshaft and water pump on my 4.2 1966 S1.
Getting confused with the array of pulleys available throughout the different years and models. Early 3.8 cars have single V-belt and crankshaft pulley looks to be fine for my car. But for the water pump early 3.8 looks different?

Would appreciate help with partsnumbers for the correct replacements.

[paulsco]

Hi Mikael,

I had this dilemma as I wanted to power an AC pump and a small alternator.

The bolt pitch circle on the 3.8 water pump is wider than the 4.2, so the pulleys are not interchangeable. In fact the 4.2 water pump flange will fit through the hole in the middle of the 3.8 pulley. I couldn?t say if the water pumps are interchangeable, but I don?t think so.

I had wondered if the Series Two pulley would do the job.
http://www.sngbarratt.com/ProductDetail ... b0a48b&l=7

But I couldn?t get one when I was doing mine.
I ended up buying an aluminium single V pulley for an early Mk2 and made up a top hat adaptor to enable it to fit the 4.2 pump, which works well.
I used an XJ6 crank pulley; not sure which model, I think series 3, which I mounted on the original 4.2 damper.

The bolt pitch circle of the 3.8 crank pulley is different from the 4.2.

I run my alternator from the V pulley on the damper.

Paul

[Mikael B]

Thanks Paul, my idea was to run both the new alternator and AC pump with the same single V-belt together with the water pump.

The S2 water pump pulley looks very promising I will order one and test.
Xj6 crank pulley would be available from any scrap yard, I will try source one to test.

Thanks for your input.
Mikael

[paulsco]

Mikael,

I think you may have problems running the water pump, AC pump and an alternator from the same belt; there is unlikely to be enough contact area on the pulleys and the belt will slip.

I have fitted the alternator low between the frames and run it from the V grove on the damper pulley.
I have mounted the AC compressor where the alternator would normally be and this is driven by a second V belt from the pulley on the crank, together with the water pump.

Paul

[Mikael B]

Ok it sounds like a good idea, I guess there is not many options considering the limited space available.
I have seen all components driven by one belt on internet but maybe this is just a intermediate solution prior to finding out about slippage as you have done.
Your solution will be my first to test once I have sourced the correct pulleys.
Thanks again
Mikael

[64etype]

Ok it sounds like a good idea, I guess there is not many options considering the limited space available.
I have seen all components driven by one belt on internet but maybe this is just a intermediate solution prior to finding out about slippage as you have done.
Your solution will be my first to test once I have sourced the correct pulleys.
Thanks again
Mikael

Single belt designs incorporate a strategically located "reverse" idler pulley (backside of the belt) in order to maximize contact surface on each of the components.

[paulsco]

I don?t know if this will help, but the 420 crank damper C23363, which is also suitable for the XJ6 Series 1 is quite cheap and may work.

http://www.sngbarratt.com/ProductDetail ... 3&l=7&b=UK

Paul