Fan Belt Late S1 cars

[chris45]

Whilst looking to purchase the correct fan belt for my S1.5 2+2 E-Type I noticed in the Jaguar Service Bulletin for S1.5 (in E-Type Knowledge Base) that the water pump pulley and the fan belt changed at engine number 7E 54837 to increase pump flow rate. The earlier belt for S1 4.2 2+2 is C24291 but the improved system has belt C26376 and this is the one for my engine according to the bulletin.
I haven't been able to source this new belt and SNG Barratt are not aware of it. I wonder if there is much difference between the early and late belts and if the old model belt would fit. The belts also changed for the 2 seater versions at engine no 7E 17158.

I cannot find any information about this on the Internet so hoping someone here might be able to help.
Thank you.

[Heuer]

Have a look at this thread: viewtopic.php?p=128591#p128591

Specifically:

C24291 - For the 4.2 cars the belt was changed to C24291 to accommodate the alternator pulley with its different diameter to the dynamo and had a 40.5" outside circumference.

[chris45]

Thanks and I had already read this thread but it doesn't answer my query.
My query is not about the change in pulley from a 3.8 dynamo to a 4.2 alternator but rather what occurred in about 1968 to the 4.2 series 1 cars.
According to the service bulletin at engine number 7E54837 the fan belt changed from C24291 to C26376 to accommodate a further change in the water pump pulley.

I just wanted to find out if the belt C26376 is much different to the belt it replaced (C24291).

[Heuer]

Try fitting a S2 belt: https://www.sngbarratt.com/English/#/UK ... 1e742f235b

Only cost you £8 to find out if it works

[chris45]

I already have purchased a series 2 belt and it is far too small and the series 1 belts are expensive so worth checking first. I only posted this here because it does affect a large number of cars and it might be why some people are having problems fitting the fan belt, as noted on previous topics. There doesn't seem to be much of an awareness of this change in water pump pulley and belt so maybe the belt size didn't change significantly.