by JCS » Wed Mar 31, 2021 11:03 am
RollyTG
You have probably gone by the point of return, but you might want to consider the following mods that we used over 50 years ago on XK engines. I am afraid it’s from memory :-
Firstly, the fan belt loading caused Jaguar to use an automatic belt tensioner and a multi vee belt as the loadings started to rise. The increased electrical loads and more efficient water pumps and fans for example, placed that single belt drive on its limits, particularly in bad weather at night. Along came the alternators in the mid 60’s and belt problems rocketed……..we now see a repeat of that exercise taking place.
If you have not yet had the broken “Jaguar Fan Belt” experience you need to be ready, it always happens on a cold, dark, wet night when the amp meter swings to full discharge and the ignition light illuminates.
If you are having trouble mounting the dynamo / alternator and power steering pump think what is going to happen if the engine throws a belt out on the road !!
This is roughly how we made things easier on Jaguar Mk X’s and it translates to the S Type. We changed the three studs that are screwed into the rear dynamo back plate, that is the plate holding the power steering pump. The reason is, those three studs are /were threaded UNC both ends, requiring UNC nuts. If one of these nuts was to be dropped and lost, replacing them is extremely difficult, however UNF nuts are / were easier to obtain. We would therefore adapt three UNC/UNF studs as used on the inlet manifolds, so that all that assembly had UNF nuts.This was more convenient if the PAS pump needed to be detached in situ by a remote garage.
We then modified the lower dynamo bracket (see your images on 27th May) by capturing the dynamo to bracket nuts. Usually that was done by welding the nuts but some were done by drilling and tapping the bracket and nuts, when welding was not available. The term “nuts” I have used, but sometimes we would use small metal blocks, which were easier to weld. Once the nuts were captured it was possible to use set screws at each end to hold the front and rear dynamo brackets, a single spanner/socket operation. This allowed not only easier assembly, we fitted dynamo’s and pumps as one unit, as alignment and access to the two set screws was easy and simple. Not only that, but slacking off the two set screws to allow belt adjustment was a few minutes, one handed, no struggle work.
Set Screw here means shanked bolt not threaded right up to under hex head
RollyTG
You have probably gone by the point of return, but you might want to consider the following mods that we used over 50 years ago on XK engines. I am afraid it’s from memory :-
Firstly, the fan belt loading caused Jaguar to use an automatic belt tensioner and a multi vee belt as the loadings started to rise. The increased electrical loads and more efficient water pumps and fans for example, placed that single belt drive on its limits, particularly in bad weather at night. Along came the alternators in the mid 60’s and belt problems rocketed……..we now see a repeat of that exercise taking place.
If you have not yet had the broken “Jaguar Fan Belt” experience you need to be ready, it always happens on a cold, dark, wet night when the amp meter swings to full discharge and the ignition light illuminates.
If you are having trouble mounting the dynamo / alternator and power steering pump think what is going to happen if the engine throws a belt out on the road !!
This is roughly how we made things easier on Jaguar Mk X’s and it translates to the S Type. We changed the three studs that are screwed into the rear dynamo back plate, that is the plate holding the power steering pump. The reason is, those three studs are /were threaded UNC both ends, requiring UNC nuts. If one of these nuts was to be dropped and lost, replacing them is extremely difficult, however UNF nuts are / were easier to obtain. We would therefore adapt three UNC/UNF studs as used on the inlet manifolds, so that all that assembly had UNF nuts.This was more convenient if the PAS pump needed to be detached in situ by a remote garage.
We then modified the lower dynamo bracket (see your images on 27th May) by capturing the dynamo to bracket nuts. Usually that was done by welding the nuts but some were done by drilling and tapping the bracket and nuts, when welding was not available. The term “nuts” I have used, but sometimes we would use small metal blocks, which were easier to weld. Once the nuts were captured it was possible to use set screws at each end to hold the front and rear dynamo brackets, a single spanner/socket operation. This allowed not only easier assembly, we fitted dynamo’s and pumps as one unit, as alignment and access to the two set screws was easy and simple. Not only that, but slacking off the two set screws to allow belt adjustment was a few minutes, one handed, no struggle work.
Set Screw here means shanked bolt not threaded right up to under hex head