Section : Cooling

Water Pump type and fan belt alignment

Posted By : James Richins, 17-Aug-2006, 08:52pm

There is a definate misalignment of the fan belt between the dynamo and the waterpump/fan pulley, in my Spitfire MK III
Have a look:

[img] [/img]
[img] [/img

The fan is an early mk IV model, that much I can tell. I'm not sure about the water pump though and the belt is also slack.

My question regards whether its necessary to change the water pump or just move the dynamo back a bit, which is possible but not as it should be?.. And get a smaller fan belt.

• Water Pump type and fan belt alignment

  Posted By : Chris Taylor, 18-Aug-2006, 00:10am

  If you have the correct adjustment bracket for the dynamo, then you do need a shorter fanbelt as it looks as if the dynamo is at the limit of its travel.
  To judge whether the water pump or dynamo is the problem, you need to see how they line up with the crankshaft pulley.
  From (fallible) memory, you MIGHT have a 6 cylinder water pump which has a pulley line furtehr back, although most such do not have any holes in the end for the fan attachment bolts.
  It MIGHT also be the case that you have a 6 cylinder dynamo which is longer, although I thought the brackest accommodated this extra length "backwards" rather than forward. The 6 cylinder engines used the Lucas C40L, the 4 cylinders the C40. The designation is stamped or engraved on the casing so you can tell at a glance.
  It may also be the case that you have the crank pulley or dynamo (or alternator?) mounting from a Toledo/Dolomite engine. I seem to recall that when I fitted a Dolomite 1300 engine to my Herald ( a short term fix after it broke a piston ring) I had the same misalignment problem. The belt never came off and it did not seem to wear the water pump or dynamo bearings, so don't worry!

  • Water Pump type and fan belt alignment

    Posted By : James Richins, 18-Aug-2006, 02:46pm

    Thanks for the reply Chris. So far I can see that it is definitely the waterpump that is out of line. I'm gonna try and get it off this weekend. The dynamo is the Lucas C40. The engine I'm pretty sure is a 4 cylinder 1300, but a reconditioned unit... I want to find out about the water pump first.
    
    My question at the moment is whether this
    
    Image Courtesy of and Copyright Rimmer Bros Ltd
    
    is longer this
    
    Image Courtesy of and Copyright Rimmer Bros Ltd from the bracket to the pulley?
    
    Cheers James

    • Water Pump type and fan belt alignment

      Posted By : Chris Taylor, 18-Aug-2006, 03:22pm

      Don't know if it's longer or shorter, the bigger difference was that it was bigger in diameter. The Mk4 engines (with alternator) had a bigger diameter engine pulley, to make the alternator spin faster. But to prevent the water pump overspeeding, that too had a bigger pulley. Taken together, they needed a longer fan belt.