Fan belt slipping

[coxy123]

My fan belt is slipping when you get to higher revs. 

I've tried swapping it for a new one but the adjustments are maxed out. 

What am I missing. Cheers 

[dougbgt6]

Coxy,

What car is it? 

Doug

[coxy123]

1500 spitfire

[cliff.b]

What size fan belt is fitted?

[KevinR]

3 minutes ago, cliff.b said:

What size fan belt is fitted?

And what size is the water pump pulley ?

It's possible that you have a fan belt that is too long, or you have a water pump from a spitfire/herald that has a smaller pulley (as used on cars fitted with a Dynamo rather than an alternator. 

[coxy123]

When you pull it out it's 20''

It was part of a service kit from the club 

Avx10 1087 la

[coxy123]

Water pump pulley is 4''

[Pete Lewis]

1087 is the the belt length in mm    you need to buy a belt that is a bit shorter or modify your adjusting straps to suit 

with all the mix and swap that goes on whats in the parts list can be irrelevant   has it dynamo or alternator ???

lots of things change over the years

Pete

[coxy123]

Alternator. I was  thinking of extending adjustment slot on alternator bkt

[Pete Lewis]

if there is room to extend the slot thats fine 

Pete

[KevinR]

32 minutes ago, coxy123 said:

Water pump pulley is 4''

Which means you have the wrong water pump for a 1500.

The GWP200 has a 4" pully and is for the MKIII Spitfire and earlier.

The GWP128 has a 5.25" pully and is for MKIV and 1500 Spitfires.

There are three possible fixes :

1. Replace the water pump for the correct one

2. Fit a shorter fan belt

3. Extend the adjustment slot in the arm.

Ideally, you should replace the pump, as with the smaller pulley, the pump is rotating faster than Triumph intended.

 

 

[cliff.b]

My 1500 has the water pump with the smaller pulley and when I bought it, also had an older, heavier, 4 blade metal fan. I had the same problem with belt squealing when revving engine but got around it by fitting a lighter 7 blade plastic one. Less inertia, I presume.  

[johny]

Wonder if the smaller pump pulley also means less belt contact area plus higher pump turning torque required?

[coxy123]

Definitely a smaller pulley.

How do I check that it is a 1500 engine. 

Starting to worry now 

[KevinR]

5 minutes ago, coxy123 said:

Definitely a smaller pulley.

How do I check that it is a 1500 engine. 

Starting to worry now 

What's the engine number ?

[coxy123]

Where do I find it 

[KevinR]

[johny]

Engine number stamped not cast on a upward facing surface of the block near to its joint with the cylinder head...

[KevinR]

If it starts in FM, its a genuine Spitfire 1500 engine.

It it starts in YC, its a Dolomite 1500 engine that has been fitted to your Spitfire.

Any other prefix and its going to be a 1300 engine (or smaller)

 

 

[coxy123]

 

FM96366HF

[coxy123]

That's something then. I'm going to Silverstone, so could I get a 1300 belt until I can change pump

[Pete Lewis]

 

just extend the strap or obtain a belt 10mm shorter then change the pump when its needed if the current pump is quiet and not leaking 

pete

[cliff.b]

21 minutes ago, KevinR said:

If it starts in FM, its a genuine Spitfire 1500 engine.

It it starts in YC, its a Dolomite 1500 engine that has been fitted to your Spitfire.

Any other prefix and its going to be a 1300 engine (or smaller)

 

 

My engine starts DM and ends ESS which I believe was a factory supplied 1500 replacement engine at some point.

[cliff.b]

45 minutes ago, johny said:

Wonder if the smaller pump pulley also means less belt contact area plus higher pump turning torque required?

That was my assumption when looking at mine. 

[coxy123]

Thanks for your help guys