water pump and high engine rpm

[wagoon 2,429]

Just wondering what diameter pulley you guys are running on your water pumps when you spin your engine to 6500rpm. I am getting a pulley made and the bloke said I can have any diameter I want within reason. I know if you go to big a pulley it can effect things like water flow at idle and charge rate of the alternator at close to idle speed

 

Current pulley being used is a 4 bolt power steering pulley fabricated only to get the engine running. The outside diameter of the power steering pulley is 160mm.

[Grimmy 312]

I use a big xd/c pulley from a mechanical fan water pump . Water pump pulley size shouldn't affect the alternator at all , only the crank drive and alt pulley . Mine was also 10% under driven so was probably a bit slow with the big water pump pulley at idle , but would be good with std size crank drive

[wagoon 2,429]

Yeah good point about the charging. Do you know the outside diameter of the pulley you have? How did you workout your underdriven percentage?

[Grimmy 312]

I don't know the exact size of the waterpump pulley but I'm pretty sure it's the same size as the std harmonic balancer , so would drive 1.1 normally .

 

So to work it out you divide the circumference of the driven pulley (waterpump) by the driving pulley ( crank) and the alternator is an idler so it has no effect

 

I think !

[slydog 7,873]

A pully off a XC iron head is the perfect unit to get. Find that fit it and close the bonnet.

[wagoon 2,429]

I don't know the exact size of the waterpump pulley but I'm pretty sure it's the same size as the std harmonic balancer , so would drive 1.1 normally

Well that works out perfect cause the power steering pulley Im using is only just smaller in diameter than the standard size harmonic balancer so guess I will just stick to that size.

Thanks mate

[wagoon 2,429]

A pully off a XC iron head is the perfect unit to get. Find that fit it and close the bonnet.

Would you happen to know the dimensions on that pulley?

This custom made pulley (made out of ally) is costing me nothing other than my time. Work for free get the pulley for free, so its cheaper and easier than having to search out an xc iron head pulley. Just need dimensions to replicate the xc pulley

[slydog 7,873]

Nope not at all.They have about 10-20mm clearance between WP pulley and balancer pully.

[ando76 4,354]

XC water pump,pulley measures 170mm or there abouts. Somewhere around that would have to do the job

[wagoon 2,429]

Thanks lads thats close enough for me to work with.