Page 1 of 1
water pump pulley belt contact
Posted: Sun Jul 31, 2016 3:13 pm
by Seight-V8
hello all,
another question on my mind.
How much belt contact do you really need to drive the rover v8 water pump correctly.
I have the serp front cover on my v8 in a westfield, but the belt arrangement doesn't leave much belt contact to drive the water pump.
Just wondering if I should fit an idle pulley to make better belt contact for the water pump.
I recon at the moment the belt drive the pulley with less than 25% of the diameter of the water pump pulley.
cheers
scott
Posted: Sun Jul 31, 2016 7:16 pm
by richardpope50
Hi Scott, yes and exactly the same as mine was. See 'lesson in oils' post and my woes of cooling. When I added an idle wheel to make the contact 50+% I'm sure it made a difference even though I could not see a shiny belt, I'm now sure it was slipping and thus not pumping enough water around.
(For those keeping up with my saga, I hope to be able to get out for a very long test this Tuesday. Cannot believe I've done about 250 miles this year - just so many things get in the way.)
Posted: Mon Aug 01, 2016 9:54 am
by SuperV8
How much belt contact do you really need to drive the rover v8 water pump correctly.
Impossible question really as there are so many variables between different engines and it is directly linked to the belt tension and friction coefficient.
All you really say is that the less belt contact you have the higher belt tension you need to transmit the same power.
They sell knurled versions of the standard serp water pump so presumably some people think even with the standard belt arrangement it could be marginal?
Most water pump pulleys you see of other V8 engines have nearly 180deg contact.
Tom.
Posted: Mon Aug 01, 2016 4:35 pm
by DaveEFI
Think it matters if you have a mechanical fan too - that can take quite a bit of power.
Posted: Mon Aug 01, 2016 7:39 pm
by Seight-V8
I've done some reading up on this, and some info I found says you should have more the 60deg of belt contact, but like its been said, it is a hard one to work out.
I think personally I would like more belt contact, so will see if I can rig up an extra pulley somewhere...
I do have a spare alternator pulley, so maybe I can make a spare idle pulley from this, to give to more belt contact, but the space I have is very small.
regards
scott
Posted: Mon Aug 01, 2016 9:08 pm
by Ian Anderson
In the old days
V belt
Three pulleys, crank, water pump alternator
About evenly spaced so 120 degrees each.
A v belt used to be said was able to transfer 5 hp in this way
Ian