One of my concerns about the Rover V8 has always been that the water pump doesn’t pump enough water. While the inline thermostat mod is great and it solves a lot of issues with the cooling system, there is still an issue with the fact that the cooling system just can’t keep up at certain times. It is apparent to me in hot summer weather when either going slow while offroading and traveling at over 60. It’s a heat in versus heat out problem.

A while back, I considered the use of an electric water pump to boost the factory setup. This would allow for better control - its also a lot of pull on the alternator and is expensive.

This brought me to an idea: an overdrive water pump pulley. If I made the pulley smaller, say around 10-15%, it would spin the pump faster and therefore push more water. Would have to watch for cavitation at higher RPM, but I assume these engines really don’t spin fast enough for that to be an issue. It should give the cooling system some extra headroom.

So, I went on CAD and made one. It ended up being slightly less than a 10% reduction in diameter. I had it 3D printed. It looks pretty good. I am going to make some minor adjustments. Going to try again next time again out of plastic, then probably on to CNC aluminum.

 

Wow! Watching with extreme interest.
Good luck!

 

Wow, looks really interesting and like the idea. My non-professional engineering side is curious if this would help. Maybe the choke point for heat exchange is at the radiator and adding flow would push warmer water back into the engine faster compounding the problem. Just guessing here as I really don't know. But very interested in how this trials if you make one and test it. For your next challenge figure out how to underdrive the oil pump to add oil pressure! Good work!

 

Maybe it's just parallax error from the camera lens, but the shaft on the printed pulley doesn't look like it's perpendicular to the pulley body.

 

Is it possible for you to post your 3D solid model or perhaps a drawing of the part? I too am watching with extreme interest and have the capacity to build one, if it works I would like to pursue it!

 

I think that the fundamentals behind this idea can be proven somewhat since if you are going up a grade in D at 2000 rpm or so and the engine starts warming up, you can downshift into 3 and the rpm kicks up and the engine temp goes down. The extra rpm spins the water pump more even though the engine output remained relatively the same. The water pump spins more and brings the temp down.

The radiator is also a weak point because its a bit too small, but custom radiators are expensive and pulleys are (relatively) cheap.

On that last picture, it wasn’t quite on straight. The 3D print had a slight defect that had to be ground off. It’s sitting straight in the top picture.

Maybe if it works after I get it perfect. I wouldn't regularly run one on my truck out of 3D printed PLA. I might would consider nylon, but aluminum 6061 CNC is what I'm planning.

 

Interested in seeing how it works out as well. Think the stock belt length will be fine?

 

i was wondering the same.

i assume the tensioner would take up the slack.

 

Great job, was thinking along the same lines. Not sure I would trust a PLA printed pulley, maybe a jet fusion printed pulley but that woudl probably be 200ish. I was thinking 40% increase ish also to solve the idle issue. One characteristic of a centrifugal pumps is if you limit the output iwth a restriction like say a radiator, they don't pull more hp even though they are spinning faster. The bearings will wear out faster, but I think we are all willing to accept that. The other issue is if the fan can handle it, but again that is solvable with an electric fan setup. Getting a CNC pulley at an affordable price point would be the ultimate, I think I have a quote somewhere.

Utlimately given the choice between spending $200 on a pulley and $200 on a larger radiator I think the radiator might be the better investment.

 

Interesting following along to see where you end up