Number of Impeller Blades Important?

[CaptainBob]

I put in a new impeller when the old one failed to re-prime the system after an engine anode and water strainer check.

The new one I've put in has quite a few more, closely spaced, blades than the one I took out. Seemed like quite a tight fit too.

It works fine, but is it OK? Does the number of blades matter?

 

[KellysEye]

Your pump will have an impeller part number. You should replace the impeller with that part. It was designed for the pump.

 

[david_bagshaw]

I put in a new impeller when the old one failed to re-prime the system after an engine anode and water strainer check.

The new one I've put in has quite a few more, closely spaced, blades than the one I took out. Seemed like quite a tight fit too.

It works fine, but is it OK? Does the number of blades matter?

we have twin ford sabre 150 and have used jabsco replacement impellers, which have come in both varieties as you discribe. more thinner fins. Iwouldsuspect the thinner fins would not last as well dry running, but may be wrong.

Apart from a different noise while they bed in, I have seen no difference, in life or output. (over 20 years)

Incase the reader wonders about my mention of noise, we have a steel ship, and sounds travel in strange ways. even have rubber bushes on morse cables to remove transmitted cable noise!

 

[vyv_cox]

Disregarding the possibilities that it may be the wrong width, diameter, etc, I can't think of any reason why it wouldn't work OK. Suction and discharge are controlled by the cam shape and I think the number of blades is immaterial, except that it might affect the efficiency, which is probably not a concern. The tight fit is probably an improvement, as wear of the side faces is the usual reason that they fail to prime.

 

[sailorman]

we have twin ford sabre 150 and have used jabsco replacement impellers, which have come in both varieties as you discribe. more thinner fins. Iwouldsuspect the thinner fins would not last as well dry running, but may be wrong.

Apart from a different noise while they bed in, I have seen no difference, in life or output. (over 20 years)

Incase the reader wonders about my mention of noise, we have a steel ship, and sounds travel in strange ways. even have rubber bushes on morse cables to remove transmitted cable noise!

might be one is manufactured by Jabsco the other Johnson

my pump is Johnson but often use Jabsco impellers with differing No of blades.
cant say i have noticed any difference at all , engine temp stays the same

 

[CaptainBob]

Thank you

 

[david_bagshaw]

might be one is manufactured by Jabsco the other Johnson

my pump is Johnson but often use Jabsco impellers with differing No of blades.
cant say i have noticed any difference at all , engine temp stays the same

came in jabsco boxes.