pump noise

[rsr]

Running a jacuzzi 12wj. Recently had it rebuilt and blueprinted. Was running a 455 prior to the blueprint. Just put in a fresh 454. First time pump ran since blueprint was with 454. Noticed a loud growling noise when had it in reverse. Noise kind of comes and goes. Can slightly feel this in the boat. Did not notice this noise or vibration while in neutral or forward. Any ideas what this might be from? Pump overpacked with grease (Did notice some expected grease loss during intial runs) or possibly the impeller out of balance. Any and all help would be much appreciated.

[Jungle Boy]

Originally posted by rsr:
Running a jacuzzi 12wj. Recently had it rebuilt and blueprinted. Was running a 455 prior to the blueprint. Just put in a fresh 454. First time pump ran since blueprint was with 454. Noticed a loud growling noise when had it in reverse. Noise kind of comes and goes. Can slightly feel this in the boat. Did not notice this noise or vibration while in neutral or forward. Any ideas what this might be from? Pump overpacked with grease (Did notice some expected grease loss during intial runs) or possibly the impeller out of balance. Any and all help would be much appreciated.
I had a strange noise coming from my boat once, only at around 3500 - 4000 rpm and turning left. It turned out to be a siezing U-joint in the driveshaft. Did you have the u-joints changed when you had the motor and pump done? Also, a steel impeller can create a rattling noise at idle that a aluminum will not make. In reverse, you may be causing a slight cavitation condition in your pump that could be causing the noise.
JB

[SSTSleakcraft]

Impeller is probably standard 5 vane aluminum. Maybe impeller is shimmed to far forward, rubbing in suction piece. Best i can recall, these pumps have a plastic wear ring without shoulder. Also make sure your driveline is not bottomed on the pump shaft. This will cause thrust bearing failure in engine and or pump. 3/8" is more than adequate.

[TripleThreat]

Originally posted by Jungle Boy:
Also, a steel impeller can create a rattling noise at idle that a aluminum will not make.
JB
JungleBoy,
I have been battling with a noise at idle from my pump, and I do have a Stainless Steel impellar. Why do they rattle vs. an aluminum? Any help would be appreciated. Thanks!
Jay

[SSTSleakcraft]

I'm just guessing here, but maybe with the added weight of steel and possibly an un-lubricated bowl bushing (i.e. Dominator) with excess of .002 clearance it is harder to "find center" and rattles mainly at low RPM's.

[Jungle Boy]

Originally posted by SSTSleakcraft:
I'm just guessing here, but maybe with the added weight of steel and possibly an un-lubricated bowl bushing (i.e. Dominator) with excess of .002 clearance it is harder to "find center" and rattles mainly at low RPM's.
I agree. They are lots heavier and harmonics at low rpm must made them hard to center.