How Can You Tell?

[wmitchell]

What is the "tell" with a screwed up bowl?, from a performance standpoint what would change, rpm's top speed, acceleration...?

[BrendellaJet]

inspection would eliminate or confirm any doubts...
I would think the impeller would be the first to "go"...What symptoms are you experiencing?

[Pops@Aggressor]

What is the "tell" with a screwed up bowl?, from a performance standpoint what would change, rpm's top speed, acceleration...?
Don't know why you pick up on the bowl. Bowls are simple and can be cleaned up most times even if damaged. You need to outline your problem and board will try to help!

[wmitchell]

I had some chunks out of a couple vanes in the bowl and repaired them myself, thought maybe my repair went south as I lost 500rpm's on the top end all within an hour, first suspected the engine but can find nothing wrong. I'm not sure if a bad flowing bowl could make you loose rpm, I dont think so but thought I'd ask

[BrendellaJet]

Did you look at the impeller? If something passed through the pump and damaged the bowl Im willing to bet the impeller got hurt too. Bad repairs can hurt the pumps performance though...

[wmitchell]

Yes, sorry I was not clear the bowl was damaged when I got it and I put a new impeller in it wear ring, bearings etc etc almost replaced the bowl but thought I'd try it first just not sure if it's holding me back at this point. The pump does not work bad just not great.

[BrendellaJet]

What did the old impeller look like when you took it out? It could be that the clearances after the rebuild are so much tighter that the pump is now more efficient thus resulting in the RPM loss. What is the power plant?

[wmitchell]

Old impeller was a ss berk AB a few small dings nothing big, went to a ss A impeller engine is a warmed over zz502 makes 600hp at 5700 abd 600 lb ft at 4500. this is the rub, started out turning that A impeller to 5700 then an hour later only 5200 happened all at once, engine has no perceptable difference checked everything I could without dissassembly

[ZZ502]

Hi WMitchell,
Be sure and check your distributor and make sure it's tight and didn't slip timing. Secondly, check the connections on your tach and make sure they're tight - if they're loose you'll get a bad reading. Did you loose MPH? Also just read your other post. Keep in mind that the chart is based on stock clearances and if what you stated that your pump is really tight you probably won't hit the numbers on the chart. This doesn't translate into a loss of HP just that you have a more efficient pump.

[wmitchell]

Hey ZZ502,
Good to here from you, that's some good advice the one thing I have not checked is the tach, but I have checked and rechecked the distributor, by the way I love that engine and always get compliments on the way it sounds, but if it still seems screwy I'll take the pump apart again and see what it looks like, you know I just thought of somthing... there were two shims between the inducer and the original impeller and when I got a new imnpeller I did'nt use them because I could not get the right fit. Maybe the impeller has slid forward enough to be scrubing the shoulder of the wear ring, that would explain the loss of 500 rpm and why the low end has tightened up during idling and acceleration...Hmmm