Impeller clearances

[Taylorman]

What should the clearances be between the impeller and pump housing. I have about .120 between them so there is a pretty big gape. However, the wear ring insulator is also in that gap. How do you get impeller to the proper clearance when the insulator is about .060 thick.

[miller19j]

You should measure the clearance with the wear ring and insulator installed.
The clearance between the wear ring and impeller should be .025 - .030 ( I am going by memory so I may be a few thou off).
The front of the impeller to the suction piece should be .025-030. I have been told that this is the most important clearance to set .

[miller19j]

PS
I would recommend Buying the book “Marine Jet Drive” you can get it at amozon.com and it will walk you through the basics of jet pump rebuilding

[Taylorman]

So how do I set that clearance at .025-.030 when the insulator wear ring is thicker than that. The impeller will hit the insulator at those clearances.

[Rexone]

Link to earlier thread (http://forums.***boat.net/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=11;t=001887)

[jim@pj]

If you are running a wear ring with no step you cannot tighten the wear ring axial clearance without cutting the shaft or impeller hub to move the impeller forward. Don't do this. Buy a stepped wear ring. jim www.performancejet.com (http://www.performancejet.com)

[SoCalPower]

Taylorman:
So how do I set that clearance at .025-.030 when the insulator wear ring is thicker than that. The impeller will hit the insulator at those clearances. After installing the wear ring and insulator, trim the lip off of the insulator with a razor knife. This will expose the aft face of the register in the suction piece. Set your clearance and haul ass...........

[Taylorman]

Im not sure what wear ring i have. Its flat and is stainless. Look at the picutures. http://www.hotboatpics.com/pics/data/500/13DCP_1909-med.JPG
http://www.hotboatpics.com/pics/data/500/13DCP_1910-med.JPG .
Look at the gap from the impeller to housing. Its .120.
http://www.hotboatpics.com/pics/data/500/13DCP_1911-med.JPG
I trimmed the insulator so it not in the way anymore. I didn't realize it would cut so easy. Now what. Im thinking of having the eye of the impeller cut down about .090. That would move impeller forward .090 and my clearance would be .030. Any recommendations.

[ChetCapoli]

taylor, just buy another "lipped" style wear ring and save yourself the headache..if you cut to much off the eye there will be a lip there too and not a contour where it butts the shaft... then there is .090 more space in the back between impeller and bowl which doesnt help either. Those lipped rings are more effecient anyways and will give before your impeller does over time. (SS vs. alum or Alum vs. brass or plastic.) Is that Wear ring you have original...what the ID of it? Could be worn some.
CHET
[ March 01, 2003, 12:11 PM: Message edited by: ChetCapoli ]

[Taylorman]

ChetCapoli:
taylor, just buy another "lipped" style wear ring and save yourself the headache..if you cut to much off the eye there will be a lip there too and not a contour where it butts the shaft... then there is .090 more space in the back between impeller and bowl which doesnt help either. Those lipped rings are more effecient anyways and will give before your impeller does over time. (SS vs. alum or Alum vs. brass or plastic.) Is that Wear ring you have original...what the ID of it? Could be worn some.
CHET I bought this wear ring about a year ago. I took my impeller off about 2 yrs after I bought the boat and it has some dings in it. I brought it to Mikes in Houston and he cut the dings out. He said i needed a new wear ring and this is the one he sold me. I new nothing about pumps then. Now Im learing there a different types of wear rings. What is a lipped wear ring and how will it closed up my .120 gap between my impeller and housing and who sells them?

[jim@pj]

Taylorman... Just listen to Chet and buy the lipped ring. Jim

[Taylorman]

Can someone tell me what a lipped ring does and maybe a picture?

[HammerDown]

It is belived that the lipped Wear Ring is to help stop excess water from blowing by the Impeller...thus stopping unwanted turbulence in the aft (thrust) portion of the pump and making the pump that much more efficient...there should be a pic on one of the pump manufactures sites American Turbine, Aggressor, Legend, Domimator...except being made of different metals, they all look alike.
If you've seen the lip on the plastic insulator...well it looks like that, and should have a clearance of some .025-.030 infront of the Impeller....Hope that helps.
[ March 02, 2003, 03:46 PM: Message edited by: HammerDown ]

[miller19j]

Taylorman:
ChetCapoli:
taylor, just buy another "lipped" style wear ring and save yourself the headache..if you cut to much off the eye there will be a lip there too and not a contour where it butts the shaft... then there is .090 more space in the back between impeller and bowl which doesnt help either. Those lipped rings are more effecient anyways and will give before your impeller does over time. (SS vs. alum or Alum vs. brass or plastic.) Is that Wear ring you have original...what the ID of it? Could be worn some.
CHET I bought this wear ring about a year ago. I took my impeller off about 2 yrs after I bought the boat and it has some dings in it. I brought it to Mikes in Houston and he cut the dings out. He said i needed a new wear ring and this is the one he sold me. I new nothing about pumps then. Now Im learing there a different types of wear rings. What is a lipped wear ring and how will it closed up my .120 gap between my impeller and housing and who sells them? Cut the shoulder on your shaft not your impeller. Any machinist can cut that for you very easily and you would be able to use your current wear ring. Just make sure that you measure it properly so they don’t cut to much off. If they do cut to much off you can buy shims to bring it back.

[Taylorman]

Whats the difference in cutting the impeller or the shaft. I would prefer not to have to take my shaft out.

[cal***boat]

I read somewhere that you can not run a lipped wear ring and use a bowl stuffer at the same time.Is this true ?

[Taylorman]

It says that on Berkeleys web sight about the stuffer.

[miller19j]

Taylorman:
Whats the difference in cutting the impeller or the shaft. I would prefer not to have to take my shaft out. It is very difficult to properly cut the impeller accurately. It is hard to mount it in the lathe by itself. The shaft is much easier to chuck up in a lathe.
If you cut the impeller and then you suck up a rock and need to buy a new impeller you will have to cut that one as well. But if you cut you shaft you will most likely be able to bolt up the new impeller with out any other modifications.