stuffer to impeller clearance.

[tahitijet]

How much clearance should there be between a stuffer and impeller? I'm installing my new split bowl and doing some final setup for this weekend and When i put the bowl on (without a bowl Gasket) and rotate it the impeller face is showing slight rub marks on the top edge..
Does the impeller need to be shimmed back? or is it a combination of no gasket and the bowl not being tightend down even?
thanks

[steelcomp]

How much clearance should there be between a stuffer and impeller? I'm installing my new split bowl and doing some final setup for this weekend and When i put the bowl on (without a bowl Gasket) and rotate it the impeller face is showing slight rub marks on the top edge..
Does the impeller need to be shimmed back? or is it a combination of no gasket and the bowl not being tightend down even?
thanks
Maybe Duane can come up with an "ultimate" stuffer that self clears! :rollside:
You don't want to "shim" your impeller to clear your stuffer, that will change your internal clearances, which are more important. Besides, if your impeller is already "clearanced" properly, you'd likely run it into your wear ring shoulder or suction hsg. NOW...if you haven't checked your impeller clearances to the front, you might need to move it forward, but not arbitrarily to clear your stuffer. You can't shim it forward, either, unless it has been shimmed back. To move it forward, your shaft has to be machined. :coffeycup

[Cs19]

There are ways to get the dimensions and figure the clearances before assembly.
Put the bowl gasket on, and tighten the bowl down, see what happens.

[tahitijet]

but is it typical that you have to machine the shaft to move the impeller back when adding a stuffer? The bowl came with a stuffer preinstalled and I never gave it much thought. What is the general clearance from the impeller face to the stuffer?
The motor is still hooked to the pump and it is a royal pain to disconnect so i'm rotating the bowl itself and checking for contact. The rub marks are only on the top of the impeller so i'm hoping that clearances are supposed to be real tight and its just because the gasket wasn't on and things weren't tight (square)
My main concern is the desired clearance between the 2.. obviously if it's 1/8" i'm no where near close and if it's just a few thou.. i'm probably pretty close
thanks

[Cs19]

The clearances can be tight between the impeller and stuffer, just no rubbing.

[SmokinLowriderSS]

You sure don't want to move your impeller and alter your wear ring clearance or you blow the pump efficiency (or ruin it eating your ring) :yuk: . The Stuffer has to be close, but just clear, just like a wear ring. I believe any shimming or machining to clear are done to the stuffer. A polyurethane "Ultimate Stuffer" would be an interesting idea. How about it for another $10 part idea? :idea:
That's my best understanding but I've never done it. Folks who install them like DuaneHTP can sure correct me if I got some part wrong. :cool:

[HoffmanEagleMarine]

How much clearance should there be between a stuffer and impeller? I'm installing my new split bowl and doing some final setup for this weekend and When i put the bowl on (without a bowl Gasket) and rotate it the impeller face is showing slight rub marks on the top edge..
Does the impeller need to be shimmed back? or is it a combination of no gasket and the bowl not being tightend down even?
thanks
TJ, On most stock pump set-ups, you do not have enough room for the stuffer. A shouldered wear ring can't be used without excessive machine work to fit the stuffer. There usually is some type of modification needed somewhere to make room for the lip of the stuffer. Using clay is the easiest way to check all of your clearances. You must replace your bowl gasket when tightening all of the bowl studs/bolts. The use of the bowl gasket is very critical when claying, as this piece holds your bowl away from your impeller.
You can make room for the stuffer in a few different areas. First of all, you need a new thrust bearing. As you tighten your pump clearances, this bearing will make you or break you! Make sure that you place this bearing in correctly too. If you want to keep the front clearances within the spec's, you need to shave the lip of the insulator(this will give you .030-.050 more room to play with). Your stock front clearance should be around .025, not less than .015 thousands.
You are looking for .030-.050 on the back(impeller to bowl stuffer). If this cannot be achieved, you can cut the min. amount needed from the front of the impeller at the shaft(sometimes you only need a few thousands). Or you can cut the back of the bowl. Either way will work! Hope this helps, Doug

[steelcomp]

This is a whole lot of hullabaloo for something that hasn't really proven to do anything. Has anyone really recorded any data on a pump with, vs. without a stuffer? You can make one out of flat plate aluminum, if you really think you need one. IMO if you paid good $ for a pretty, anodized billet bling bling one, you got ripped. There are hard core racers who don't even run them. If you've got a piece of 1/4" plate as a stuffer, and you want it closer, use 5/16". If you need more clearance, use 3/16". Stuffer clearance is the least critical (as long as you're not hitting), and +/- .060" isn't going to make any difference. Also, I would not recommend machining anything off your impeller to move it, because any time you need to change impellers, you'll have to machine the new one. :coffeycup

[Heatseeker]

This is a whole lot of hullabaloo for something that hasn't really proven to do anything. Has anyone really recorded any data on a pump with, vs. without a stuffer? ...
I've wondered the same thing. I see the theory, filling a voided area in the pump. But once the area that the stuffer fills is pressurized(without a stuffer), what difference would it make?

[steelcomp]

I've wondered the same thing. I see the theory, filling a voided area in the pump. But once the area that the stuffer fills is pressurized(without a stuffer), what difference would it make?
Some argue turbulence between impeller and bowl, but if you look at the flow direction of the water out of the impeller into the bowl vanes, it seems as if it would be a "dead" area anyway. I guess it dosen't hurt to fill it, but to go to all the trouble of minimal clearances, claying, and such nonsense, I think there are better places to spend that kind of time and effort. It's very easy to measure with good accuracy. (A) Just put a straight edge across the face of your impeller and measure to the bowl flange on the suction hsg. (B) Then put a straight edge across the mounting face of your bowl and measure to the face of the stuffer. Add the thickness of the gasket to (B) (or measure with the gasket in place) and subtract A from B. There's your clearance. Under load, your impeller is only going to move away from your stuffer, so just about any min. clearance should work. Who's to say how much "too much" is?! :coffeycup

[Jake W2]

Steel you do not have to pay for a 250 cone shaped Billet CP Preformance one you can get a cone shaped cast one from Duane at HTP for about 85 bucks.
I am not sure about cutting the imp nose either but there is alot of diffrent ways you could get your clerances.I would think you would need to machine the shaft cut the insulator edge off set the imp clerance and take off what you would need off the stuffer.That would close it up front and back dont you think?
Jake

[Cs19]

I would not recommend machining anything off your impeller to move it, because any time you need to change impellers, you'll have to machine the new one. :coffeycup
Good call steel.
All these guys hack on the impellers to make something stupid like a stuffer fit correctly. Trim the freakin stuffer and leave the impeller and bowl alone, when you go and hack on the impeller here and there it just makes more problems later on down the road. I have one in my boat that has been trimmed here and there, pretty soon its a one off deal and you cannot switch impellers with your buds cause is so modified.
Set the front clearance, measure the impeller height, check the bowl depth, fit a stuffer in the gap, its that simple.

[Duane HTP]

A polyurethane "Ultimate Stuffer" would be an interesting idea.
This is funny. We made them about 15 years ago and they worked just fine. I still even have some of them on the shelf. We do feel though, that the cast machinable stuffers are a little easier to work with and set up correctly. They are made to fit a Berkeley, American Turbine, Dominator or Aggressor bowl. But like said above, don't cut the impeller or the bowl to make them fit. Machine the stuffer itself to get the right fit. Here are pictures of it.
http://www.hi-techperformance.com/images/Hi-Tech_Stuffer_Plate_FT.jpg
http://www.hi-techperformance.com/images/Hi-Tech_Stuffer_Plate_BK.jpg
I like to see .015-.020" clearance between the bowl and the stuffer.

[sdpm]

I like to see .015-.020" clearance between the bowl and the stuffer
Don't you mean impeller and stuffer?

[Duane HTP]

Absoultely! Thanks for the correction. My wife says I need corrected quite often.

[steelcomp]

Absoultely! Thanks for the correction. My wife says I need corrected quite often.
You mean "need correcting" or "to be corrected"...
(sorry...couldn't resist) :D :D

[sdpm]

I'm right there with ya! Sucks getting old!! :eek: