Clearancing Impeller

[Taylorman]

I just put a new impeller and inducer in my boat. What a pain in the a** it is to get a feeler gauge in there to clearance front of impeller with an inducer in the way. I tightened up my clearance to .030 after running it one time. I set it at.035 for the first time cause i wanted to make sure my impeller did not hit the wear ring cause i did not change my bearing. No contact so i took .005 clearance out.

[HammerDown]

Another way, take some 1" pieces of thin gauge lead solder and stick it to the inside of the Wear ring/lip in a cross section. Install Impeller, nut, Torque and don't forget to install the Bowl. Then pull it apart and measure/mic how much the Lead compressed...there's your measurement.
Keep in mind, if the (new) Impeller has not been trued/zeroed out on the Shaft in use, it could be out by several thousands!

[RICHARD TILL]

if you`ll never start the motor on the trailer set it to .010 and throw the inducer away. with close tolerances it wont help your hole shot and will slow your top end speed down. i tried them on a 10 and a 11 sec. bracket boat and lost 3 mph on both. was running B SS impellers. i`m not guessing at this. i proved it by the clock at two different associations. i think the inducer is snake oil. maybe they work for other people but not me.

[IMPATIENT 1]

Shaft in use, it could be out by several thousands!
very true! i put a "good" impellor i had on my shaft, stuck it in my uncle's lathe and it wobbled like crazy on the wearsurfaces, we trued it up but i stuck it back under my work bench for a spare(its gonna need a different ring now too), then ordered a new atj impellor and ring to match.i stuck it on the lathe and its spun soooooo purdy:D

[Taylorman]

Another way, take some 1" pieces of thin gauge lead solder and stick it to the inside of the Wear ring/lip in a cross section. Install Impeller, nut, Torque and don't forget to install the Bowl. Then pull it apart and measure/mic how much the Lead compressed...there's your measurement.
Keep in mind, if the (new) Impeller has not been trued/zeroed out on the Shaft in use, it could be out by several thousands!
Why install the bowl?

[IMPATIENT 1]

Why install the bowl?
you can't measure the proper clearence till the shaft is centered up in the bowl which in turn should make the clearenece the same all the way around the impellor to ring shoulder clearence the same

[IMPATIENT 1]

kevin, just stick 4 bolts in the bowl opposite from each other, tighten em up good then measure clearence

[Taylorman]

That makes sense. Crap i may have to pull it apart again.

[HammerDown]

Why install the bowl?
The Bowl supports the rear of the shaft. And as mentioned only 4-bolts in a cross section are needed for the setup/test.

[IMPATIENT 1]

That makes sense. Crap i may have to pull it apart again.
pull the inspection plate and check it;) i like 25 between the 2, but that's real tight on a used thrust bearing.did you change it out recently(bearing)?

[FOURQ]

set it to .010 and throw the inducer away. .
thats some funny shit there....... the bearing will expand a min of .015.
that may be how you do it but its not right.If you set it at .020 or .025 thats a close setup. lots of good advise from all the newbies.. NOT
:D

[blue wonder]

if you`ll never start the motor on the trailer set it to .010 and throw the inducer away. with close tolerances it wont help your hole shot and will slow your top end speed down. i tried them on a 10 and a 11 sec. bracket boat and lost 3 mph on both. was running B SS impellers. i`m not guessing at this. i proved it by the clock at two different associations. i think the inducer is snake oil. maybe they work for other people but not me.
just a question???...did you cut the impeller down approx one cut size???...if not adding the inducer is like adding a cut size...for ex..if you have a B and add an inducer its like running an A...if you cut it down to a C then put the inducer its like running the same size impeller but you should see a holeshot and e.t. improvement...the idea is to get the rpm back to the same so the motor is still happy and not lugging down....just my 2 cents

[Taylorman]

pull the inspection plate and check it;) i like 25 between the 2, but that's real tight on a used thrust bearing.did you change it out recently(bearing)?
No, its a few years old. I bolted the bowl on and its has about .030 clearance. Im gonna run it and make sure i don't get any contact then take 5 out if it doesn't hit the wear ring.

[Cs19]

Wow, some good stuff here....
:eek:

[jweeks123]

fur sure. if you saw it on the internet it must be right
jw

[Taylorman]

Wow, some good stuff here....
:eek:
What do you mean. I dont work at a pump shop so im no expert.

[tahitijet]

What do you mean. I dont work at a pump shop so im no expert.
from how i was told to do it from the pros your on the right track. i set mine at .025. If you pull the handhole cover bolt up your bowl you can spin the shaft to a point where you can squeeze around the inducer.
I'm no expert on pumps but there are 2 or 3 posts in this thread that are horrible advice or most likely just b.s... I'm pretty sure thats what CS is refering to sarcasiticly.

[IMPATIENT 1]

from how i was told to do it from the pros your on the right track. i set mine at .025. If you pull the handhole cover bolt up your bowl you can spin the shaft to a point where you can squeeze around the inducer.
I'm no expert on pumps but there are 2 or 3 posts in this thread that are horrible advice or most likely just b.s... I'm pretty sure thats what CS is refering to sarcasiticly.
kevin's been here long enough to know which to ignore and which folks know what they're talking about;) :D your on the rite track kevin!

[Duane HTP]

Kevin, If you listen to half the BS on this thread, you'll trash your new impeller.
Some of these people are either newbies without a clue, or someone just jacking with you. Give me a call if you are having any problem. 316-794-8616

[Taylorman]

Thanks Duane, no problem. I was just making a comment not asking a question about how it was difficult to get a feeler gauge in with the inducer in. Im good.

[RICHARD TILL]

FOURQ, I was told about the .010 measurement by people allready doing it, were winning races and have forgotten more than i`ll ever know about a pump. Its been working great for me about 10 years now without a single problem. One of the pumps was in a high points champion boat for two years in a row. blue wonder, I did`nt make any impeller change at all. I have never had an impeller cut. Since 1980 i have never bought anything but a "B" cut.

[cyclone]

FOURQ, I was told about the .010 measurement by people allready doing it, were winning races and have forgotten more than i`ll ever know about a pump. Its been working great for me about 10 years now without a single problem. One of the pumps was in a high points champion boat for two years in a row. blue wonder, I did`nt make any impeller change at all. I have never had an impeller cut. Since 1980 i have never bought anything but a "B" cut.
Do you have a method for making sure the wear ring is still round after its installed in the suction housing?

[blue wonder]

FOURQ, I was told about the .010 measurement by people allready doing it, were winning races and have forgotten more than i`ll ever know about a pump. Its been working great for me about 10 years now without a single problem. One of the pumps was in a high points champion boat for two years in a row. blue wonder, I did`nt make any impeller change at all. I have never had an impeller cut. Since 1980 i have never bought anything but a "B" cut.
we have noticed that if you stay with the same size impeller and add an inducer...unless your are making a shit load of power and need to bring down the rpm anyway then the performance has suffered....just what we have seen;)

[Pops@Aggressor]

Do you have a method for making sure the wear ring is still round after its installed in the suction housing?You can get extended feeler gauges that are long enough to reach. Sears-
A thrust bearing allowance in forward motion should be .018 thousands (forward motion) per mfg.
Race Pumps are set up @ a verity of standards. some like a .005 thousands undersize (@ 12 1/2 thousands per side). Hi Tech Produces a burn in type wear ring. I think a lot of it is over kill and record boats have set and maintained records with stock application set up's.
A lot of this (today) comes from the old dogs which include V grooveing the wear ring and almost 0 tolerance on set up or radius grinding the end of the Impeller vane at the thrust point. The real reason is back then the HP and Torque was so low it did matter. Today add some margin to it- Your running almost 1 to 1 on each.
Thats like running 65-70 pounds Intake pressure-
You can get the job done at 30 pounds and maybe one day 0. That pressure is a negative drag wall you are pushing. or a five gallon gas can your pushing down the track.