Final pump autopsy...with a moral at the end....
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Final pump autopsy...with a moral at the end....

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    Senior Member lbhsbz's Avatar
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    Default Final pump autopsy...with a moral at the end....

    ...measure measure measure....

    Got set to machine my impeller wear ring pilot undersize tonight for the new pump, and I've determined without a doubt exactly why the old one failed...

    new impeller wear ring pilots should be 7.225". My impeller (which I beleive was a A/T stainless) after contacting the wear ring and being cleaned up using emery cloth, measured 7.228" when I mic'd it today....strange that it was oversize...but I checked it with 2 different mic's and a couple sets of digital calipers and got the same number, so it must be. I checked the runout of my new A/T 17-4 shaft between centers and found it to be acceptable at 0.0008". I installed the impeller on the shaft and using a 4 jaw independent chuck, centered everything so that I saw 0 runout near the chuck and the same 0.0008" at the spot on the shaft where I'd previously measured it. The impeller wear ring surface (there was still about 1/8" of good spot) indicated .004" of runout. I also indicated off the machined hub that the nut seats against...and also saw .004" of runout, which means the center hole was bored .002 off center when the impeller was manufactured. This explains the huge imbalance that MPD saw when he did some impeller work for me.

    The oversize, as well as the off-center hole means that at one spot, the impeller to wear ring clearance will be reduced by .0035". I think the standard total clearance should be 0.025" total diameter difference, which leaves only 0.0125" measureable clearance, - .0035 = .009" gap under static conditions. Spin it at 6000 rpms and pump water through it...and it'll probably expand a bit under dynamic conditions. throw in excessive clearance in the bowl bushings and there is no doubt as to why it the impeller made contact with the wear ring.

    I've trued the wear ring area of the impeller to the center hole, and according to my balancer (spin the lathe to 4600rpms with a 1/2 empty bottle of beer sitting on the headstock...watch for ripples in the beer bottle..LOL) it's still pretty well balanced.

    I'm an amature machinist, and it took me a couple tries to get things right, but the old 1942 Clausing lathe did a good job and I learned a few things about measuring tonight. This is the first time I've dealt with tolerances of less than 0.010...most of the stuff I do is pretty forgiving. I cut the impeller dead nuts to 7.2050 and trued it to the center hole and shaft within 0.0005", which I thought was pretty damn impressive.

    This post is to reinforce the importance of measuring...cuz you don't know whether its good or bad unless you check it.

    EDIT:...oh, and happy new year

    A couple pics....cuz everyone likes pics...

    Cutting the impeller



    Checking balance...no ripples in the Newcastle (fancy beer tonight...it's new years)...and a nice shot of the old girl (1942 clausing...I think)



    Finished product, OD to 7.2050 and faced off

    Last edited by lbhsbz; 01-01-2010 at 12:45 AM.

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    Senior Member GT Jets's Avatar
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    Quote Originally Posted by lbhsbz View Post
    ...measure measure measure....

    Got set to machine my impeller wear ring pilot undersize tonight for the new pump, and I've determined without a doubt exactly why the old one failed...

    new impeller wear ring pilots should be 7.225". My impeller (which I beleive was a A/T stainless) after contacting the wear ring and being cleaned up using emery cloth, measured 7.228" when I mic'd it today....strange that it was oversize...but I checked it with 2 different mic's and a couple sets of digital calipers and got the same number, so it must be. I checked the runout of my new A/T 17-4 shaft between centers and found it to be acceptable at 0.0008". I installed the impeller on the shaft and using a 4 jaw independent chuck, centered everything so that I saw 0 runout near the chuck and the same 0.0008" at the spot on the shaft where I'd previously measured it. The impeller wear ring surface (there was still about 1/8" of good spot) indicated .004" of runout. I also indicated off the machined hub that the nut seats against...and also saw .004" of runout, which means the center hole was bored .002 off center when the impeller was manufactured. This explains the huge imbalance that MPD saw when he did some impeller work for me.

    The oversize, as well as the off-center hole means that at one spot, the impeller to wear ring clearance will be reduced by .0035". I think the standard total clearance should be 0.025" total diameter difference, which leaves only 0.0125" measureable clearance, - .0035 = .009" gap under static conditions. Spin it at 6000 rpms and pump water through it...and it'll probably expand a bit under dynamic conditions. throw in excessive clearance in the bowl bushings and there is no doubt as to why it the impeller made contact with the wear ring.

    I've trued the wear ring area of the impeller to the center hole, and according to my balancer (spin the lathe to 4600rpms with a 1/2 empty bottle of beer sitting on the headstock...watch for ripples in the beer bottle..LOL) it's still pretty well balanced.

    I'm an amature machinist, and it took me a couple tries to get things right, but the old 1942 Clausing lathe did a good job and I learned a few things about measuring tonight. This is the first time I've dealt with tolerances of less than 0.010...most of the stuff I do is pretty forgiving. I cut the impeller dead nuts to 7.2050 and trued it to the center hole and shaft within 0.0005", which I thought was pretty damn impressive.

    This post is to reinforce the importance of measuring...cuz you don't know whether its good or bad unless you check it.

    EDIT:...oh, and happy new year
    Measure twice cut twice..

    I have access to a CSI 2130 vibration analyzer and have dynamically balance stainless impellers using similar methods....You can balance them , then put it it an static stand, give it a spin and go have a sandwich, it will still be spinning when you come back from lunch...

    With pictures this could have been a badass blog...

    GT
    GT


    Quote Originally Posted by Quickjet View Post
    Put a 300 on the back of it, Flywheel it and a nosecone. $15,000 later you'll have a 65 mph pile of shit......

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    Senior Member lbhsbz's Avatar
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    Quote Originally Posted by GT Jets View Post
    Measure twice cut twice..

    I have access to a CSI 2130 vibration analyzer and have dynamically balance stainless impellers using similar methods....You can balance them , then put it it an static stand, give it a spin and go have a sandwich, it will still be spinning when you come back from lunch...

    With pictures this could have been a badass blog...

    GT
    Added pics. I'd like to have you dynamically balance the whole shaft/imp. assembly..are you set up to do that?

    I'll get in touch with you next week.

    My dad always brings up what some kid in his highschool shop class said once...."but Mr. Leland...I've cut it twice and it's still too short"...and it always makes me giggle. Measure twice...or 20 times, and cut once. I measured 50 times and cut twice tonight. I need to order a .020 over wear ring instead of the .010 over wear ring...because the first time I cut it...I didn't even think about the hole being off center until Duane brought it up, so I'd referenced off of a good spot on the wear ring register of the imp...indicated it to zero, and cut. Then I went back out and double checked and I screwed up, so I re-indicated everything and started from scratch...and only then noticed how far out the impeller was...

    I'm not gonna make the Tom Papp deal, but I'll have a proper pump at the end of the day, so we're good.

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    Quote Originally Posted by lbhsbz View Post
    ...measure measure measure....



    A couple pics....cuz everyone likes pics...

    Cutting the impeller
    new years)...and a nice shot of the old girl (1942 clausing...I think)



    NICE WORK! you should think about some nails to hang some key chains and some decal/banners....that wall is kinda bare dont ya think?

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    We balance on our Stewart Warner crankshaft balancer. We can balance items up to 12' long as well as crankshafts.

    We balance numerous industrial items by spinning them on their shafts or making an arbor and spinning them up.

    The beer bottle method is good for checking the chuck and chuck drive balance along with the impeller
    If For Some Reason I Do Something Worthy Of Recognition. God Provided The Ability And Deserves The Credit.


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    Senior Member kdub's Avatar
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    Nice job dude, you would be surprised how many impellers and shafts are out of round and machined off center. Its like finding core shift in a block and deciding to try and machine around it or find better parts. I have found American Turbine to have pretty high quality control over others as far as pump parts go.

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    B.A.M aka "Black Azz Mike 396_Ways_To_Spit's Avatar
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    Quote Originally Posted by rondane View Post
    NICE WORK! you should think about some nails to hang some key chains and some decal/banners....that wall is kinda bare dont ya think?

    Hey Miss Jane!!!!!! Where ya been????
    G H E T T O F O E L I F E
    Quote Originally Posted by cave View Post
    They bout shit themselves when yelled in Messican, "No brakes no brakes."
    I showed them all the sticker on the side that reads "Driver Ricky Bobby" They just looked at me and nodded yes yes
    Quote Originally Posted by Kyle View Post
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    I have seen several new impellers out of round. Who did the pump work for you?
    G H E T T O F O E L I F E
    Quote Originally Posted by cave View Post
    They bout shit themselves when yelled in Messican, "No brakes no brakes."
    I showed them all the sticker on the side that reads "Driver Ricky Bobby" They just looked at me and nodded yes yes
    Quote Originally Posted by Kyle View Post
    Some peeps just build it 1 part, 1 week, 1 paycheck at a time

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    Nice work, but i see two main problems right off the bat...

    for one, you have half of a Newcastle on top of the lathe, and there's an empty tecate can next to it....i see a lack of commitment to a certain brand/location of beer.
    1992 Eliminator Daytona 21'

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    Senior Member lbhsbz's Avatar
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    Tecate is my beer...but you can't see through the can for balancing operations....so I got newcastle for this occasion.

    Plus the tecate can has little pieces missing off of it that I cut out to use as pads between the chuck jaws and my work when dealing with aluminum...can't do that with a Newcastle bottle. You need the right beer for the job.

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    Senior Member lbhsbz's Avatar
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    I was gonna do some impeller and bowl detail work this weekend...but last week I found that all my sander roll arbors had the tips busted off of them, so I ordered more, and they came in...and I can't find where I put 'em....and UPS sucks. I had all the new parts shipped 3 day select on monday...hoping I could get it together to make the tom papp run, (monday + 3 days = Thursday....right?) but it's looking like nothing will arrive hear until the 4th or 5th.

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    Bostick Racing Engines six-oh-nine's Avatar
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    Quote Originally Posted by lbhsbz View Post
    Tecate is my beer...but you can't see through the can for balancing operations....so I got newcastle for this occasion.

    Plus the tecate can has little pieces missing off of it that I cut out to use as pads between the chuck jaws and my work when dealing with aluminum...can't do that with a Newcastle bottle. You need the right beer for the job.
    Ahh... Tecate... breakfast of champions!


    nice to see another jetboater who appreciates being percise and drinking quality beer...
    The Bostick®

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    Quote Originally Posted by lbhsbz View Post
    I was gonna do some impeller and bowl detail work this weekend...but last week I found that all my sander roll arbors had the tips busted off of them, so I ordered more, and they came in...and I can't find where I put 'em....and UPS sucks. I had all the new parts shipped 3 day select on monday...hoping I could get it together to make the tom papp run, (monday + 3 days = Thursday....right?) but it's looking like nothing will arrive hear until the 4th or 5th.


    Use the post office for delivery. They are kicking azz on shipping these days
    G H E T T O F O E L I F E
    Quote Originally Posted by cave View Post
    They bout shit themselves when yelled in Messican, "No brakes no brakes."
    I showed them all the sticker on the side that reads "Driver Ricky Bobby" They just looked at me and nodded yes yes
    Quote Originally Posted by Kyle View Post
    Some peeps just build it 1 part, 1 week, 1 paycheck at a time

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    [QUOTE=lbhsbz;944604]...measure measure measure....

    Got set to machine my impeller wear ring pilot undersize tonight for the new pump, and I've determined without a doubt exactly why the old one failed...

    new impeller wear ring pilots should be 7.225". My impeller (which I beleive was a A/T stainless) after contacting the wear ring and being cleaned up using emery cloth, measured 7.228" when I mic'd it today....strange that it was oversize...but I checked it with 2 different mic's and a couple sets of digital calipers and got the same number, so it must be. I checked the runout of my new A/T 17-4 shaft between centers and found it to be acceptable at 0.0008". I installed the impeller on the shaft and using a 4 jaw independent chuck, centered everything so that I saw 0 runout near the chuck and the same 0.0008" at the spot on the shaft where I'd previously measured it. The impeller wear ring surface (there was still about 1/8" of good spot) indicated .004" of runout. I also indicated off the machined hub that the nut seats against...and also saw .004" of runout, which means the center hole was bored .002 off center when the impeller was manufactured. This explains the huge imbalance that MPD saw when he did some impeller work for me.

    The oversize, as well as the off-center hole means that at one spot, the impeller to wear ring clearance will be reduced by .0035". I think the standard total clearance should be 0.025" total diameter difference, which leaves only 0.0125" measureable clearance, - .0035 = .009" gap under static conditions. Spin it at 6000 rpms and pump water through it...and it'll probably expand a bit under dynamic conditions. throw in excessive clearance in the bowl bushings and there is no doubt as to why it the impeller made contact with the wear ring.

    I've trued the wear ring area of the impeller to the center hole, and according to my balancer (spin the lathe to 4600rpms with a 1/2 empty bottle of beer sitting on the headstock...watch for ripples in the beer bottle..LOL) it's still pretty well balanced.

    I'm an amature machinist, and it took me a couple tries to get things right, but the old 1942 Clausing lathe did a good job and I learned a few things about measuring tonight. This is the first time I've dealt with tolerances of less than 0.010...most of the stuff I do is pretty forgiving. I cut the impeller dead nuts to 7.2050 and trued it to the center hole and shaft within 0.0005", which I thought was pretty damn impressive.

    This post is to reinforce the importance of measuring...cuz you don't know whether its good or bad unless you check it.

    EDIT:...oh, and happy new year

    A couple pics....cuz everyone likes pics...

    Cutting the impeller



    Checking balance...no ripples in the Newcastle (fancy beer tonight...it's new years)...and a nice shot of the old girl (1942 clausing...I think)



    Finished product, OD to 7.2050 and faced off

    [/QUOTE
    just a thought, you might want to check the alignment of the bore of the wear ring in the suction housing in relation of the shaft, sometimes i have found these to be off.

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