SoCal Jet Boats

Tech Talk => Jet Pumps => Topic started by: lbhsbz on January 01, 2010, 02:16:03 AM

Title: Blowed up pump autopsy...and the rebuild
Post by: lbhsbz on January 01, 2010, 02:16:03 AM
...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
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv201%2FmachschnelGTI%2FIMG_2437.jpg&hash=83f26a478d1e324ebfee62cdc972f131145bbba5)

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)
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv201%2FmachschnelGTI%2FIMG_2439.jpg&hash=54b79d6af77fcc926a95ae334f054246efd0104b)
Finished product, OD to 7.2050 and faced off (https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv201%2FmachschnelGTI%2FIMG_2438.jpg&hash=95de87901164b1a07348ab6b48a1ca54a26d6d4b)
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: Luckie Stiff on January 01, 2010, 09:30:28 AM
Looks good Pat. Maybe I'll bring you my impeller for balancing, 'cept I drink Coors so you may have to adjust your standards a bit.
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: BOOST on January 01, 2010, 09:37:50 AM
  Looks good x 2 Pat very good info bud  :thumbup: Thanks again for the gas over @ Big river couldn't  made it back down river with out it.
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: lbhsbz on January 01, 2010, 11:12:45 AM
Looks good Pat. Maybe I'll bring you my impeller for balancing, 'cept I drink Coors so you may have to adjust your standards a bit.

Coors won't be as accurate, but hey...its your impeller. :thumbup:
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: beerjet on January 01, 2010, 11:39:26 AM
When I was chatting with Jack a couple of years ago or so , I remember him saying that berkely's old casting looked good but weren't the best quality ss.
The newer casting look like hell and need alot of attenting but the ss they used was alot stronger, thus the rust.
I cant remeber (if he said anything at all) what he said about the AT's
looks good .

-beerjet-
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: lbhsbz on January 01, 2010, 12:00:33 PM
The A/T impeller that I've got....I think they could've done better for the price they charge.  It's all over the place when it spins.   I think you can see one of the spots where a bunch of material was removed by Jack @ MPD.  The blades are pretty nice, but the shell could be a lot cleaner.  I'll probably play with it a bit more and do some cleanup work, then get the whole thing down to a proper balancer so it's perfect. 
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: beerjet on January 01, 2010, 12:07:43 PM
The A/T impeller that I've got....I think they could've done better for the price they charge.  It's all over the place when it spins.   I think you can see one of the spots where a bunch of material was removed by Jack @ MPD.  The blades are pretty nice, but the shell could be a lot cleaner.  I'll probably play with it a bit more and do some cleanup work, then get the whole thing down to a proper balancer so it's perfect. 
Thats pretty much what I've always heard also.
SS impellors are pricey and they always need tons of work .
At least all the SS impellors I've have .

-beerjet-
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: lbhsbz on January 03, 2010, 04:40:59 PM
Quick update...I screwed up a little...a couple times, but I've fixed it.  I'm learning quite a bit about machining and measuring.
The impeller now sits at 0.030 under. 
After I did a some detail work on the impeller...mainly just cleaning up the surfaces in hopes that it'll blow less bubbles, I reinstalled the impeller on the shaft, and chucked it back up in the lathe to make sure that things were still good before I bring the shaft/impeller over to my balancer in the morning...and I measured 0.003" runout in the impeller wear ring pilot.  I cursed at it and kicked the dog and even that didn't help, so I started thinking..(dangerous...I know)...and loosened the impeller nut just a bit.  I set up one indicator on the shaft and one on the impeller pilot and zero'd both, then tried to move the impeller back and forth...and saw the impeller move 0.0035 while the shaft only deflected about .0002".  I came to the conclusion that the impeller is too loose on the shaft.  I can remove it with absolutely no effort.  Since the objective in making the perfect pump is to have absolutely zero runout on the shaft or impeller, I determined this "play" to be unacceptable.  I grabbed my knurling tool and put a light knurl in the shaft...just to displace enough material to make the shaft grow a couple thou so the impeller would be press fit.  I've been told it shouldn't be a press fit, but the only way to get a consistant zero runout condition is to have everything positively located before final machining and during service after final machining...so I made it a press fit....and took yet a 3rd pass at it.  To make double extra sure that this would be the last screw up, I once again used my 4 jaw chuck in the headstock and a live center the tailstock and indicated the shaft at every inch all the way down...I found that the pilot hole in the splined end was about 0.0003 off center, rsulting in .0006" of false runout at the splined end...so i rigged up another 4 jaw chuck in the tailstock and centered that for zero runout...then rechecked my runout all the way down the shaft....ending up with less than 0.001 " at the worst spot, which isn't bad over a 2 foot long shaft I don't think.....I double and triple checked runout on everything and after confirming that everything was at zero, took my 3rd pass taking the impeller down to 0.030 under.  It has been assembled and removed from the shaft several times and reset into lathe with repeatable resuts, so it looks like I've finally got it.   

now I see why the big boys get the big bucks for this stuff.
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: enginedoctor on January 03, 2010, 05:18:46 PM
Knurling  does not last...IMHO ???...replace/bush parts as needed...just my thought ;D
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: GT Jets on January 03, 2010, 05:26:02 PM
I would use Loctite #680 on the knurling, we use it by the bottle, good stuff with fairly easy disassembly with little heat...

http://www.useloctite.com/products/product_details_retainingd119.html

GT
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: enginedoctor on January 03, 2010, 05:33:16 PM
I would use Loctite #680 on the knurling, we use it by the bottle, good stuff with fairly easy disassembly with little heat...

http://www.useloctite.com/products/product_details_retainingd119.html

GT

Really dont know about you GT.....but holding a run out of    .0003/10  ...on a 2 foot shaft...is amazing....have this guy call me and I will bury him w/work :sly:.......3/10??..(On a 60 yr old machine....GEEZ!}
that means... +/- .0001/5 per side ....WOW!
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: lbhsbz on January 03, 2010, 06:27:32 PM
The shaft has just under .001.....not under 0.0001 (of runout...I'm not concerned with taper so I didn't even measure for it.)...so I left it alone, cuz there's no way in hell I could do better than that..especially without a follower rest, which I really don't feel like trying to track down for my antique machine right now.  The shaft started out at 0.0015 right in the center, but I smacked it with a hammer a couple times on V-blocks and got it under .001, so that's fine....that's the worst runout in the whole damn assembly. 

I think the knurl will hold up OK...or at least serve it's purpose OK.  I figure that the impeller will come off the shaft 1 or 2 more times during assembly and then I plan on not touching a damn thing again until it breaks, at which point it will all come appart so I can fix things as necessary.  The impeller has been on and off the shaft (I made a slick little billet aluminum puller out of piece of 3" roundstock, a hose clamp, some engine stand bolts and an old balance puller ;D) about 4 times and still requires a couple smacks with a mallet to get it over the knurled section.  I'm contemplating adding a centerdrilled 5/16 threaded hole in the center of the shaft so I can use an installation tool rather than impact the bearing while the pump is together, but we'll see. 

A machine is as accurate as the operator...which in my case...isn't very accurate.  That's why I've got about 5 or 6 hours into setup and 3 tries at getting this right.  I've learned A LOT during this project...I even went and bought a couple of test indicators.  I'm slow at setting up work on a 4 jaw...but I'm getting quicker.  With my 3 jaw, I'd have dicked everything up.
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: lbhsbz on January 03, 2010, 06:29:19 PM
Hmm...something wierd keeps happening after I type about 20 lines or so...Brad?  What's up with that?  It won't let me see the line I'm typing after a certain point...

It's probably some default "STFU" notification.
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: OC2Vegas on January 03, 2010, 06:36:28 PM
Hmm...something wierd keeps happening after I type about 20 lines or so...Brad?  What's up with that?  It won't let me see the line I'm typing after a certain point...

It's probably some default "STFU" notification.

If you have Internet Explorer 8 (latest version) you can hit the "Compatibility View" button and it should solve your problem. Looks like this:

[attachimg=1]

Its the little broken page one highlighted blue
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: GT Jets on January 03, 2010, 06:42:50 PM
If you have Internet Explorer 8 (latest version) you can hit the "Compatibility View" button and it should solve your problem. Looks like this:

(Attachment Link)

Its the little broken page one highlighted blue


Are you the Video Professor?   ;D

GT
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: enginedoctor on January 03, 2010, 07:11:42 PM
Ok.   :screwy:.......whatta I know  ???..frustrated..bigger hammer for 3 jaw :sly:

"The shaft has under .001......Sorry my mistake guys....   .0005/10 per side, I missed it by .000.2/10."
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: OC2Vegas on January 03, 2010, 07:45:28 PM

Are you the Video Professor?   ;D

GT

No, just do the computer thing for a living!
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: Brad @ SCJB on January 03, 2010, 09:44:13 PM
If you have Internet Explorer 8 (latest version) you can hit the "Compatibility View" button and it should solve your problem. Looks like this:

(Attachment Link)

Its the little broken page one highlighted blue

ya what he said. theres an update to my code to fix that, just havent gotten around to it.

use firefox and it will all be ok  ;)
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: enginedoctor on January 03, 2010, 10:34:11 PM
X 2 Brad :sly:
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: GT Jets on January 03, 2010, 10:47:21 PM
X3   besides that, makes drunk posting a breeze  (spell check)   ;D

GT
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: enginedoctor on January 03, 2010, 11:01:18 PM
X3   besides that, makes drunk posting a breeze  (spell check)   ;D

GT

This thread....brings to mind a guy running a lathe....alone after hours.
He had been drinking, this happened about 10yrs ago.
Fkn guy falls into the turret/chuck........end of story.

Can't f/around with equip. like this :thumbdown:
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: GT Jets on January 03, 2010, 11:17:10 PM
This thread....brings to mind a guy running a lathe....alone after hours.
He had been drinking, this happened about 10yrs ago.
Fkn guy falls into the turret/chuck........end of story.

Can't f/around with equip. like this :thumbdown:

Holy crap, that story for real???

That's F'ed up...


I remember a story about a dude that was working on a cement truck about 1990, had a few drinks with dinner and came back to work to finish some stuff up, this is one of those cement trucks that had the two foot in diameter sprocket and chain setups run by an Orbit hydraulic motor, I guess the gear caught his jacket and wound his poor ass up into the gears...DRT...

I have seen some stuff in my days (drove a tow truck for a very little while), but that had to be gnarly....

I guess now that I think about it, those older lathes had a compound gearbox and could run over 100:1 ratio's....

GT
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: enginedoctor on January 03, 2010, 11:18:18 PM
I did not intend on being offensive to ANYONE on this thread......But for all machinests out there:
1. No horse play
2. loose clothe
3. jewelry...or hair out of place.!

Machine away at your own risk.........I've seen too many injuries....At this since 1973.

I'm outta this thread.

I did'nt enjoy seeing the beer on the lathe gear box :thumbdown:
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: enginedoctor on January 03, 2010, 11:21:08 PM
Holy crap, that story for real???

That's F'ed up...


I remember a story about a dude that was working on a cement truck about 1990, had a few drinks with dinner and came back to work to finish some stuff up, this is one of those cement trucks that had the two foot in diameter sprocket and chain setups run by an Orbit hydraulic motor, I guess the gear caught his jacket and wound his poor ass up into the gears...DRT...

I have seen some stuff in my days (drove a tow truck for a very little while), but that had to be gnarly....

I guess now that I think about it, those older lathes had a compound gearbox and could run over 100:1 ratio's....

GT
     Yes this is one of many I know of GT.
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: beerjet on January 04, 2010, 09:37:42 AM
Holy crap, that story for real???

That's F'ed up...


I remember a story about a dude that was working on a cement truck about 1990, had a few drinks with dinner and came back to work to finish some stuff up, this is one of those cement trucks that had the two foot in diameter sprocket and chain setups run by an Orbit hydraulic motor, I guess the gear caught his jacket and wound his poor ass up into the gears...DRT...

I have seen some stuff in my days (drove a tow truck for a very little while), but that had to be gnarly....

GT
There was actual pictures on RD's place a year or so ago.
FUUUUUUUUUuuuukin nasty !
Just a chucked up project that had a males upper body twisted around it and literally flesh blown all over the place.
Makes my stomach turn just thinkin about it .
 :thumbdown:

-beerjet-
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: lbhsbz on January 04, 2010, 10:10:37 AM
Relax....I was done...inside drinking my beer and went back out to snap a couple more pics. 

Title: Re: Blowed up pump autopsy...and the rebuild
Post by: enginedoctor on January 04, 2010, 06:50:05 PM
Welcome to the site....Just concerned ;D
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: lbhsbz on January 12, 2010, 12:51:59 AM
Pump ran great at the Tom Papp deal....comes out the hole HARD. 

I fired the boat to run it 20 feet up on the trailer at the end of the day and had a strange groaning/whining noise. 

Tore the pump down again tonight.  Impeller looks good, wear ring looks untouched, bowl bushings look good, thrust bearing is somewhat audible turning the shaft by hand.  The "wiggle" test with the impeller on the shaft showed .032" of clearance between the impeller and wear ring...which is a bit concerning.  I cut the impeller before I had the ring, so I guess I deserved that.  I was gonna yank the motor anyway...and it's easier than dealing with silicone on the transom plates, so I'll pop it apart and disassemble the bearing to see if something looks strange. 

I used valvoline synthethic grease, per the A/T website...about 60 pumps or so....till grease was puking out of the bearing.   Installed the driveshaft and wiped up the excess.  I dunno.  Koyo is a good bearing.  Can't imagine that it failed this quick.  I turned up a little spacer to use on the press when installing the bearing on the shaft so only the inner race was loaded...snap ring is snug against the bearing too.  Maybe it's not the pump but I can't find any thing else that might make noise. 
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: GT Jets on January 12, 2010, 07:55:23 AM
Pump ran great at the Tom Papp deal....comes out the hole HARD. 

I fired the boat to run it 20 feet up on the trailer at the end of the day and had a strange groaning/whining noise. 

Tore the pump down again tonight.  Impeller looks good, wear ring looks untouched, bowl bushings look good, thrust bearing is somewhat audible turning the shaft by hand.  The "wiggle" test with the impeller on the shaft showed .032" of clearance between the impeller and wear ring...which is a bit concerning.  I cut the impeller before I had the ring, so I guess I deserved that.  I was gonna yank the motor anyway...and it's easier than dealing with silicone on the transom plates, so I'll pop it apart and disassemble the bearing to see if something looks strange. 

I used valvoline synthethic grease, per the A/T website...about 60 pumps or so....till grease was puking out of the bearing.   Installed the driveshaft and wiped up the excess.  I dunno.  Koyo is a good bearing.  Can't imagine that it failed this quick.  I turned up a little spacer to use on the press when installing the bearing on the shaft so only the inner race was loaded...snap ring is snug against the bearing too.  Maybe it's not the pump but I can't find any thing else that might make noise. 

Depending on how much time you have on the bearing, I would say it is "possible" it was over greased and overheated...

Without touching, tasting and smelling it, that is what I feel could have happened.. ;)

GT
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: lbhsbz on January 12, 2010, 09:27:27 AM
The bearing has less than 30 minutes of use.  The strange part is...while beating on it all day there was no noise, even while cruising across the lake there was no noise.  Only at idle when I fired it back it did I hear some noise. 

I'll have it with my pasta for dinner tonight and see how it tastes.
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: GT Jets on January 12, 2010, 06:20:52 PM
The bearing has less than 30 minutes of use.  The strange part is...while beating on it all day there was no noise, even while cruising across the lake there was no noise.  Only at idle when I fired it back it did I hear some noise. 

I'll have it with my pasta for dinner tonight and see how it tastes.

I think you are hearing driveline noise...Mine used to do it before I started using my secret weapon.....It could be the "slop" in the splines and just giving you an audible run conformation...Somewhat normal. ;)

GT
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: enginedoctor on January 12, 2010, 06:44:18 PM
..X 2 ! :thumbup:
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: lbhsbz on January 12, 2010, 09:55:34 PM
I heard the typical driveline noise when idleing through the no wake zones...this was different...quite a bit more pronounced.  I thought I'd make it home early enough today to light it up with the pump disconnected, but I didn't.  I'll play with it saturday.  If I don't hear anything I'll put the bowl on (no impeller) and hook things up and see if that makes noise. 

It's very strange...I dunno.  The bearing is cheap...I'll replace it again anyway just to be safe.
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: Willow Wog on January 13, 2010, 08:54:38 PM
This thread....brings to mind a guy running a lathe....alone after hours.
He had been drinking, this happened about 10yrs ago.
Fkn guy falls into the turret/chuck........end of story.

Can't f/around with equip. like this :thumbdown:

I work at a big ass machine shop and my boss sent us these just to remind us what could happen and to watch our asses.If this is too much brad delete it please...

(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi52.photobucket.com%2Falbums%2Fg22%2Fgbrmotorsports%2Flathe1.jpg&hash=a76b7c4106282d34343267dc817ecfd6ddbe654b)
Title: Re: Blowed up pump autopsy...and the rebuild
Post by: honda1 on January 14, 2010, 05:00:41 AM
a very hard lesson learned :(
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