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· Living in a cage of fear
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16,524 Posts
Discussion Starter · #1 ·
Mocked up the new impeller and wear ring. Wear ring went in very smoothly, checks out even all the way around.
Sucked impeller on and she bound up.
Ended up shimming with .120 total to get .030 clearance all the way around front lip.
Is that uncommon to have to shim that much??

Haven't checked the clearance at the bowl yet.

PS- I removed U-Joints first, thrust seem just fine. No end to end slack and turns very smooth.
 

· Premium Member
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Agree with Old squirt , sd's like alot , perhaps some prior "builder" did some shaft workto move your Impy fwd measure from the impeller shaft register to the thread and PM me your new stnls should need about a third of that with a shouldered wear ring Tom
 

· Jet boat service
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119 Posts
I agree with Tom. I have seen this often, where previous builders cut the impeller shaft to move the impeller forward to fit tighter with the case when using a stock berk ring. Shiming this out does not hurt in my opinion, I have done this before. JIM :)
 

· Premium Member
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7,314 Posts
I agree with Tom. I have seen this often, where previous builders cut the impeller shaft to move the impeller forward to fit tighter with the case when using a stock berk ring. Shiming this out does not hurt in my opinion, I have done this before. JIM :)
As Jim will likley agree a basic Berk pump o'haul on a "virgin" drive is "cake" but get one that had bowl shaft and or impeller mods and everthing changes frankly I dont see how alot can be done with out a lathe and mill Tom

PS Agree on the "shimmage" just put the skinny ones in the middle of the "sandwich" if you stack em' :)
 

· Living in a cage of fear
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16,524 Posts
Discussion Starter · #6 ·
It was a JC originally. Had it built with the same suction and shaft, JG bowl and new aluminum A. The one that got wasted.

There was no shims on it when I disassembled it. So it is likely that shaft mods were done?

I did not trim the liner "edge" and it is a shouldered ring. Please tell me I do not need to pull the ring again??

Tom, I'll PM that measurement in a little while, got some banking to do first.
 

· mo balls than $cents$
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11,635 Posts
if you went from a non shouldered to a shouldered, you'll have that big ole clearence to make up in frt of the impellor:)bulb also could be a difference in the impellor, some are 3/4 surface, some are 1
 

· Living in a cage of fear
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16,524 Posts
Discussion Starter · #9 ·
if you went from a non shouldered to a shouldered, you'll have that big ole clearence to make up in frt of the impellor:)bulb also could be a difference in the impellor, some are 3/4 surface, some are 1

Yeah, that is going on also. The ring sticks out the back, but fits the SS impeller.
Going out to screw with it now, will post some pics and take some measurements.
 

· Registered
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if you went from a non shouldered to a shouldered, you'll have that big ole clearence to make up in frt of the impellor:)bulb also could be a difference in the impellor, some are 3/4 surface, some are 1

This...


I dont see where you say whether the old ring was a shouldered one or not...
 

· mo balls than $cents$
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11,635 Posts
there's a local "pump guru" that did a local guy's pump awhile back(actually ended up doin it 3 times that summer) and by the time i got to look at it, he'd cut the shaft to push the impellor forward, sometime prior the ring had spun/and or thrust went out, so he cut the suction housing some to move the ring forward a tad:)sphss talk about living dangerous, imagine how thin it was in the ring area on that suction piece:)st bowl had almost a 1/4 inch took off it to to bring it in:p wayyyyy past the oring area suction housing split on him when he was out jumping wakes, go figure:)sphss
 

· Living in a cage of fear
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16,524 Posts
Discussion Starter · #13 ·
Old ring non-shouldered, new ring is shouldered.

Measurement A= Tip of shaft to first thread. 2.865"


Measurement B = shim register to first outboard thread. 3.825" ( I bumped the dial while taking pic, it is 3.825"! )


Measurement C = Shim register to inboard chamfer. 2.640"

 

· Boat Nut
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4,935 Posts
Why would one go to the trouble of cutting the shaft to clearance an impeller? It seems the impeller is the sacrifical piece in the build, a quick mill on the hub of the impeller would suffice. The newer shafts are now under cut with a radius where the impeller butts the shaft. Could go either way here, but just curious....
 

· Living in a cage of fear
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16,524 Posts
Discussion Starter · #18 ·
It WAS a complete build last Winter. Has less than 4 hours on it. Aluminum impeller was TOTALED!!

It was a stock JC, had it built by a well regarded builder with a JG bowl, droop, diverter, detailed aluminum A.

Just changing ring and impeller this time. Everything else looks to be OK. Few dings in the bowl from shrapnel. Blew out lube holes and thoroughly cleaned tail bearing area. Have the impeller tightened on now, clearance is .030 at ring. (Checked it through the intake underneath.) Thrust checks out great.
Also have fitted the new top loader in and will install after final assembly of bowl and final clearance check.

Am leaving for the week end so will assemble on Monday.
 

· Premium Member
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7,314 Posts
Why would one go to the trouble of cutting the shaft to clearance an impeller? It seems the impeller is the sacrifical piece in the build, a quick mill on the hub of the impeller would suffice. The newer shafts are now under cut with a radius where the impeller butts the shaft. Could go either way here, but just curious....
Chuck ! what the matter with you ? your thinking logically ;)

(go to Tommys pics and check the area forward of the key broach ,it appears to have been been cut by about .125 or so (best guess) <BTW Tommy I'm gonna have you measure the bowl too ,oft time when the shafts been cut so has the bowl register !
 
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