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Post by pitciblackscotland on Jan 22, 2015 11:56:07 GMT -5
Hi Mitch, That's a good price for one of those motors, it could be a cheapy knock off one but it all comes down to your budget and i always check the sellers feedback aswell which is good so go for it mate. Good to have a spare pump on hand.
Cheers, Mark.
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Post by racket on Jan 22, 2015 15:40:41 GMT -5
Hi Mitch
Yep , thats a very good price , looks exactly the same as the $90 one on the scooter site
Cheers John
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mitch
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Joined: August 2014
Posts: 285
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Post by mitch on Jan 22, 2015 20:21:03 GMT -5
As usual, someone bid on the procon pump at the last minute for about $1 more than me, so I didn't win the bid. As for the motor, I will probably purchase it this week if I get the chance. I have a transmission that needs to be pulled off of a car and rebuilt before spring, so that will be taking up a good amount of my workshop space and time!
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mitch
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Joined: August 2014
Posts: 285
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Post by mitch on Jan 25, 2015 19:22:25 GMT -5
I have some bad news, For anyone familiar with the ST-50 it will make sense
I tried to fit the turbine shaft into the bearing housing, while the piston ring seals were on the shaft. The turbine wheel and shaft slid down into the bearing housing, and the bottom ring expanded and caught on the lip between the housing and the bearing support/bearing surface area. I had no way to get the turbine shaft out of the bearing core but to hit the shaft with a soft faced hammer. This marred up the outer bottom edge of the bearing core, and completely broke the second piston ring off of the turbine shaft. The land is still fine, and the first turbine seal is fine too. I reassembled the entire turbo, and everything spins freely, with a little up and down and in and out play. I am worried that once the turbo is used as the free power turbine with oil flowing through it, the seal (the only one that is left) will leak.
I am considering getting a bearing kit for it, which I think is still available to purchase, and I may be able to have a friend tig the marred up internal part of the bearing core, then dremel the welds smooth. Another exciting day working on the turboshaft!
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Post by racket on Jan 25, 2015 19:38:26 GMT -5
Hi Mitch
As long as you have one serviceable ring that will be OK , all of our Garrett turbine wheels only have I ring .
Cheers John
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mitch
Senior Member
Joined: August 2014
Posts: 285
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Post by mitch on Jan 25, 2015 19:40:01 GMT -5
Here is a picture of the ring. I do not have a picture of the housing at the moment
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mitch
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Joined: August 2014
Posts: 285
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Post by mitch on Jan 25, 2015 19:42:12 GMT -5
Racket, Phew. That makes me feel a lot better! Also I think a ball bearing for support on the end of the free power shaft the play from the journal bearing will be taken up.
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Post by racket on Jan 25, 2015 21:39:15 GMT -5
Hi Mitch
You were fortunate that the ring broke and allowed you to extract the shaft .
Cheers John
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mitch
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Joined: August 2014
Posts: 285
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Post by mitch on Jan 25, 2015 23:05:26 GMT -5
Yeah, I am. I wasn't thinking while I was putting it together.
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mitch
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Joined: August 2014
Posts: 285
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Post by mitch on Jan 26, 2015 8:35:15 GMT -5
It was one of those "here we go again" moments that I find myself in so often
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mitch
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Joined: August 2014
Posts: 285
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Post by mitch on Feb 6, 2015 23:24:14 GMT -5
Good news, I took the GT37 out of the stand/ cage that it sits in for engine testing, and replaced it with the ST-50 so I could do oil pressure testing. I found that with my 5 gallon per minute pump and ~35-40 degrees Fahrenheit oil, I was able to make good pressure. I cracked the bypass valve open at just under 50 psi. The shaft play was almost all taken up by the oil pressure, and the shaft spun freely and felt good. I torqued the compressor nut to 20 ft-lbs, does anyone know the correct spec? I found some conflicting information on google. The turbine side did not leak any oil, even with only a single seal, and the compressor side didn't leak either. All in all I am pretty happy so far with the purchase and I think it will serve well as the free power section.
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mitch
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Joined: August 2014
Posts: 285
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Post by mitch on Feb 17, 2015 11:34:03 GMT -5
Got a little bit done this weekend, came up with a rough design for the free power turbine mounting position. Highlighted in red are the frame mounting arms that the free power turbine will be mounted to. I will include gussets to make sure that they can hold the massive st50 in place securely. Here are the turbine mounting arms that will be welded to the frame mounting arms, they will ultimately sit on the opposite side of the turbine housing flange, just have them in the position pictured for demonstration:
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Post by racket on Feb 17, 2015 18:38:59 GMT -5
Hi Mitch
Coming along nicely :-)
Cheers John
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mitch
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Joined: August 2014
Posts: 285
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Post by mitch on Feb 17, 2015 18:59:24 GMT -5
Thanks racket! Also found a guy near me on craigslist, selling 2 of the exact same gt3788va turbos near me for a great price... Might have to buy them for spare parts, should anything happen to mine! Also, should the free power turbine be as close to the gas producer as possible? I was thinking of using about a 4" long pipe between the two.
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Post by racket on Feb 17, 2015 19:30:38 GMT -5
Hi Mitch
A spare won't go astray 4" is fine :-)
Cheers John
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