Notices
YS Engines Support Direct support from YS Performance Engines by Dave Shadel

ST61ST1, Runout

Old 05-15-2002, 03:49 AM
  #1  
Al T
Junior Member
Thread Starter
 
Join Date: Feb 2002
Location: Victoria , BC,
Posts: 24
Likes: 0
Received 0 Likes on 0 Posts
Default ST61ST1, Runout

Dave
I have A YS engine with the performance upgrade, Shadel Piston and liner. It's mounted in an Xcell Se. About 200 plus flights on the engine. I never did a runout on it bcause it has the uniball clutch and self aligning hub to the engine with the tappered collars (maybe I should have). Anyhow, I had to drop the engine out and decided to dial indicate the hub. I'm getting about 10th runout at tdc. where the piston and liner have the interference fit. Is this normal or is there a problem with a worn bearing or something? Is there anything else I should be looking for?

Al
Old 05-15-2002, 02:14 PM
  #2  
Dave Shadel
Senior Member
 
Join Date: Apr 2002
Location: Gardnerville, NV
Posts: 5,385
Likes: 0
Received 1 Like on 1 Post
Default ST61ST1, Runout

Where are you checking the runout? If it's .010" just in front of the front bearing, you have a big problem. Were you having problems with the operation of your heli before you pulled it apart? If not, I would not worry about it, but since it's apart it's easy to put a new set of bearings in it. Cheap insurance!
Dave
Old 05-15-2002, 06:27 PM
  #3  
Al T
Junior Member
Thread Starter
 
Join Date: Feb 2002
Location: Victoria , BC,
Posts: 24
Likes: 0
Received 0 Likes on 0 Posts
Default ST61ST1, Runout

Dave
The readings on the runout are being taken at the hub, after the cooling fan which would be equivalent to being at the end of the threaded portion of the crank shaft. I have not figured out how to position the dial indicator on the shaft at the front bearing or how I can turn it over by hand with the fan assembly off(It's a good interference fit at TDC so you can't turn it by hand but I guess I could put a nut on the crank shaft). SO what should the runout be at that point? Bearings replacement, pobably best to do both front and back at the same time?
Thank you in advance for your reply

Al
Old 05-16-2002, 01:29 AM
  #4  
Dave Shadel
Senior Member
 
Join Date: Apr 2002
Location: Gardnerville, NV
Posts: 5,385
Likes: 0
Received 1 Like on 1 Post
Default ST61ST1, Runout

It's difficult to know whether you are measuring actual runout or a combination of tolerances. The part that the dial indicator is bearing on may be out of round, it may not be concentric with the shaft. Normal runout on the shaft should be near zero, by itself. If you install it in a case with bearings, .002" would be good. If you are going to replace the bearings, do both.

Good Luck,
Dave

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.