Thorp Air Command - T18.net

Supporting Owners, Builders and Pilots of the Thorp T-18 and its variants.
It is currently Fri Aug 17, 2018 8:22 am

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 11 posts ] 
Author Message
Ryan Allen
PostPosted: Sun Oct 15, 2017 3:31 pm 
Sr. Member
Sr. Member
User avatar

Joined: Wed Oct 21, 2009 6:10 pm
Posts: 730
Images: 0
Location: Louisiana
Well, see the photo below. There is a second broken stud on the underside of the cylinder too. How can this be fixed?

Attachment:
Resized_20171015_123235(1).jpeg
Resized_20171015_123235(1).jpeg [ 855.7 KiB | Viewed 1293 times ]


Top
 Profile Personal album  
 
Jeff J
PostPosted: Sun Oct 15, 2017 3:52 pm 
Sr. Member
Sr. Member

Joined: Wed Aug 31, 2016 8:18 am
Posts: 361
Images: 0
Location: eastern OK
The stud should thread out once you can get a hold of it. Replacement studs can be a bit of a pain with the minimum torque requirement and getting the proper length remaining out of the case to put the nut on.

I have seen the threads get pulled out but this the first broken cylinder stud. If it was a through stud the case would have to be split.

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson


Last edited by Jeff J on Sun Oct 15, 2017 4:00 pm, edited 2 times in total.

Top
 Profile Personal album  
 
Ryan Allen
PostPosted: Sun Oct 15, 2017 3:57 pm 
Sr. Member
Sr. Member
User avatar

Joined: Wed Oct 21, 2009 6:10 pm
Posts: 730
Images: 0
Location: Louisiana
Thanks Jeff. How would I get out the lower stud out which appears to have broken off flush with the case (rather than flush with the cylinder flange in the photo above).


Top
 Profile Personal album  
 
fytrplt
PostPosted: Sun Oct 15, 2017 4:05 pm 
Sr. Member
Sr. Member
User avatar

Joined: Tue Oct 20, 2009 8:07 pm
Posts: 793
Images: 2
Location: Lakeland, Florida, USA
I'm thinking you are looking at a through bolt and not just a stud. Even if is just a stud, the amount of corrosion on the remaining studs would make me want to tear the engine down for a complete inspection.

_________________
Bob Highley
N711SH
SN 835
KLAL


Top
 Profile Personal album  
 
Jeff J
PostPosted: Sun Oct 15, 2017 4:08 pm 
Sr. Member
Sr. Member

Joined: Wed Aug 31, 2016 8:18 am
Posts: 361
Images: 0
Location: eastern OK
I hate to say it but I think the jug will have to come off for both. Probably have to drill the bottom one and use an easyout. How hard they come out will depend on what, if anything, was used as a thread locker.

I think the through bolts are on the back side of number 2.

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson


Top
 Profile Personal album  
 
Ryan Allen
PostPosted: Sun Oct 15, 2017 4:09 pm 
Sr. Member
Sr. Member
User avatar

Joined: Wed Oct 21, 2009 6:10 pm
Posts: 730
Images: 0
Location: Louisiana
The white stuff on the case and bolts is actually baby powder that I put on the case a couple hundred hours ago in search of an oil leak.


Top
 Profile Personal album  
 
1albee
PostPosted: Sun Oct 15, 2017 8:09 pm 
Sr. Member
Sr. Member

Joined: Sat Oct 31, 2015 6:58 pm
Posts: 162
Images: 0
Looks like a no fun job. My concern is what caused them to fracture in the first place ? You may want to contact someone like Divco, there phone # is (918) 836 9101 they have been working with engine cases for 40+ years. They may be able to lead you in the correct direction before you get into something that could have been repaired before messing with it and causing a larger issue.

Phil
118BC


Top
 Profile Personal album  
 
Rich Brazell
PostPosted: Sun Oct 15, 2017 9:55 pm 
Hero Member
Hero Member

Joined: Wed Oct 21, 2009 12:33 pm
Posts: 2856
Images: 64
Location: Jamul, CA (San Diego area)
You probably did this , but I'll say it anyway . Soak the nut/stud with something like PB blaster or Kril oil . ;)

RB O0


Top
 Profile Personal album  
 
Jeff J
PostPosted: Mon Oct 16, 2017 10:26 am 
Sr. Member
Sr. Member

Joined: Wed Aug 31, 2016 8:18 am
Posts: 361
Images: 0
Location: eastern OK
I was just looking at the picture zoomed in. It looks to me like there might be some kind of sealant under the cylinder base. If true, that can cause all kinds of nastiness down the road to include broken cylinder studs and possible catastrophic failures. Those mounting flanges need to be clean. Mike Busch did a good article about it...
https://www.savvyaviation.com/wp-conten ... -ya-in.pdf

_________________
Thorp T18
O-320-B3B (160 HP)
68x74 Sterba Propeller

"The joke in aviation is, 'If you want to make a million, you'd better start with £10m.' " -Bruce Dickinson


Top
 Profile Personal album  
 
james peran
PostPosted: Mon Oct 16, 2017 6:20 pm 
Newbie
Newbie

Joined: Thu Oct 22, 2009 1:42 am
Posts: 33
Location: Australia
i would pull the cylinder off . Remove and replace all studs and nuts. Fit new studs with thread sealer to stop corrosion developing . There is enough stud
sticking up to apply the stud removal tool. can buy at any good hardware shop .. J.P..


Top
 Profile  
 
james peran
PostPosted: Mon Oct 16, 2017 6:22 pm 
Newbie
Newbie

Joined: Thu Oct 22, 2009 1:42 am
Posts: 33
Location: Australia
i would pull the cylinder off . Remove and replace all studs and nuts. Fit new studs with thread sealer to stop corrosion developing . There is enough stud
sticking up to apply the stud removal tool. can buy at any good hardware shop .. J.P..


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 posts ] 

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

[ Time : 0.078s | 12 Queries | GZIP : On ]