On Apr 8, 2020, at 10:25 PM, Jim Patillo <logistics_engineering@...> wrote:



Why did he have to pull the cases apart to install a heli-coil for a cylinder?

Jim

N46JP Q200

Sent from Outer Space

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From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Bruce Crain <jcrain2@...>
Sent: Wednesday, April 8, 2020 8:19:48 PM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Ready for Spring Fling!!

 

Go carefully when you torque up the driven studs and then the cylinder base  nuts!  Imraan and I pulled a stud when re installing his number 3 cylinder.  He had to  have the case apart and have heli-coils installed.  Not fun!

Bruce

---------- Original Message ----------
From: "Jim Patillo" <Logistics_engineering@...>
To: "main@Q-List.groups.io" <main@Q-List.groups.io>
Subject: Re: [Q-List] Ready for Spring Fling!!
Date: Thu, 9 Apr 2020 00:38:01 +0000

Thank you Bruce for all your help. I don�t have any heli-coils installed (yet). But I get what your saying. Will let you know when I get there.

 

Jim

N46JP Q200

 

Sent from Outer Space

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From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Bruce Crain <jcrain2@...>
Sent: Wednesday, April 8, 2020 5:19:25 PM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Ready for Spring Fling!!

 

Say Jim when  you go back in with the thru bolts for cylinder #4 you will obviously have to thread the bolts back into the opposite case.  When I pulled my #4 I tried to re-torque the thru bolts "driven studs" to spec of 300 inch lbs or 25 foot lbs because one of the studs seemed a little long when I originally mounted the cylinder at overhaul.  And because I was curious about their original torque.  As I started to torque the two it seemed they were going in a bit further than I thought they should.  So I stopped and then remounted the cylinder and torqued the cylinder base bolts to the prescribed >490 inch lbs or >40 foot lbs for 7/16-20 bolts and >410 inch lbs or >34 foot lbs for the 3/8 -24 bolts.  

 

I called Buddy at D and B Engines the next day and asked him what was going on with the driven studs not making torque.  He said you most likely have a heli-coil in place and the heli-coil has drilled hole at the end of it which makes the end of the hole further in from the heli-coil.  I know clear as mud, but think about how you drill and screw in a heli-coil.  I may have been bottoming out the threads on the bolt and screwing in the heli-coil more than originally mounted from Divco in Tulsa when they re built my case halves.

 

So unless you have a thru stud sticking out to far to get a cylinder base wrench on it when you mount it you might measure the other cylinder base bolts to see if they are sticking out any extra.  If you have any questions I would direct you to Buddy at D and B.  It seemed so much more simple when he described the procedure.

 

Bruce Crain

P.S.  I put the picture of  you and Bob Farnam 2 ship on Face Book and branded you two of the fastest Q's flying!  Hope you didn't mind!  That is a beautiful picture!