shop-talk
[Top] [All Lists]

Re: [Shop-talk] stripped screw hole in carb

To: Randall <TR3driver@ca.rr.com>
Subject: Re: [Shop-talk] stripped screw hole in carb
From: Bob Spidell <bspidell@comcast.net>
Date: Sun, 19 Jun 2011 10:28:59 -0700
re: "... the repaired threads are actually stronger than the originals, 
especially in soft metals like carb bodies ..."

I like thread inserts, but I've given this a lot of thought because I sometimes 
use them in critical applications (shock 
mounts where the Armstrong shock is actually the upper suspension arm).  While 
a steel thread is stronger than soft 
metal threads, the joint itself can only be as strong as the weakest part; i.e. 
at some load the screw/bolt will pull 
the insert out of the brass or other soft metal.

Anyway, I think what you meant is the threads themselves are stronger--i.e. 
less likely to strip--which should be the case.

BTW, I used the Locktite product to 'fabricate' new threads for a clutch slave 
cylinder mount on an aluminum housing, 
and with a little trial-and-error was able to get pretty good torque on the 
bolts.  I will, however, install inserts 
next time the gearbox is out of the car (an Austin-Healey 3000).

Bob


On 6/19/2011 9:37 AM, Randall wrote:
>> 2. us JB weld with soap on the bolt.  Once the epoxy has cured,
>> unscrew the screw.
> Although I've not tried that on a carb, I have in other places where the
> loading was light.  The JB Weld is still too weak to take threads, IMO.
> Loctite makes a similar product specifically for repairing threads:
> http://media.midwayusa.com/pdf/instructions/Loctite_stripped_threads.pdf
> which comes with a chart of allowable torque values for the 'repaired'
> thread.  23 INCH pounds for a 1/4" bolt isn't much!
>
> So if you can find a Helicoil in the appropriate size, that would be my
> suggestion.  They aren't cheap, but the repaired threads are actually
> stronger than the originals, especially in soft metals like carb bodies.
>
> -- Randall
>
>


-- 
*******************************************************************
Bob Spidell           San Jose, CA            bspidell@comcast.net

*******************************************************************
_______________________________________________

Shop-talk@autox.team.net
Donate: http://www.team.net/donate.html
Suggested annual donation  $12.96
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums

<Prev in Thread] Current Thread [Next in Thread>