View Single Post
  #5  
Old February 11th 05, 09:26 PM
Jon A.
external usenet poster
 
Posts: n/a
Default

On Fri, 11 Feb 2005 14:36:50 GMT, "Jay Honeck"
wrote:

The point I'm trying to make is it appears that some bolts being torqued
have been overlooked and what is the chance that the cylinder nuts & thru
bolts had been overlooked also?

Simply, You don't know until you check. It'll require 10 minutes if you
have easy access to the engine.


I'm having my shop check these this morning.


Good for you.

To those who think that the bolt might have been loose from the start,
remember: I watched the shop build this engine, and I personally saw them
check the torque on the engine case bolts. They *were* tightened to spec.


New bolts, new nuts, new lock washers, torque wrench calibrated
recently?

I also know that they never re-checked them, however, and my main mechanic
has admitted that they never check these as a matter of course.


Tsk, tsk! What else do they not do?

In the case of the O-540, anyway, the case bolts are torqued surprisingly
low, and they are not secured in any way. No cotter pin, no safety wire, no
LocTite, no lock washer -- NOTHING prevents those nuts/bolts from loosening
over time. It seems like a ridiculous over-sight, but that's the way it
is.


If all of the engines would have failed, they would have changed the
procedure. Something else is wrong.

A guy on the Cherokee Chat actually had a case bolt FALL OUT after loosening
over time from vibration, so this is not an unheard-of problem. I'm
surprised it's never been addressed in this forum before -- at least not in
my 7 years here.

I've bought a torque wrench, and I'm going to be checking ALL of these bolts
every time I change the oil, from now on.


Have it calibrated, and remember that each time you torque it, the
bolt stretches. Some years ago, when it was credible, AVWEB had an
article on torque. You can probably still pull it up.