connecting rod nuts
 

I am rebuilding a 350 Chevy small block engine. Having seen what happens
when a connecting rod is "thrown" I am wondering if it might be beneficial
to use Loctight thread locker. Anyone ever use thread locker with
disastrous results? Recommendations for or against using thread locker on
the connecting rod bolts would be appreciated?



Blue, Red or High temp?



Dave

"David A." > wrote in message
...
>I am rebuilding a 350 Chevy small block engine. Having seen what happens
> when a connecting rod is "thrown" I am wondering if it might be beneficial
> to use Loctight thread locker. Anyone ever use thread locker with
> disastrous results? Recommendations for or against using thread locker on
> the connecting rod bolts would be appreciated?
>
>
>
> Blue, Red or High temp?
>
>
>
> Dave
>
>
Do not use anything on the bolts use new conrod bolts and torque properly.
If your conrods bolt holes are sloppy get new ones.

--
HarryS

>

the proper way to torque rod bolts is
to measure the rod bolt stretch while torqing to specified value.
rod bolts/nuts should not be re-used
especially in a H/P application.

--
Mad-Dog
'79 Chevy K-10
Slightly modified
http://mad-dog16.tripod.com/
--
"David A." > wrote in message
...
> I am rebuilding a 350 Chevy small block engine. Having seen what happens
> when a connecting rod is "thrown" I am wondering if it might be beneficial
> to use Loctight thread locker. Anyone ever use thread locker with
> disastrous results? Recommendations for or against using thread locker on
> the connecting rod bolts would be appreciated?
>
>
>
> Blue, Red or High temp?
>
>
>
> Dave
>
>
>

I have never heard of measuring bolt stretch before, not that I would have
any reason to know such things. How would that be done? I have a few
Micrometers and a set of calipers so I could measure each bolt before
installation to get a base line, but measuring each bolt for stretch while
in the process of, would present a few obvious difficulties.



Is the suggested torque based on the stretch that will theoretically occur
to the given bolt? Is this a percentage of the length or the diameter of
the bolt?



I did feel what seemed to be a slight give while tortuing down the
connecting rod bolts but assumed that I was in the early stages of stripping
the threads. To be honest I thought I had over torqued the bolts and did
order new ones. I then posted to the news group with my question.



Being ignorant of the proper technique I thought it best to ask for help.
Perhaps my first attempt was correct and I just didn't know it. Either way
I have new bolts now and would very much like to feel confident in my
assembly of same.





Dave.


"Mad Dog" > wrote in message
...
> the proper way to torque rod bolts is
> to measure the rod bolt stretch while torqing to specified value.
> rod bolts/nuts should not be re-used
> especially in a H/P application.
>
> --
> Mad-Dog
> '79 Chevy K-10
> Slightly modified
> http://mad-dog16.tripod.com/
> --
> "David A." > wrote in message
> ...
> > I am rebuilding a 350 Chevy small block engine. Having seen what
happens
> > when a connecting rod is "thrown" I am wondering if it might be
beneficial
> > to use Loctight thread locker. Anyone ever use thread locker with
> > disastrous results? Recommendations for or against using thread locker
on
> > the connecting rod bolts would be appreciated?
> >
> >
> >
> > Blue, Red or High temp?
> >
> >
> >
> > Dave
> >
> >
> >
>
>

Should I lightly oil the bolts before I install them or just install dry?

45 lbs. of torque as per the guidelines or a different torque when dry?



"HarryS" > wrote in message
...
> "David A." > wrote in message
> ...
> >I am rebuilding a 350 Chevy small block engine. Having seen what happens
> > when a connecting rod is "thrown" I am wondering if it might be
beneficial
> > to use Loctight thread locker. Anyone ever use thread locker with
> > disastrous results? Recommendations for or against using thread locker
on
> > the connecting rod bolts would be appreciated?
> >
> >
> >
> > Blue, Red or High temp?
> >
> >
> >
> > Dave
> >
> >
> Do not use anything on the bolts use new conrod bolts and torque properly.
> If your conrods bolt holes are sloppy get new ones.
>
> --
> HarryS
>
> >
>
>

Bolt stretch is the BEST way to measure the actual clamping force of a
fastener, BUT for some applications it isn't possible. So folks came up
with a torque table and the angle gauge systems as a tool to help in
those applications. However con-rod bolts are easy if you have a gauge.
Since you don't you could use mics but it may take a while. I have a
bolt gauge that slides over the rod and reads stretch directly off the
bolt (looks like a C-clamp with a dial indicator on the top. The stretch
amount varies though depending on grade of the bolt and manufacturers
specs.

--
Steve Williams
Near Cooperstown NY


"David A." > wrote in message
...
>
>
> I have never heard of measuring bolt stretch before, not that I would
have
> any reason to know such things. How would that be done? I have a few
> Micrometers and a set of calipers so I could measure each bolt before
> installation to get a base line, but measuring each bolt for stretch
while
> in the process of, would present a few obvious difficulties.
>
>
>
> Is the suggested torque based on the stretch that will theoretically
occur
> to the given bolt? Is this a percentage of the length or the diameter
of
> the bolt?
>
>
>
> I did feel what seemed to be a slight give while tortuing down the
> connecting rod bolts but assumed that I was in the early stages of
stripping
> the threads. To be honest I thought I had over torqued the bolts and
did
> order new ones. I then posted to the news group with my question.
>
>
>
> Being ignorant of the proper technique I thought it best to ask for
help.
> Perhaps my first attempt was correct and I just didn't know it.
Either way
> I have new bolts now and would very much like to feel confident in my
> assembly of same.
>
>
>
>
>
> Dave.
>
>
> "Mad Dog" > wrote in message
> ...
> > the proper way to torque rod bolts is
> > to measure the rod bolt stretch while torqing to specified value.
> > rod bolts/nuts should not be re-used
> > especially in a H/P application.
> >
> > --
> > Mad-Dog
> > '79 Chevy K-10
> > Slightly modified
> > http://mad-dog16.tripod.com/
> > --
> > "David A." > wrote in message
> > ...
> > > I am rebuilding a 350 Chevy small block engine. Having seen what
> happens
> > > when a connecting rod is "thrown" I am wondering if it might be
> beneficial
> > > to use Loctight thread locker. Anyone ever use thread locker with
> > > disastrous results? Recommendations for or against using thread
locker
> on
> > > the connecting rod bolts would be appreciated?
> > >
> > >
> > >
> > > Blue, Red or High temp?
> > >
> > >
> > >
> > > Dave
> > >
> > >
> > >
> >
> >
>
>




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David A. wrote:

> Should I lightly oil the bolts before I install them or just install dry?
>
> 45 lbs. of torque as per the guidelines or a different torque when dry?
>
>

Most torques specs are based on dry threads if it is not stated
otherwise. If you use oil, you will over torque and amy strip them. If
you felt them *give* as was stated in your previous post, throw them out
and start over.

yes, I will start over. thank you.


"Rob Munach" > wrote in message
...
> David A. wrote:
>
> > Should I lightly oil the bolts before I install them or just install
dry?
> >
> > 45 lbs. of torque as per the guidelines or a different torque when dry?
> >
> >
>
> Most torques specs are based on dry threads if it is not stated
> otherwise. If you use oil, you will over torque and amy strip them. If
> you felt them *give* as was stated in your previous post, throw them out
> and start over.

Steve W. > wrote:
> Bolt stretch is the BEST way to measure the actual clamping force of a
> fastener, BUT for some applications it isn't possible. So folks came up
> with a torque table and the angle gauge systems as a tool to help in
> those applications. However con-rod bolts are easy if you have a gauge.
> Since you don't you could use mics but it may take a while. I have a
> bolt gauge that slides over the rod and reads stretch directly off the
> bolt (looks like a C-clamp with a dial indicator on the top. The stretch
> amount varies though depending on grade of the bolt and manufacturers
> specs.

> --
> Steve Williams
> Near Cooperstown NY


> "David A." > wrote in message
> ...
> >
> >
> > I have never heard of measuring bolt stretch before, not that I would
> have
> > any reason to know such things. How would that be done? I have a few
> > Micrometers and a set of calipers so I could measure each bolt before
> > installation to get a base line, but measuring each bolt for stretch
> while
> > in the process of, would present a few obvious difficulties.
> >
> >
> >
> > Is the suggested torque based on the stretch that will theoretically
> occur
> > to the given bolt? Is this a percentage of the length or the diameter
> of
> > the bolt?
> >
> >
> >
> > I did feel what seemed to be a slight give while tortuing down the
> > connecting rod bolts but assumed that I was in the early stages of
> stripping
> > the threads. To be honest I thought I had over torqued the bolts and
> did
> > order new ones. I then posted to the news group with my question.
> >
> >
> >
> > Being ignorant of the proper technique I thought it best to ask for
> help.
> > Perhaps my first attempt was correct and I just didn't know it.
> Either way
> > I have new bolts now and would very much like to feel confident in my
> > assembly of same.
> >
> >
> >
> >
> >
> > Dave.
> >
> >
> > "Mad Dog" > wrote in message
> > ...
> > > the proper way to torque rod bolts is
> > > to measure the rod bolt stretch while torqing to specified value.
> > > rod bolts/nuts should not be re-used
> > > especially in a H/P application.
> > >
> > > --
> > > Mad-Dog
> > > '79 Chevy K-10
> > > Slightly modified
> > > http://mad-dog16.tripod.com/
> > > --
> > > "David A." > wrote in message
> > > ...
> > > > I am rebuilding a 350 Chevy small block engine. Having seen what
> > happens
> > > > when a connecting rod is "thrown" I am wondering if it might be
> > beneficial
> > > > to use Loctight thread locker. Anyone ever use thread locker with
> > > > disastrous results? Recommendations for or against using thread
> locker
> > on
> > > > the connecting rod bolts would be appreciated?
> > > >
> > > >
> > > >
> > > > Blue, Red or High temp?
> > > >
> > > >
> > > >
> > > > Dave



A little overkill don't you think? For stock rods with stock bolts
just torque to spec's and all should be well. Rod failure tends to
happen once the bearing spins.

>From: Edward Strauss

> Rod failure tends to
>happen once the bearing spins.
>
>

its all connected(no pun intended).... the bearing usually spins due to too
much clearance, which can alot of times be a direct result of the rod bolts
stretching, causing excessive clearance. this usually does not happen in stock
engines that are run the way they were intended, but does happen when stock
rods are used in performance applications.... ARP rod bolts are a great upgrade
for this reason....
-------------------
Chris Perdue

"Sometimes you're the windshield, sometimes you're the bug!"

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