Continental Engine Hardware

[cessna170bdriver]

Are parts in the Continental Illustrated Parts List that are labeled as "plain" nuts and washers something special, or can "plain" AN hardware be substituted? For example, can a Continental part # 2441 be replaced by an AN345-624? I haven't priced either one, just wondering if I have the option as I compile parts lists for overhaul.

Miles

[Bruce Fenstermacher]

Doesn' this just drive you "plain nuts" Miles. Went through the same issue when I rebuilt my engine. I seem to remember using AN but I'd had to loock at my records at home.

BTW I used plain nuts and lock washers per the parts manual instead of the self locking nuts some people to include my IA thought I should use. When questioned I just pointed to the manual and let them cry in their coffee.

If you don't get an answer by tonight I'll look in my records and get back to you .

[Dave Clark]

You got it all wrong....use PLANE nuts!

AN hardware is fine. Using any locking type nuts makes it impossible to torque properly and nylock type nuts should not be used on an engine or anywhere subject to high temperatures.

[Bruce Fenstermacher]

Dave you are right of course about the self locking nuts and torque.

Your logic about nyloc nuts on an engine is also what I was taught and holds true except where the manufacturer specifies otherwise which is the case on our engines (c-145) to hold the starter to the accessory case as I recall.

[GAHorn]

Dave you are right of course about the self locking nuts and torque.

Your logic about nyloc nuts on an engine is also what I was taught and holds true except where the manufacturer specifies otherwise which is the case on our engines (c-145) to hold the starter to the accessory case as I recall.

...and the generator.

[FredM]

Impossible to properly torque a self locking nut? where did that come from? I have been torquing them for 20 years now. Of course I could have been doing it wrong for 20 years. What makes it impossible?

[squaretail]

I am doing an OH now. I found some parts supply places have good prices on some items while not so good on others. I went with new supeior cylinders.New TCM crankshaft,new cam and lifter assy.New oil pump gears.I bought all over the place and am very pleased with the price I have into it.Shop around if you have not already.

[zero.one.victor]

What are you overhauling-- a C-145? I didn't know new cranks were available from TCM for this engine. I have heard scuttlebutt that the IO-360 crank can be used, but don't know if that's officially OK.
What's a new crank cost?

Eric

[Bruce Fenstermacher]

Eric you can torque a self locking nut. But if no specific torque value is given for a self locking nut in that application and you use standard torque values you would be wrong.

In other words in an application that calls for a self locking nut that has a torque value, the torque value takes the drag of the self locking nut in to consideration.

[squaretail]

I am overhauling a C145-2 . Air power has the best price on a crank $3,095.00 I bought the Millenium cylinders from them.Premium has best price on new cam and lifters.Fresno airparts on new oil pump kit and bearings.I hope to be able to pass this on to my kids.Going new now as much as possible will hopefully keep it flying another fifty years or more for them.
Also I was told by all of these parts places that continental parts will have up to a 7% increase in less than 30 days.

[Bruce Fenstermacher]

Squaretail lets get more specific. Most knowledgeable people would tell you that NOBODY was making or would have a NEW crank for a C-145-2. Good used ones are hard to find.

Are you saying you where able to purchase a NEW crank with an 8 bolt flange for a c-145 or was it a new crank for a newer 0-300-D lets say?

I'm sure it was a dampened crank as well?

[squaretail]

Well I guess I am not as knowledgeable as most. It is a new crankshaft and yes it is a C model.

[doug8082a]

So, to clarify... is that an O300-C or a C145-2? New crank or used/yellow tagged?

[thammer]

You got it all wrong....use PLANE nuts!
Using any locking type nuts makes it impossible to torque properly...

The procedure for torquing a self locking nut is to take note of the running torque or friction torque when running the nut on before it contacts the washer and add that to the final torque value. That is specified in AC43-13.1b. Pretty simple and the same technique is used in submarine/ship systems where those type fasteners are used.

Using the torque values from AC43-13.1b on a self locking nut would not be wrong.

Manufacturing specs for running torque on a self-locking nut would allow for a range of acceptable friction. That range would introduce an error into any table because of the differnces between each nut in a production run.

Also, keep in mind that it is permissible to re-use a self locking nut provided it cannot be run on using your fingers. (Unless otherwise called out in the applicable maint manual) That there introduces a huge variable if you were to try to make a torque table for self locking nuts.

That is why noting running torque is necessary. While I don't have anything specific on paper in front of me I'd really doubt that an engineer would try to take the friction of a self locking nut into consideration in creating the final torque value in a table. Too many variables and it's too easy to measure running torque and eliminate the variable. They might though, if you know of such a table, where can it be found?

Naturally if the applicable manufaturers maintenance manual has a torque table for self locking nuts and a footnote that says that running torque is included you would be correct to simply torque to that value. Otherwise, if you fail to include running torque you are under torquing the fastener.

[squaretail]

It is a C145-2 with a New C crank. The only thing I am using that is not new are the cases,rods.rocker arms and cam.crank gear.I bought everything else New.