McCauley Prop Bolt Length

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RichardMaxted
Posts: 34
Joined: Sat Feb 28, 2015 12:23 pm

McCauley Prop Bolt Length

Post by RichardMaxted » Tue Jul 11, 2017 2:52 pm

A quick request for help. I have a McCauley IB90CM 7048 installed on my C85-F engine on my Cessna 120.

The prop bolts do not protrude from the flange by the usual number of threads we expect to see with other nuts. They are basically flush with it. I have some replacement parts on order (AN6H-32A) which equate to the A-2513-8 bolts supplied by McCauley. However, these are on back order - time of delivery indeterminate.

There are some comments on the Cessna 120 website that the prop bolts on a IB90CM do not protrude.

Does anyone have one of these props fitted to their aircraft with the paperwork to show that the correct bolts are fitted ? Would you be prepared to share a photograph of the bolts and how far they protrude ?

Whilst I am happy to replace the bolts when they eventually arrive I am fairly convinced that what I have fitted currently are the correct bolts but, in the absence of evidence to back up that this is what the bolts should look like when fitted and torqued correctly, I can see myself going round in a bit of a loop trying to find bolts that meet the usual practice.
Richard Maxted
035156

Matt Dovey
Posts: 27
Joined: Wed Jun 04, 2008 10:42 pm
Location: hertfordshire

Re: McCauley Prop Bolt Length

Post by Matt Dovey » Thu Aug 17, 2017 6:18 pm

Richard,
Prop bolts are not standard AN bolts. The thread portion on a prop bolt is longer than on a standard bolt. They should protrude through the back of threaded inserts. If they don't they are not engaging correctly. If they don't engage correctly they are not transferring the load correctly. Its a long time ago since I had to order a single bolt so cant point you in the right direction. But I should think the normal parts stockist can get them for you. When I've had to fit new props they have been supplied with a set of new bolts of the correct type and length. If you have an IPC for the aircraft that should give you the part number of the bolt. If not try the prop manufacture.

Matt
032340

RichardMaxted
Posts: 34
Joined: Sat Feb 28, 2015 12:23 pm

Re: McCauley Prop Bolt Length

Post by RichardMaxted » Tue Aug 22, 2017 7:00 pm

Thanks Matt - I had a feeling that this might be where I ended up. Worth checking before ordering from the USA just to be sure.
Richard Maxted
035156

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