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mhamer
Joined: 19 Apr 2013 Posts: 17
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Posted: Wed Jun 03, 2020 16:05 Post subject: R-2800 Mounting Bolts |
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I am ready to mount my R-2800 to the frame. I use a Convair 440 engine mount that has 4 bolt holes. The holes are only 1/2in diameter. So I ll use 4
AN 8 bolts from airfasco. They are tested to required tensile of 18500 lb and actual of 23420 lb each. Yield is 14190 required and 22936 actual.
The bolts are alloy steel per AMS 6300C Type 4037 .515” produced per NASM 6812.
The bolts seem quite small for such a heavy engine.. I wonder what anyone here have used as far as mounting bolts. Of course the 2 top ones have the most tinsel stress and those are the ones I worry about
I could drill the mount to fit a an9 but it’s an original mount. I wonder what Convair used...
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rwahlgren
Joined: 15 Aug 2003 Posts: 323
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Posted: Thu Jun 04, 2020 18:40 Post subject: |
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If some of us gear head types were to build an aircraft it would be too heavy to fly. Yes mounting bolts as well as the whole engine mount seems very light for what it is required do, especially as compared to say a prop shaft. If the holes are 1/2 inch then the attachment bolt or stud would be sized slightly smaller. I don't think you want the threads in the area that passes through the mount though.
Edit to correct spelling
Last edited by rwahlgren on Wed Mar 03, 2021 22:48; edited 1 time in total |
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mhamer
Joined: 19 Apr 2013 Posts: 17
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Posted: Sun Jul 19, 2020 07:55 Post subject: |
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Thanks. It’s impressive what a small bolt can handle. Most loads on it will be static, so no hard landing will stress it excessively. Once driven around I will support the motor also from the prop shaft.
Last edited by mhamer on Sun Aug 09, 2020 16:43; edited 1 time in total |
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wstuddert
Joined: 26 Jan 2015 Posts: 17 Location: Australia
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Posted: Wed Jul 22, 2020 17:16 Post subject: Mount bolts |
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If you look up the NSN number for the part number it should give the tensile strength of the Convair bolts. I have chanced an engine on the airplane, and needed to make a jig to align the Dynafocal mounts with the mount ring, some guide pins helped. |
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mhamer
Joined: 19 Apr 2013 Posts: 17
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Posted: Sun Aug 09, 2020 17:13 Post subject: |
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Thanks, it’s hung. There was no undo stress on the frame as I drilled the holes using the mount as guide to locate the holes, the bolts slid right in.
Drove around and no cracks anywhere,
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wstuddert
Joined: 26 Jan 2015 Posts: 17 Location: Australia
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Posted: Sun Aug 09, 2020 17:46 Post subject: |
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What a nice looking engine, pity to have to run it, but a very nice job. |
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rwahlgren
Joined: 15 Aug 2003 Posts: 323
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Posted: Mon Dec 07, 2020 01:05 Post subject: |
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That is a nice set up. Though with out fenders those tires could toss some stones and dirt into that engine. |
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mhamer
Joined: 19 Apr 2013 Posts: 17
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jsteele
Joined: 19 Nov 2013 Posts: 11
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Posted: Thu Jan 07, 2021 19:29 Post subject: |
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mhamer,
Man, that's a great looking job!! What version is that, a CB-16? I don't recognize the deflector plate style.
Best, John |
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mhamer
Joined: 19 Apr 2013 Posts: 17
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Posted: Fri Jan 08, 2021 14:14 Post subject: |
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Hi, Thanks. I can move it around that way. It’s a 99w from Nash Kelvinator
1954.
I polished the deflectors or (coil brackets) they are usually painted black. I still have a lot to do. Setting up relays and a control panel with gauges now.
I have a nice prop that I d hate to cut... I have all the prop tools as well. |
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