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A Nutty question

NYTOM

Well Known Member
I have absolutely no info on the proper nuts to attach my carburetor to my O-360. Elastic stop, all metal stop, drilled hex with safety wire, lock washers. I know this sounds like a dumb question but if there was anything I want properly installed to keep tight it?s the carb.
Thinking about vibration and heat. Received new engine with the Carb in its box and no nuts on the mounting studs.
 
Thick or thin washer, internal star lock washer, followed with a plain nut. (All aircraft quality of course.) If the part practically NEVER gets removed, I will leave the flat washer off, but that is my idiosyncrasy. If you really want to be anal, a small dab of blue lock-tight wouldn't hurt.
 
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Thank you dwrichie. If this were my tractor that?s exactly what I would do. Who?d a thought it would be the same for a aircraft. On this plane I question every move I make cause on a plane, it?s just ain't the same. This has been holding me up a little so I really do appreciate your help. :)
 
I had the same question regarding the throttle body attachment to my IO-540 on my RV-10. Found the answer in the Lycoming Parts Catalog document PC-215-1A, which is available on Lycoming's website.

For the IO-540, on pages 6-7 and 6-8 Lycoming specs:
WASHER, 5/16 plain
NUT, 5/16-18 plain
LOCKNUT, 5/16 palnut

Not sure if this is the same for the O-360, but you might want to check Lycoming's parts catalog document for your engine.
 
If this were my tractor that?s exactly what I would do. Who?d a thought it would be the same for a aircraft.

Well....

The Lycoming is similar to either an old tractor motor or a ditch pump, so you should be fine using the same methodology :D
 
all metal lock nut 1/4-20?

Hi,

Has anyone been able to find something like an AN363 1/4-20? I can only find -28. Currently using star lock washers, but would prefer a real lock nut if I can find it. There are several places on the engine where the stud is 1/4-20.

Thanks,
Mickey
 
Hi,

Has anyone been able to find something like an AN363 1/4-20? I can only find -28. Currently using star lock washers, but would prefer a real lock nut if I can find it. There are several places on the engine where the stud is 1/4-20.

Thanks,
Mickey

AN363-420 at B&B Aircraft or Wicks.
 
OK now I getting a little confused. Somebody mentioned 1/4 x 20 nuts.
After checking the Lycoming O-360 parts blow-up photo and parts catalog I?m seeing 5/16 X 18 nuts and 5/16 washers being used. Did I just order the wrong stuff? Wouldn?t be the first time. :eek:
 
OK now I getting a little confused. Somebody mentioned 1/4 x 20 nuts.
After checking the Lycoming O-360 parts blow-up photo and parts catalog I’m seeing 5/16 X 18 nuts and 5/16 washers being used. Did I just order the wrong stuff? Wouldn’t be the first time. :eek:

Changing the stud is another option to work with the "hot locker" nuts.
 
OK now I getting a little confused. Somebody mentioned 1/4 x 20 nuts.
After checking the Lycoming O-360 parts blow-up photo and parts catalog I?m seeing 5/16 X 18 nuts and 5/16 washers being used. Did I just order the wrong stuff? Wouldn?t be the first time. :eek:

You are correct. On my IO-360-MIB they call out 5/16-18 for sump studs to attach the servo to. Although RV8CH asked for a source for 1/4-20 and that is what I gave him.
 
Locking Hardware

All metal locknuts are not a bad idea, but the lockwashers specified by Lycoming work fine if properly installed. Installation error is a bigger worry than the lockwasher not doing its job. I?ve found just a couple loose or missing fasteners over the last 40+ years inspecting 100?s of aircraft. Once or twice a year take the time to check the torque on everything you can reach. I?m fine with the stock hardware on the RV and Pacer

Don Broussard A&P/IA/ATP ect
RV9 Rebuild in Progress
57 Pacer
 
Like some others have mentioned, check the Lycoming parts catalog. It should show the recommended hardware. The older engines use PAL nuts as a safety. Depending on your particular setup, these can be real pain. Superior's FAA certified 0360 clone engine uses star washers instead of PAL nuts so it's reasonable to assume this would be acceptable on an experimental.

DEM
 
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