O-435 Cylinder Base Nuts

[Jan Johnson]

Striking out everywhere I’ve tried. Called Ly-Con and they could only scratch their heads.

I need one set of four 9/16” nuts and one set of four 3/4” nuts plus washers.
Anyone?
Thank you.
Jan

[admin]

Jan,

Lycon should have known better. The O-435 is no different than any other Lycoming opposed engine. The hardware is generic and you should be able to get them anywhere that sells aircraft hardware. Many repair shops keep them on hand but you should be able order them from Aviall, Lycon, Univair, Gibson, Superior, Aircraft Spruce, etc.

According to the manual, the sizes of the cylinder base nuts are 1/2″ and 3/8″, which are based on the stud size, not the wrench size.  The original Lycoming part numbers are:

1/2-20 Original: STD-528 nut with STD-529 washer                                                                            Modern: STD-5020 nut

3/8-24 STD-383-B nut with STD-39 washer                                                                                           Modern: .375-24 Hex Nut

[p.s. STD= Lycoming Standard per O-435 parts manual]

• This reply was modified 5 years, 5 months ago by admin.
• This reply was modified 5 years, 5 months ago by admin.
• This reply was modified 5 years, 5 months ago by admin.

[admin]

.375-24 hex nut [STD-383-B] at Aircraft Specialties, $4.76 each. http://www.aircraftspecialties.aero/nut-375-24-hex-383-b/

STD-528 at Univair,  $3.82 each.                                    https://www.univair.com/engine-parts/lycoming/std-528-lycoming-nut/

 

 

 

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