[Grandy]

I need to find a couple slightly longer bolts for the case top where the fuel injection divider goes on an IO-360 B1B. They look like an AN4-15, but they have course threads and don't seem to be listed in the usual places.

Does anyone have a part number or source for these?

Thanks in advance

 

[Steve]

AERO

I think the bolts are 1/4-20 UNC. Call AERO. They may source the bolts from Superior who may source them from Lycoming.

 

[rocketbob]

They're just grade 8 bolts, you can buy them at Tractor Supply.

 

[PCHunt]

They're just grade 8 bolts, you can buy them at Tractor Supply.

Bob, are you certain of this? Grade 8 bolts are fairly brittle. Would Grade 5 be better?

I'm not a metallurgist!

 

[frankh]

Napa

They have quite an assortment of grade 5 and 8 UNC bolts..I believe they are grade 8 but don't quote me.

Frank

 

[rocketbob]

Bob, are you certain of this? Grade 8 bolts are fairly brittle. Would Grade 5 be better?

I'm not a metallurgist!

The Lycoming instructor that teaches engine overhauls told me to "use any good quality grade 8 bolts". So yes I am certain. There should be no concern about the strength of the bolts...after all they bolt aluminum case halves together.

 

[caryr]

there's not much magical about the case bolts.

they are 1/4 - 20 coarse threaded. Hardware store variety will work in a pinch.

The length of thread is the only thing that makes them unique to lycoming.

the unused threads within the alum housing can fret the engine case.

 

[Sheldon]

The larger ACE hardware stores seem to have a pretty good selection of grade 5 & 8 bolts.. Might check them out....