Starter studs too short on O320

[sblack]

I only have 1/4" of stud sticking out of the starter flange on 2 of the studs. I suppose I could jam 2 nuts on to the stud and back it out, but then it would be loose and if I use lock washers on the nuts vs safety wire the the studs can back out. Is this a common issue? Any suggestions?

Thanks

[g zero]

not sure the reason for studs in some places and bolts in others . How about installing longer studs ? I replaced the studs for the prop gov due to them being short .

[mahlon_r]

Assuming experimental,back out confirm thread engagement into case and reinstall with Loctite to the depth you want. They will never come loose with Loctite on the threads.
Good Luck,
Mahlon

[sblack]

What is min req' thread engagement?

Thanks

[mikeyj350]

Originally Posted by sblack

What is min req' thread engagement?

Back each stud out to just the point where the starter rips itself from the case, and then turn it back in one half-turn.

Sorry had to. Although I'm not much help on the aviation side of things on this topic, I have heard of car starters ripping themselves free from their bolts if they weren't threaded in all the way. Something like too many shims and maybe too short of a bolt. Similar situation maybe. My thoughts are, there is a lot of force on these bolts and your aluminum case, it may be safest to find a longer stud and keep as much thread as possible in the case.

[spark68]

Thread engagement would normally be 1 1/2 x diameter, but I would not feel comfortable with less than 2 x dia for a starter. Longer stud may be the best course?

Hi Mahlon, Good to see you posting.

[sblack]

I kinda thought these would be standard on all o320s. Silly me

[az_gila]

Originally Posted by mahlon_r

Assuming experimental,back out confirm thread engagement into case and reinstall with Loctite to the depth you want. They will never come loose with Loctite on the threads.
Good Luck,
Mahlon

Mahlon, which version/color of Loctite is best on engine parts?

Would it be this one?

http://www.loctiteproducts.com/p/10/...er-Red-271.htm

[climberrn]

Could not find longer studs at Napa aviation. All their studs had coarse thread/fine thread. Found a grade 8 black oxide Allen bolt that was 2 inches long, and all thread. Trimmed the Allen head off, and works perfect. I think the full thread in the engine case is a good idea. Not worth getting stripped out.

[sblack]

This was in the non-certified section at Napa right? great idea thanks.