Changing prop lugs O-320

[punkin]

In my attempt to make the best correction for CG on my airplane, I spoke again with Sam @ Saber, who made my prop extension and crush plate. He said I can go to a 20lb crush plate, but he wants me to upgrade my bolts from 3/8" to 7/16".

His logic makes sense, so I'm not questioning that, and he can do all the changes to the prop extension...

The question is, can an average guy swap out the lugs on the engine without special tools and lots of cussing, hassle, or damage? I'm not a builder, I run an automotive shop --I've just never messed around with something like this.

No problem? Use caution? Run away? What sayeth the experience of this group?

[Vern]

Easy-peasey

Just use some sockets to make a 'press' and a bolt . They will come right out.

[punkin]

I can't imagine there is clearance to reverse the process...do I just tap them in? Do they "seat" to a specific depth, or is there a depth stop?

I haven't had my prop off in some time, so I'm struggling to visualize exactly what I'll be tackling...

Thanks!

[Vern]

Install just the reverse. Use the sockets and a bolt to pull them into place. The have a ledge on them that will stop when they are fully seated.

[az_gila]

And used prop lugs are usually available from engine rebuilders who save them from rejected crankshafts.

[rvsxer]

Check out this Lycoming Service Instruction, 1098K:
https://www.lycoming.com/sites/defau...20Location.pdf

This S.I. shows the stock bushing configurations for the Lycoming engines, and even gives the dimensions of each P/N bushing. If any are loose in the flange, they can be had with oversize O.D. (P05, P10). Use this S.I. and advice from Saber to help get and install the correct bushings.

I just switched from a Sensenich FP to a Hartzell CS prop and had to change all my bushings. Our local engine shop exchanged them, no charge.

[punkin]

Thanks guys for all the great info! Sounds like I need to go schmooze an engine guy!

[Weasel]

Anyone out there happen to have a set of 3/8" lugs for an O-320?

Working on a prop swap.

[snopercod]

Originally Posted by punkin

...he wants me to upgrade my bolts from 3/8" to 7/16".

Wait a minute now...isn't he talking about the prop bolts, not the bolts that hold the extension onto the crankshaft? Those are already 7/16", I think. I have a wooden prop with 3/8" holes which I had to drill out to 7/16" to accommodate the Saber extension.

[6 Gun]

Use a 6" c-clamp and a socket to take out and install.
Bob