Engine hardware

rjcthree · #1 09-30-2008, 06:02 PM

It appears that the case bolts, etc, that I removed from my H2AD are nothing special - as in it's a place if I wanted to use some fresh fasteners, I can use AN hardware.

Or I could pay $1.48 per 1/4-20 bolts from Lycoming - maybe not!

THoughts? Rick

mannanj · #2 09-30-2008, 08:11 PM

Rick:

I'm not sure that I'd use AN bolts here. If you're not going to certify your engine (ie: experimental), I should think grade 5 Hardware Store bolts, nuts and washers would be sufficient. If you get really paranoid, use grade 8.

The 1/4in. bolts around the case halves only get torqued to 70 in. lbs.

jarhead · #3 09-30-2008, 09:34 PM

I'd go with the AN hardware as long as you're talking about the hardware around the case perimeter.. Quality control is a lot better with AN-spec hardware than with ANY of the hardware store stuff, regardless of grade.

Lionclaw · #4 09-30-2008, 09:39 PM

I was thinking about this when I tore mine down as well. The parts catalog shows 16 of the std-1215 bolts for the case. ECI has a PMA'd version for $1.32. Even with the washers, I don't think new hardware would add up to all that much.

I started a spreadsheet a while back with a per-figure parts breakdown and cost from the catalog. I'll see if I can finish it off and send it to you tomorrow Rick.

mannanj · #5 09-30-2008, 09:42 PM

X-rayed, Non Destructive Testing for 70 in. lbs???????????????

My goodness we might die!!!!!!!!!!

Notice that these bolts are 1/4in x 20 threads. NOT the normal 1/4 x 28 AN threads. 1/4 x 28 threads torqued to 70 in. lbs will exert more clamping pressure than is necessary for the flange. You can find 1/4 x 20AN bolts but WHY???? Grade 5 hardware bolts are more than what is necessary here and are much easier to find!

jarhead · #6 09-30-2008, 10:34 PM

Why not hardware-store bolts?

Because I have PERSONALLY twisted the head off a 1/2" x 13 Grade 8 bolt (non-aviation project) with nothing more than a Craftsman 3/8"-drive ratchet & socket on the bolthead, and a wrench on the nut. No cheater bars, no power tools... and I'm no Hercules, either.

OTOH, I've personally seen Grade 8's resist the TQ applied by a 220lb mechanic doing pull-ups on a 4-foot cheater bar over a 1/2"-drive breaker bar.

In other words, the quality of hardware-store hardware is inconsistent, and that's why I won't use it on any aircraft I work on.

My opinion - worth every cent you paid for it...

PCHunt · #7 09-30-2008, 11:09 PM

Quote:

Originally Posted by rjcthree

....... if I wanted to use some fresh fasteners, ......... Rick

What's wrong with the ones you removed?

az_gila · #8 09-30-2008, 11:18 PM

Quote:

Originally Posted by PCHunt

What's wrong with the ones you removed?

...just replace the locking hardware - the lock washers in this case.

Just like Lycoming recommends for a major overhaul....

ADDED

Lycoming even put this SB on line for your reference....

http://www.lycoming.textron.com/supp...dfs/SB240T.pdf

rjcthree · #9 10-01-2008, 05:15 AM

The hardware removed is just ugly and painted over and oily. I would like the paint to stick to my new motor. I may just soak them in thinner and see, but I'm sure I lost one or two along the way . . .

And I've suffered H2 embrittlement before in my work life. I know, just bake 'em out . . .

I will replace all the locking HW and washers for sure, that's a simple matter.

The H2AD/H3AD used 1/4-20 case bolts, generally more standard pitch HW all around, for those of you that noted the difference.

Rick