And now for something completely different, installing an engine

Background: Brother is building an RV-6 and around Christmas time the big brown box from Lycoming showed up. An early Christmas present of sorts. He had a few items to contend with before hanging another 180 lbs off the front end of the airframe so he's been busy since the big brown box's arrival. Two weeks ago, I get the "Do you want to help hang the engine?" e-mail. Um...let me think about this for a nanosecond or two. Heck yeah, I'll be there. Last Saturday was the day.

After a 2.5 hour IFR (I Follow Roads, 0 AGL via non-flying Civic) trip to Bro's house, it was time to start the fun. In addition to my brother, his buddy, a fellow airplane builder, joined the festivities.

Baby Lycosaur waiting to meet Mr. Engine Hoist. This looks so familiar as it's essentially the same engine in our Arrow except it's not fuel injected (an extremely expensive option BTW).


Hooked up and ready to move:
The three of us were extremely careful not to bump anything hanging off the rear of the engine (prop governor in particular) against the RV's engine mount or firewall. There was a small bracket to remove from the governor that made things easier in this regard. In general, getting things to line up so that we could start fitting the upper mounting bolts through the engine mount and Lord mounts was fairly straightforward.

Inching closer, being extremely careful while moving 180 lbs of metal towards the engine mount and firewall:

Closer. This is where "bolt #4" aka "the evil bolt" holds the engine...but I'm getting ahead of myself :-)

We were working from some instructions written by another builder who had experience installing a few engines in RVs. Unfortunately, the instructions were not written up in a checklist fashion. Instead, you had to wade through several paragraphs that contained forward references to other paragraphs.

The top two mounting bolts installed with relative ease. A couple adjustments of the engine hoist, pull engine here, push engine there and we could thread the nuts onto the engine bolts.

Things are looking good:

The first of the bottom bolts was somewhat more difficult to line up in order to get the bolt through the required hardware. At this point, things are looking better and better. The three of us are thinking wow, this isn't all that hard. We were seriously wrong about this but wouldn't realize so until hours later.

At this point, it was time to make a parts run as one of the four engine bolts had a manufacturing defect. Parallel to the bolt, there were a couple of indentations that looked as if you'd crimped the bolt with a set of pliers. Seeing as any reduced strength from one of four engine bolts that secure a very expensive engine to the airframe would be a bad thing, it was a no brainer option to replace the defective bolt. Fortunately, my brother's friend has the same engine mounting bolts awaiting his future engine installation so it was a matter of a short road trip. For me, it was a chance to see an RV-8 under construction. Very cool.

Once we returned from the parts run, things started getting interesting. Ok, not really interesting, more like hard, difficult, a pain, less than fun, etc. since the fourth bolt hole just didn't want to line up. Here's what it looked like:

We push/pull/grunt/groan/lift engine/lower engine for a long time but the alignment doesn't improve. Some movement of the engine makes it worse, some makes it better. Since each engine bolt angles inward and down (top bolts) or up (bottom bolts), it's like solving some strange multi dimensional geometry problem but where certain movements had the opposite of the desired effect.

We try using a drift pin to line things up but it doesn't help much. The defective engine mounting bolt meets an untimely demise and is converted into a larger drift pin after it meets Mr. hacksaw and Mr. bench grinder. It's sacrifice was in vane, this doesn't help either.

Frustration sets in.

We bust out the Van's instructions for installing the engine. These are much shorter but don't offer a ton of help. Briefly, we contemplate removing the engine mount from the firewall, mounting it to the engine, then the entire assembly to the firewall. In short order, we're convinced that this doesn't really change anything. Hmmm, what to do, what to do?

We talk about removing bolt #3 (the other bottom bolt), and install bolt #4. Maybe bolt #3 going on last will be easier(?) It seems reasonable so we proceed. Unfortunately, it doesn't really improve things. It seems as if both bottom bolts are now looking like the above picture, maybe each is slightly closer to being centered. Better seems relative at this point.

More contemplation, more frustration, more reading of the installation instructions. At a critical point, Bro's friend takes him away from the scene for a much needed milkshake at In & Out.

I have an idea. At least I think it was me but by now, it's hard to remember the sequence of things. What if we can push up on the bottom of the engine to improve the alignment of the bottom bolts? A couple of 2X4s and the scissor jack from sister in law's car get added to the mix and things look better but not quite good enough for both bottom bolts to align. Things are better. At this point, that's a good thing.

Disclaimer: The details are starting to get fuzzy in my brain so the following may not be entirely sequentially correct. At some point, we manage to get bolt #4 lined up and the nut threaded on. Bolt #3 is not installed so we've essentially shifted the original problem to the other side of the engine. The bad news is that the misalignment looks maybe the same, maybe slightly worse. It's hard to tell. More pushing/pulling/grunting/groaning/etc. but things don't change a lot.

I think it was Bro's friend that thought of the next idea. What if we can move the Lord mount out of the cup like structure of the engine mount and get the bolt through the engine boss? We proceed.

In an almost anti climactic finish, less than five minutes after this idea was considered, shazam, Bro announces "it's through". He threads the nut onto the bolt and we wiggle the engine to get the Lord mount to seat into the engine mount. Tightening up all of the bolts, removing the scissors jack from below and the engine hoist from above and this is the final result:

And that's all there is to it! Take three Engineers and given enough time in one day, they actually can install a Lycoming engine on an airframe.

In the end, it was a fun and educational experience for me, the only non-builder of the installation team. The next time I'm at my favorite airplane repair facility, I need to ask my favorite A&P about engine installation tips/tricks. For some reason, I have a feeling I'll walk away smacking myself on the forehead and having visions of the "Wow, I could have had a v-8" TV commercials.