Engine Mounting - What is the secret?

[514S]

I give what is the secret to mouning the Lycoming engine in the RV9A? I tried following the method posted on this web site and got one top bolt in but could not get the second. So I tried the bottom bolts first. Got the bottom two in but can not get the holes lined up for the top two. Is there a secret to this process? I read people taking an hour or less. After six hours I have two bottom bolts in. In serious need of help again.

[Vlad]

514S,
There are several secrets I discovered. I am not a professor on engine installations but I did it solo in couple hours. Secret 1 - start in the morning when you are fresh. Secret 2 - go by the book or by instruction from this site. Secret 3 - sequence important, if next bolt doesn't go, take a walk in the park for 30 minutes then proceed. Secret 4 - tape rubber halves and big washers to the mounts and tape them good.
You will get it, just start well rested.

[lostpilot28]

Well, Vlad makes some good points, but I think the easiest most effective thing to do is to buy tapered pins. Basically they're tapered bolts with the heads cut off (they look like bullets).

When I installed my engine I didn't use them and it was a pain lining up the holes! They were close, but off by maybe a 1/4-inch. Very frustrating. It took several hours to get the engine mounted.

A friend of mine mounted his with the help of an A&P who had the tapered pins...took them all of 1/2-hour to do everything.

[Kyle Boatright]

Originally Posted by lostpilot28

Well, Vlad makes some good points, but I think the easiest most effective thing to do is to buy tapered pins. Basically they're tapered bolts with the heads cut off (they look like bullets).

When I installed my engine I didn't use them and it was a pain lining up the holes! They were close, but off by maybe a 1/4-inch. Very frustrating. It took several hours to get the engine mounted.

A friend of mine mounted his with the help of an A&P who had the tapered pins...took them all of 1/2-hour to do everything.

Bingo.. I did it solo in 1/2 hour. Made 4 tapered pins and used them to align the motor. Once the pins were in, I snugged the engine up to the mount using a strap, then used the real bolts to push the tapered pins through and out the other side. Getting the engine snugged up tight against the mounts is critical in minimizing the difficulties in aligning all 4 bolts.

If you have a hard time getting the tapered pins in, use phillips screwdrivers that are smaller in diameter than the pins to get your initial alignment.

[frankh]

Our natural tendency is to leave all the bolts loose until we gat all the bolts installed.

This will NOT work in this instance..Think about it..All the bolts are pointed inwards..so the ONLY time they will all line up simultaneously is when they are tight!

OK so now you understand this the ONLY way to get the top bolts in is when the bottom ones are tight.

So install bottom bolts..Let a little bit of the engine weight down to compress the rubbers lightly..Now tighten the bottom bolts.

Voila! as you tighten the bottom bolts the top ones will be pulled into line.

You could also use tapered pins to help but they are not necessary when you realise the above enlightenment.

Have fun

Frank

[514S]

Great news, the engine is now installed on the plane. Thanks for the information.

Got any advice on installing the engine cowl?

[frankh]

cut,cut,cut..realise you've cut to much..swear a lot and start building up the edges again..its an iterative process..

Frank