I hesitated to bolt the engine down. It just didn’t feel right.
In a boat, the motor rotates the transmission that rotates the shaft that rotates the prop that pushes water aft that pushes the shaft forward that pushes on the transmission that pushes on the motor mounts that makes the boat move. Like all boats this vintage, the motor is attached to steel studs that are attached to rubber isolators that are attached to fiberglass-wrapped wood stringers with lag screws. Lag screws are just big screws with hex heads like bolts.
You can see the old fastener hole just to the right of the new fastener. I shifted the engine about two inches forward and repaired the old fastener holes.
Standard practice is to align the engine, then lag the mounts to the stringers, then adjust the alignment. Typically 3/8″ x 3 1/2″ lags are used, so you can adjust the engine position using the slop in the mount holes. I started with 3/8″ lags.
You can see how sloppy the whole thing is. When the lag loosens even slightly, the motor can move and lose alignment, causing noise and vibration and the shaft falling out of the boat.
I didn’t like it. So I switched to 4 1/2″ long 1/2″ lags in very tight 7/16″ holes. The bolts are tight in the motor mounts and tight in the 5/16″ thick fiberglass wrap around the stringers, so even if they loosen (relax) slightly, the shaft will push on the transmission will push on the mount will push on the stringer and nothing will move. Nothing.
Luckily, the preliminary alignment held while I installed the lags, and the engine is now perfectly aligned and very, very solidly mounted.
By the way, I used galvanized lags instead of stainless, even though they’re not as pretty. Two reasons: galvanizing sticks to wood like stink, and stainless fasteners don’t belong in tight, potentially wet holes. It’s all about crevice corrosion. Oxide layers and anaerobic conditions. Dude.
The day started out great. Look how blue everything is.
Before we installed the engine, we had to install the new shaft. This is because the rudder is in the way of installing the shaft from the outside, and we don’t want to pull the rudder. Pulling the rudder means lifting the boat six feet higher than it is and literally dropping the rudder out of the boat. Yuck.
So instead we slide the shaft into the shaft tube from the inside, through where the engine goes. But before we install the new shaft, we have to remove the old, worn cutless bearing. The cutless bearing is a rubber and bronze thing that forms a water-lubricated journal bearing just forward of the propeller. Water actually makes a terrific lubricant and rubber makes a great bearing material against the steel shaft. I’d explain it in more detail, but it’s all covered in the second semester of the junior year in the mechanical engineering curriculum. I’d hate to spoil the joy of discovery for you.
So I used the Dremel tool to dig out the epoxy around the bronze sleeve of the cutless bearing. This was my first chance to use an amazing Dremel bit I’ve had for several years.
They use a magnet to get little carbide slivers to stick to the tool shaft in a prickly way, then braze the carbide slivers to the shaft while they’re still stuck there. It works like crazy, stays sharp, and doesn’t load up.
Anyway, I dug and I dug and didn’t get to the end of the epoxy that was holding the cutless bearing in. By the way, the dark inner circle is rubber, the patina’ed outer ring is the bronze tube, the white circle is where I dug out the fiberglass and epoxy (see the layers?), and the blue is the outside of the boat.
So plan B:
I used the sawzall, borrowed from the yard, to cut the bronze sleeve in two places. Not difficult, actually. Then I used a non-borrowed pipe wrench to crush what was left of the bronze tube and pull it from the keel.
Out it came, leaving a fiberglass hole that I cut in several places trying to remove sealant that wasn’t there.
The new bearing will slide right in, when the time is right.
So we slid in the new shaft and got ready to install the new engine. First we had to remove everything that wasn’t 19 inches wide.
Some old shirtless guy with saggy skin showed up to help.
Then we lifted the motor with a forklift stinger/poker/extension/long deal and a chainfall.
The hole in the boat is 19 inches wide. The motor didn’t fit one way, but we swung it 180 and it dropped right in.
It was terrifying. By the way, the engine weighs 1000 pounds, more or less. Probably 800 as lifted. Not something you want to get under. Once it was in the boat, we added the transmission and the engine mounts and pushed it sideways into place, then dropped it onto the engine beds. It, miracle of miracles, fit.
Nobody died, nobody got hurt. What a great day.