Yanmar 3gm30f Diesel Motor Test Fit in Brizo - 1970 Pearson 33

Post date: Apr 19, 2016 2:8:50 AM

Busy weekend working on Brizo.

Started off with the lower 4x4's of the new engine beds shaped to fit in against the old motor mount. The top of the old motor mount is our reference for the Yanmar template.

First step was gluing in the lower 4x4's with tiger hair (shredded fiberglass in resin). The lower's are set exactly 3.5" below the top of the old motor mount. With the addition of the upper 4x4's, we'll be even with the old motor mount. However, because the space between the old mount's vertical risers is smaller than the oil pan on the 3gm30, we have to cut out the old risers. You can see the tiger hair under the front of the 4x4's, as well as one riser cut and the other in progress. I run the vacuum while cutting to keep the fiberglass dust down (and I wear a mask!)

With both risers cut out.

Next, laying in the uppers with 11" between them (oil pan = 10" wide).

Now the uppers have had their aft ends shaped to the hull form, cantilever to make room for the oil pan (much more than will be needed) and the template layed in showing general alignment with the prop shaft coupler! Love seeing plans come together!

Now it's time to hoist the Yanmar diesel 3gm30f from the cockpit where it has spent the winter, into the engine compartment, to test layout and make sure that none of the engine bits intersect with any part of the beds or other boat parts. The upper beds are temporarily screwed in place.

I wrapped a bit of stout line around the boom 4 times and tie with a square knot. When hooking up the chain hoist I pass its hook through all 4 loops of the line. Its hard to see in this shot but I've attached the main halyard to the tops of the same 4 loops of line. The load from the chain hoist is really being borne by the halyard, with the boom taking only the amount of load necessary to hold the apparatus out from the mast. Another line is tied to the 4 loops and run aft on the boom to a cleat to prevent the hoist and halyard from sliding towards the mast. Lastly, a line around the transmission keeps the engine away from scraping the companionway as I lift the engine.

The engine was lifted with the chain hoist, the rear transmission line loosened to allow the engine to hand straight down where it was then lowered to rest on the companionway while the 4 loops of line on the boom are loosened from the boom cleat and slide forward. Then the boom cleat is tied off tight again. Since the halyard is now closer to the mast, it also needs tightening.

Now the engine is fully inside and ready to be lowered. As I lower it, I have to push it forward so it clears the various boat bits on the way down.

Once it's down far enough I remove the wood blocks from the engine mounts and set the engine down on the new upper engine beds (that are held in place with screws temporarily).

Now it's just a matter of unhooking the hoist and scooting the engine forward. Almost looks like she's always live there!

The most important bits are the alignment with the prop shaft. Left to right, up and down and the front to back angle. Alignment is checked where the transmission and shaft coupler connect together. At first I'm a good 2" off.

Now we're pretty close. At least close enough to determine the upper beds' final locations. We'll do the final alignment after the beds are finished and the engine is back in. (note the cleaned stuffing box and new hose and clamps to the stern tube. Don't skimp on hose and clamps. They tend to live there for decades since you have to take the prop shaft out to change them. I use the new teflon packing material. This stuffing box takes 5/16. I used the PTFE grease on them too.

Now after marking the upper bed locations, the engine comes back out with the chain hoist, but this time just set further forward in the cabin. The upper beds will be glued to the lower beds with a thin layer of thickened epoxy and then lag bolted. The heads of the lag bolts need to be recessed so that the engine mounts don't hit them. Each hole is first drilled for the width of the galvanized 1/2" washer (1.5" bit), then drilled down thru the upper bed with a 1/2" bit and then a 3/8" bit to drill the pilot hole in the lower bed. Here's we're all set for glue and galvanized 1/2" lag bolts.. but I ran out of steam. Next weekend! P.s., note the carriage bolts reinforcing the connection of the lower beds to old motor mount.

Lastly, the test fit was intended to ensure that everything else was going to fit.

Transmission cable mount: Will need some adjustment, cable is too far forward.

Raw water pump: plenty of room.

Raw water strainer: will fit on starboard on a piece of plywood I'm installing.

Diesel fuel filter: on port engine room bulkhead (visible above).

Coolant overflow: This is tricky. Will probably have to go on the other side of the port bulkhead, which puts it under the galley sink. We never go down there so that's fine.

Goes to show, one guy can do pretty much anything with the right tools and planning.