I’ve been busy for the past few weeks modifying my engine bed. The reason I had to do this is that the engine that came with the boat has never been in the boat before. The previous owner told me that the old engine was a Volvo, as is the new one, but it was a different model. So the mounts were placed differently. Now the front mounts are about 16″ apart even though the engine beds were only 12″ apart. To accommodate that, I built up the surface on the outside of the bed using Coosa Board.
Since the engine bed was at an angle, I had to stack up several 1″ thick pieces on each side and then fair down the whole surface on top until it was flush, leaving each piece a bit too tall, to account for error.
I will really fair it down flat when I’ve got it all in place.
As for the rear mounts, they were located next to the flywheel, also 16″ apart.
I couldn’t install the rear engine mounts as they are because the hull is so narrow in that place that they would not fit in the boat. The only way to fit them is to have new mounting brackets made so the mounts will be hugging the sides of the transmission, 7″-8″ apart, which should fit on my new surface. I extended the surface back to 1″ in front of the prop shaft coupling and I narrowed it, too.
Since Coosa Board is a softer material than G2, etc. I filled and drilled the holes for the bolts so they would tap better than they would if going directly into the Coosa Board. First I used the West System epoxy but I didn’t like how much it bubbled (first pic). The second below pic is when I re-drilled the holes and used Gel Magic, which is pre-thickened and doesn’t bubble at all. In the second attempt I also changed the hole placement.
I changed the hole placement because there is a piece of metal in between to function as a support that I will be bolting in.
I’ve got seven 3/8″ hex bolts for each side piece. I realized I should place as many holes as possible so that I can reach around the backside to put nuts on as many bolts as I can. The more bolts I can use than tapping screws, the better. Further back than that, I will have to use tapping screws to secure the metal plate.
Here was the test fit of the side pieces with the bolts:
Those bolts will be recessed into the fiberglass when I glass all this in. I got some spade drill bits to make sure I can recess the surface enough so they aren’t sticking out or in the way of anything.
And then I cut some small pieces of Coosa Board and faired it down on the sides to the shape of the Hull, to fill in the space left on the side:
Here is the whole surface right before I began to epoxy everything together.
I’ve since decided that one of the pieces on the right was not cut well enough so I re-cut it.
On Wednesday it was over 90 degrees in Seattle and probably closer to 100 inside my boat. My fan was not hooked up yet. But I had to keep working if I was going to stick to my deadline. I epoxied my pieces in place.
I used the Gel Magic epoxy putty for the vertical parts to keep it from running out the bottom and I used West System’s lower viscosity epoxy for the horizontal parts because it won’t run as much if horizontal and doesn’t need to be thickened. The advantage of West System over Gel Magic in almost 100 degree weather is that an exothermic reaction will happen slower with thinner epoxy because there is more flowing and movement so more heat can escape. (And it did happen to both epoxies while I was working. I touched the epoxy about half hour after I applied it and it was already hard in every spot I touched.) Also West System is cheaper for the amount you get so unless the other option is better for an application, why not save $?
I have to finish epoxying next time I go to my boat. I also have to cut a big hole to make room for the flywheel. After that I have to create a plywood mock-up of new engine mount brackets. Then I will take the mock-up to Collins Machine shop near South Park Marina, where Mike Collins has said he will make them for a very reasonable price. (He’s also going to drill new holes in my prop shaft coupling so they will match the transmission coupling.)
I was originally thinking I’d have the new brackets made *before* I put the engine in the boat, and also that I’d glass in the Coosa Board with several layers of fiberglass mat and resin before getting the engine hoisted up there. Now I’m thinking it’ll be better to do both things after I’ve got the engine hanging down in the engine compartment from the boom (or sitting supported on some blocks stacked up in the bilge), so I can see where things will line up. Then I can modify the Coosa Board here and there if I need to before glassing it in.
It’s pretty exciting because I’ll have the engine in the boat in a couple weeks now probably, which was the last major thing on my list. After that, everything will just be tweaking, hooking up wires, and other minor projects. Meredith will align it so I don’t have to do that!