1969 Chris Craft Roamer 46 Refit: Cummins Engine Install –DriveSavers & Spacers

I’m still working on getting the engines installed while the scorching hot summer passes by. Since I’ve never done a complete engine swap before, the learning curve here is pretty steep and my assumptions about many things have been wrong. Fortunately, once I work out the process with the first engine, the second one will be a snap by comparison. πŸ™‚

The inner stringer isn't square at the that up in the next step

The basic problem: the top of the inner stringer isn’t parallel with the outer stringer

Rear spacers bonded with epoxy, cabosil, and atomized aluminum powder

Rear spacers bonded with epoxy, cabosil, and atomized aluminum powder

Rear spacers read for final install

Rear spacers ready for final sanding and installation

Epoxy thickened with cabosil and atomized alumnum powder will fill the gap between the stringer and the spacer

Epoxy thickened with cabosil and atomized aluminum powder will fill the gap between the stringer and the spacer

Rear spacer leveled side to side and bolted in place

Rear spacer leveled side to side and bolted in place

Thickened epoxy has excellent compression characteristics, and its only purpose here is to level the spacer. In addition to being bonded with epoxy to the stringer top and side, I also bolted it through the side. The vibration isolators use 1/2″ bolts that will go all the way through the isolator, the spacer, the stringer, and a 3/8″ backing plate I’ll use on the underside of the stringer when I put it all together. The combination of the epoxy bond and heavy mechanical fasteners should keep everything together nicely and perfectly aligned.

At the front, thickened epoxy clamped to level the stringer top

At the front, thickened epoxy clamped to level the stringer top

The 3/4″ plywood scrap in the pic above has a strip of mold release tape attached to it so the epoxy won’t stick to it. The plywood is just wide enough to span the stringer top and land on the piece of 3/8″ aluminum angle that’s epoxy bonded and clamped to the stringer.

Voila!

Voila!

Flat

The top of the inside stringer is now flat and on the same plane as the outside one

Front stringer is ready to test engine fit and shaft alignment

Front stringer is ready to test engine fit and shaft alignment

I’ll remove the bolts, sand, and paint this whole area white after I’m done test fitting the engine.

DriveSavers arrived!

DriveSavers arrived!

The DriverSavers permitt me to move the engine, vibration isolators, and spacers forward enough so the rear vibration isolator bolts will clear the transverse frame under the gear; a problem I described in my last article. That’s one expensive piece of rubber, but it will also lessen vibration and electrically isolate the shaft and prop from the rest of the boat. All told, it’s well worth the price.

Next up on our 1969 Chris Craft Roamer 46 Refit: Cummins Engine Install – Shaft Alignment and Front Engine Mount

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4 comments on “1969 Chris Craft Roamer 46 Refit: Cummins Engine Install –DriveSavers & Spacers

  1. Doug says:

    Those drive savers are identical to the drive shaft connection in my 1949 Mercedes Benz 170V instead of U-bolts! Old idea, new application.

  2. Kent says:

    Nice progress on the engine instillation..

    May I ask– What do you do for work? An engineer maybe?

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