1969 Chris Craft Roamer Refit: Installing the Port Engine

Having installed the starboard engine, I learned many of the pitfalls to avoid and a few tricks that make the job easier. Installing the port engine should be much easier.

Read, set...GO!

Read, set…GO!

Sleeping Beauty

Sleeping Beauty

Aside from rolling the engine over every few months, the starboard engine hasn’t budged since we craned everything into the boat through the salon roof hatch back in 2012. There’s a special tool for turning over Cummins engines, but I saved myself $50 and just bar it over using a wrench on the alternator pulley bolt. The pulley gives ~3:1 mechanical advantage, so I don’t even need a breaker bar to rotate this high compression diesel engine. It’ll be nice when I can just turn the key on and fire it up.

Lining up my home-built gantry

Lining up my home-built gantry with the propeller shaft

Floors braced...ready to lift

Floors braced…ready to lift

Once lifted, I can move the 1-ton engine with one hand

Once lifted, I can move the 1-ton engine with one hand

My custom-made shaft positioning tool

My custom-made shaft positioning tool

It might look like just some cobbled-together blocks of wood, but my shaft positioning tool is designed to rigidly hold the shaft in place even if it gets tapped by the gear coupler. A block on the bottom allows me to clamp the whole thing to the stringers, and I used a hole saw to make a cut-out on the top  block that just fits the shaft. Once I get the shaft aligned in the log side-to-side, sliding the tool back and forth on the stringers adjusts the height.

Dial indicator makes centering the shaft super easy

Dial indicator makes centering the shaft super easy

First, I position the dial indicator then let the shaft drop until it hits the bottom of the log. I take a reading, then I lift the shaft straight up until it hits the top of the log. Take another reading, subtract to find the distance to within 0.001″, and divide that number in half…there’s your center. There was .240″ total clearance, so I raised the shaft 0.120″ from the bottom of the log, and locked down my shaft positioning tool. Doing this on the port engine took the better part of a day. This time, with my fancy tools, it took about an hour.

Original engine bed boxes have to be cut out

Original engine bed boxes have to be cut out

One quick pass with a circular saw just about does it

One quick pass with a circular saw just about does it

One thing I really like about aluminum is that you can cut it using carbide woodworking tools. With a sawsall, it took the professional “marine engineer” who failed to install the engines in 2012 about 20 minutes to cut off one of these boxes. So instead of using a metal cutting blade on a sawsall, I just use a circular saw blade that’s intended for demolition work to make a long cut through the weld.  With my circular saw, it took about a minute for the first cut.

One minute with my Harbor Freight sawsall does the rest

One minute with my Harbor Freight sawsall does the rest

In the pic above, you can see that I clamped a 2×4 to the stringer. I used that as a guide to keep the line straight when I made the cut with the circular saw.

Done in 3 minutes

All four engine bed boxes cut off in 25 minutes

Custom engine alignment tool: a framing square clamped to a piece of aluminum angle

Custom engine alignment tool: framing square clamped to a piece of aluminum angle at the halfway mark

Custom engine alignment tool: a framing square clamped to a piece of aluminum angle

Front engine mount needs modification, same as the port side did

I know from installing the port engine that with my down-angle ZF 280A gear, the engine will sit nearly level with the stringers when it’s finally in place. So I’ve got to have the vibration isolator landing pads on the front engine mount cut off and raised 3/4″, with the slot cut inboard by about an inch from the original.

Inner rear mount needs machining, too.

Inner rear mount needs machining, too.

After blocking the engine above the stringers, I dropped the mounts off at a local machine shop for modification. In this one day, I accomplished what took three weekends the first time around on the port engine. Once I get the mounts back, I’ll clean them up and paint them, then scrub the engine bilge, grind off the remnants of the welds from the original engine beds, and make the spacer blocks for the vibration isolators. I’ll wrap it up by painting the stringers and bilge with Devoe Bar Rust 235 epoxy coating, positioning the engine, final alignment, and then I’ll bolt it all in place.

Next up in our 1969 Chris Craft Roamer Refit: Installing the Port Engine II

 

 

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3 comments on “1969 Chris Craft Roamer Refit: Installing the Port Engine

  1. My Info says:

    My one man trick was a necessity because the engines would un align when splashed, had to leave the boat at rest for a couple of days so the fiberglass hull would flex for the new pressure area’s, subsequently needing realignment , not familiar with the aluminium hulls

  2. victor says:

    My one man engine alignment trick, I will stuff the feeler gauge into the coupler sandwich that needs to open up snug so it doesnt fall down, usually hanging down, raise or lower the appropiate motor mount untill I hear the feeler guage fall, repeat around the.clock tightening flange bolts as I go, when I,m done shaft will rotate by hand, in neutral of course

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