1969 Chris Craft Roamer 46 Refit: New Riser Materials

Having wasted time trying to modify new exhaust risers that simply won’t work (cost effectively) for this application, I decided to do what I’d been toying around with all along: buy some stainless tubing and mandrel-bent elbows, a new TIG welding machine, and make my own risers.

What have we here?

What have we here?

Verocious Motorsports stocked the items I needed, and the shipping was very quick and well done. While they’ve got 90° mandrel-bent elbows in the 4″ size I need, those only come with a 6″ radius bend. But I need short radius bends coming off of the turbos and also at the turn at the top of the engine room. Fortunately, the 120° mandrel-bends come in a 4″ radius. Perfect.

I also got one-foot sections of polished 316 stainless in straight 6″ tube that I’ll use for the showerheads. Seaboard Marine out in California (owned by Tony Athens, of boatdiesel.com fame) sells Cummins turbo flange kits at a fair price, so I picked up a couple of those, too.

All the bits and pieces

All the bits and pieces

In addition to the turbo flange and the curvy bits and pieces on the blanket, I also picked up a 5-foot stick of 4″ tube, a 5-foot stick of 2-3/8″ tube, and two 4-foot sticks of 1-1/2″ tube. The 4″ tube is for the exhaust system, the other two are for the fuel tank inlets, which originally were made up of Schedule 40 galvanized pipe and lengths of hose. The stainless tubing will save 100 pounds off the stern over the galvanized pipe and I’ll  fit it a lot tighter to the hull and frame than the original-style hose.

More fancy bits for the fuel inlet tubing

More fancy bits for the fuel inlet tubing

I got the 2-1/2″ to 1-1/2″ reducers because the original fuel inlets are beautiful chromed bronze, but the new aft fuel tank has 1-1/2″ inlets. The 45° and 90° elbows will help get all the bends right.

The OE 2-3/8" bronze fuel inlet and the new stainless

The OE 2-3/8″ bronze fuel inlet and the new stainless

I’ll cut the original fuel inlet bronze pipe in half–it doesn’t need to stick into the aft stateroom that far. A short hose will connect the bronze pipe to the 2-3/8″ stainless tubing, which will drop down a couple of feet  along the transom on each side, then transition to the reducer. From there, the straight 1-1/2″ pipe will drop down to the 45° elbow, turning the pipe diagonally inboard toward the keel, where the tank is (but still running tight along the transom frames). Straight pipe will then run down to the 90° elbow, where it makes the final turn toward the fuel tank inlet. One final short length of straight tubing will get within a couple inches of the tank inlet, with a short section of hose connecting the two.

The 2-3/8″ stainless pipe is an odd size, and I don’t need anywhere near 5-feet for this fuel inlet. But, I’ll use the scraps to practice with the new AHP AlphaTIG 200X welder that’s on its way from the factory. I highly recommend Tiger Sales (tigersalesco@gmail.com ) if you decide look into buying one of these. You might be able to find the machine for a bit less, but Tiger’s pre- and post-sale support is second to none. Reports are that it’s a fine welding machine for a hobbyist like me. Time will tell. It will reportedly arrive in early March, so I have until then to cut and fit all of the stainless pieces. In the meantime, there’s plenty more that has to happen if we’re going to splash later this year.

Next up in our 1969 Chris Craft Roamer 46 Refit: Turbocators!



3 comments on “1969 Chris Craft Roamer 46 Refit: New Riser Materials

  1. Doug says:

    Nice material! Love your work. Do you have to worry about dis-similar metals (connecting bronze to stainless) in a fuel system, like you would in a cooling system?

    • 1969roamer46 says:

      Thanks, Doug! There will be a hose separating the stainless from the bronze, but a strap is required between them for grounding. With no water (or worse, saltwater) bridging the two, there shouldn’t be a problem with dissimilar metals. Even in the original system, it was bronze to galvanized steel pipe to a galvanized steel tank, connected to copper tubes that supplied the engines and vents.

  2. Kent says:

    Cool stuff– Can’t wait to see the final product..

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