1969 Chris Craft Roamer 46 Refit: Fuel Filters

I recently learned that the marina my boat is at is once again under new management. The first thing they did was bump yard space rental by 33% with no commensurate increase in services (they haven’t cleaned the yard toilet in at least a year…). So I have even more incentive to get the boat out of the tent and splashed before November. Getting the fuel system done is a high priority that I want completed before the boat splashes.

The fuel gauges, supply manifold, and on-engine hoses are already done. Next I installed the fuel filters.

I went with SMX filter heads from Tony Athens’ Seaboard Marine

Primary filter head casting and finish quality are top notch

I’ll use these for the 20 mil “mud catcher” fuel/water separators, AKA Fleetguard FS19513.

Secondary filter heads need off-side ports plugged

I’m using the near-side ports on the filter heads for vacuum gauges and manifold connections

The vacuum gauges will indicate high vacuum if there’s a clogged or waterlogged filter.

I secured the threaded filter adapters with Locktite

The thread pitch is different between the primary and secondary filters. So there’s no chance of putting on the 10 mil secondary filter (Fleetguard FS1000) where the 20 mil mud catcher is supposed to go.

I next applied Gasoila thread sealant on the fitting joining the primary and secondary filter heads

Et voila!

That’s one bullet-proof fuel filter setup.

Starboard filters are attached to the fuel manifold

Primary filter vacuum gauge is installed

Two gauges will help me figure out which filter is clogged when it eventually happens. That’s better than guessing and well worth the investment.

Next I installed a filter priming bulb

Tony Athens recommends using a priming bulb because it’s simple, easy, and it always works. I don’t know if I’ll stick with it in the long term, but for getting the boat splashed it’s the way to go.

Cutting 1/2″ stainless tubing for the port filter-to-manifold connection

Ready for the port filter assembly

Oops

When I pivoted the filters into position, the PVC spacer blocks I made ran into the manifold mounting bolt.

A little router work and the bolt clearance problem was resolved

Perfect!

Locking down all of the Swagelok fittings is a process

First, I lubricate the threads with Gasoila to avoid stainless galling (a kind of cold weld thing that can happen with stainless). Next, I hand-tighten the fittings until they’re snug. Then mark a line across the nut and Swagelok fitting with a Sharpie. Then put a wrench on the nut and another on the fitting. Rotate the 1/2″ fitting nut 1.25 rotations, so one full rotation plus a quarter turn after the Sharpie lines are lined up.

I only apply the Sharpie lines immediately before torquing the fitting nuts, and I leave the lines after I’m done as a tell-tale that each joint is torqued.

Final step is installing port plugs on the far-side of the primary filter heads

Done!

Main propulsion engine filters are installed and ready for service!

This is a huge step. Just a few more and the fuel system will be complete.

Next up in our 1969 Chris Craft Roamer 46 Refit: Installing the Forward Fuel Tank Supply Line

1969 Chris Craft Roamer 46 Refit: Fuel Supply Manifold

With the on-engine supply and return fuel hoses installed and fuel gauge at the helm working, next I finished assembling the fuel supply manifold.

I bought all of the stainless fittings, connectors, and valves I thought I’d need more than five years ago. They were sitting in a box in my garage taking up space, so it was nice to finally put them all together.

One challenge I encountered was that all of the fittings, connectors, and valves use 1/2″ NPT threads. The manifold is basically a loop with valves, inlets, and outlets, but it’s impossible to thread fittings together to make a loop. I resolved that problem by making two halves of the manifold, then used Swagelok 1/2″ NPT to tube adapters to slide them together and complete the loop.

Swagelok tube fittings let me assemble the two halves of the manifold

I’ll attach the manifold to some 1/2″ thick PVC backing board I found in my garage. So I made some stainless straps to hold it all together. I bent the stainless around a handy 3/4″ pipe first to put a curve in it.

Bench vise brake makes nice 90° bends in stainless strap

Next I drilled screw holes in each strap

Gasoila seals all the joints and prevents stainless galling

I used 1/2″ full port stainless valves in the manifold to reduce restriction. The up-side of a manifold like this that allows me to feed each engine on separate tanks or all from any of the three tanks onboard. The downside of it is the number of 90° fittings, each one of which adds friction to the system equivalent to ~7′ of 1/2″ straight hose or tubing. In normal service, with each tank fed by its own respective tank (stbd-stbd, port-port), just going through the manifold adds 14-feet worth of straight pipe friction (~.1″ HG/ft).

Nice!

This explains what each port will connect to

The best place for the manifold will be under the big Kidde CO2 tank

Test fitting the SMX fuel filter

Several years ago I bought two SMX filter heads and Fleetguard 19513 “mud filters” from Tony Athens’ Seaboard Marine in anticipation of this day. Good thing I had them on hand! It quickly became obvious that I’d need to mount the filter heads ~1.5 inches away from the plane of the manifold so the valve handles would clear the filter heads.

Uh…Houston…we have another problem

With the manifold backing board clamped to the best spot under the CO2 tank, there’s not enough clearance to remove and install the fuel filters. Good thing I had lots of that 1/2″ PVC backing board laying around…

Trace the SMX fuel filter head base on the 1/2″ PVC

ShopSmith bandsaw makes quick work of the PVC

Same ShopSmith machine also has a 12″ disk sander that comes in very handy

I rounded off the sharp edges to match the SMX filter head base

Then I screwed three of the 1/2″ PVC pieces together to make 1-1/2″ filter head spacers

I also made PVC spacers that will allow me to locate the manifold outward and higher up on the Kidde CO2 tank support frame.

These spacers on the back of the manifold backing board will give me the clearance I need

1.5″ inboard and 6″ higher…final test fit looks good!

Tefgel protects the aluminum frame from the stainless bolts that attach to the PVC backer board

I use a touch of Tefgel to lubricate threads and isolate the aluminum AN fittings from the stainless ones

Looks good!

Starboard engine diesel supply hose is attached to the supply manifold!

It’s not so consequential, connecting the on-engine fuel supply hose to the fuel distribution manifold. But there are only so many connections between the tank pickups and the engines. Each one that I complete gets me substantially closer to being able to fire these Cummins 6CTAs up!

Next up in our 1969 Chris Craft Roamer 46 Refit: Engine Room Ventilation Fan