1969 Chris Craft Roamer 46 Refit: Fischer Panda Marine 12 Mini DP Genset

I think I’m still on track for getting the boat out of the tent and splashed this year. Somebody ought to set up a betting pool…

I bought a 200-hour Fischer Panda 12kw genset back in 2009, shortly after the paperwork SNAFU got resolved. I had it craned into the boat along with the Cummins engines, the refrigerator, and washer and dryer. Fischer Panda is a German genset with a Kubota 3 cylinder engine, and it’s quite small for the amount of power it produces.

Getting the genset installed is a priority for splashing the boat because I’ll need a surveyor to give his stamp of approval to put the boat back in the water. Since there’s a raw water thru-hull and seacock (valve) for the genset, I suspect the surveyor and insurance company will, in the very least, want to see hoses fully connected from the inlets to proper outlets.

I’ll be installing the marine air conditioners for the same reason: any system that uses raw water should be in such a condition when the boat is splashed that it doesn’t pose an unnecessary sinking hazard. If there were no hoses hooked up and the seacock was the only thing keeping water on the outside, it’s a single point of failure. Having the hoses and equipment hooked up eliminates that potential problem.

I positioned the Panda on the port side since that’s where the original gasoline powered Kohler 10kw unit was installed, and the exhaust thru-hull is on that side. But for a few years now I’ve been pondering over the weight distribution. Many heavy things, like the water and forward fuel tanks, are on the boat’s centerline, so side-to-side weight distribution is irrelevant. Other heavy things, like the aft fuel tanks and engines, are distributed equally side-to-side.

But my gut tells me that having the washer, dryer, black water tank, and three marine air conditioners, in addition to the genset, all on the port side will give the boat a nasty list. The house battery bank will be on the starboard side, but that’s not enough ballast to compensate. So I decided the Panda has to be moved to the starboard side. Needless to say, that complicates things.

Another thing that came up over the years was hearing from many boating forum contributors complaining about Fischer Panda gensets not lasting long. Being German, I expected the engineering to be good, but the general consensus I gathered was that they took an incredibly reliable Kubota diesel and made it less reliable by over-engineering it: too many sensors packed into too small a space, any one of which can shut the whole thing down. Fortunately, mine is the antifreeze-cooled, mechanical model, so there are fewer sensors and none of the proprietary digital bits that are prone to failure.

Another issue that came up was more troubling: many complain about Pandas dying with very few hours on the clock, almost always due to water from the water-cooled exhaust showerhead getting sucked back into the engine. But several sailing forums have Panda technician contributors, and every one of them stated emphatically that the problem isn’t with Fischer Panda’s design…it’s with the installers who do goofy things that condemn equipment to an early death.

So…I have a low-hour, 420-pound Fischer Panda genset that needs to be moved from the port to the starboard side. I have the gantry I built to install the Cummins engines, but it won’t fit between the engine room ceiling and the genset, so I’m going to have to get Egyptian again. And then I need to install it in perfect compliance with Panda’s owner’s manual, the most recent version of which contains many pages of examples of what not to do if you want your Panda to live a long, productive life. BUT, the genset exhaust outlet on my Roamer is on the port side, and I don’t want to drill any new holes through the Awlgrip paint job. So I had to come up with a way to safely route the exhaust to the opposite side of the engine room.

First, let’s see what the manufacturer has to say.

Fischer Panda’s installation manual mentions powerboats in passing, but all of the graphics and most of the text are about sailboats

The exhaust hose has to drop down into the ‘water lock,’ or waterlift muffler, and it should be directly under the genset. The idea is that, when the genset is shut down the entire liquid contents of the exhaust system that doesn’t drain off the boat should be able to easily fit inside the muffler. The shorter the hoses are below the genset, the less the volume of water will be in the muffler at any point in time.

Sailboats can heel over 45°, which can put some of that water up inside the exhaust manifold if the installation is done poorly and there’s too much water remaining in the system. Sailors don’t even learn that they drowned their Pandas until later when they try to fire up the gensets. But in my years driving Chris Crafts, I’ve never experienced being heeled over 45° for an extended period of time. I don’t think muffler placement is as big a deal on a motoryacht as on sailboat. But Panda says to put the muffler directly under the genset, so that’s what I’ll do.

Putting all of the parameters together, here’s what I came up with after years of pondering:

Two exhaust routing options, one with a loop and one without

Reading further in the Panda installation manual, they recommend using a siphon break loop on the raw water side. Again, this is absolutely necessary for sailboats but my gut tells me maybe not for powerboats. But the waterline on my Roamer is 10″ above the engine stringers. It will be very near the spill-over point for the genset raw water pump, and it’s just below the level of the exhaust showerhead outlet. So, again, I’ll take Panda’s recommendation and install a siphon break loop.

Elsewhere in the manual, Panda recommends gas-water separators in the exhaust system. Gas-water separators, just as the name suggests, separate exhaust gases from the cooling water used in marine exhausts. Water and steam make up a large volume in a marine exhaust system, which is why boat exhaust pipes are so big compared to exhaust pipes on land-based applications using the same engine but with dry exhaust.

Separating the water from the exhaust gas does some very interesting things: it eliminates the splashing sound of water leaving the boat with the exhaust when the genset is running. You get a nearly silent genset, which is nice when you’re at an anchorage. It also eliminates the problem of water accumulation in the long horizontal hose run I’ve got crossing from the starboard to port side.

Also, I’ve still got the OEM standpipes that let out under the waterline, which were connected to the onboard toilets in the days before black water tanks. When you flushed the marine toilets back in 1969, the contents went directly into the body of water the boat was floating in. We’re more civilized these days (in some ways), so I don’t need the standpipes for evacuating turds and can use the forward one instead as the outlet for water from a gas-water separator.

A better approach

At first I was considering Centek’s Gen-Sep gas-water separator, but I finally settled on Vetus, which also sells a plastic siphon break and plastic raw water strainers in the sizes I need.

Vetus LGS (Liquid Gas Separator) is a slick design

So, with the plan for installing the Panda genset worked out over years of pondering, I got to work. Step one involved “getting Egyptian,” using levers, a jack, 2x4s, and 1-1/2 PVC tubing to roll the genset from the port side to starboard. Check it out!

Next up in our 1969 Chris Craft Roamer 46 Refit: New Mounts for the Panda Genset