Delfin
Grand Vizier
- Joined
- Jan 20, 2010
- Messages
- 3,851
We have a Northern Lights 20kw genset on board (I know, it's big, but it came with the boat, brand new). I installed a Puradyn bypass filter on the main CAT 3306 a number of years ago, and have been meaning to install one on the genset as well. The basic reason is that OEM filters are designed to handle particles in the 20 - 40 micron range, but most wear on parts occurs from particles quite a lot smaller than that, or so I am told. A bypass filter simply supplements this stock filtration with a separate path for the oil to flow through that incorporates either a much tighter mesh in a filter cartridge, like the Puradyn that filters down to 1 micron, or via a centrifuge that spins the oil and separates particulates from the oil to about the same level - 1 micron. These particles collect on the side of the centrifuge and can be cleaned out at oil changes, or before if desired.
I thought some members might want an assessment of the difficulty, time and cost of installing a centrifuge as I can't see the downside of having cleaner oil.
The one I purchased for the 33 hp genset is from Dieselcraft, an OC 25. They make an OC 26 that covers 50 to 500 hp. The picture shows the unit as mounted. Oil comes under engine oil pressure enters the unit via the black hose and gets the centrifuge spinning around 6,000 rpm. Another port sprays oil on the inside of the spinning centrifuge, and separates rubbish from oil, which flows out the top of the unit, and drains back to the sump via the blue hose. The little silver box to the left is a small air pump Dieselcraft supplies to help push the oil back to the sump so the drain hose can be small i.d. They told me the unit process about .4gpm of oil.
The unit comes with the bracket shown that allows it to be mounted on any angled surface. They supply some hose, and all the fittings needed to make up the connections. You need to locate a source of 12 vdc power for the pump that is only on when the motor is running. In the NL's case, I could make a connection at the engine kill unit that is activated by the various Murphy switches on the engine. It is a normally closed switch that opens and stays open as long as the engine is running and no low oil pressure or high temperature condition is detected. You tap into the pressure side of the oil path in the engine - usually these taps can be found near the oil filter - and connect the supply line. The return line can be more problematic. In my case, I have the sump of the NL plumbed to an oil extraction pump for oil changes, so it was easy to pipe into that, but absent that, tapping and drilling the oil cap, or worse, the pan itself might be needed. The whole installation took me about 4 hours. Cost for the filter is $420 delivered, plus a few extra parts for plumbing.
The only tricky bit was finding a metric to pipe adapter, but Amazon came to the rescue. The tap on the block of the NL unit is an M10 x 1.0, and all the fitting for the Dieselcraft are pipe fittings.
The OEM filter on the NL is really small, and I suspect that may be why the oil change interval is 100 hours. While they say you can significantly extend oil change intervals with any bypass filter, I have never done so. Oil seems cheap compared to the cost of repair, so saving $100 once a year in oil I could have kept doesn't seem material enough to worry about, given other boat expenses.
I thought some members might want an assessment of the difficulty, time and cost of installing a centrifuge as I can't see the downside of having cleaner oil.
The one I purchased for the 33 hp genset is from Dieselcraft, an OC 25. They make an OC 26 that covers 50 to 500 hp. The picture shows the unit as mounted. Oil comes under engine oil pressure enters the unit via the black hose and gets the centrifuge spinning around 6,000 rpm. Another port sprays oil on the inside of the spinning centrifuge, and separates rubbish from oil, which flows out the top of the unit, and drains back to the sump via the blue hose. The little silver box to the left is a small air pump Dieselcraft supplies to help push the oil back to the sump so the drain hose can be small i.d. They told me the unit process about .4gpm of oil.
The unit comes with the bracket shown that allows it to be mounted on any angled surface. They supply some hose, and all the fittings needed to make up the connections. You need to locate a source of 12 vdc power for the pump that is only on when the motor is running. In the NL's case, I could make a connection at the engine kill unit that is activated by the various Murphy switches on the engine. It is a normally closed switch that opens and stays open as long as the engine is running and no low oil pressure or high temperature condition is detected. You tap into the pressure side of the oil path in the engine - usually these taps can be found near the oil filter - and connect the supply line. The return line can be more problematic. In my case, I have the sump of the NL plumbed to an oil extraction pump for oil changes, so it was easy to pipe into that, but absent that, tapping and drilling the oil cap, or worse, the pan itself might be needed. The whole installation took me about 4 hours. Cost for the filter is $420 delivered, plus a few extra parts for plumbing.
The only tricky bit was finding a metric to pipe adapter, but Amazon came to the rescue. The tap on the block of the NL unit is an M10 x 1.0, and all the fitting for the Dieselcraft are pipe fittings.
The OEM filter on the NL is really small, and I suspect that may be why the oil change interval is 100 hours. While they say you can significantly extend oil change intervals with any bypass filter, I have never done so. Oil seems cheap compared to the cost of repair, so saving $100 once a year in oil I could have kept doesn't seem material enough to worry about, given other boat expenses.
