Date: Tue Nov 6, 2001 8:44 pm

Measure the thread size and type of the existing drain plug. Very likely it is 1/2" NPT (national pipe thread). Buy a brass, 1/2" NPT male fitting to a 1/2" barbed hose adapter. Fit a length of oil resistant, neoprene, high pressure hose with a pressure fitted receptacle, (easily made at any bar-b-que gas grill or gas log outlet), with a 1/2" NPT female fitting and insert a 1/2" NPT pipe plug into the receptacle. Slip the open end of the neoprene hose over the adapter on the barbed end and hose clamp tightly. Reach under the oil pan and screw in the new assembly in place of the old drain plug.

When draining the oil place a 4 liter, rectangular, plastic jug (usually found as the discarded container of deep fry oil at almost any fast food restaurant) into the flat spot in the bilge and open the new drain plug, empty the waste oil into the jug. Replace the drain plug into the hose adapter and discard the waste oil at almost any filling station,

Sent: Saturday, November 10, 2001 7:29 PM

The Diesel, Care and Feeding

Paul Watson - November 10, 2001

As the diesel engine thrives on providing a high degree of effort from combustion provided by compression-generated heat, the exposure to internal damage from this process is far greater than in a gasoline engine.

Engine Oil

The considerably higher compression ratio puts 30% more stress directly upon pistons, wrist pins, connecting rods, bearing surfaces and the crankshaft. Most manufacturers build most of these components heavier to compensate for the predictable wear and tear. However, the soft, replaceable bearing surfaces for wrist pins, camshafts and crank journals are made from pretty much the same material as their gasoline driven sisters although the surface area is most often increased in the diesel engine.

Oil pumps circulate oil throughout the engine, providing recycled, cleansed oil from the reserve in the sump to lubricate the contact surfaces.

Most technicians and manufacturers will recommend oil changes each 100 hours of service. Using the formula that was previously provided, as one to predict engine life expectancy, we can equate 100 hours as about 6,000 driving miles for a car engine. My fairest assumption is that due to various factors this should probably be halved to provide motivational diligence for maintenance and understanding that oil has a few built-in, predictable failures.

Unless you have weaned your engine to the more modern, synthetic compounds be aware that petroleum based engine oil has a few different dysfunctions but does have a useful, if limited, life span under stress.

1. Heat is probably its worst enemy. Although almost all-internal combustion engines loose about 90% of the heat generated in the combustion chambers through the exhaust system. This relates to about 75% of the total heat generated. About 15% is whisked away by the cooling system, 5% convected by the external surfaces of the block and cylinder head and the rest by the oil cooler and oil pan.

2. Oil is graded quite magically and mysteriously to any number of specifications that provide a measure of viscosity or its ability to maintain a predictable thickness under a range of conditions. The amount of cleansing agents by volume to scrub the various acids, deposits and carbon sludge collected as it travels through the engine. Unfortunately, Ďhigh detergentí oils are not particularly kind to the soft metal compounds in the bearing surfaces.

3. Oil filters are not all alike either. Flow-through filters generally provide an allowance factor to prevent built up contaminants from slowing the flow of oil by providing a bypass route within them. If clogged sufficiently much of the oil races through the bypass and back into service within the oil passages, still carrying much of the destructive material it was supposed to trap within the screening filters contained.

4. Others are built with a pressure valve that prevents the engine from draining down after shutdown. This holds a small amount of oil in the upper bearing surfaces of the camshaft and valve train so that upon startup these vulnerable bearing are prevented from turning "dry" until adequate oil pressure is once again achieved. Cold starts, when the oil is the consistency of glue, may actually let the engine run dry for twenty or thirty seconds each time.

Generally speaking oil filters manufactured by WIX, Fram, Purolator and Power Part (Perkins) serve quite well as each is produced to very high standards with very well graduated filter elements designed to remove most particulate sizes and each has pressure relief valves that once clogged will then flow through the bypass.

Oil filters, recommendations:

Dale White

Pick Pocket K14

In Pensacola

I have the 1975 Four-91

Fram PH-16

One Fram catalog calls for PH8A

The Puralator cross is PER-17

A fairly simple analysis of just how your particular engine is used coupled with your own diligent maintenance may help you to decide the grade of oil you should be using. Viscosity is really quite important, as it is the operating range temperature that determines the viscosity you choose. The smaller number indicates the thickness the oil will maintain at its lowest temperature. Presumably a cold engine using a 10W-30W lowest grade in the multi-grade should not fall below a thick 10-weight when started or idling. The higher number, "30", indicates just how thin the oil should be when operating at nominal use or when pulling its designed load over any period of time at its designed engine coolant temperature.

However, unless you are a petro-chemist it is virtually impossible to be sure of the actual compound by reading the label on that plastic bottle. From what I have found, virtually all multi-grade oils contain detergents. The amount varies by refinery and specification. Detergents will probably lessen the life span of your diesel by some degree, particularly if you tend to ignore the factory recommended change interval.

Most marine engine manufacturers insist upon a maximum of 100 hours of operation as the interval and most seem to recommend a single viscosity, straight 30 0r 40 weight.

In any case, if your use is but 50 hours for the season, you are not exempt from frequent changes either. Condensation builds up in crankcases over time and adds moisture to the lubricating oil. Passage through the oil pump, oil filter and its own rapid expansion from internal heat and movement through the tiny oil passages in the block and head quickly emulsify this moisture. Only after a long run have you significantly reduced the minute amount of water built up in the system by heat. The naturally occurring accumulation of acid solids in the filter, from oil breakdown, is diluted and begins re-circulating through the soft bearing surfaces once again.

Winter storage allows quite a good opportunity for condensed water to collect and this oil should be changed at the very first opportunity before launching or running any length of time.


1568 Feb 21, 2002

It has always been my philosophy that if you do nothing else, changing the oil at the beginning and end of the season is a must. I would like to put in a permanent oil change pump and a T fitting at the bottom of the dip stick would facilitate doing it. Please keep us apprised of your progress as well as the specifics for the parts.



1571 Feb 21, 2002


Hansen Marine in Mass has a kit which screws into the oil drain plug and then attached to that fitting is a approx 2í hose with end cap. To drain the oil you open the cap and capture oil. It saves having to access the oil drain plug to change oil.

Phil #116

1572 Feb 21, 2002


I have a W-30 and have to drain the oil through the dipstick holder. Is there an oil drain plug someplace that I donít know about?


1573 Feb 22, 2002

I do and always have as you do, Howard. Pump it out thru the dipstick, a brief but miserable little job. I donít understand Philís explanation of how Hansenís modification works, but......Iíd like to and probably get that kit!

Doug Smith -59K

1574 Feb 22, 2002 8:50am

The new oil pan on my W-30, even the original pan, contained a standard NPT drain plug and was almost impossible to reach previous to my overhaul. At that time I just extended it with a reinforced, high-pressure, neoprene hose with two threaded end fittings. The advantage is not only access but larger diameter capacity than the slender dipstick access tube and the ability to insure that last cup of fouled oil is actually removed.

Several, mounted, oil-drain pump kits are commercially available, the one I seem to find favor with is optional equipment for Perkins. Its small and efficient and can be mounted to a "T" off the drain plug and bolted to a block fitting on the W-30.

Paul, Sea Quill #29K

1575 Feb 22, 2002


I should note: even as the W-30 has what appears to be quite adequate crankcase breathing I have experienced, now twice, the creation of oil leaks due to unfortunate oil changing procedures.

Always open the oil filler cap before suction pumping out the sump! I have had to change various gaskets (in two customers engines) after the suction caused the gaskets to be drawn inward and ruptured. Both of these were Perkins 4-108 engines by the way, each equipped with oil changer pumps.

Paul, Sea Quill # 29K

1576 Feb 22, 2002


I purchased from Hansen or Westerbeke a fitting that is installed where the oil drain plug was. The fitting has attached to it a 2í hose which ends in a plug which can be unscrewed to drain the oil. Essentially it moves your oil drain plug from the bottom of the oil pan to the end of a 2í tube. Opening the plug at the end of the tube and placing a container under it allows easier draining of the oil. I also open the oil filler cap so no vacuum is developed in the engine during draining.


1594 Feb 25, 2002

My Westerbeke 30ís dipstick tube is dismountable at the base. I recommend emptying the used oil that way, rather than pumping through the dipstick, at least once every 3 oil changes, or whenever the sediments are heavy. Is there a special advantage to your special fitting, except that it may reduce the mess which occurs unplugging the dipstick tube? Bert dF

1594 Feb 25, 2002

My Westerbeke 30ís dipstick tube is dismountable at the base. I recommend emptying the used oil that way, rather than pumping through the dipstick, at least once every 3 oil changes, or whenever the sediments are heavy. Is there a special advantage to your special fitting, except that it may reduce the mess which occurs unplugging the dipstick tube? Bert dF