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Rebuild partsI've received the following information from Ron Benveniste:
Having rebuilt the engine on my 1979 Pearson 32, I found that the only parts I needed to get from a Universal supplier were the complete gasket set (the water pump impeller gasket not included), and if needed the valve camshaft bearings. These bearings as well as the valve guides could also be done by a machine shop at less cost.
Rings: Made by Hastings Part # 6520-std,or 6520-10,-20,-30 for oversize
for larger pistons Price U$ 30.00/set
Items to note: From the people I spoke to, unless the engine is really tired the block will not have to be rebored. Due to dirty oil the crank takes a beating and usually requires grinding. It is important to check the end play at the front with the new bearings as it should be a two thousands clearance. If it is any greater than four thousands it will be difficult to keep the oil pressure at the required levels. To solve this problem you must spray weld the crank. After grinding the crank it is a good idea to have it hardened.
My boat was originally from salt water and had the regular problems. A chemical engineer told me to run the engine up to operating temperature by recirculating the exhaust water mixed with phosphoric acid. At 140-160 degrees the acid reacts with the salt and disolves it. Be sure to remove the thermostat and pinch the bypass hose that leads to the thermostat housing to force all the flow through the block. While the engine was out I painted it with a base coat/Urethane clear coat paint as on cars. It makes it easier to keep clean and the finish is less affected by salt.
Warning about a potential hazard involving the mechanical fuel pumpsAs these work horses get older the diaphram in a mechanical fuel pump wears out and eventually gas will migrate into the crankcase. This is easy to check by pulling the dipstick and smelling for a STRONG odor of gas in the oil. You also might smell an unusally strong odor in the engine compartment. These smells may also be caused by a stuck float in the carb, but it has been my experience that the pump has been the culprit more than not. This condition is very serious and should be checked by a marine mechanic.
The remedy is to replace the mechanical with an electric pump. These pumps are sold in kit form for aprox. $240.00 and include all necessary hardware. In addition to all this it is reccomended a rebuild of the carb. Since fuel pressure is restored to a higher level all the gunk sitting in the bottom of the fuel bowl goes directly into the jets resulting in an extremely rough idle. The mechanic will be taking the carb. off anyway so save some labor $'s and have this repaired at the same time. Thanks for listening.
contributed by firstname.lastname@example.org
Warning about head gaskets
Several years ago the 'aftermarket' head gasket was blowing out. They would last anywhere from a few minutes to many hours. These gaskets are white in color.
For repairing the Atomic 4 you should only use the real Westerbeke GREEN head gaskets; the rest of the aftermarket gaskets seem to be fine. It takes two gaskets for the head.
This is one place that I would not trust your local mechanic. I was told by several, including one major company in Annapolis that the white ones were good. Annapolis NAPA was really good on this and set me on the right track.
contributed by Jim Davis
I just orderd a head gasket from Hansen Marine Engines Inc.. I asked him about the color. He told me that Westerbeke now makes only one gasket in stead of the two. It is of carbon design and only one is needed.
I spoke with Westerbeke about the head gasket. They informed me that a service bulletin was out on the replacement gasket, the number of the bulletin is 223, the part number of the gasket is 263776.
contributed by David Lackovic
Warning about GP DR106 rotors
I've had a report about a bad experience with GP DR106 rotors. Karin Rohman "experienced misfiring, poor power and arcing of the coil."Investigation showed that the rotor "was shorter in length by 1/8 inch." Replacing the GP rotor with an Elchin part cured the problem. Perhaps it was a single bad one, but I pass the information along.
Water pump source
Oberdorfer Water pump impeller: The impeller is 2" diameter, 7/8" wide, with a 1/2" dia. single flat drive. West Marine has a long life Niprene impeller replacement made by Globe, #815, for $15.00, West Marine #241044.
Mechanical fuel pump replacements and rebuild kits:
Old Lyme Marina Inc.
I came across this on an AOL A4 discussion board.
"DEPCO Pump Co. in Clearwater Florida at 1-800-445-1656 sells a brand new water pump for the A4 for $118.00, their model 202M-7 Oberdorfer Unit. Rebuild kits for $20 include impeller, two seals and the gasket."
contributed by Ron Davis
I replaced my Atomic 4 with a Kubota 3 cylinder 25hp diesel. It's made to fit the same engine mountings and space, and has been very reliable. Engine + fitting + exhaust + new fuel tank about $9000 (Canadian)
contributed by Stephan Larsson
Corrosion and Overheating
Regarding your suggestion to keep the engine painted, one of the prime areas for leaks and corrosion is under the cooling passage cover. The bolts leak through their threads and corrode out the side of the block. No amount of Permatex seems to stop the leaking. THERE IS A FIX! Don Moyer sells a kit which replaces the bolts with studs, which are permanently installed in the block using JB epoxy. The cover plate is then installed with washers and nuts. Presto, no leaks.
The #1 Atomic 4 problem is probably overheating, and the #1 diagnostic is to plug or clamp off the bypass hose. This forces all the water through the block, and often results in an engine that suddenly runs cool. The overheating problem can then be isolated to a corroded thermostat housing, a faulty thermostat, or perhaps something else that I haven't found yet. I replaced my thermostat housing ($100+), still overheated, swore a bit, and installed a valve in the bypass line. No more problem - I can make the engine run at whatever temperature I like. Most mechanics don't seem to like the valve fix - they feel that the problem should be fixed. I'm just happy that it went away.
contributed by email@example.com
Thermostat and Hot Water
Thermostat : I have been quoted various prices from $120 to $175 Cdn from advertisers in GAM. I used a Volvo bypass T/S (170F). Only mod reqd was a 1/8" thick gasket to give sufficient clearance since the replacement was deeper. I think cost was about $25US. I used VOLVO PENTA Thermostat kit no. 875781-7.
I can not confirm this is the "best" replacement, I simply gave my old Holley 3-spring unit to a stores person at a Marina with lots of spares and after a long time he reappeared with this. At first sight I thought it was a perfect match but on installation found the flange of the T/S was approx 1/8" above the head gasket face. I cut a new gasket out of 1/8" high pressure steam gasket sheeet and the T/S flange now sat properly on top of the thick gasket. I guess a better method would be to use a 1/8" thick mild steel spacer shaped like a gasket with paper gaskets above and below to complete the seal.
I have used this for about 3 seasons with no problems. Operating temperature is 160 deg F.
Hot water modification : I really like this one! Not my idea unfortunately. Remove the temp sensor and substitute a tee fitting on a short nipple. The temp sensor is replaced in the top tee thread and a hot water valve in the other. Normally when motoring the hot water valve is shut off in case of hose failure. In my case the shutoff is permanently hosed to "Laundry" mixer faucets in the galley and bathroom. I use a Par electric pressure pump to supply cold river water. From a cold engine the water is already hot after 1 min and very hot after 3min. Washing up is now a pleasure! My Oberdorfer uses the thin shoe ( approx 1/8" thick) in the impellor chamber. I find the delivery OK but I understand from DEPCO it could be increased by using the thicker shoe ( approx 1/4") M202-7 versus M202-3. One installation I heard about used a garden hose long enough to reach the cockpit..... makes a great shower.
contributed by Tom Birbeck
A slightly hotter plug
Just a note - Don Moyer has started recommending a slightly hotter plug, Champion RJ12C. This cross-references to Autolite 308.
I am currently using this plug, and it does not seem to get quite as much carbon build-up as the RJ8C.
contributed by David Swanson