Re: 1986 Rinker 180 c/w 3.7l motor
I have an '89 3.7L, a motor that has sparked a lot of debate on this forum. Mercruiser made this engine and the original design was Ford. It has some unique design issues, but for the most part is considered very mechanically dependable. The earlier versions were known as 470's, you can search this forum or Google for "470" or "3.7L" and find alot of info. Most of the controversy is related to its charging and cooling systems. The engine is a 224 cubic inch inline 4 cylinder, which makes for a large bore and stroke by 4 cyclinder standards, a real torque monster.<br /><br />As for the charging system...the original was a stator running off the crank shaft. It constantly provides charge and uses a water cooled voltage regulator to regulate charge to the battery. It is a poorly designed system and most have been replaced with a normal alternator system. I did mine 3 years ago, it's easy and costs under $400 (don't pay more for the conversion kit). Should have done it years ago. Here's the scoop...<br />
http://www.jimthompson.net/boating/Electronics/Voltage_regulator.htm <br />Here's a site that deals a lot of 3.7L parts<br />
http://ebasicpower.american-data.ne...GY&Store_Code=ebasicpower&Category_Code=MER6A <br /><br />Note: Conversion kits vary depending on whether you have power steering or not.<br /><br />The cooling system...all the 3.7 used a closed cooling system. Early version used a 3 inch exchanger which proved marginal, later it was changed to the 4 inch variety to provide better colling capacity. Both depend significantly on the lower unit (raw water) pump/impeller to drive water to the exchanger. As a result, regular maintenance on the impeller is important (I change mine every other year). Also, the circulating pump (engine coolant) is driven directly of the cam shaft, which is not an issue until the seals wear. Depending on the design of the boat, this can be done easily without engine removal, or may require removal. I have never had to deal with this, but mine can be done with engine in the boat. Here's the scoop on this issue:<br />
http://www.sterndrives.com/470information/470coolantleakrepair.html <br /><br />Overall, aside from the original charging system and ruining the impeller as a novice and having cooling problems (ran engine without muffs), I have had great dependability from this engine, it's simple and easy to work on, and gets phenomenal fuel economy. Others, however recognize it as a rogue, different than the standard Mercruiser 4, 6 or 8 cyclinder engine.
