Friday, August 3, 2012

Prologue


Our 2010 cruising year was taken up with mostly maintenance, with the aforementioned exhaust and injector pump problems consuming the majority of the time.  In between those maintenance tasks we did manage to squeeze in a three week trip to the Gulf Islands, during which our port engine would occasionally leave a trail of white smoke, overheat at any speed above about 1300 rpm and developed the injector pump fuel leak that sidelined us for the rest of the year.  We could go into more details here, but that's already in another book!

We were certain of one thing - that we had squeezed the last pleasure trip out of our Perkins engines.  The white smoke hinted strongly at either a blown head gasket, worn rings or burnt valves - none of which would be an easy repair or even possible given the scarcity of parts for this particular model of engine.  The engines were 40 years old and had already been obsolete long enough that replacement parts were not only no longer being made, they just couldn't be found anywhere.

That fall I began doing research on repower projects in general, as well as on likely candidate engines to use as replacements.  If at all possible we wanted to retain our existing running gear - shafts, propellers and transmissions.  Those items alone could cost as much as the engines themselves to replace.  This meant I'd want to find engines that not only had a similar horsepower rating to the Perkins, but that also developed that horsepower at around the same rpm.  The Perkins were rated as having 225 horsepower at 2500 rpm, so right away that ruled out engines that developed their horsepower at much higher or lower rpm, as that would require different gear ratio transmissions and/or propellers.


Marine diesel engines are expensive; brand new from the factory typical engines to meet our requirements would cost in the neighborhood of $25,000 to $35,000 apiece - and that doesn't include installation costs.  We hoped to find either RTO (Running Take Outs) engines with low hours, or get rebuilt engines to reduce our cost.  Both Craigslist and Ebay became regular shopping sites, and early on I found a pair of John Deere 6 cylinder engines that were to be removed from a fishing boat in Westport at the end of the season.  Although they had higher hours on them than I'd like, the top ends had recently been rebuilt.  The owner, as a matter of course, routinely replaced the engines every 5 years or so.  I was invited to not only come hear them run, but to go along on a fishing expedition for the day.  I didn't, but I did investigate John Deere engines further and discovered they were very highly rated and in general trouble free.  I shopped around to see if I could find some rebuilt ones, and discovered that rebuilts seldom found their way to the market.  If one was ever rebuilt, it was so the owner could keep it for himself for another 20 years.


The John Deeres were still in use, and I wasn't real keen on engines from a charter fishing boat no matter how well maintained as they put on at least 2000 or 3000 engine hours per year.  So, my shopping and research next led me to consider the Cummins 6B series of engines.  They are also highly regarded, and definitely plentiful as they're not only used widely in marine applications but are also used for industrial purposes and in Dodge Ram pickup trucks.  The 6B engine displaces 5.9 liters, and can range in horsepower from 180 to 370 - the more air and fuel that can be shoved through it, the more power they have and, not coincidentally, the quicker they wear out.  We focused on the 210 and 250hp models as likely candidates for us.  They have the reputation of being more 'bullet-proof', serving 15,000 to 20,000 hours or more without a rebuild.  In recreational use that is a lifetime.  Sometime early on in our Cummins research a pair of used 250hp engines showed up on Ebay.  They had around 1100 hours on them and were going to be removed from a boat to upgrade to larger engines.  They were located in Florida, about an hour's drive south of my brother Jim's place.  Jim went down there to take a look at them, and even sent back a video clip of them starting up and running.  They had a reserve price of $10,000 for the pair, and in hindsight I probably should have bid but we weren't quite ready to take the plunge.


By fall of 2010 I had located a shop, also in Florida, that had quite a business rebuilding these engines, and they also had a supply of the 210hp models that had been removed from military boats.  Their procedure was to test these engines on a dynamometer - if they achieved their rated horsepower and rpm without a lot of smoke or blow-by,  they would just clean them up, service and repaint them and sell them as used with unknown hours for $6000 apiece.  Those that had problems with the dyno test would be rebuilt and would sell for $9000.  They also offered a rebuilt 250hp version for $10,000.  The rebuilt engines were offered with a 6 month warranty.  Locally, I could get the same engines for about $15,000 to $18,000 apiece with a two year warranty.  I still wanted to do a little more research as well as some measuring in our engine room, but considering the cost savings versus some risk of a shorter warranty period and a provider on the other side of the country we thought that risk would be worth it.  This seemed to be the way we would go for our new engines.


We first conjured up an ambitious plan of repowering through the winter/spring of 2010/2011, with all being ready for the 2011 boating season.  That didn't happen.  Turns out it's cold, rainy and dark through those months, and I probably wasn't quite to Stage 5 Acceptance yet either.  Instead, we decided that we should fix the leaky injector pump in the port Perkins engine, as it would be a bit easier to sell those engines if they were both in running condition, albeit with their other existing problems.  This we managed to do, ultimately with the 69 cent O ring mentioned previously.  We made a sea trial run in Lake Washington in March of 2011, and both engines performed well with even the port engine overheating problem at least partially resolved, although it would still billow out the white smoke at certain throttle settings.  The blown head gasket / worn rings / burnt valve problem was still with us but at least they were both in running condition.  This was the last trip the Potentate made under Perkins power; in April we began disconnecting them in preparation for their removal.


Since we would not be changing our shafts or propellers we planned on doing the engine exchange with the boat in the water.  We are moored at Washington Boat Center in Lake Union, adjacent to Gallery Marine Services.  They have a hydraulic crane capable of lifting our engines, and the boat could be walked/poled from our slip to their work area, so the logistics were quite convenient.  We planned to do as much work as we could ourselves to keep costs down; and when I say we I'm referring to Erin's dad Ray Ames and myself.  Ray is a retired tool & die maker and machinist as well as an excellent woodworking hobbyist and is well equipped to make and shape all sorts of things of metal or wood.  As for myself, I'm the other member of the team.


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