Sunday, July 1, 2012

Engine Part 1 of many...

It has been much, much too long since I've last updated this blog.  Sorry, we get caught with so many projects and trying to update the blog at the same time is very time consuming.  I enjoy it because it chronicles everything we have ever done on Moitessier, but the act of sitting down and writing can very easily be put off when you are caught up in other projects.  Many apologies!  Our engine is finally sitting inside the boat.  About a month and a half ago, we hired out the yard to make engine mounts adaptors so that the new engine can fit on the old stringers.  The way the yard accomplished this was to first try to get the engine to sit where it needed to sit by hanging it from a crane and aligning it to the shaft.  Once the engine was floating and aligned to the shaft, they then took the measurements required to make the new mounts.  John, the owner of our yard, came onto the boat, and aligned the engine in a matter of, what seemed to me, a few minutes.  The way he did it was impressive to say the least.  What he did was dangle the engine into our engine room, using his crane, and sat there as he positioned the transmission to the shaft coupling.  As he eyed it, he shouted out commands to the crane operator to either lift the engine up half an inch up or down to get it be exactly as he wanted.  This was done through him relaying a message to his assistant who then shouted out via our portlight to the crane operator.  He also fine tuned it using a chain adjuster and ratchet straps.  When he finally got the engine to were he wanted it in relation to the coupler, .004 of an inch , he simply clamped the two together using lock jaws.  He then took measurements of the engine in relation to our stringers and measured to make new engine mounts to accommodate for the difference in space.  Had we gone a different route, we would've had to modify the entire engine bed and do some fiberglass work to build up to the appropriate amount for where the new engine sits.  This would've been very sloppy and would've taken us quite some time. In a matter of hours, he fabricated some pretty nice lookin' steel mounts that compensates for our new engine's smaller size.  

John adjusting the engine via crane

Shaft coupler lockjawed to transmission

New mounts! Sitting on Polyflex plastic isolators.
In the meantime, we had to get a custom lift muffler made.  We had been searching for weeks for a lift muffler that would fit within the existing space in relation to the our new engine, Apparently lift mufflers only come standard in sizes and configurations that are right for every other boat but ours.  There were a list of problems that made for finding an off the shelf muffler next to impossible that lead to us having to get yet another thing custom made, much to our chagrin.

The first major obstacle was finding a lift muffler that had an inlet and outlet that could accommodate our shaft running down the middle of our boat.  Because most off the shelf lift mufflers have the inlet and outlet on their centerline, and our shaft runs right above the centerline, we didn't have the clearance necessary to accommodate the exhaust hose. This meant that we needed to have a box with the inlet and outlet to one side that was also large enough to hold the water in the 20' long exhaust run. We had looked into Vetus Water-locks,  but the largest ones they had that could accommodate a 3" exhaust only held up to 5 gallons.  We have a 20' exhaust run, that's right 20' as our engine sits pretty much amidship, so it really had to be a far bigger than that.  The sole purpose of a lift muffler is that it needs to be large enough to hold the volume of water in the exhaust hose so that when the engine shuts off, the exhaust water does not back siphon into your engine.  Using the volume of a cylinder (of the exhaust hose) formula, pi x radius squared x height, we were able to figure out that the lift muffler box needed to hold about 7 gallons of water.  We added to that an extra 20% buffer as is recommended, and though the hose is not always completely filled with water, these are the recommended guidelines in case of rough seas.  We didn't want to risk every getting water into the engine, better to err on the side of caution.

My technical drawings to Centek..

The process of the designing the custom box started with making up a template.  After guesstimating an approximate size, we built a template out of poster board and placed it in the space.  From there, we figured out where the the inlet and outlet would be positioned as well as at what angles they needed to bend at so that when we connected the 3" hardwalled exhaust hose, we wouldn't have to do too much wrestling as we've learned that hose is really hard to bend and manipulate.  From there, we drafted up a couple of technical drawings with measurements for where everything was supposed to be and the exact angles they were to be at and sent them over to Centek Industries.  After reviewing the drawings and discussing your needs, they draw up their own technical drawing and get your final approval and send it out to be fabricated.   We finally received the box this week, a month and a half after initial contact with the company.  I can't say much for their customer service as the salesperson I worked with was really, really frustrating to deal with as he never got back to you for days on end and  even then it was because I would call and follow up/harass him.   I'd hate to complain but it really was the worst customer service I have ever dealt with, but on the brighter side the box did come out exactly as requested. We just have to keep our fingers crossed and hope that it fits, which won't be until we lift the engine out again, and put in the new box in (we're thinking of bolting it to a piece of starboard that would be attached to the old wooden/fiberglass stringers. Before all of that, the shaft and coupler need to go to a machine shop to be faced and mated before the engine can set down for its final fit. Then, it would be a matter of  bolting the thing down, installing the exhaust system, and doing some wiring.  We have the control panel and wiring harness mounted and run, and Frank was able to make a shelf out of the preexisting cutout to our old control panel so it all looks cohesive and not sloppy. We are looking to hook our alternator up to an external regulator as well but thats for later. More to come on the engine project in future posts.....

Centek's Technical drawing to us...
The finished lift muffeler
Frank's new shelf...can't even tell that
it used to be a control panel

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