Repowering Anju - Part 2 "The Exhausting Part"
11th November 2007- 11th January 2008
All that remained to be completed on our
re-powering project was design and installation of the exhaust
system. After our difference of opinion with our mechanic on
this subject, we'd decided to carry out this work
ourselves. The design he'd intended to install may well
have worked but, cautious as ever, Team Anju decided to install an exhaust
system with a dry riser, to ensure that our new engine wouldn't slowly be
killed by excessive back pressure.
We already had the muffler, which in any case hadn't fitted in the spot where the mechanic assured us it would go. Our new design meant that the hot gas and cooling water would leave the engine separately, to be reunited just before the muffler, which was now to be positioned much higher in the engine room. Both of these changes would have a positive effect on the back pressure situation.
Once the location of the muffler was decided, Harry set to work to fabricate the dry riser to carry the hot air to the muffler. Due to its high temperature, this would need to be manufactured of steel pipe with a flexible stainless section, to allow for engine vibration. Once the flanged pipes were manufactured, they were fixed to the engine and supported from the engine room with rubber exhaust hangers.
Now the huge muffler could finally be secured in
position. The hot exhaust gas and cooling water would be
mixed in the muffler, meaning that the temperature of the exhaust from that
point out of the boat would be much cooler.
The exhaust piping from the muffler to the outlet on the side of the boat would be fabricated of fibreglass exhaust pipe, with special angled pieces being glassed-in, to allow for the twists and turns that it would need to make. We got hold of the pipe and connectors, mocked everything up and cut the required pieces to size and prepared to fibreglass them together. Then, we decided to change the whole design to incorporate a check valve!!
|Although probably not strictly necessary, we decided to install the check valve to ensure that no water could flow back towards the engine if we were heeled over at sea. Many people told us it wasn't needed as our exhaust piping went high above the water line, which should prevent the ingress of water but as usual our attitude was "better safe than sorry". Of course a check valve for exhaust piping three inches in diameter was quite a hefty thing to find space for but after ensuring that we could make it fit, we went ahead and ordered one.|
Cutting the fibreglass exhaust piping to size.......
checking the check valve.
The check valve duly arrived but Phil was
concerned when he inspected it. Sure enough the
pipes into and out of the valve were three inches in diameter, the rubber
check flap was three inches in diameter but behind that, the hole though
which the gas and water mix would pass was only an inch and three quarters
in diameter. This didn't seem to make any sense, surely
this would increase the back pressure on the engine as the out-flowing
exhaust mix would have to pass through this severe
restriction. On calling the manufacturers, a
replacement was somewhat reluctantly shipped to us, with a certain amount of
disbelief on their part.
Next day the replacement valve was in our hands and was exactly the same as the previous one we'd had, despite assurances that it had been quality checked prior to despatch. We were back on the phone again, by now beginning to doubt our own sanity as the engineer on the other end talked us step by step through how to measure the size of a hole. "You'll see it is two and three quarter inches in diameter as specified", we were told. Not if the inches on our tape measure were the same as the inches on the engineer's tape measure, it wasn't!
The engineer even rang us back a little later, just to double check we knew how to measure. Eventually we gave him the batch number of the two check valves, both manufactured on the same day and he headed off to his warehouse.......Some time later we received another call. It seemed that particular day at the check-valve manufacturing plant had not been a good one and all the valves with that batch number were, like the two we had received, incorrectly manufactured. A new one from a different batch, personally measured by the engineer, was on its way to us. By now we were losing faith that anything we would ever order for the boat would be delivered right first time!
Check valve finally installed.
Everything was mocked up again, so we could work
out where to cut the three inch hole in the side of the
boat. Making big holes in the boat was a pretty serious
undertaking and we had to be sure we got it in the right
The through-hull fitting was installed with a clam-shell cover on the outside of the hull. Finally it was the moment of truth, time to turn the key and see if our new engine would work! First we had to improvise cooling water flow into the heat exchanger using a hose pipe. The next step in the handbook was to crank the engine a couple of times to get the oil around all its parts before starting it. "Crank it with your finger on the stop button", was the instruction. No instruction was given, however, on what to do if your over-eager new engine started first time, even when you had your finger on the stop button. After all the hard work it was such a relief to hear the sweet sound of the engine starting up!
|Of course we couldn't test it out properly until we were back in the water but it was very reassuring to hear it run. We couldn't launch until we re-installed the hydraulic steering system, so that was our final pre-launch project.|
As we'd had no choice but to rip the steering
system out of the cockpit to make the new soft-patch, we decided to take the
opportunity to optimise the steering set-up. The hydraulic pump
would now be located in a specially fabricated aluminium box in the cockpit,
Harry's work again. The steering position would be moved
over to the port side of the cockpit, instead of the centre and we would
change from the existing 3 foot diameter wheel, to a smaller one, making it
much easier to move around in the cramped cockpit. The three
foot diameter wheel had been needed originally when we'd had cable steering
but now with hydraulic, a joy-stick would have been enough to do the job.
On arrival, the new steering wheel wouldn't fit on the existing, naturally non-standard, spindle on the binnacle and our friend John came to our rescue yet again, machining everything to fit in his machine shop.
New steering set up
Hydraulics were another unknown field to us but
the hydraulic pipes were cut to the correct new position and re-connected,
ensuring everything stayed spotlessly clean. New pipes had
to be manufactured to connect the autopilot pump in its new position, so the
local hydraulics company's expert was called in and the pipes made on site.
Next we needed to fill the system with new hydraulic oil and it took much phoning around to find the correct viscosity of oil for our system, which used a much lighter oil than the local standard. Another road trip to collect the barrel of oil and it was time to re-fill the system, ready for bleeding out of the air. The oil was poured into the top reservoir in the cockpit and then began to flow back out into the engine room through the new hoses manufactured by the expert! Aargh!
Back came the expert to make the hoses fit properly, the system was bled and seemed to work fine. It was time to hit the water!
By now Christmas was fast approaching and our
yard crew arrived in the travel lift in festive spirit, complete with Santa
Saying we were nervous would have been a major understatement. Were the hull repairs good? Would the dripless stern fitting actually be dripless in water? Would the new engine run? Would the steering work? Countless other worries ran through our minds.
Anju, in true antipodean style, had no worries, entered the water like a true lady and took to water again without a hitch. She must have been happy to be back in her element after ten months ashore!
We were glad to be in the water for Christmas
and proudly put up our festive lights. It was a novelty for us
to spend Christmas away from the UK. Needless to say,
Christmas didn't turn out to be all play, as we laboured for five days,
trying to get the on-board heads, or toilet, working. The
system was practically all new but stubbornly refused to flush
properly. Of course when something is almost all new the
fault could lie anywhere, so the whole system was repeatedly stripped down,
checked out and put back together again but persisted in its refusal to
function properly. After three days of this labour, we
were still unable to get it working and Christmas Day found us spending yet
another unpleasant morning disassembling the toilet again before we were
able to enjoy the delicious pot-luck Christmas Dinner in the
Blow don't suck Captain!
Finally on the fifth day, we found
problem. A Y-valve, used to direct the water from the
toilet either to the holding tank or overboard, depending on whether we were
at out at sea, was allowing air to sneakily leak into the system but showing no
visible signs of a leak. Testing was carried out by the
Captain bravely blowing into the valve to check for air leaks - better the
Captain than anyone else, yeuch!
Next we realised that our on-board batteries were no longer up to par and although working fine with constant shore power to charge them, we were concerned about what would happen when we went to anchor. After more testing we decided to go ahead and replace them whilst we were still on the dock. This proved much easier than the previous time we'd done this from the dinghy, whilst at anchor in Grenada.
It was almost time to provision the boat and
head to the Bahamas for some much needed rest and fun when we suddenly
realised that our fridge wasn't working properly and was running constantly,
which would drain our new batteries at anchor in no time at
all. Back to the marina office we headed to order a new
fridge. We were greeted by Crystal with, "Now you
have practically a new boat wrapped around an old stove - it's the only
thing you haven't changed yet!" Give it time!
Finally after many engine trials we decided we were ready. After making a last provisioning run, the camper was cleaned and prepared for storage and we headed out for a couple of nights on the hook, anchored just off the marina, to get re-acclimatised to the cruising life. The supplies were all aboard, the weather looked promising and we were ready to go......then we got the call from the UK that we were needed at home due to serious illness in the family.........
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