Re-engining "Collage", 1980 Mirage 30
(Photos follow text)
The decision to replace the original Yanmar 2QM20
in Collage followed several years of increasing difficulty in obtaining
spares down here in Cornwall. Corrosion problems both superficial
and with bolt threads when anything was stripped down, a worn gearbox,
deteriorating engine mountings, and worn ancillary gear such as
Morse controls, gradual power loss, etc. The final straw, (in September
2007), was an acute overheating problem as we exited the Helford
River in the face of the biggest Spring tide of the year, with absolutely
no wind, and ended up going backwards through the moorings whilst
trying to anchor. The cause was a dissecting aneurysm in a rubber
raw water hose, causing a complete block, which blew the hose off
its spigot, filled the engine compartment with steam and fogged
up my glasses when I took the steps off. This was nothing to do
with the age of the engine, but led to a total collapse in confidence
and a serious examination of the state of Collage's machinery.
The plan was to replace just the engine, wiring and controls, as
the fuel tank and lines, prop shaft, stern gland and prop appeared
to be fine. - How optimistic this was will become apparent. The
choice of replacement was locally determined by the availability
of service. Discussion down the sailing club soon rapidly narrowed
the choice to one independent engineer, - Simon Caddy, - who was
happy to work with the owner and do as much or as little work and
handholding as required. Whereas the large, marina-based firms wanted
the whole job and had reputations for grossly exceeding estimates.
Simon measured up and recommended a Beta as an engine designed for
re-engining a variety of boats, (with a corresponding variety of
options), and smaller and lighter than the existing Yanmar. The
engine was ordered. - A Beta 20, with 70 amp alternator and polyvee
belt drive, high rise, cross-over exhaust injection bend, shallow
sump and special feet, and it was agreed that I would get on with
stripping all its connections to the boat.
The wiring was easy, the armoured diesel line was removed at the
engine and temporarily sealed and the control cables released. In
an attempt to slow down the superficial corrosion on the Yanmar,
I had been merrily lathering it in fogging oil for years, - which
meant all bolts, exhaust clamps, etc. including the rigid gearbox/prop
shaft flange bolts undid easily, (but I appeared to have dissolved
the flexible engine mounts). The engine was fastened down by coach
screws, 2 per foot, on two glassed-in timber engine bearers. These
were difficult to remove, but I interpreted this as a tribute to
the soundness of the underlying wood. The bearers were not accurately
aligned fore and aft and the mountings were at varying depths and
angles in the underlying GRP.
The liberated engine was lifted by the yard crane, (driven with
aplomb by an apparent 12 year old), using a heavy rope sling with
an attached dangling line to control "swing". We were
able to steer it out of the cockpit floor opening by angling it
slightly diagonally and down at the gearbox end and had no problems.
The crane driver dropped it to within one cm of the floor of Simon's
van and we pushed it in. I got Simon involved at this stage as I
figured he was insured. I got £400 for the old Yanmar from
him and it is now in an old open work boat.
The prop shaft had to be removed to fit the new gearbox/shaft mounting
flange, by withdrawing it into the cabin via the companionway steps.
The prop was removed by the engineer with great difficulty, but
the Woodruff key was totally cold-welded to the shaft and had to
be ground down to allow passage through the cutlass bearing, stern
tube and stern gland, essentially ruining the shaft for future use.
A new prop shaft with new flange was immediately refitted, as it
formed the reference point for the engine alignment. Mysterious
strings and pencil lines on the engine bearers led to a decision
to make new angle-iron engine mounts fitted with athwart ship bolts
through the bearers, rather than the original vertical carriage
screws. Mounts were cut to length and sent off for heavy galvanising.
Meantime, I ground down the uneven GRP on top of the bearers, levelled
it and re-glassed it flat, to allow the mounts to bed down snugly
on Sikaflex.
For the first time in its life, the empty engine compartment was
now available for thorough degreasing and cleaning and the remnants
of the old oil-soaked foam soundproofing were removed and partially
replaced with shiny new foil-covered sheets. The exposed engine
bearers and floor were painted in dazzling white bilge paint. On
return the following day, I noticed a slight pink diesel stain below
the side panel between the engine compartment and the starboard
cockpit locker containing the diesel tank. On removing the panel,
I saw that the locker contained about ten gallons of loose and liberated
diesel brimming at the edge of the lower lip of the locker and just
beginning to trickle over. Squatting in the engine compartment,
I used the hand bilge pump from the inflatable to transfer the fuel
into a bucket, lowered the bucket over the side to the ground, climbed
off the boat and tipped the diesel into a plastic can. Many panicky
repeats of this technique cleared the locker diesel, but it now
was apparent that the remaining fuel in the tank was dripping off
the shelf supporting the tank. The tank was drained into the bucket
via the diesel line from the tank tap and several trips later, the
drip stopped. So I ripped the tank out. Close examination revealed
a series of corroded pinholes along the vertical welded seam that
had been tight up again the hull and therefore invisible when the
tank was in situ. Why it suddenly decided to give up, I don't know.
Faced with a decision to repair or replace, I decided to go for
future proofing and fit a new plastic tank from Tek-Tanks, easy
to access, easy to replace. On receiving the tank, I constructed
a deep tray in epoxied marine ply, bolted to the original shelf,
to support it, the tank being retained by the tray sides and straps.
Next problem, - the original deck filler had a 1&3/4'' tail,
the new tank a 38mm filler hose attachment. So, the old deck filler
was removed, the hole glassed in and gel coated and then a new hole
for a new filler cut with a hole saw. A breather pipe was fitted
to the new tank and diesel hose run from the tank via an on/off
cock to a new Delphi fuel filter from eBay. - Sounds simple, but
the differing spigot and thread sizes needed to run from tank to
engine through cock and filter needed several visits to a local
hydraulic company, Lucas diesel agents, etc., but, because the engine
bay was empty, I could squat and work inside it. All lines were
secured using mounting blocks and cable ties, (Merlin Motorsport.co.uk).
At this point, I went to Australia for six weeks to see my son.
By the time I returned, Simon had done his stuff and there was a
brand new, bright red Beta engine sitting on its beds attached to
the prop shaft via a flexible coupling and driving a brand-new prop.
All I had to do was join all the inputs and outputs and we were
there. The Beta engine comes with a selection of instrument panel
options, but I had gone for the miserly non-waterproof version which
was small enough to fit in the old recess in the cockpit side. A
new plywood panel, liberally coated in epoxy followed by twin pack
polyurethane, was made up to take the plastic instrument panel,
bedded in silicon and bolted in place. The recess was then covered
by a hinged acrylic flap closing on to neoprene tape. I did this
thoroughly as stories abound of wet panels refusing to disengage
the starter motor or refusing to stop the engine when requested.
The wiring loom supplied was plenty long enough, but the pre-fitted
plug required the drilling of two largish holes through a bulkhead
and an engine bay panel, - both of which were then filled and grommeted
using the hole-saw waste. The plug then simply pushed in to the
corresponding engine fitting, but a trick of the trade, suggested
by the ever-helpful Simon, was to peel back the rubber seals on
both male and female connectors, lard them with Vaseline, push firmly
together and then secure with a single cable tie around both before
rolling the seals back in place, - apparently some have vibrated
adrift in the past. The loom was secured along its run using mounting
blocks and cable ties, (Merlin Motorsport), and supported with spiral
binding where appropriate. The engine-to-anode leads were reconnected
and the non-conducting prop shaft flexible coupling was bridged
using two made-up straps attached to two of the bolts. A friend
of mine in the Wash recently dissolved both his shaft anode and
a good deal of his prop by not doing this.
Working system-by-system, the next simple job I had naively assigned
to myself was to fit the ball valve and engine intake filter to
the original through-hull, join that to the intake on the engine
raw water pump and then fit the exhaust. A faint memory of a "technical
officer's note" in the Snapdragon and Mirage journal began
to itch, grew into a scratch and , remembering that corrosion, like
rust, never sleeps, I got completely sidetracked into checking and
renewing a total of four through-hulls, including the toilet, and
fitting new ball valves in place of the old gate-valves. The sexy
and quickest way to remove the originals, according to Simon, -
"you'll end up doing this, so do it first", - is to use
an angle grinder to stroke away the metal of the outside flange
of the through-hull, until left with an almost foil thickness at
the junction of flange and the tube through the hull, break away
the flange and drift the through-hull and fitting into the boat
interior. Quick but scary. All new DZR skin fittings and ball valves
were bedded in Sikaflex 291 (not a leak on launching!). So I could
then get back to engine refitting.
The Beta engine is run before dispatch and comes with a temporary
copper pipe fitted between the engine and exhaust bend. This is
removed and you have to sort-out your own anti-siphon loop. My previous
Yanmar had a simple loop up to the cockpit floor, but this time
I took reinforced heater hose through into the port locker and fitted
a Vetus anti-siphon loop as high as possible, returning with the
same hose to the exhaust bend. Both these pipes were covered in
Cooltek thermal sleeve (Merlin motorsport).
Exhaust tubing was fitted from the exhaust bend to the original
water lock, (and refitted, with a steeper down-going slope, when
Simon saw it), and from the water lock into the port cockpit locker
in a loop as high as possible, joining the original exhaust pipe
with a Vetus angled connector.
Having read the Italian English instructions, I was desperate not
to fit the controls and cables, but Simon refused to let me off.
However, he did relent sufficiently to demonstrate on another engine
he was fitting, using Tippex dots on the gear change lever and adjacent
engine to clearly show fully engaged ahead, neutral and reverse.
As it turned out, fitting the control lever was the pits, complicated
by the available space to 'lift' the knob to move from neutral and
'pull out' to disengage the gears for starting, rather than any
complex adjustments for cable travel. The existing hole for the
old lever was covered with my usual marine ply panel (epoxied and
varnished), bedded and bolted on silicon for future removal, and
cut to take the new assembly. Fitting the cables as the last job
after the engine siphonic tubing, exhaust, wiring and diesel lines
allowed the best possible run to be obtained. Any cable approaching
anything potentially hot was covered with Cooltek sleeving.
On being invited to inspect, Simon queried "Where's the diesel
return line?" - The Yanmar didn't have one, - so I had to run
a loop from the engine down to the bilge alongside the starboard
engine side and up to the attachment of the breather pipe to the
tank and an asymmetric T-piece fitted there. After bleeding the
diesel (I didn't know the efficacy of the manual lift-pump depends
on the cam position until it was pointed out) and attaching a hose
and water reservoir to the engine water intake, the engine was started
(first time) checked for leaks, run up to temperature, and coolant
level checked and topped.
After antifouling and launching two weeks later, there was a slight
trickle from the (old type) stern gland that resolved on greasing.
Engine trials involved running and warming-up on the swinging mooring
using the Beta check-list. The most disconcerting change from the
old Yanmar is how quiet the new Beta is and how fast it revs. At
start up, it sounds like a transit van rather than the old "donk,
donk" I'm used to, and I tended at first to under rev it. I
immediately noticed the markedly improved and precise control of
what is a relatively heavy bilge-keeler when picking up the mooring,
coming alongside, etc. Sea trials involve running the engine at
stepped increases in revs (each 15-20 minutes) until flat out -
when my wife and I tore round the Carrick Roads in our respectable
Mirage 30, giggling. On completion of these, as the engine and alignment
were fine, Simon signed off the installation and commission check
list, the engine came under Beta's warranty and the job was complete.
It has not been the best season to enjoy Cornish cruising, but what
little we have snatched between rainstorms has been superb, helped
by the removal of niggling doubt about Collage's power. I'm convinced
she sails better with the reduced weight, but this might well be
self-delusional.
Using an independent engineer allows the defining of the skilled
aspects of the job, such as engine alignment, fabricating prop shafts,
etc. and access to specialised tools, pullers, etc. that the average
owner would need once or twice in a lifetime. In turn, this delineates
the time-consuming, relatively unskilled parts that any practical
owner can carry out and have the satisfaction of simultaneously
saving large amounts of money on labour charges. Any article I have
read and my own experience indicates that any major boat job will
have hidden snags and unforeseen problems, which are interesting
to consider and solve if you know you are not constrained by soaring
labour costs, but simply spending your own time. Also, you have
access to a local source of information, tips and advice whenever
you get stuck, - something I exploited shamelessly, - and someone
who knows where to obtain parts locally and nationally (or will
obtain them for you). As a not-insignificant bonus, you end up totally
familiar with your boat's mechanicals.
Costs (ex VAT) in £s:-
Engine. 3355
Engine mounts. 252
Prop shaft. 281
Prop. 186
Fuel system. 234
Cooling system. 174
Exhaust. 68
Controls. 133
Soundproofing. 145
Batteries. 102
Through hulls, etc. 203
Labour. (25/hour) 1327
Yard charges. 27
TOTAL 6487
Suppliers:-
Beta Marine Limited. www.betamarine.co.uk
Mylor Chandlery. www.mylorchandery.co.uk
Simon Caddy Marine Engineers. caddymarine@tiscali.co.uk
ASAP supplies (soundproofing). www.asap-supplies.com
Merlin motorsport. www.MerlinMotorsport.co.uk
Tektanks. www.tek-tanks.com
Armada marine hydraulics. sales@armadamh.co.uk
John Barker.
|