had decided that water
is a much better lubricant than the nice engine oil
I was feeding it. It also has a noisy gearbox
that the surveyor
felt this was due to a worn bearing. To get at the gearbox
requires sliding the engine forward. I am in Croatia
and it is very difficult to find mechanics I would trust with an engine rebuild
where it is not possible to supervise the work.
I am still exploring the possibility of replacing the head gasket
(hopefully this is the problem rather than a cracked cylinder head
) or even adding a sealant
(steel seal) to the water
as a stop gap measure. My preference is to fit a new engine as I am likely to be in the south pacific
in a few years and want something ultra reliable.
The existing engine is a Nanni 5.280 62 hp model which is no longer made. I am not sure how well this powered the yacht (LOA 14.56m centre cockpit
aluminium boat Displacement
14.5T) because the Tachometer was reading incorrectly. (I have not managed to locate an optical tachometer yet). The yacht has a Maxiprop and would only do 5 Knots at an indicated 2300 rpm
. I think the 2300 was incorrect, but as it was possible the Maxiprop had been adjusted to too fine a pitch
I was not willing to push the revs higher until I had calibrated the Tachometer.
The Yacht sails
beautifully even in light air, so I rarely motor
and the limited speed under power was not a great problem but now I need to think about a new engine.
My choices, that ,are as follows
A Beta 60 (58Hp)
I think after careful measurement the above three engine will fit. My preference is for a Yanmar 75 but the exhaust
diameter of the existing engine is 60mm and a reasonably long (because it is a centre cockpit) but smooth run. Both Yanmars (54 and 75) specify a 76mm exhaust
. The exising exhast trvels trugh 60mm muffler
hose to a water trap to a swan neck and exits through a 60mm 2m long pipe that goes through a watertight collision
bulkhead and exits above the waterline. It will be difficult to fit 76mm hose in the existing space and very difficult to to increse the diameter of the 2m pipe.
assuming the exhaust system is not upgraded is it still viable to fit the the 75 hp Yanmar (a turbo charged engine) or do I need to drop down to the 54hp Yanmar or is even this unsuitable for the exising exhaust ? Would your advce vary if I can upgrade the flexable hose to 76mm but still leave the 2m pipe at 60mm ?
The Beta 60 only requires a 50mm exhaust but the delivery
time in croatia
is very long and my prefrence is for the Yanmar if it is OK.
What sort of performance can I expect with a 54hp motor
in my boat. I would be quite happy to motor at only 6 or 6.5 Knots but it would be nice to still make some forward progress under motor if my anchor
drags in 50knots of wind
I have emailed the Yanmar dealer here and he has replied that the 75hp should be fine with a 60mm exhaust but goes on to say that excessive backpressure can cause burnt out exhaust valves!
Sorry for so many questions in one post but I have found this forum gives some great advice and I need some of that now.