[Peter McKibbin]

Will be back at the boat next week Tony, will snap some high rez pics and post them.

Am wondering what regulates the high pressure that the gearbox uses to lower pressure for bearing lubrication.

 

[Peter McKibbin]

Many thanks, Tony, will give the two stroke oil a try until I can find a shop familiar with these pumps.

[Peter McKibbin]

Forgot to add, that CPL numbers are 1247

[Peter McKibbin]

Engine serial numbers are 44548566 and 44558483

Attached is a photo of the engine after it was removed showing what I think is a CAV pump, will be back at the boat in the new year if model and serial numbers are required.

[Peter McKibbin]

I had a similar issue with a 6BTA and found it was a failed gasket between the exhaust manifold water jacket and turbo.

[Peter McKibbin]

Thanks Tony.
Might lose a bit of area due to flange size of units but will try and keep as close to 50″sq as possible.
Certain that a moisture eliminator will improve not just the quantity of air in engine room but quality as well.

[Peter McKibbin]

Found what I was looking for to cover air intakes, they are called Moisture Eliminators.

Use similar on offshore vessels I worked on previously but didn’t know if they were available for smaller applications.

Standard Rectangular Moisture Eliminators

[Peter McKibbin]

Thanks for sharing Tony’s rule of thumb Rob.
So I’ll need a minimum of 125″sq for each 250 HP engine.

Thinking it would be easiest to chop out and rebuild a portion of the rear cockpit and glass over external intake vents.
The new section will be radiused and come out 8″ from the side, into deck area then forward, the existing angled portion will be completely removed.
Opening in new section will face aft which will reduce noise in the cockpit.
4″ lip off the deck to try and reduce water entering cutout, the total cutout area will be 8″ x 16″= 138″sq.

Any suggestions for grill over the opening to stop water and crap entering?
Was thinking an air-con intake screen or similar on the inside.

[Peter McKibbin]

Glad to see you resolved the issue David.
Going the same route with two 6BTA JWAC engines in a new to me boat.
Max I can get is app. 1600 rpm with a huge amount of black smoke.
Traveled from Batam, Indonesia, to Port Klang Malaysia (app. 300 NM) at a painful 1250 RPM.

Using Seamax instruments and exhaust temp was constant at app. 850 deg, not yet wired up boost gauge.
Am thinking that vessel, Baha Cruiser 310 SF, had petrol Volvo’s originally and were changed for 6BTA’s.
Suspect that props were not changed and it is over geared as per article in Tony’s Tips.
Talked with Austral props and settled on replacements which are four blade 18″ X 15.5″ with 1/2″ Cups.
Original props are three blade 18″ X 22″ with 1/2″ Cups.
Props will be changed during current haul out.
Hope to have it back in water mid may.

Turbos are good, no sign of raw water entering from riser and exhaust has decent drop as per Tony’s Tips.
Fuel tanks cleaned, lines and filters replaced prior to trip, app. 2,000 ltrs of hi spec fuel used since.
About to use a can of brake cleaner on each after cooler as they have an light coating of oily soot on inlets.
Engines have unknown hours however top ends were rebuilt a few hundred hours before I got them.
Blowby from engines does not seem excessive, no noticeable drops of oil of sludge under vent hose.
Can anyone suggest where this light coating of oily soot could have come from ?
Thinking it could indicate leaking turbo oil seals.

Peter McK

[Author]

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