lancing marine
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robin3boats
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lancing marine
Went to Lancing Marine yesterday and dropped of my diesel pumps and injectors for check and re-build.they seemed very knowledgeable and helpfull so hoping for good results.Have also ordered a new canopy and frame from JB to replace the hidious one on Sabre at the moment.
Will see if they deliver as promised!
Robin
Will see if they deliver as promised!
Robin
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PerHansson
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robin3boats
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robin3boats
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- Scott Pett
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What boost pressure; speed; rpm are you actually getting?
(Some of the) Reasons for lack of pressure:-
Blocked inlet tract - Intercooler full of crud
Air leak in inlet tract - check with washing up liquid on the joints between the various components.
or Turbo compressor snail not fitting well on the centre part of the turbo.
Only takes a pin-hole somewhere to lose a lot of air pressure.
or - lack of load on the engine. Boat too light; engines too powerful; prop pitch too small.
Cheers,
S
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Tim Russell
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robin3boats
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Hi,have inspected and cleaned turbo snails-seemed fine and not too dirty,cant find any leaks anywhere,engines run to 3050 rpm free but only 2400 under load-boost is about 1.2 bar.
No smoke to speak of
Engines are ford sabre 275
Props are 21/24
Max speed 28 knots
Havent as yet looked at intercooler except at inlet end-looks clean
Turbos dont have any play
Boat pickes up well and is good to 25k then boost doesnt rise any more!
The hull is clean!
No smoke to speak of
Engines are ford sabre 275
Props are 21/24
Max speed 28 knots
Havent as yet looked at intercooler except at inlet end-looks clean
Turbos dont have any play
Boat pickes up well and is good to 25k then boost doesnt rise any more!
The hull is clean!
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Tim Russell
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Doesn't seem right that you are only getting 2400 under load. You will only get full boost under full load. But if there is no black smoke than it suggests that overload is not the problem, and there is plenty of combustion air - implies that turbos are getting enough air in for the amount of fuel you are burning. Makes me think that you may be short of fuel - injection pumps would put more fuel in if they could, but there is an obstruction elsewhere. Perhaps check lift pumps, filters, vents on fuel tanks. And look at throttle linkage - though the fact you are getting full speed unloaded suggests that is OK.
- Scott Pett
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High Idle at 3050 is good;
1.2 Bar is 17+ PSI which is about right for a Sabre motor.
2400 RPM is about right too.
Winding the fuel pumps up much higher would risk the camshafts I fear. But a word with Mike Bellamy would be useful regarding how far you could wind them up; rev and boost limit
How accurate is your speed reading?
GPS or Log?
Have the log and tachos been calibrated?
So the only other aspect to the equation is weight.
How much fuel/water plus weight of Mother-in-Law etc...?
Cheers,
Scott
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david timothy mark rhodes
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Ah what fun engine diagnostics, I think I am right in saying that the 275 hp sabre must be a dover basically, I was told that a good ford when stretched should leave a vague smoke astern, if its burning too lean then its basically not enough fuel or alternatively you could say its rated conservatorily, as I recall there is a form of non electronic boost control, basically a small metal pipe from the inlet manifold to the fuel pump, as pressure increases in the manifold a diaphragm moves and allows the rack to move and introduce more fuel.
I think the diaphragm is in a squarish box type structure on the fuel pump, check the small pipe for a good airtight connection, small leak here will lead to not enough push on the diaphragm and thus not enough fuel, the rubber of the diaphragm is also worth checking.
If all that comes to nought then there is a further tweak available to the brave, on the side of the pump is a square cover, its normally lockwired in place, behind this is a couple of adjustments, one alters the rate of increase in fuel vs boost and the other the max fuel amount,much fun can be had fine tuning these I was told that engine manufacturers used to send engineers out on new boat proving runs and set them up!!
Good luck if you have a go, the safer bet is to get an engineer on board who really knows their stuff and leave them to it!!
I think the diaphragm is in a squarish box type structure on the fuel pump, check the small pipe for a good airtight connection, small leak here will lead to not enough push on the diaphragm and thus not enough fuel, the rubber of the diaphragm is also worth checking.
If all that comes to nought then there is a further tweak available to the brave, on the side of the pump is a square cover, its normally lockwired in place, behind this is a couple of adjustments, one alters the rate of increase in fuel vs boost and the other the max fuel amount,much fun can be had fine tuning these I was told that engine manufacturers used to send engineers out on new boat proving runs and set them up!!
Good luck if you have a go, the safer bet is to get an engineer on board who really knows their stuff and leave them to it!!
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Paul Foulston
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Robin,
Not sure why ripping into fuel pumps was your first port of call for a performance problem, should always be the last......No matter whats done is done.
Sabre 275 in my book has two stage CAC. Raw water aftercoolers are invention of the Devil and you have Sabre/Serck set up with two heat exchangers in two stages, double trouble.
CAC's should ALWAYS be serviced regularly, in my book every three years. Oil carryover from turbo on the air side and debris on the sea water can both cause performance to drop off the edge. When were your CAC's last done?
Unless you are 100% comfortable re-sealing and pressure testing after cleaning your CAC's have them done professionally. Seawater leaking into your air side causes tears before bedtime.
As suggested by others confirm your #'s are real using photo tach.
What were your original performance numbers??
Paul
Not sure why ripping into fuel pumps was your first port of call for a performance problem, should always be the last......No matter whats done is done.
Sabre 275 in my book has two stage CAC. Raw water aftercoolers are invention of the Devil and you have Sabre/Serck set up with two heat exchangers in two stages, double trouble.
CAC's should ALWAYS be serviced regularly, in my book every three years. Oil carryover from turbo on the air side and debris on the sea water can both cause performance to drop off the edge. When were your CAC's last done?
Unless you are 100% comfortable re-sealing and pressure testing after cleaning your CAC's have them done professionally. Seawater leaking into your air side causes tears before bedtime.
As suggested by others confirm your #'s are real using photo tach.
What were your original performance numbers??
Paul
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robin3boats
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Jonathan Napier
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