Do I need to lose weight ?

[gery w]

Hi Colin I would replace the dodgy o rings on the intercooler pipework. When I done mine the old o rings looked ok but the new ones were a much more snug fit, I also found other boost leaks using a soppy water solution sprayed onto the fittings when the boat is at near full load.
After all that and still no luck I plumbed in temporary boost gauges and it became clear that the turbo's themselves were not up to scratch so sent them off to turbo dynamics for repair....27/28 knots now no problem

 

[gery w]

Also best to remove exhaust elbow and remove the smoke limiter altogether as the elbows and solenoid to operate are quite pricey with no real difference in emissions

 

[Colin K]

Hello,
Update. Smoke limiters have now been fixed open and the exhaust elbows cleaned, Intercooler and pipes serviced.

I am not sure but I think that I have had a break through!!! I read a thread on here I think and someone mentioned a sticking pin in the Bosch pump. I took off the top diaphram all ok and the coned control pin came out easily in fact too easily as the pin that rests on that the "Guide pin" was not touching it. In fact it ws stuck. I think that this pin allows more fuel when the boost pressure increases and pushes down the pump diaphram. Could this be my demon?? Watched Mr You tube and found that you simply WD it up, let it soak overnight and then move it many many times back and forth getting to it via a blank plug. Now it rests against the coned control pin.
Also got the turbo off at the moment to check the bearing free play and all seems ok so a clean up tomorrow and refitting at the weekend. I was amazed what movement is allowed (up to 0.69mm). But now realise that this bearing gap is for the oil to flow through fair enough.
Sea trial pretty soon and I will report back.

Cheers, Colin.

 

[Bandit]

The general condition of the turbo and the blade tip gap/wear against corrosion on the casing makes a big difference.

 

[Colin K]

The general condition of the turbo and the blade tip gap/wear against corrosion on the casing makes a big difference.

Thanks for that the blades all look in really good condition no nicks etc. Not measured the gap between the tips and the casing but I cannot quite get a piece of playing card paper between them all around, Not sure if there is a more technical way of measurning it. I measured the sideways play in the shaft at the rotor blades with a micrometer and its 0.52mm (0.69 max allowed). So fingers crossed. When reving her at rest the newly installed boost gauges twitch a bit but I guess the sea trial under load is the tester.

Cheers, Col.

 

[[2068]]

I would have thought that "more fuel" is not what you need if there is lots of unburnt fuel coming out of the back as smoke.

If the props are propeller shaped and not cauliflower shaped, you have boost tested the turbo, and are happy that there's enough air getting squashed in there, then I would be testing the injectors for abnormal spray patterns (a Bosch place that does trucks should be able to help).
Watch out for the sleeves if you do remove the injectors.

 

[Colin K]

Hello,
Wow its been so long since she stopped working properly and I guess that I have been playing with her all Winter.

Thank you everyone for all of your comments and advise.

To recap port engine got to full revs but starboard one only got to 2700 with lots of black smoke.

I found a fair few faults and so one of them or a combination was my problem.

- Air cleaners a bit dirty.
- possible leaks on the pipes going from turbo to intercooler
- Pin in the diesel pump stuck. (Found this on an American you tube truck forum) gives more fuel when the turbo cuts in.
- Stripped turbo. Cleaned off a good 2mm of carbon off the turbine blades.

Apprehensivly sea trialed her today and opened her up. Initially got a bit of black smoke but then she jumped up onto the plane both engines getting to 3600 rpm cruised around nice at 24.3kts full fuel and water tanks. Phew. Summers here.

Once again thanks to everyine who posted.

Cheers, Colin.

 

[Colin K]

Hello,
Also I have fitted boost pressure gauges. Flat out they are both reading 18ish psi. Think thats about right?

Cheers.

 

[superheat6k]

Hello,
Wow its been so long since she stopped working properly and I guess that I have been playing with her all Winter.

Thank you everyone for all of your comments and advise.

To recap port engine got to full revs but starboard one only got to 2700 with lots of black smoke.

I found a fair few faults and so one of them or a combination was my problem.

- Air cleaners a bit dirty.
- possible leaks on the pipes going from turbo to intercooler
- Pin in the diesel pump stuck. (Found this on an American you tube truck forum) gives more fuel when the turbo cuts in.
- Stripped turbo. Cleaned off a good 2mm of carbon off the turbine blades.

Apprehensivly sea trialed her today and opened her up. Initially got a bit of black smoke but then she jumped up onto the plane both engines getting to 3600 rpm cruised around nice at 24.3kts full fuel and water tanks. Phew. Summers here.

Once again thanks to everyine who posted.

Cheers, Colin.

Nice one Colin. Did you try the K&N air filters ?