Back to the UK for a winter refit

[Portofino]

The basic aspiration profile of the engines, as I understand it, is that 0-1500 rpm is normal aspiration; 1500-2500 is supercharged; 2500-3500 (wot) is turbocharged. Rpm response 0-2500 is the same between the two engines; above 2500 the stbd engine lags the port engine..

Aire d Boom are €78 /hr HT and strong VP agents as well as others MAN,CAT MTU ect -they have good spannermen .
A turbo was wearing out on my previous boat KAD 300 -( with similar aspiration pattern ) symptoms were no lag from 2500 ,just hit a wall at 3100 ie matched rpm to 3100 and stayed there while other increased .
It came on gradually and in the beginning was kinda intermitant -often a long hard run would ease it up -no warning lights or codes .
I,am no expert but turbo failure from the symptoms would be low down on the Dx list .
Just returning to the new riser ,from my childhood hobby days messing with modal engines the shape of the pipes or "tuned pipes " on 2strokes were important -in relation to full revs, power .
Assuming there is no fuelling issue ( hard to tell sat Here ) then may be ,stress - just maybe it's a back pressure issue .?
I hope it is not .i,am just going on all things being equal -what's changed ??
Depend on how it knows ,cos if it's fuelled without a sensor the gas will just blast out ,but with a sensor it will tell it to ease up .?
Of course it would be nice to find a loose / corroded contact ,pulled wire ,etc -the road transport up may have shaken somthing loose in / around a black box ?

at this stage IWould just run it more and see if it shakes off -

 

[jfm]

Hmmm, yep P, failed/stiff turbo bearing is a plausible cause, because it wouldn't trigger any error code I think. Terrible diagnosis in terms of access to the thing on the T40 though...
Jimmy, were the turbo bearing lube pipes removed/refitted during the engine work? Were the turbos stripped down and rebuilt? What hours are you on? Can you think of anything relevant in the recent history?

 

[jimmy_the_builder]

Hmmm, yep P, failed/stiff turbo bearing is a plausible cause, because it wouldn't trigger any error code I think. Terrible diagnosis in terms of access to the thing on the T40 though...
Jimmy, were the turbo bearing lube pipes removed/refitted during the engine work? Were the turbos stripped down and rebuilt? What hours are you on? Can you think of anything relevant in the recent history?

But wouldn't turbo failure or poor performance show up on the Vodia tool as boost pressure?

Checking my notes, we didn't do anything to the stbd turbo during the refit (the port turbo was removed and oil feed/drain pipes replaced). Hours are 590. Performance was good before the refit.

I think I need a sea trial with a Vodia tool and engineer on board. It's the only way we're going to get more data.

 

[jfm]

But wouldn't turbo failure or poor performance show up on the Vodia tool as boost pressure?

Checking my notes, we didn't do anything to the stbd turbo during the refit (the port turbo was removed and oil feed/drain pipes replaced). Hours are 590. Performance was good before the refit.

I think I need a sea trial with a Vodia tool and engineer on board. It's the only way we're going to get more data.

Yep, it would I expect show up on Vodia. What I meant was it wouldn't sound an alarm to the user, but yes it should show up on vodia, assuming there is a pressure transducer which surely there will be

We're all agreed - you need a Vodia diagnosis! Fingers crossed it is something simple.

 

[MapisM]

Hmmm, yep P, failed/stiff turbo bearing is a plausible cause

Agreed.
Incidentally, just after putting my boat back in the water, I thought to make a visual inspection of the cold side of the turbo.
That's easy peasy on my Cats (just by removing the air filter), also because they are well accessible, but I'm not sure about the D6 and their installation in the T40.
Anyway, I'm mentioning this because, if feasible, such inspection should at least reveal any rotation stiffness/dirty blades/axial play.
Nowhere near the accuracy of proper diagnostics of course, but depending on the installation that could be an easy check worth making.

 

[Hurricane]

That's easy peasy on my Cats (just by removing the air filter), also because they are well accessible,

Thats an understatement - you could hold a dance in your engine room.
Fantastic access to everything.

 

[vas]

stiff, well actually stuck and rusted solid turbo was the problem I faced on the delivery trip on my port engine. As MM, easy access, easy to remove the filter and try spinning the turbo...
All in hindsight though.

I guess no boost pressure gauge onboard, right?
Seeing the layout, I sincerely wish it's something else

cheers

V.

 

[jfm]

Jimmy's port engine turbo is reachable, but stbd engine turbo is "fit and forget" (to borrow a phrase). See picture above. There's no hope of reaching the compressor side (inlet air) but maybe 1/2 a chance of disconnecting the exh riser and feeling the turbo side

 

[jimmy_the_builder]

Jimmy's port engine turbo is reachable, but stbd engine turbo is "fit and forget" (to borrow a phrase). See picture above. There's no hope of reaching the compressor side (inlet air) but maybe 1/2 a chance of disconnecting the exh riser and feeling the turbo side

I think to even do that I have to remove the engine fire extinguisher (as well as obviously the garage floor etc). I'm working on the sea trial w Vodia tool plan though, I've just had a quote in from Sud Diesel for a one-hour sea trial - €246...

Oh and per your previous post, the IAT sensor is actually a combined temp and pressure sensor, so both metrics are displayable on the Vodia tool.

Edit: you can get an idea about the access constraints by looking at the engine removal pictures waaay back in post #1.

 

[benjenbav]

I think to even do that I have to remove the engine fire extinguisher (as well as obviously the garage floor etc). I'm working on the sea trial w Vodia tool plan though, I've just had a quote in from Sud Diesel for a one-hour sea trial - €246...

Oh and per your previous post, the IAT sensor is actually a combined temp and pressure sensor, so both metrics are displayable on the Vodia tool.

Edit: you can get an idea about the access constraints by looking at the engine removal pictures waaay back in post #1.

I think you have no realistic choice other than to go ahead with the sea trial with the vodia tool and see what data can be obtained.

Presumably the high-idle numbers match across the two engines and it's only under load that the starboard engine fails to reach the target rating?

 

[MapisM]

Edit: you can get an idea about the access constraints by looking at the engine removal pictures waaay back in post #1.

Blimey, I didn't remember that.
What were they thinking at Oundle, that as long as they could stick the engines inside the hull before fitting the whole superstructure, that was good enough?
My "ballrom like" e/r, as Hurricane aptly called it, indeed is a waste of space in some respects (driven by the commercial heritage of the yard), but I believe they went a tad too far in using space on the T40 for anything else than e/r access...!

Good luck for the sea trial, looking forward to hearing the results.
Btw, while at that, I'd take the opportunity to ask the engineer a detailed report on the engines behavior (load, fuel burn, temperature, pression, etc.) throughout the whole rpm range.
That shouldn't take much longer than just troubleshooting the problem at WOT, and it might come in handy for future reference.

 

[jrudge]

In fairness as a former T40 owner general access is not bad, made better by the ability to remove the garage floor, and made even better if you are a midget ( I am not!) The garage floor removal however is (never done it but suspect) a real pig - forklift?? I propped it open once about 6 inches for access to something or other but it was not a light piece of GRP!

 

[jimmy_the_builder]

In fairness as a former T40 owner general access is not bad, made better by the ability to remove the garage floor, and made even better if you are a midget ( I am not!) The garage floor removal however is (never done it but suspect) a real pig - forklift?? I propped it open once about 6 inches for access to something or other but it was not a light piece of GRP!

I regularly open the floor up for maintenance and fettling, you can prop it at 60cm at the rear edge for max access. The issue though with the stbd turbo is that it is under the companionway, not the garage floor, and the gap between the bottom of the companionway moulding and the top of the engine is only about 20cm - and that is also where the big engine room fire extinguisher is fitted.

You can get the floor moulding completely out, but you need three or four people to move it. Getting it off the boat and on to the quay would be a bit of a challenge I think.

 

[jrudge]

I now know where you mean. You need a nice slim friend. I would offer but ....

I could hire out a 7 year old!

 

[Richard Shead]

I regularly open the floor up for maintenance and fettling, you can prop it at 60cm at the rear edge for max access. The issue though with the stbd turbo is that it is under the companionway, not the garage floor, and the gap between the bottom of the companionway moulding and the top of the engine is only about 20cm - and that is also where the big engine room fire extinguisher is fitted.

You can get the floor moulding completely out, but you need three or four people to move it. Getting it off the boat and on to the quay would be a bit of a challenge I think.

And I would imagine sink rather majestically to the bottom if you were to drop it.....whilst watching it of course

 

[Hurricane]

I regularly open the floor up for maintenance and fettling, you can prop it at 60cm at the rear edge for max access. The issue though with the stbd turbo is that it is under the companionway, not the garage floor, and the gap between the bottom of the companionway moulding and the top of the engine is only about 20cm - and that is also where the big engine room fire extinguisher is fitted.

What about creating a special access through the companionway floor.
Might pay for itself the first time you use it.

 

[jimmy_the_builder]

What about creating a special access through the companionway floor.
Might pay for itself the first time you use it.

Nice thought, but would be very tricky - firstly, the companionway floor is teaked, secondly, there's a passerelle locker below that, and then thirdly the space that you would create access to isn't big enough to completely accommodate you.

Short of removing the engines again, which I'm not doing, then the best access is achieved by removing the garage floor, removing the fire extinguisher system, and removing a prop which supports the companionway floor. Once those things are all out of the way you can sort of jam yourself in the resulting gap and just about get to everything on the outboard side of the stbd engine..

 

[longjohnsilver]

I'm no engineer, but is there anything you can squirt into the turbo (assuming that's where the problem lies) to help free it up? WD40?

 

[RogerRat]

Jimmy,
One more simple thing to check is the fuel lines to injectors. If they were removed, it is possible to cross them over on reinstalling on some KAD ewngines, I don't know if possible on D6 but this effectively changes the firing order and will make it slow to pick up and limit revs to about 75%

Don't ask me how I know this. :encouragement:

RR

 

[jimmy_the_builder]

No progress yet with power issues - haven't been back to the boat. Planning to head down this weekend.

In the meantime, one slightly more successful project was the new cockpit table. This was supplied by Wattsons Teak in Northants. Really great people to deal with, a very can-do approach. Perhaps not the cheapest option but it's hard to think of a better one. The overall dims of the table are the same as original, although because I've gone for a thicker top the new table is (by design) about 13mm higher than original.

Table arrived heavily overpacked - two layers of shrink-wrap plastic, over a box, over four layers of cardboard packing. They were taking no chances!

Inside

First job is to nail the existing table spider to the new table. Bit nerve-wracking drilling holes in your brand new teak table...

Then, set to with the teak oil

After two coats, turn it over and stick it on the pedestal

Two coats on the closed faces

Opened up you can see the difference between raw and oiled. I prefer the oiled.

Two coats on the opened face

The final effect