Do I need to lose weight ?

[volvopaul]

I've has 2 corniche over the years both with 41 engines and shaft drive, they both gave 30 knots at 3800 rpm, I'd say your hitting a brick wall at 2750 where your turbos should cut in but as you have black smoke your getting fuel but no boost, I'd suggest you check for a seized turbo on one engine or leaking intercooler , intercooler pipe o rings causing low power.
A simple engine if looked after, where are you based?

 

[Colin K]

Hello,
Thanks for the reply Paul and hope you are well? Wow 3800 rpm and 30 kts but hey I guess you would be the man!
Best I have had is 3600rpm and 26kts. Four bladed props.
There was just a wee bit of resistance to the turbo spinning this is on the port engine that will only make 2750 rpm but I sort of had it in mind that the exhaust side of the turbo would start her spinning but turbos all new to me. Now I put my finger on the vanes and they spin with no effort at all.
Pic of turbo vanes enclosed good old mobile phone cameras!. Boat is in Ipswich. On board one night next week so stbd engine air filter out and see if that turbo has the same initial resistance.
I have to get her tip top for this Summer hence starting early I have got boost gauges to go onto the inlet manifold (now I can see the stud that I should use) and vacuum gauges for between the filters. Like to mount them on the saloon dash but not sure what sort of pipe I should use (copper or decent flexi)

Thanks for your help as always, Cheers, Col.

 

[Elza_Skip]

Hi Colin

I had a Corniche with TAMD41bs on shaft drives for 5 years so here are my thoughts based on my own experiences

Losing weight helps but you should certainly be able to get on the plane with full tanks and crew

24 knots at 3600 sounds about right, unlikely to get more than that. A dirty bottom is the first culprit for a loss of performance but you have fixed that. As for the Trilux on the props I have used that on ally props before and it worked well as it is quite a slippery coating- I am sure it would be just as fine on Bronze (but I bet it will not last all that long!)

We had a problem like yours, but it came on suddenly. It turned out that the oil mist from the engine breather had caused the air filter to become blocked and it suddenly collapsed. A dirty air filter will give no problem at lower speeds but as you open up and the turbo tries to draw in much more air its effect chokes the engine- This would be my first thought as to your problem. I always carries spare air filters and replaced them mid season

The turbos could be a problem but your hours are low and they would not both go at the same time. A loss of boost on one engine might stop you getting onto the plan for sure, but you would see one engine reaching higher revs than the other

The next thing to look at is the fuel supply, assuming the filters are changed then diesel bug can collect around the entry to the dip pipe in the fuel tanks. Not actually that hard to lift these to clean them. Although some might say that fuel starvation would not be the problem due to the black smoke I would say that not having enough power to get out of that 2600 rpm range could still be an issue. There is also the possibility of diesel bug blocking other areas of the system. However with 2 separate fuel systems I would not think both engines would be affected

I assume you have the twin tanks with cross over systems? If so make sure that the valve in this are correctly set as per the manual so each engine is drawing and returning fuel to the tank on its side

As for the props, as the boat had aged and lost a little power we reduced the lead on the props by half an inch in order to allow the engines to reach specified WOT revs. I do not think this is your problem given you have seen 24knots in the past

Good luck, I hope it turns out to be something simple

 

[Bigplumbs]

Colin

I am certainly no diesel engine expert but read this complete thread with interest as I live very near Ipswich and do most of my Boating on the Deben. Reading the whole thread tonight and in particular VPs post it sounds to me very much that you have a problem on the slow engine with the Turbo.

I would be very interested to hear how you get on and will keep an eye out for you in my neck of the woods. What is your boat called

Regards

Dennis

 

[superheat6k]

Hi Colin - I would listen closely to VP advice. Also worth checking the after cooler is clean on the air side. Black smoke is over fueling so the engine is trying to get more power but insufficient air to deliver what is required.

The air filter doesn't look that bad but i fitted K&N to my Turbo 36 TAMD61C and they worked a treat and were less cost (like half) than one off replacement original Baldwin air filters.

 

[Colin K]

Hello ,
Thanks for the replies and personal experience. I think that I have a plan. Thursday night on board and have Friday morning to remove intercooler exchangers And check other turbo, Think its ok and the port engine ok but held back those couple of hundred revs by the dodgy stbd one? Take intercooler elements home for cleaning.

Back Saturday to refit intercoolers although bet I will need new seal set? Fit new air cleaners,all fuel filters, Indeed check that maze of fuel switchover valves (good point)
I will have my 10 year old lad with me so he can feed the pipes to the new boost and vacuum gauges for me from the inlet manifold and fuel lines to the dash. Just need to ascertain what type of pipe I need to use and get a tapping from the manifold as Im not sure of the thread size of that.
I am pretty sure my props are alloy prior to me Triluxing them. I have got an underwater cctv scope that reaches half way across the hull so interested to see how last Julys antifoul has done.
She is called Rogue River and I keep her inside the lock in Ipswich.

Once again thanks for the advise all,

Cheers, Colin.

 

[Colin K]

Hi Colin - I would listen closely to VP advice. Also worth checking the after cooler is clean on the air side. Black smoke is over fueling so the engine is trying to get more power but insufficient air to deliver what is required.

The air filter doesn't look that bad but i fitted K&N to my Turbo 36 TAMD61C and they worked a treat and were less cost (like half) than one off replacement original Baldwin air filters.

Hi Trevor,
Yes thanks for that and VP advise spot on as always. Glad he likes the Corniche ha ha .
Until I looked at Mr Youtube on how to check the intercooler I had no idea how accessable they are!

The air cleaner so close to the breather is a bit odd? But hey ho. I prob need to carry plenty of spares.

Hope you are well, Cheers. Col.

 

[superheat6k]

Colin

I have heard very good reports about Velox propellor anti fouling using hammerite special metal primer as the base. I will be trying it this year.

https://www.marinesuperstore.com/paint-cleaners-care/antifoul/velox-antifoul

 

[Sailorsam101]

I don't think you are overloaded at all.

I had 7 big blokes on my targa 33 and could still cruise at 25kts easily. So that was a loading of about 750kg of people..500 ltrs of fuel and a fair bit of beer.

This was with a clean bum on AD41p_a's with 550 hours on each.

Mike

 

[gordmac]

Have you checked you get maximum revs in neutral?

 

[Colin K]

Hello,
Golly yes I think I have tried that and think that yes they will rev to max. I must confess ruled it out as a point as the engines are not under load. However if relevent? On board on Thursday night and so will check this before I take the intercoolers out.
Cheers. Colin.

 

[oldgit]

I am pretty sure my props are alloy prior to me Triluxing them.

Bronze !

 

[Colin K]

Hi,
It was from glancing at this shot taken just after her jet wash. Looking at another close up yup tinge of bronze. Alloy mainly for stern drives I guess??

 

[oldgit]

Hi,Alloy mainly for stern drives I guess??

Yup all outdrives were designed wether by purpose or accident to dissolve on contact with water .

Alloy props would deform like putty on shafts.
OK for seagull outboards and stuff like that

 

[Colin K]

Hello,
Update ! Got on board yesterday afternoon. Took the whole air cleaner assembly off and so able to wiggle the turbo blades in all planes. Great no play and runs free. With it so exposed I sadly videod the turbine as I started her and found that the vanes spin as soon as the engine fires, After I warmed her up gave it some revs and sounds good.
Thinking about VPs comments about intercooler pipes/leaks I took off the pipe from the turbo to the intercooler box.The exhaust style clamp has seen better days but nipped up ok on rebuild however I wonder if a standard twin flange style exhaust clamp would be better? The big o ring on the intercooler end looked great and bit but the turbo end one looked too small! And I think that it was on the wrong bit of the flange (there is a stub to locate first). I replaced this with a bigger one on the mating faces which squeezed when tightened.
Took out the intercooler which looks ok. No oil debris in the bottom. Seals look good and I can see through the air vanes ok.
Needed or not I have brought it home to clean vanes with a bit of diesel, I guess water side with ??? Vinegar type stuff .??
Got all the gauges and fittings to fit boost meters for the turbos and vacuum for the fuel lines.
Supposed to be back tomorrow but running out of steam ha ha.

Happy Weekend, Col.

 

[Colin K]

Hello,
Update, and Aaaaaaaah. With a bit of advise from here and elbow power I cleaned my intercooler and refitted it.
The intercooler pipe from the turbo def had dodgy o rings and so replaced following VP's ideas. Thanks.
Not sea trialed yet but she revs ok not under load and the turbo pulls in an impressive amount of air.
So before I left her I pictured my work to death as being sad on those rainy days at home I look at them and dream. Then Horror !!! Noticed a cable clip on the wastegate lever! Its even got a bit of Volvo green on it?? I have had the boat for over two years now and she "used" to perform great up until my recent troubles. Cable clip should not really be there should it? Has someone fitted it in the past to hold the wastegate closed? Why would they do that.

Any thoughts appreciated, Cheers, Colin.

 

[Portofino]

Pic on post # 22 ,the turbos have worn -there's a huge gap between the blade tips and the housing .leads to lost boost pressure .
Combo of engine HP on the edge , fouling and the real killer weight for planing boats.Leads to overloading ,excess EGT ,VP turbo tips burn out -= lost boost pressure .

As its comes on slowly the symptoms , one engine dropping revs for a few seconds ,then longer and longer ,boat slows down ,drops off rhe pane .Operator pushes the taps fwd , cause over fuelling rise in EGT -= accelerated turbine tip burn out and a vicious circle of lost boost more and more as gap widens , until there's simply never enough boost pressure , to provide the Hp to spin the props at the correct rpm .
folks initially look for fuel filter issues or air leaks . Cheap easy fix .
Once you start to burn one out ,it's tempting inadvertantly to push the good one ,that then folows - burns its tips .

solution

A pair of new turbos
and
Keep an eye on the weight

Previous owner ? Tied waste gate (s) shut to mask failing turbos @ yours sea trial ??

 

[gery w]

Tamd 41 engine's don't have a waste gate for the turbo's, what your pic shows are the smoke limiters fitted to the exhaust elbow which by the look of it is tied in the open position?
From this you can also tell that the engines are tamd 41 A

 

[Colin K]

Thanks you are a gem she has the usual smokeyness on start up which goes when hot and on the move I will now try Mr Google for info on them and I am sure there have been a few threads on here about them.
On my next visit I will be piping up from the inlet manifold to my newly fitted boost gauge panel which I made at home and fitted a cpl of days ago. Keen now to see how the boost is on the turbos so the fuel vacuum connections can wait!!
Appreciate that the proof in the pudding as to speak is when I take her out and put the turbos under load but wonder if I will get some indication revving her in neutral?
Thanks for your help.

Cheers Colin.

 

[Seastoke]

Thanks you are a gem she has the usual smokeyness on start up which goes when hot and on the move I will now try Mr Google for info on them and I am sure there have been a few threads on here about them.
On my next visit I will be piping up from the inlet manifold to my newly fitted boost gauge panel which I made at home and fitted a cpl of days ago. Keen now to see how the boost is on the turbos so the fuel vacuum connections can wait!!
Appreciate that the proof in the pudding as to speak is when I take her out and put the turbos under load but wonder if I will get some indication revving her in neutral?
Thanks for your help.

Cheers Colin.

hard to see when on the move