Re: [Amel Yacht Owners] Expected RPM at WOT


 

I absolutely agree that you have eliminated every possible cause of resistance causing the low RPM. And, since Volvo specified the sizes of the AutoProp and the fixed Prop, Volvo cannot claim that the Prop is over-sized or over-pitched. There is one series of connected things left that are suspect for not only this issue, but previous issues: The Volvo Computer and connected wiring and sensors.

Best,

CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus

Amel School  http://www.amelschool.com
720 Winnie St
Galveston Island, TX 77550

+1(832) 380-4970

Any opinions and conclusions expressed in this message are solely those of the author and should not be construed as representing the opinion of an expert. Manufacturers' and Expert's precautions must be considered when dealing with mechanical and/or electrical systems to ensure that you are NOT harmed, and/or the device and/or system is NOT ruined. If in doubt, do not touch any mechanical and/or electrical device or system referred to above.


On Fri, Aug 31, 2018 at 12:52 PM Porter McRoberts portermcroberts@... [amelyachtowners] <amelyachtowners@...> wrote:
 

Today’s test results WOT comparison of peak RPM: out of gear and in gear but with prop removed. 


After warming up engine to working temperature. 
Out of gear WOT: 3200 RPM
In gear (but no prop) WOT: 3190 RPM 

Can I say with near certainty the problem must lie within the engine itself as the gear presents negligible resistance?  


Thank you all!!

Porter
A54-152

Excuse the errors..  
Sent from my IPhone 

On Aug 31, 2018, at 11:30 AM, Nick Newington ngtnewington@... [amelyachtowners] <amelyachtowners@...> wrote:

 

We all feel for you Porter,


"There but for the grace of God go I”

In your video, at first view, it looked like overload, but was there black smoke at the same time? I doubt it as you would have said, therefore it is likely to be fuel starvation which brings us back to the whole box of magic namely the computerised fuel control and its associated sensors and wiring. So yes I agree with Bill and what is now becoming the general consensus. It is a sensor or computer problem!!!!

You will be at the mercy of the almighty VOLVO agent. You would have thought that the Volvo agent’s diagnostic computer that plugs in below the cockpit instruments (in the locker above the sink) would diagnose such a failing in moment. Alas I guess not. It might be worth checking that they are fully paid up to Volvo and have access to the Volvo system.

I have  mixed experience of Volvo agents. And am now beginning to wonder if your problem is not Turbo related. 

This is my story:

In Grenada I had a fault code on the EVC, I called the agent and he came on board in St Georges and said that the wifi was too slow to access Volvo. Then I sailed to Grenada Marine (St Davids Harbour) and went alongside the agents dock. He still could not access the diagnostic database. I was furious. I had sailed up especially. It transpired that he had not paid his fee and his access code had expired. He then said my fault was the 12v alternator over charging as it was at 14v, which was too high.  I told him to forget it as I knew he was talking rubbish. I refused to pay. (the voltage regulator on that 12v alternator specs it to that voltage, I checked)

I gave up, and sailed to Trinidad and the Volvo agent there diagnosed the problem to the Turbo. He plugged in and accessed the system, the fault code went away.  The boat was out of the water at the time and he said that the problem would be solved by servicing the turbo. So I removed it and had it serviced in the UK. They said it was perfect and did not need servicing.  When I launched and left to sail north I gunned the engine and the fault code came back as before. I continued to sail without the turbo kicking in, so achieved only 2200 RPM. Sound familiar??

I sailed to Martinique. There the Volvo agent plugged in the computer and said it was the boost sensor. He replaced it there and then as it was in stock. Problem solved. Touch wood. Have boost pressure under load get full RPM etc etc. Have fully tested it all. Now some 9 months later, I am happy we got there in the end.

So eventually on the third Volvo agent the problem was correctly diagnosed and fixed.

1.You will forgive me for being so cynical as to suggest you check that the agent has fully paid up for access to Volvo diagnostics. 

2. It will be interesting to hear your news re prop removal.

3. Did you get boost pressure kicking in at about 1400/1500 RPM when the prop was on? If not suspect the boost sensor.



Nick 

(Amelia) missing her already.




On 31 Aug 2018, at 16:06, Porter McRoberts portermcroberts@... [amelyachtowners] <amelyachtowners@...> wrote:

So rational. Thank you Bill

I am gearing up to get under the boat, take off the prop, while reading kids book reports!  
My engine report to follow this afternoon!

Porter
54-152

Excuse the errors.  
Sent from my IPhone 

On Aug 31, 2018, at 9:51 AM, Bill Rouse brouse@...[amelyachtowners] <amelyachtowners@...> wrote:

 

Porter,

Some random thoughts...read the last paragraph/suggestion.

I believe any alignment problem will present itself with considerable vibration.

I think you should press Volvo, but I guess you could disconnect the Vetus coupling and see what RPM you can achieve with the transmission in gear. I don't know what the RPM should be in this case, but probably very close to the RPM achieved in neutral. 

I believe an alternator could be a source of too much load, however, if you achieve high RPM in neutral, the alternator(s) can be eliminated.

We must remember that the Volvo computer is designed to prevent sending more fuel to the injectors than the engine is capable of burning. This minimizes pollution, which was the primary goal of the D3. The best example of pollution caused by sending more diesel to diesel cylinders is exhibited by large trucks accelerating with plumes of black smoke (unburned diesel).

What about this scenario:
Remembering that Volvo specified the prop, what about an RPM test with no prop? I believe if you achieve high RPM, you have eliminated all connected sources of friction and proven that the only source of your problem is the Volvo engine and probably, wiring, sensors, or computer.

I hope this helps.

Best,

CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus
Amel School  http://www.amelschool.com
720 Winnie St
Galveston Island, TX 77550
+1(832) 380-4970

Any opinions and conclusions expressed in this message are solely those of the author and should not be construed as representing the opinion of an expert. Manufacturers' and Expert's precautions must be considered when dealing with mechanical and/or electrical systems to ensure that you are NOT harmed, and/or the device and/or system is NOT ruined. If in doubt, do not touch any mechanical and/or electrical device or system referred to above.


On Fri, Aug 31, 2018 at 8:27 AM Porter McRoberts portermcroberts@... [amelyachtowners] <amelyachtowners@...> wrote:
 

Bill 

As always I really appreciate your thoughts on this... I think it is the computer or sensors too. Also we were getting 2600 rpm before that long block exchange (with poor compression). 
So today I’ll try and wiggle the fixed prop off and run the naked spline. 

And I’ll take you up on your offer of a letter to Volvo. 

Thanks again Guru

Porter. A54-152

Excuse the errors.  
Sent from my IPhone 

On Aug 30, 2018, at 4:36 PM, Bill Rouse brouse@...[amelyachtowners] <amelyachtowners@...> wrote:

 

Porter,

If you can easily spin the prop in neutral with the shaft brake OFF, the C-drive isn't adding friction.

I think that you have two remaining possibilities:
  1. The brand new transmission is faulty, when it was not faulty before the long block change (I think very, very unlikely)
  2. Volvo Computer is not allowing higher RPMs for some unknown reason.
With a new transmission, a changed prop (which Volvo spec'd in the 1st place), and the c-drive tested, I have to believe that the problem is with the Volvo Computer. There is one more reason I point to the Volvo Computer: Of all of the possibilities, it is the most likely because of our combined experience with Volvo, the D3 and its computer.

I will happily write Volvo a more detailed explanation when you get to that point..

Best,

CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus
Amel School  http://www.amelschool.com
720 Winnie St
Galveston Island, TX 77550
+1(832) 380-4970

Any opinions and conclusions expressed in this message are solely those of the author and should not be construed as representing the opinion of an expert. Manufacturers' and Expert's precautions must be considered when dealing with mechanical and/or electrical systems to ensure that you are NOT harmed, and/or the device and/or system is NOT ruined. If in doubt, do not touch any mechanical and/or electrical device or system referred to above.


On Thu, Aug 30, 2018 at 2:05 PM Porter McRoberts portermcroberts@... [amelyachtowners] <amelyachtowners@yahoogroups..com> wrote:
 

Nick. Yes. Thank you. 


Re WOT out of gear: 3100rpm

The transmission is fairly new:  replaced in he spring. 


Re friction within the cdrive. 

With engine idling in neutral, brake open I swim under the boat and can easily spin the prop. 

How can I better evaluate resistance in the system?: motor—New ZF tranny—vetus(friction??)— cdrive— prop. 

I think the next step is to take the fixed prop off. 
I need a gear puller to get it off I think (which I don’t have and need to get (any recommendations?).... Unless anyone has another suggestion? Tying the autoprop puller to the fixed prop using low stretch amsteel?  

Again all very good suggestions. 

Let’s say it is the cdrive. What then??????

Thank you all!!

Porter 

Amel 54-152

Excuse the errors.  
Sent from my IPhone 

On Aug 30, 2018, at 12:47 PM, Nick Newington ngtnewington@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Sorry Porter,


Just going over the email again.

You have max RPM of 2200 at WOT with the new fixed prop, right? If so that can not be correct. It should be around 2850.  I doubt Amel would supply a spare prop that is not correct for the engine, at least not to that degree. To be so far from the desired RPM at WOT may cause problems with your new engine. 

What RPM can you achieve out of gear? 

What about the C drive? Have you checked that is working without friction? 


On my 54 with 2006 D3 110 and the Autoprop I get 2850 at WOT, with a clean prop and hull. 

Nick



On 30 Aug 2018, at 15:46, Porter McRoberts portermcroberts@... [amelyachtowners] <amelyachtowners@...> wrote:

Thank you everyone for your thoughts re our engine woes they are quite appreciated. 


May I ask thoughts re expected rpm during WOT with the supplied fixed prop on the Amel 54?


Has anyone with the fixed prop determined an observed RPM with WOT?  Volvo is telling me that they think 2200 is due to too large a prop. Now I know the H6 is a slight over propping, reducing the expected 3100-3200 Volvo D3-110 to your observed 2900ish range. 

But 2200 (our WOT RPM with the fixed prop in calm seas) is much lower than 2900, and I have a hard time thinking such a great drop is due to the lack of prop arm adjustment for appropriate bite as seen with the autoprop. 

Any data would be very appreciated. 

Many thanks

Porter Helen Grace and Lilly
S/V Ibis A54-152
Isla Contadora, Panama

Excuse the errors.  
Sent from my IPhone 

On Aug 30, 2018, at 5:40 AM, Nick Newington ngtnewington@... [amelyachtowners] <amelyachtowners@...> wrote:

 

Hi Porter,

I watched the video that is a massive reduction in RPM.. Is their black smoke when it does that because it looks like the engine is seriously overloaded and about to stall?

So the fixed blade prop stops it right. Therefore there is nothing wrong with the engine itself.

Thus it must be something to do with the Bruntons Autoprop, which is a variable pitch prop.

The pitch varies automatically in order to maximise efficiency. "The Autoprop blades, unlike those of conventional propellers, maximise the thrust delivered whatever rpm the yachts engine is running at “

quote from Autoprop website.

So if the thrust  is maximised at all times then load on the engine must vary a bit. Just like say the big alternator kicking in when one runs a heavy load off it, say a toaster for example. So I would expect a slight variability in the rpm as the load on the engine varies but not like in your video.

Agreed there is something wrong with the prop. You could strip it down yourself, it is pretty easy, before returning for service.


Nick

Amelia (Amel 54 019) back at home for a bit.

On 30 Aug 2018, at 10:44, trifin@... [amelyachtowners] <amelyachtowners@...> wrote:

Porter,

Wow, that is a pretty major "wander" in the video, so glad to see it was resolved by changing prop.  
Your numbers look ok, except for WOT 2200 seems awfully low. I think you do need to follow that up with Volvo, particularly with the fixed prop now in place.

I checked my WOT this morning in flat water/no wind and it was stable at 2920rpm.  

I also took a short video of the wandering I was referring to, its in the" ZF25 Transmission" folder in the files section.  It shows a variation from 1170 to 1210, difficult to hear the engine note on the video, but 40rpm variation is just enough to make the ears prick up!. Given yours and Mohammad's observations, i'll put it down to propeller effects..

I've also uploaded my Sea Trial results from a few weeks ago after we had the gearbox fitted.
It was a bit choppy and breezy, so the speeds are a bit lower than we get in flat water.

Danny, and others - I've solved my oil leak.  Not sure exactly what to attribute it to.
I found an extra 1/4 turn on one of the fwd end sump bolts, but I've also done my regular oil/filter change including replacing the Oring on the oil filter cap.  One of those things solved it - I suspect the filter cap may have been the culprit.   

Cheers
Dean
SY Stella
AMEL 54 #154













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