Re: Wide open throttle

Porter McRoberts

Congratulations Susan and David:

We (Helen) and I own A54-152, your brother!
We have a new (relatively) “H” model D3-110 since 2019.  Wonderful engine.  
We get 2700 at WOT, clean hull and Brunton autoprop.  Bill R is correct, even a single barnacle spoils the party.
We rarely run WOT as when posed (your and my conventional wisdom)  to the North American lead engineer for Volvo, who helped install our new D3 then replied, “No not at all, the computer should perfectly calibrate the fuel/air mixture, regardless of throttle position.”  I found that quite interesting, and wasn’t convinced at the time.  

A symptom of fuel:O2 mismatch (in my thinking) is carbon, in the turbo, and on the side of the hull, aft of the exhaust port.
We indeed had that, common Amel finding, before the D3-110 “C” engine change.  
We’re now 1200 hrs into the new engine.  No soot on the hull, not even a slight amount.  And when I took off and inspected the turbo and exhaust elbow recently, the thinnest of dust layers.  And interestingly, oil color at 200hrs: dark honey.
Our typical rpm is 900-1200.  Occasionally above, but less than 1% of the time. And we rarely do the burn out/ tune up.
Temp always between 79-81d C.

I offer the above to our collective for the following reasons:

I was quite down on Volvo for a variety of reasons, but principally I thought we (it's a family disease) got a bad D3 engine, death pronounced around 1100 hrs, despite significant recussitory effort, and sadly no DNR in place.
Volvo paid for our new one, I would have preferred a Beta, still think them excellent (especially during electrical storms), but have been very happy with the D3-110 “H” I think they may have actually NOW “marinized” the D3-110, in this “H” configuration.

There is a definite improvement in combustion cleanliness, efficiency, and sound: in that order.

We still “only” get 2700 rpm.  Not the advertised 3000.

Congratulations on your Dragonfly, an amazing boat. It makes me smile, envisioning your future!

Porter and Helen McRoberts
A54-152 S/V IBIS

On Jan 15, 2022, at 10:30 PM, David Odell <david.wanderer@...> wrote:

This is my first post as my wife Susan and I just bought A54 #153, originally named Aora, now Dragonfly. Excited to be a part of this community, and what great boats these Amels!
My question pertains to running the Volvo Penta at wide open throttle. I previously had a trawler with a 170 hp Lugger diesel. The Lugger technical support manager advised the fleet to run the engine at wide open throttle after 6-8 hours of engine usage. We would run wide open throttle for 5-10 minutes to burn off all of the carbon build up and to heat up the gaskets and seals. Engine temperature would go from 180 degrees F to about 195 degrees F. We would never let the engine temperature exceed 205 degrees F. 
A few questions:
1.  Do you run your Volvo Penta at wide open throttle and for how long?
2. What is your normal engine running temperature, and what does the temperature reach at wide open throttle?
3. Under normal engine operating conditions, is there an RPM “sweet spot” where the engine is happy and the fuel burn is efficient?
Thanks in advance. 

David Odell
A54 #153 Dragonfly
Southport, North Carolina
Currently lying Le Marin, Martinique

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