2015 R31 needs new engine

C

Captain Pat

Member
Joined
Jan 20, 2017
Messages
5
Fluid Motion Model
C-302 C
Vessel Name
SLOW RIDE
The wait for a new Volvo is 9 months to a year. My mechanic is recommending a repower with a Nanni. The 6 cyl is not emissions compliant and be is recommending the 4 cyl that is only 265 HP. I think the 8 cyl with 320 HP would be better. The 8 Cyl could be rated as high as 370 HP so the engine would be derated as opposed to getting the most out of the 4 cyl. The 8 cyl is the same width and lower but is 3 inches longer. The torque is around the same for the Volvo and the 4 and 8 cyl Nanni. The mechanic likes the smaller 4 cyl since it would be easier to service. The gph looks bout the same. I go slow most the time so may not need the extra HP. I’m looking for suggestions, now the Ranger is putting the 320 in the R29 and R31 I am not sure I want to go smaller. Any advice would be welcome!
Pat Patterson
Slow Ride
R31S
Charleston SC
 
if it's the same engine i'd get the 370... :-D
 
What created the need to replace your engine?
 
Unless there are service points you can not get to at all with the 8 cylinder engine at 320 HP, that is what I would get. We have the Volvo D-4 320 in our R29S and it is not overpowered. It goes slow when you want it to, and on those occasions when you want to outrun a storm or climb a big wave the power is there. Sorry to hear you are even faced with this issue.
 
Sorry to hear about your engine. Last year I had to replace a VP D3150 in my 2014 RT25SC. I went with a smaller engine, a Yanmar 4JH110 and so glad I did. I lost about 4 knots at cruise however, I gained significant easier engine maintenance, significantly quieter operation, and better fuel efficiency.

I enjoy being on the water and not concerned about being the first to arrive, so the loss in speed is not an issue. Some folks are concerned about out running bad weather, however I have found that with proper training and preparation weather should not be an issue.

If you do repower with a different engine make sure you chose a yard that has experience in repowering. Everything including mounting engine, exhaust, fuel system, engine controls and monitoring, prop & shaft may need to be redesigned.

Good luck!
 
Perhaps a bit off topic, for which I apologize, but it is a bit discouraging to hear of diesel engines from 2014 and 2015 model years needing replacement. What were the issues?

Larry
 
So far I haven't seen a compelling reason for a new engine versus a simple field overhaul.
How many gallons of fuel have gone through this engine? In diesels it is the total gallons burned, not the hours, that determines need for an overhaul.
Is a piston burned? Broken crank?
Barring unrepairable mechanical destruction, the world of diesel operators replace the bearings and rings and grind valves and send the injectors out for overhaul. This is a whole lot fewer dollars than a different engine and all the gotchas that involves.
 
Larry,

The engine failure in my case was due to water in the engine. The VP D3-150 I had never gave me any trouble. The water was ingested during a water tow (with the raw water sea cock closed) because of a reverse gear failure. The reverse gear clutches failed and shifted the reverse gear from forward into reverse while at crusing speed leaving me with a reverse gear housing with briken parts inside.

I have not had a good explanition of how the water got into the engine. The yard that did the repower said that the Ranger Tug exhaust system design was marginal and potentially caused the water ingestion. I do know that the engine installation was flawed. Within less than 200 hours of operation the cutlass bearing failed and the prop shaft was starting to ware through the stuffing box. After some inspection and measurements it was found that the engine was 1/2 inch too low. Since the engine mounting adjustment was already at the top we needed to place 3/4 inch bocks under the motor mounts to obtain proper shaft engine alignment. This led to the next problem that the engine hatch would not close without removing the engine cover.

I do believe that the engine alignment problem was a factor in the premature failure of the reverse gear wich started a chain of events causing the engine failure. If you look at my posts over the last few years you will get more details on the subject.
 
Pat,
The nanni engines look interesting. They have a few of their blocks that are john deere. I noticed that they also have the similar use ratings of use just like john deere. I would look at an engine and also go on the premise of how many liters is the engine size. when john deere rates an engines for long term durability, its de-rated and based on roughly 2 gallons per liter. My Cw-28's D4-260 is 3.7 liter and I try to keep it at around 7+ gallons per hour. Actual numbers at this amount, 16.2 m/hr, 7.4 gal/hr, boost 12 psi, engine rpms 2650. So looking at what block I still base these numbers on the liters, not whatever magic they use to boost the horsepower, so the same block will have different horspower ratings, but the fuel burn is what counts.

Stuart
 
dclagett said:
Sorry to hear about your engine. Last year I had to replace a VP D3150 in my 2014 RT25SC. I went with a smaller engine, a Yanmar 4JH110 and so glad I did. I lost about 4 knots at cruise however, I gained significant easier engine maintenance, significantly quieter operation, and better fuel efficiency.

I enjoy being on the water and not concerned about being the first to arrive, so the loss in speed is not an issue. Some folks are concerned about out running bad weather, however I have found that with proper training and preparation weather should not be an issue.

If you do repower with a different engine make sure you chose a yard that has experience in repowering. Everything including mounting engine, exhaust, fuel system, engine controls and monitoring, prop & shaft may need to be redesigned.

Good luck!
Click to expand...
 
Hi dclagett,
I have been reading your posts about your experience of repowering your R25.
I am going to have to replace a Yanmar 4BY-180 in my RT 25 2012.
I am also thinking of going with a 4JH 110. It seems that the size is a tight fit but can work, plus there do not seem to be a lot of other options.
Questions:
1. Once the 4JH was installed how is the access for basic filter maintenance and impeller changes?
2. What were the major challenges and modifications that were required for the refit?
3. I live on Salt spring island in British Columbia and am looking for a good outfit to do the work -
4. Also, if you don't mind me asking, what was the final cost for the engine and installation?
5. Are you happy with the 110 hp performance?
Many thanks for any feedback!
Stewart
 
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