Getting close on an Ocean 46. Looking for surveyor recommendations for hull and Series 60 engines. Thank you in advance.
Your going to need a MTU/DD shop for the best Series 60 survey. Sadly, the later DDs are under the MTU brand. I do like the 60s. There was some bugs in the earlier exhaust manifolds and alternator brackets that were to have been corrected long ago. Still a fave in the large cars.
Prop question from the survey. Engine would not turn up to rated rpms. Owner says: The current S&S props that are on vessel now are; 28 X 38 4 blade #8 cup NI.. The original props from Ocean Yacht (spares) are; Hy-Torq 28 X 36 4 blade M-cup boat propellers. Huge difference between the 2 sets. Several years ago when I was doing a lot of off shore tournament fishing, I outfitted the boat with custom S&S props to meet several objectives. Reduce the white water at the corners of the boat while trolling, add pitch at the mid-range RPM of engines to better maximize the manufactures torque curve for speed, efficiency, and GPH. Also on the list was to reduce noise, singing, and vibration while ultimately catching fish closer to the transom. The 2300 is the engine horse power usage while the engines torque curve is in the 1500 -1900 rpm range. I am trying to keep a long explanation brief. Understanding that the engines de-rated at the 2250 -2270 rpm range is probably correct. If I put the original wheels (spares) back on with the lesser pitch, the engines would not reach 100% load prematurely and would not overheat the charge air and go into de-rate. 2300 would easily be achieved with original wheels and 100% load would be moved up over the 2300 rpm mark. Please note that the current prop & engine configuration was designed for the use in which we operated or ran the vessel for highest efficiency and comfort. The 2 props that are currently on vessel cost over 11K. If further discussion or explanation is required, please do not hesitate to ask. I also have the latest prop scan reports on the S&S props for the buyer to review or have for his records for future tuning or adjustments. Opinions on the above proping potentially damaging engine or reducing life. Thanks
I would have some pitch backed off on the S+S props so the engines achieve 2335-2350 WOT full full. Would 30-50 rpms really hurt the engines, probably not, but might shorten the life a little.
As info only: my 1983 46 Sunliner has 24" 3 blade, 23-1/2, props. Full load RPM is 2500. From the notes I have found on her, the previous owners did run her at cruising speed, making 24 knots.