Wow! What a difference. I have a 43 in my boat, so I know exactly what your talking about. Good luck on the sea trial. Looks like a nice clean setup. I am interested in the performance change. Keep us posted.
A couple of questions for you...
Looks like the exhaust is outlet through the transom vs. through the drive. Is that the case?
You have another season under your belt on the Halibut Grove - how many hours are you up to? Any comments on your experience to date?
Do these engines have some sort of variable geometry turbine on their turbo?
Do the drives have engine driven power steering or a seastar retrofit?
Vek, we decided to do thru hull exhaust for a couple for reasons. I've had a customer who did a swap keeping his existing Volvo 290 and exhausted through the drive but found that the bubbles from the exhaust were impacting his transducer while in neutral so he decided to thru hull the exhaust. He found that his EGTs dropped as a result and was seeing slightly better fuel economy as well. The second reason was to just reduce any heat transfer into the drive from the exhaust. Anything to keep them cool is a good thing.
Originally Posted by Vek
The first engines imported and installed in the Halibut Grove were variable geometry, Garett turbos. They since have gone to a fixed vane version and the latest version has a water cooled turbo bearing housing and heat shield. I'm on my fourth season using the FNMs and up to 2600 hours total. Since the 300hp engine are just as compact, I've considered upgrading but since I'm already cruising at 29-30kts I'm not sure the extra cost is worth another 2-3Kts.
The drives have a hydraulic cylinder powered by the motors hydraulic pump. You can use a Seastar system but I've found the best thing to use is a standard Teleflex or Ultaflex rotary helm and cable. The steering is much more responsive. We yarded out the hydraulic system in the Bold Eagle and opted for the Ultraflex. No more need for a suicide knob on the steering wheel just to make a turn.