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We tuned the props and had the Volvo tech come out to certify the D-4's.

Went smooth, no problems.

With the Volvo computer hooked up we got the following info for final setup at the owners cruise speed.

WOT engines turn 3600.

2800 rpm cruise
22.5 knots
67% engine load
7.5 gallons per hour burn each engine(total 15) with his 263 gallon tank, that would give him a 15 hour run time and a 388 mile range.

Not bad at all.

Volvo tech and I talked quite a bit. Has not seen much problems with the D-4 and 6 series engines.
He agreed with me that they are the easiest of all electronic engines to setup and install.

We talked about the ips drives.

He's seen an bunch. The transmission is part of the drive.

They are designed to break off it you hit something real hard at a point that won't breach the hull and leave you floating. Drives are nibral construction.

They are a module design that is lowered in place delivered by Volvo to the boat maker. They are not for repowering as the boat has to be designed to use this drive system form the start.

They have a joy stick control for steering and throttle control with both drives acting independantly for remarkable docking or manuverability.

Steering 100% electronic.

His comment about the Cummins/Merc Zeus drive was they were having problem getting the steering system to work properly.

He gave it a big thumbs up.

Bruce, if you get a chance to run a boat with the joystick, do yourself a favor and take it. Every person I've seen use it, including me, can't help but grin...

CMP

After talking with him in depth about the technical aspects and construction I will track one down. With the boat show next week it might happen.

Anything that is hit hard enough to break off the drive would drive a pair of struts up thru the hull.

I've seen aluminum outdrives hit stuff pretty hard and not shear off. An no the tilt up function under those circumstances does not really work.

And unless you can stop the water from comming in, replacing the drives will be cheaper than repairing a sunk boat.

There was some talk on this board about the testing that Volvo was doing - I think it was Kevin - Any results or observations?

The Cummins/MerCruise people have been testing the Zeus drives here in Islamorada. They welded up a huge steel frame that sits just beneath the surface and ran over it a few times with a Zeus-equipped Sea Ray. They definitely tore some stuff up but they have been pleased with the results, by all accounts. It sounds like very thorough testing.

Using a Sea Ray as a test platform is a wise choice. If a Clorox Bottle Boat can survive a sheared lower unit, better quality boats will have little to fear...

Are they doing a full structural survey on the hulls after the impact, or only looking at the drive damage?

Br,

Patrick

Pretty sure they're doing structural and drive damage inspections. They had a ton of engineers down here and are coming back soon for round 2.

There is one question I have on the performance of these drives that I have not seen in any articles about them. I know we all have our thoughts on them good and bad. But in all of the articles, no one has said how the boat performance changes in heavy weather. We know that at times in rough seas the props will some times come out of the water.
What happens to that same boat with the drives. It would seem to me that the tendancy to grab air might be greater on a steep wave. As the bow goes up and over the top, do the drives clear the top of the wave and come out of the water before the bow is ready to come down the back side.?
If the dirves do grab air, then there is a loss of propulsion and I would think the boat would want to slide back or the bow would want to fall off the wave. On a shaft driven boat since the prop is all the way in the stern, the boat continues to be pushed up and over the top of the wave and in the case of some people maybe launched off the wave but thats another story for another day. Tony Meola

I don't think ventilation will be an issue. The IPS props may be slightly forward from where conventionally shafted props would be, but not much. And if the props were airborn before the bow came down in steep waves, it seems to me you'd be driving the boat way too hard for the conditions.

And if the props were airborn before the bow came down in steep waves, it seems to me you'd be driving the boat way too hard for the conditions.

This can happen at nine knotts........every seven seconds.....for eight hours.

Ask anyone who has been out to the canyon with me......

Mike knows!!

Mike,
Your an animal.

anyone look at shinecock inlet yesterday....bet it was pumping.....10 foot groundswell and northwest winds.....tubeular

Was not that bad early like 7am but maybe after I left it got big

Mike, been there & know that feeling. Tony Meola