Thanks again for your help Super T, I apprieciate it, Jeff
Cobra, as I said... I may be a little harsh and it may be a different and better product, it's just that I've been told that story before. I've had problems with the KAD44 package and was assured that KAD300 will be the business. Well, no luck even though Volvo people were always there for me and do stand behind their product (over here at least). However, this does not eliminate downtime. And I really didn't want any downtime on a diesel-powered 40' express cruiser which tops out at 40 mph. It's not like I bought a 120+ V-bottom with blown V8s. So, maybe DPR will work out, I'm trying to keep my mind open but I do have a bad taste in my mouth.
Jeff, I would go with a twin 440 application and it's just a question of balance. If I had a choice b/w a 3 engine and a 4 engine application, I would choose a 4 engine boat for the same reason. The only reason a 3 engine setup would be better is if you can get on plane with only two engines running. But with two 315s, I doubt it. In terms of consumption, I believe it would be a close call. Not sure but I even have the feeling that the twin boat would do a bit better in terms of fuel economy.
In terms of Arnesons vs. Weismann drives, I believe Weismanns would be a bit faster getting on plane and would be easier for docking. But not really sure, I don't know Weismanns very well, not a great deal of experience there. I believe that Arnesons are not bad for docking. It takes some time to get used to them but they're OK. However, I do believe Arnesons will give you a higher top end. So IMHO, it's gonna be a slight advantage to Weismann for getting on plane and docking, slight advantage for Arnesons in terms of top end performance. Not really sure though...
As far as tuning Yanmars is concerned, just turn up the fuel supply. About 500 to 550 can be done safely, after that I don't really know. I've heard stories of over 600hp. with more extensive modifications (turbo) but don't know how well that worked or if it happened at all.
Seateks are realible if you do your maintenance regularly. Don't expect to get the reliability usually associated with diesels. My experience is: 250 to 300 hours, they need to be serviced, the sort of thing I expect you would do with an HP500 after say 100 hours. After 3 of those, a full rebuild is required so you could go for up to 1000 hours before this is required. Then, the best thing to do is to pull them and send them back to the factory where they rebuild them better than new. It's costly but then you basically have new motors with a 6 month warranty (may be 1 year now since new EEC regulations stipulate that). How many times you can do that before you have to bin the block, I don't know... But in general, it's how you treat them. With proper warm-ups, regular oil changes and routine checkups, I've seen people do 500 trouble-free hours without opening them. Then again, I've seen people behaving badly and needing rebuilds after little over 100 hours. BTW, this is for versions with closed cooling. If you can fit the exchanger and don't mind the extra 80 lbs. or whatever it is, take them. Actually, even if you do mind the extra 80 lbs, do not make that mistake because it is a big one...
Thanks again for your help Super T, I apprieciate it, Jeff
http://compmillennia.com/index.php/lightspeed/ Building composite fishing and pleasure catamarans.
Super T what do you mean by do not make that mistake it's a big one?Originally Posted by super termoli
Again is there any mfg putting these in a go fast with a single engine?
I want to be able to call Pantera or Formula and order a 28'-30' with a single diesel set up right at the factory.
I've looked into this a few times and think it is the wave of the future. Everyone thought I was crazy when I suggested it in 96, now its much more common. Biggest problem is till the drive. How big a problem depends on you opinion. I spoke at lenght with Cummins and Yanmar in 2001 about building a Eliminator 36 cat with twin TDs. Cummins had done extensive testing with the Bravo but found they consistantly failed around 1200-1400 hours. The testing involved running the engine at 100% and cyling the prop in and out of the water on a big vertical sled. Basically simulating the worst conditions possible. This was a regular Bravo, so the XR and XZ should last longer. So who cares if it lasts 1500 hours, the second problem is the rpm range. You need a two speed tranny if you want to go fast. If you prop the boat for 80 mph, the props are too big to get on plane and if you go smaller you lose top speed. So now we need a tranny. The dream solution to me is to get the new Ford 6.0L powerstroke into a boat. It has a very broad power range with a max rpm of around 4000, making it much more managable. Pair that to an Bravo XR and put two of them in a 30-35' and you have a great package. Maybe someday, for now I am happy with my 525's. BTW, how about a turbine!!!!
Is there a 2 speed diesel trans available?
Twin Fords......YEAH BABY!
It would be heavy but the ride would be nice. I could afford to drive the thing at least.
Trying to bring this post back.
When I was in Cape Cod a couple weeks ago I spotted a twin cat powered Outerlimits dry docked. Looked like something was being worked on but not sure.
Man those were some huge exhaust pipes on that mother!!!
Just to wet your appetite a little. We are prototyping and testing a current V-8 electronic twin tubo diesel motor that will be 500HP+ -750+ torque and will run thru a semi-automatic 2 speed tranny and a bullet proof outdrive. The whole package weighs about 1450 lbs with closed cooling and will fit in most boat engine compartments. Will obvoiusly cost more than gas engine package, but when you consider mileage, crusing range and engine life it will be attractive to many, including those damn insurance companies! Should push most performance hulls equal to about 550HP gas and get a lot better mileage.I can't discuss specifics now but it should be ready for market in about 9 months. I'll keep you posted when I can discuss more.
Ray @ Raylar - "Where innovation fuels applications"
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