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Old 05 November 2003, 15:47   #71
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???

Just to recap whats the best Diesel?
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Old 05 November 2003, 15:50   #72
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Rover

Check this for lots of info on Redbay Cabins and pics slightly off the point
http://rib.net/forum/showthread.php?...ght=cabin+ribs
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WHEN THE CAT IS AWAY THE MICE GO TO REDBAY..............
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Old 05 November 2003, 17:07   #73
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Thanks for the pics gavin . JW, torque determines acceleration and is more of a "real-life" measurement than power, as power is something which really only affects the top end performance. So what is the torque value? (please tell me no matter .what you think of the previous statement)
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Old 05 November 2003, 19:46   #74
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Power is the product of torque and rpm. Your notion that the two are entirely separate is incorrect. When an engine is described as being 'torquey', it usually implies that the engine produces a good measure of power at low(ish) rpm. There is no such thing as 'a torque value'. It can only be quoted at a given rpm. It is the turning force applied by the engine.

For the KAD300, max. torque occurs at approx. 3350rpm and it's value is about 573Nm.

Something else you need to consider is the duty rating of the engine. This is related to the length of time the manufacturer considers it is advisable to run the motor at full power.

The Yanmar 6LPA-STZP's continuous max. power is 255hp @ 3600rpm. The KAD300's is (reading from a wee graph) approx. 262hp at 3400rpm.

Somthing else, again, is the power produced before the turbo becomes effective. This will determine the driveability of the boat in a biggish sea where you need to be able to climb the faces of the waves. This is the reason Volvo use a supercharger on the KAD motors.
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Old 05 November 2003, 21:06   #75
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That's significantly less torque than the Yanmar. It manages 740Nm at only 2600 rpm and has above 700Nm between 2200 and 3200rpm. That's hard to argue against.

That has definetly got me leaning more towards the yanmar, but the point about the turbo kick in point means i'm still not entirely sure.

JW, do you use the diagnostic ability of the EDC equipped KAD? Is it useful? The EDC offers so many other benefits that make the engine more refined, quieter and more economical than the Yanmar, which is a big plus. However the boat will be based on a reasonably remote island where the simplier technology of the yanmar makes more sense. But then the volvo is 1500 cheaper. This ain't going to be an easy decision .
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Old 06 November 2003, 03:22   #76
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Quote:
Originally posted by Redbay Rover

That has definetly got me leaning more towards the yanmar, but the point about the turbo kick in point means i'm still not entirely sure.

.
Point is that if you a driving heavy on the throttle as you invariably have to in a big sea and you need to rapidly apply power to lift the bow to meet a sea the turbo lag could really give you a problem. Those few seconds delay could make all the difference.

I've driven a Yanmar 300 equipped boat and its not an insurmountable problem but you do need to keep the revs in the the turbo band for better response. Problem is that conditions might mean that this is too fast to be comfortable.

I'm no expert on diesels and its your hard earned at the end of the day. My only comment would be to be wary of Bravo 3x drives on the Yanmar - they are very much the weak link!
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Old 06 November 2003, 05:17   #77
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Well all this talk about engines just got me more confused.

What about this baby, it will run on allmost anything.

http://www.turbokart.com/turbineboat.htm


Oki, I know it's not a RIB, but just take a look at the engine, stuff that in the RIB and your out of here. Not too heavy, but you might need to do something about the noise.


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Old 06 November 2003, 05:57   #78
DGR
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Make: Ribcraft
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MMSI: 235020218
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Yanmar vs Volvo...

I might be missing something here, but if the decision is between the Yanmar and the Volvo KAD300, what's wrong with the Mercruiser?

Any horror stories out there?!? Or is it merely that the Yanmar and Volvo are just 'better' in some way?

Answers on a postcard......

Dylan...
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Old 06 November 2003, 06:02   #79
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Engine: 315hp Yanmar Diesel
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Mercruiser

I have seen 2 mercruiser diesels go bank and a few in Belgium where the bearings have blown which is quite common on these engines and it costs about 1900 to replace them. I personally dont like them as.


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Old 06 November 2003, 07:51   #80
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Quote:
Originally posted by Redbay Rover
But then the volvo is 1500 cheaper. This ain't going to be an easy decision .
Not when I bought mine! The Volvo was close to 2500 more expensive. You're either getting a poor deal on the Yanmar or a good deal on the Volvo. However, you can get a KAD44 a good deal cheaper and this is also an option, given that both the Yanmar and the KAD are not rated to use full power for prolonged periods.
If it were me, at this time I'd be waiting to see how the new engines pan out. The D series Volvo looks very good but it's more weight and, at present, more cost. It's capacity is big so it'll produce good low-down power. Volvo have produced a new, allegedly, drive to go with it.

Just over a year ago, I was where you are and it's a difficult decision. What swung it for me was the failure rate of the Bravo drives and the benefit of the supercharger. If you are down on the South Coast where you are likely to get help without difficulty, then a leg failure is just a leg failure. Up here, when out on the water, it is rare to see other boats except for commercial traffic. A leg failure is going to mean a rescue. If you are travelling in a remote area, you are f***ed. For that reason, I have a diesel outboard. It's still in the back of my car at present, but it'll be mounted soon.
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