KAD 44 Supercharger

Dazzajohm

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Hi all,

I'm sure I've seen the answer to my question on here somewhere in the past but after search I cannot find it now.

Is it OK to run a KAD 44 within the supercharger range?

Obviously it's far more enjoyable to run at 6knts either before it kicks in or after the turbo has taken over because of the bloody noise it makes but I was told by an engineer when I got the boat that I should never run it for too long with the charger running as something or other can heat up and eventually will cause damage (I'm not mechanically minded). Another engineer has since told me that's rubbish and as long as you can put up with the noise it's perfectly fine to run the engine with the charger engaged.

It's easy to say just keep to either 5/6 knts or 20/22 knts but sometimes (if it's a bit lumpy) I might want to stick at 12/15knts and want to make sure it shouldn't blow up :-)

Cheers
D
 
I have occasionally run my kad32's in the supercharger range with no issues that I am aware of.
However it is probably not economical to do so. I therefore keep this to a minimum.
 
No it won’t it will place the engine into limp mode and throw up a fault code .

Paul, I assume the pre EDC engines would try and run as before (no error) but you'd run the risk of over fuelling?

Also, before anyone suggests this, neither the KAD44 or KAD300 manuals discourage users from running with the superchargers engaged. Personally, whilst I wouldn't want to run with the superchargers on all the time, I wouldn't be concerned with running them for the odd hour or so if conditions dictated.
 
Paul, I assume the pre EDC engines would try and run as before (no error) but you'd run the risk of over fuelling?

Also, before anyone suggests this, neither the KAD44 or KAD300 manuals discourage users from running with the superchargers engaged. Personally, whilst I wouldn't want to run with the superchargers on all the time, I wouldn't be concerned with running them for the odd hour or so if conditions dictated.

+1

You’ll generate more belt dust and a bit of additional heat, but I’d be happy to run one for an hour or so if it meant comfortable progress. I wouldn’t recommend disconnecting the clutch wire on a KAD44/KAD300, although you can do this on KAD32/KAD43 you are probably running at a point on the load/speed curve that was not intended, with unknown consequences. A new supercharger clutch isn’t the end of the world.

The manuals only advise to stay out of the range where they are kicking in and out continuously.

I’d definitely be double-checking the supercharger oil level.
 
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Personally, whilst I wouldn't want to run with the superchargers on all the time, I wouldn't be concerned with running them for the odd hour or so if conditions dictated.

It would be poor design if that was not okay.
I would say avoid running on the point where the supercharger cuts in or out as i feel this may stress the clutch.

On some engines the supercharger runs all the time - my wifes mercedes car for example.
A supercharger is a compressor . These can run many hours in industrial applications. Thay get an easy life on a boat .
 
Paul, I assume the pre EDC engines would try and run as before (no error) but you'd run the risk of over fuelling?

Also, before anyone suggests this, neither the KAD44 or KAD300 manuals discourage users from running with the superchargers engaged. Personally, whilst I wouldn't want to run with the superchargers on all the time, I wouldn't be concerned with running them for the odd hour or so if conditions dictated.

No risk of over fuelling as the boost pressure opens the fuel rack with boost pressure on the 43 series non edc engine , controlled electronically on the 44 and 300.
 
+1. There is a lot of myths about in the boat world. A kad supercharger is pretty much the same as a Mercedes or Jag supercharger which I believe, is permanently engaged
 
Great, think this has helped me a bit thanks...

So in summary, although of course in an ideal world we dont want to run it with the supercharger on, if conditions dictate I need to slow down a bit I wont do any harm running it with the charger on for an hour or so.

The supercharger is regularly maintained along with the rest of the engine so I'd hope it's all in good condition :-)

Cheers
D
 
OK, so how do I check the supercharger oil level?
Am I right in thinking it kicks in at 1200 rpm and off again at 2500 when the turbo kicks in?
So if I want to just plod along, keep below 1200rpm? I guess the super charger will remain idle, is there any benefit this as opposed to say 1500rpm with the SC engaged?
I have to say I've never noticed the noise.
 
I have to say I've never noticed the noise.

I notice the superchargers on my kad32's - on sterndrives . (I used to have single engined s23 and the noise from the supercharger was very loud due to being very close to the engine bay and a much smaller boat.
But on my pals F36 the engines are (from the flybridge) so well muffled you don't hear much at all.

Supercharge dipstick/filler is hex plug on top of supercharger.
 
Will check that oil at the weekend, thanks for the info

Always drive from up top, F36 so probably explains why I can't hear anything
Last boat was a twin diesel sports cruiser and quite noisy underway so the the Sealine feels quite calm by comparison
 
Ogura the OEM , in their marketing blurb tout their clutch as reducing wear and increasing longevity by only bringing in the root charger when necessary. Volvo tout the root charger as a boon to getting onto the plane. None say it's bad to run on the charger continuously, but you wouldn't expect them too. Comparing these chargers to those on cars etc is an apple orange affair. Each is built specific to it's intended purpose. And one also should look further than the charger itself to ascertain whether its good or not. Plenty anecdotal evidence on some KAD variants that sustained use of the root charger will cause the black box to over heat. I can believe that. Here is one of mine off a KAD42. Then there are other factors such has heated compressed air, that riding in that range you are lugging the engines neither on the plane or wholly out. If you are ever in doubt on that score watch what your engine temps do during that particular transition. If ever you were going to overheat that is the most likely point. i.e. even if the root charger can take sustained use, overall it is not a good place to be - IMHO

 
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