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Old 07 November 2008, 13:42   #11
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On my KAD300 and I'd guess the KAD32, the supercharger blows at tickover while the engine comes up to working temperature. Then the clutch releases the drive from the belt and it drops to normal aspiration until the throttle is opened.

I don't know the change over revs for the 32 from supercharger to turbo but it's possible that when the supercharger clutch releases at speed the bearing, which then comes into action within the clutch, begins to scream. This would coincide with the turbo coming on song and could easily be presumed to be a turbo noise. Just guessing.
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Old 07 November 2008, 14:26   #12
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that would make sense, its probably a sealed ball race in the middle of the blower clutch?
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Old 07 November 2008, 17:54   #13
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On my KAD300 and I'd guess the KAD32, the supercharger blows at tickover while the engine comes up to working temperature. Then the clutch releases the drive from the belt and it drops to normal aspiration until the throttle is opened.

I don't know the change over revs for the 32 from supercharger to turbo but it's possible that when the supercharger clutch releases at speed the bearing, which then comes into action within the clutch, begins to scream. This would coincide with the turbo coming on song and could easily be presumed to be a turbo noise. Just guessing.
Thats the sound i thought could be confused with a turbo bearing, i had just lifted the cover while bob was driving and seen that clutch kick in and start to scream , by the way it expanded I presumed it was some sort of governer It does make a fair noise when the cover is off
Anyway its all clearer to me now what was going on there .
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Old 08 November 2008, 14:24   #14
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Thats the sound i thought could be confused with a turbo bearing, i had just lifted the cover while bob was driving and seen that clutch kick in and start to scream , by the way it expanded I presumed it was some sort of governer It does make a fair noise when the cover is off
Anyway its all clearer to me now what was going on there .
Do you mean it makes the noise when the clutch disengages and the turbo charger takes over from the rootes blower? if so theres probably a pair of 5 bearings in the middle you can press out and change like on an aircon clutch?
I have done a few of them, silent with the aircon on, scream like a banshee when you turn it off.
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Old 08 November 2008, 16:00   #15
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Do you mean it makes the noise when the clutch disengages and the turbo charger takes over from the rootes blower? if so theres probably a pair of 5 bearings in the middle you can press out and change like on an aircon clutch?
I have done a few of them, silent with the aircon on, scream like a banshee when you turn it off.

Its hard to say if the noise is normal without comparing it to another one . Its randski's boat and i just had a brief look at it after helping him fit new belts . When the revs increase to about 2k I guess ,the centifugal clutch opens up and there is a whirring or whining noise . I thought it was just the noise the compressor made ,
but if the clutch releases when it expands and the compressor stops turning and a bearing inside the clutch begins to spin then yes there could be a bearing making the noise in the clutch .

i thought the clutch was switching in the compressor as the revs increase and the noise was the compressor working
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Old 08 November 2008, 16:06   #16
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my understanding of compound charging is the turbos do the high rpm boost, the supercharger does the low rpm, and the supercharger disengages when the turbo starts to build boost, so if the noise starts at 2krpm then i would guess its the bearing n the middle of the clutch thats U/S
probably best to take the belt off and check the bearing with the clutch disengaged, if the bearing fails completley then the belt could do a bit of mischief too!
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Old 08 November 2008, 16:25   #17
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Its hard to say if the noise is normal without comparing it to another one ....
There should be no noticeable noise from the clutch. The blower makes a kinda mid range shoooooshy hiss.

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...the centifugal clutch opens up and there is a whirring or whining noise...
The clutch is electrical in operation. You should be able to find the wires and a connector in the vicinity of the clutch. You could check for a faulty clutch by increasing the revs a bit and the clutch should engage and be silent. Disconnecting the cable will prevent the clutch actuating and you would then hear the noise, if any.
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Old 08 November 2008, 17:04   #18
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Hmm 2 different theories here , don't remember seeing any wires etc the clutch is on the front of the pulley top left as you face the engine driven by a multi v belt and its silent untill the revs increase , comes in with a heavy click and appears to be centifugal force that does it .

I would like to see a manual

Are all Cad 32's the same? do they all have turbo's and compressors ? do some just use a compressor and no turbo ? I dunno never seen one before Bobs
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Old 08 November 2008, 17:56   #19
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you probably wont see the wires, they will be tucked around the back well away from the belt like on an aircon compressor clutch.
I am not saying its not centrifugal but i think its unlikley, to work properly it needs to disengage when the turbo generates boost so its more likley to work of a manifold pressure switch? after all the boost the turbo generates its not rentirely rpm reliant but load too, so the rpm at which it needs to disengage may vary. I suppose there could be a big overlap though, any i digress.......
sounds like you found the problem though!
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Old 08 November 2008, 19:58   #20
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Compressor and clutch

Note the cable and connector hanging from the clutch. The actuation is magnetic and the cable supplies the current to energise the electromagnet.
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