Kad 300 supercharger advice

[jon and michie]

Hi - I took the boat out today after a rest period of a month so there was growth on the Hull.
So was slow to start with managing to get to 2700 rpm.
However this was for a while at these rpms.
After a while we heard like a screatch noise which didn't sound normal so we dropped the rpms right off and limped back to our marina.
After about an hour I re started the engine which sounds quite normal again.
Could I have damaged anything??
Jon

 

[Portofino]

Clean your props , lift them up and reach over .
Find a AF that works local to you .

 

[jon and michie]

Clean your props , lift them up and reach over .
Find a AF that works local to you .

Thanks Portofino literally I have just done them in readyness for tomorrow.

 

[jon and michie]

would long periods of super charger use possibly damage it ?

 

[Portofino]

would long periods of super charger use possibly damage it ?

Yes .
We have had arguments on here many times .You need to drill down into the particular Ogura modus operandi .

 

[petem]

would long periods of super charger use possibly damage it ?

Nah. Could just have been a slipping belt or tensioner issue. Unlikely to have done any serious damage. Just have a good poke around and see if anything is amiss.

Give it a scrub too and see what happens.

 

[petem]

Incidentally,. it's worth checking your supercharger oil level in case a lazy mechanic hasn't done it.

 

[Portofino]

Incidentally,. it's worth checking your supercharger oil level in case a lazy mechanic hasn't done it.

Adding to Petes good advice, it shouldn’t be coffee coloured .It starts off almost clear and iirc should be replaced every 200 or is it 400 hrs ? - consult the service manual to check that .
Not related to the oil level ……but …

I did 1000 hrs in my KAD 300s and never had any SC clutch issues what so ever .I never ran it continuously in the SC rev range iirc 1400- 2800 rpm .Either under or over .Not in between .
No fryed clutch, no electrotwackery over heating , no ECU burn outs , no fuse tripping etc etc .

 

[jon and michie]

Thanks for your replies so far - I have scrubbed the props - and started the engine yesterday after some cooling time and it sounds quite normal now - the belt appears to be OK will double check the tensioner - I changed the oil level about 2 - 3 years ago and still looks normal not coffee coloured.
Hopefully get her out Today for a run and will report back.
Jon

 

[jon and michie]

Right I have just checked the tensioner and appears to be ok no wobbling when tightened up (checked without the belt on).
However when I restarted the engine and leet it warm up a bit so the supercharger clutch dis engages and quietens down - I put the edc lever in neutral mode and started to take it up to 1500rpm I heard a small squeel which lasted about a second then if I took it up quickly to 1500rpm there is a large whining noise (like being at a saw mill) and at the back near the turbo the connecting rubber expands.
I will up load a video shortly.
Jon

 

[BruceK]

The Ogura Supercharger can be run indeffinetly provided it's speed does not exceed 11k rpm. At 2700rpm engine you must be approaching that. In those instances the main back bearing can heat up and start degrading it's oil seal but they are pretty damn robust. However once that seal is gone the whole SC needs replacing as it is epoxied in and so non serviceable

 

[BruceK]

Right I have just checked the tensioner and appears to be ok no wobbling when tightened up (checked without the belt on).
However when I restarted the engine and leet it warm up a bit so the supercharger clutch dis engages and quietens down - I put the edc lever in neutral mode and started to take it up to 1500rpm I heard a small squeel which lasted about a second then if I took it up quickly to 1500rpm there is a large whining noise (like being at a saw mill) and at the back near the turbo the connecting rubber expands.
I will up load a video shortly.
Jon

This being the connecting silicon rubber hose on the inlet manifolds? They will ballon but should not leak. However the saw mill sound is almost certainly a loose crank to water pulley. They will operate just fine being slightly loose until you load up the supercharger or even the alternator charge. When they slip it can make the most horrendous buzz saw sound rather than squealing. Particularly prone to this if the engine has stood for a while and you have flash rust development on the pulley surface

 

[jon and michie]

@BruceK so only short runs up to 2700 then the turbo takes over and the supercharger rests for a while

 

[BruceK]

no, you can safely run your supercharger indefinetly except at the limit of its revs. Think of it as a car engine. Good for 200 000 miles unless you race it at max revs around the race track at Le Mans. 11k is it's max revs. I surmise but havent worked it out that 2700 engine rpm must equate to that. So extended periods at that speed should probably be avoided. However say it only reached 8krpm and that gave you 15 knts, well then, carry on doing 15 knts to your hearts content. However if you want to go balls to the wall the supercharger is designed to spool up a rather small turbo (the combination eliminates turbo lag). At this point (2500 - 2700 rpm )the turbo should really take over and release the SC. However turbo wear can leave a torque gap and the transition is not always as seamless as it's meant to be.

 

[BruceK]

However turbo wear can leave a torque gap and the transition is not always as seamless as it's meant to be.

or an air leak in the manifold system

 

[jon and michie]

Right just checked water pulley (I did adjust this the other month).
There is about 10mm play on the belt but on the pulley there is a bit of movement
not much.
When I take the revs up slowly everything seems fine - if taken up quickly then the squeel / whine kicks in.
@BruceK - I will send the video via email

 

[BruceK]

I will wait on the email. In the meantime do the Volvo Paul trick. Run the engine with the SC engaged and double check each joint and seal with a piece of tissue paper for any leaks. Eliminate that first. 10mm play in the crank pulley to to water pulley belt is not the best measure. A belt tensioner tool is best but bear in mind this belt is meant to be tensioned to 65-75kg when new and 40 -45 kg used. If you arejust using spanners that is a eat your weetabix first and give it welly when tightenning

 

[jon and michie]

Disregard my last post as I miss identified the pump the pump above is the steering pump - got to the circulation pump with the other tensioner on - does this belt need to as tight as the supercharger belt as I can turn the tensioner around by hand?
Jon

 

[petem]

Can you post the video to YouTube?

 

[BruceK]

Just seen your video. 100% crank to water pump pulley based on my experience. If anything else sounds like that I havent heard it.