Aquastar 38 purchase - Survey & Sea Trial tomorrow
- Thread starter superheat6k
- Start date
Portofino
Well-Known Member
Apologies.Await Trevors view .
petem
Well-Known Member
The Volvo manual does not say...
"Actually the manual does pertain to operation rpm iirc .
Say s something like cruise at 200 rpm or 400* rpm of WOT ."
...as you said in an earlier post.
What is says is
"Avoid running at full speed to obtain the best operating economy. We recommend a cruising speed of at least 10%
lower than the maximum rpm at full speed (wide open throttle)"
Note the words "at least 10% lower".
I wold suggest that you have a look at the definition of "continuous" in the dictionary.
Sorry, but you are wrong. There is nothing in the VP manual or the Ogura that suggests that these superchargers cannot be run continuously.
petem
Well-Known Member
Talk about desperation!Same part PeteM ……..irrc “ 911 “
View attachment 129419
View attachment 129421
A few yrs apart and very different.
Car analogies are always irrelevant. In this case, 911's are commonly know by the model designations 993,996,997, etc.
petem
Well-Known Member
We've had this discussion before but Porto keeps regurgitating nonsense. It's important that the truth is told.
Portofino
Well-Known Member
Those two have 911 on there arses though .Chosen carefully to illustrate sometimes part numbers are the same but as time goes by differences crop up .
The Kad + D 6 are not the same .
petem
Well-Known Member
I didn't say they were the same.
What I am saying is that the Ogura low inertia TX model super charger is fitted to both engines. And that supercharger is rated for continuous use.
Or do you think that Ogura TX low inertia supercharger fitted to KAD's is somehow fundamentally different to the Ogura TX supercharger fitted to D6's and somehow the latter is suitable for continuous use and the former isn't?
I know you've got a massive chip on your shoulder for Kad engines but this really is getting ridiculous.
What I am saying is that the Ogura low inertia TX model super charger is fitted to both engines. And that supercharger is rated for continuous use.
Or do you think that Ogura TX low inertia supercharger fitted to KAD's is somehow fundamentally different to the Ogura TX supercharger fitted to D6's and somehow the latter is suitable for continuous use and the former isn't?
I know you've got a massive chip on your shoulder for Kad engines but this really is getting ridiculous.
SC35
Well-Known Member
It might be rated for continuous use, but on most correctly propped planing boats, continuous use implies that either you are late for lunch at the top of the harbour, or that you are failing to get planing.
Either way, either book lunch a bit later next time, or clear off the fouling and get planing properly.
Either way, either book lunch a bit later next time, or clear off the fouling and get planing properly.
Portofino
Well-Known Member
Yeh and nothing saying you should either it’s silent except what I pointed out .
Exactly 10% of wot is near enough 400 to drop it waaaay over 2800 the SC upper limit .From 3900 or what ever .
Did you miss the “ irrc “ bit ?
They have a clutch to prevent continuous running .Why in the KADs?
Crikey a clutch for gawd sake to run them intermittently.
Permanent SC applications do not have clutches .Blimey !
The internal components of KADs can’t cope and the internals of the engines as well to sustained permanent SC + turbo running Its either or ..
Now as the D6 evolved circa 2018 it got whole new set of revisions of the pistons , head , gudgeon pin and much more to cope with the uplifts .The latest version might well have a newer ( 25 yr tech ) Ogura SC capable of and designed for continuous running .But we not talking 2022 D6 fitted to IPS .
KAD 300 irrc was run from 2001 - 2004 .Older Ogura .
You are comparing that 1972 911 with a 2020 something because they are both badged 911 .
I have no skin in this game but do not want anyone to get the idea running a KAD full time / continuous/ normally with the SC running is recommended it ain’t .
If you do = ££££ repair bills sooner .
Basics
The whine .
Car SC s those permanently on have a gentle whirl , hum .
They do not scream of whine like the KAD Ogura .What do you think that is Pete ? It’s the metal on metal “ chips “ forming .
There own blurb says so .Infact counters it with its special surface coating which is meant to catch the “ chips “ you know minimise ingestion of metal into the combustion chamber .
No chip on my shoulder the” chips “are from Ogura SCs
.I had a kad and ran them above 3000 out of SC range but below 10:% or what ever of wot …….As they were intended .
This is about the suitability of of re powering this boat with KADs .If Trev end up running it at a speed predominately whereby the SC s are continuously creating “ chips “ and heating the oil and wearing bearings for hrs and hrs .
I am suggesting its a bad idea to run one of theses continuously in the SC range .
Those Ogura s will not stand it .
petem
Well-Known Member
The issue is that that a semi displacement boat might be in the supercharger rev range for more time than a full planing boat might be. Assuming the noise is bearable, it's therefore quite important to understand if the superchargers will wear prematurely as they're £3k a side to replace (re-builds might be feasible).
petem
Well-Known Member
What a load of old waffle. KADs have a clutch because the turbo is a better solution for higher revs.Yeh and nothing saying you should either it’s silent except what I pointed out .
Exactly 10% of wot is near enough 400 to drop it waaaay over 2800 the SC upper limit .From 3900 or what ever .
Did you miss the “ irrc “ bit ?
They have a clutch to prevent continuous running .Why in the KADs?
Crikey a clutch for gawd sake to run them intermittently.
Permanent SC applications do not have clutches .Blimey !
The internal components of KADs can’t cope and the internals of the engines as well to sustained permanent SC + turbo running Its either or ..
Now as the D6 evolved circa 2018 it got whole new set of revisions of the pistons , head , gudgeon pin and much more to cope with the uplifts .The latest version might well have a newer ( 25 yr tech ) Ogura SC capable of and designed for continuous running .But we not talking 2022 D6 fitted to IPS .
KAD 300 irrc was run from 2001 - 2004 .Older Ogura .
You are comparing that 1972 911 with a 2020 something because they are both badged 911 .
I have no skin in this game but do not want anyone to get the idea running a KAD full time / continuous/ normally with the SC running is recommended it ain’t .
If you do = ££££ repair bills sooner .
Basics
The whine .
Car SC s those permanently on have a gentle whirl , hum .
They do not scream of whine like the KAD Ogura .What do you think that is Pete ? It’s the metal on metal “ chips “ forming .
There own blurb says so .Infact counters it with its special surface coating which is meant to catch the “ chips “ you know minimise ingestion of metal into the combustion chamber .
No chip on my shoulder the” chips “are from Ogura SCs
I had a kad and ran them above 3000 out of SC range but below 10:% or what ever of wot …….As they were intended .
This is about the suitability of of re powering this boat with KADs .If Trev end up running it at a speed predominately whereby the SC s are continuously creating “ chips “ and heating the oil and wearing bearings for hrs and hrs .
I am suggesting its a bad idea to run one of theses continuously in the SC range .
Those Ogura s will not stand it .
You say that Ogura's won't stand continuous running but have given no proof or references to back up your claim.
I've given citations for everything I've said.
Regarding whine/noise, I pointed that out in my first comment.
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SC35
Well-Known Member
I think if I owned such a boat, and for example top speed was 24kts and cruise was 17kts, I wouldn't want that 17kts to be with superchargers engaged.
If only for noise / belt wear reasons.
Sea trial would make that obvious either way?
D4-260 kompressor is electronically controlled, and doesn't come on in any fixed rev range.
It's entirely possible to get planing without it engaging at all.
Not sure if KAMD300 is similar.
Previous KAD32's kicked in at fixed rpms.
Several of the newer D4/D6 engines for shaft drive have no kompressor at all: it might be worth considering why that is.
Also consider that a KAMD300 is the very highest output from the 3.6L block - I'd quite happily have these in a lighter boat with a high top speed where it spent most of the time dialled back.
I remain to be convinced that it's a great choice for a heavy semi-D boat.
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Flynnbarr
Well-Known Member
I thought accepted wisdom on a heavy SD boat was big lazy six cylinder lumps that bumble along with the occasional burst not 3.6L screaming banshee’s?
Volvopaul’s opinion would help…..maybe he's given it to the op and it’s not relevant at all ?
Volvopaul’s opinion would help…..maybe he's given it to the op and it’s not relevant at all ?
Bigplumbs
Well-Known Member
I think maybe the point was to start a separate thread so people can argue with Porto all they want. So as not to mess up this thread
petem
Well-Known Member
KAD300 compressor is set to come on between 1000rpm and 2800rpm - a wide band.
Belt wear is another good point. We used to have a twin KAD32 Targa 30 that we kept in Port Solent. It was quite a schlepp to get through the harbour so we used to motor at just under the 10kt speed limit. Even on a brand new boat the engine room got filthy with belt dust.
"I remain to be convinced that it's a great choice for a heavy semi-D boat" - Irrespective of the durability of the supercharger, I agree.
petem
Well-Known Member
Of course, there is another option. A lot of KAD44/300 users in the US use their boats for fishing. They install a switch that overrides the engagement of the supercharger. I'm not a fan of messing with things but it doesn't seem to do the engines any harm.
Perhaps it's because the KAD44/300 electronically governed fuel pump delivers just enough fuel for the demand? It must know that the supercharger isn't engaged and can adjust fueling accordingly. @kashurst any thoughts?
If this is a route that Trevor wishes to go down then some research would be advisable.
Perhaps it's because the KAD44/300 electronically governed fuel pump delivers just enough fuel for the demand? It must know that the supercharger isn't engaged and can adjust fueling accordingly. @kashurst any thoughts?
If this is a route that Trevor wishes to go down then some research would be advisable.
Portofino
Well-Known Member
Only the 44 .
The 300 s electrotwackery…..it’s EDC needs SC working a signal otherwise as you say you start to get into fuel mapping issues .
The brochure of the KAD 300 states “high speed planning boats “ or words to that effect .
The SC side is only to lower the torque spread it down lower rpm during acceleration.Which is great for the hole shot in a high speed planer .
Prolong SC use with KADs version will shorten its life for the reasons I have already discussed.Basic engineering principles.
https://ogura-clutch.com/downloads/editorials/OguraSuperchargesintoMarineDieselMarkets.pdf
Bruce here —— @ #4
supercharger
I stand by my recommendation to NOT were possible run kad SC s continuously. In the interest of longevity.
Use them as intended to hole shot a fast planing boat .
But let’s wait and see how the sea trail went with this specific boat .Get sone real rpm / knot numbers and see if it’s a workable re power ?
petem
Well-Known Member
Wrong again, the KAD44 and KAD300 are essentially the same engine with a few modifications to get a little more power out of the block. The technology is identical (same number of sensors, etc).
Portofino
Well-Known Member
Nope you can’t do it Pete thats my point . Simply switch them off .I was working from first principles of the EDC electrotwackery side ….you know figured it out as normal .
Its the none EDC where it splits the lower 42 /43 s you can fit a switch .
My point stands .Your idea is nuts .
Stop trying to polish this turd of a motor for a heavy SD .
Off switch for a supercharger on a volvo diesel
petem
Well-Known Member
As I said, there are many people in the States who already do this on KAD44/300.Nope you can’t do it Pete thats my point . Simply switch them off .I was working from first principles of the EDC electrotwackery side ….you know figured it out as normal .
Its the none EDC where it splits the lower 42 /43 s you can fit a switch .
My point stands .Your idea is nuts .
Stop trying to polish this turd of a motor for a heavy SD .
Off switch for a supercharger on a volvo diesel
You really need to keep an open mind. That way you might learn something.
