Volvo KAD43 running without compressor

[BruceK]

Contradicting nicely what Bruce infers in his diatribe of post #6 . .

How so? I'd agree with him. Maybe you should read past the first sentence.

 

[SimonD]

We considered a Broom 38cl that had KAMD44’s and concluded that they were just the wrong engines for that type of semi-displacement cruiser. Not many had them - most were Perkins or Yanmars.

May I ask why you concluded they were the wrong type of engine? Was it to do with the compressor?

 

[Chris_d]

Boating on Ye Thames.
Chum has a Faultline Brava 36 or 37 ( depending on the broker selling it) with pair of KAD 235 HP.
The constant racket and banshee howling of these engines along with the crunching lurch as the compressors cut in and out when the skipper desperately tries to maintain a constant 8 kms speed is less than relaxing !
Main memory of delivering the boat from Limehouse to Bray was trying to hang on as the boat surged back and forth and the racket from the engines while standing on the aft deck even though the patio doors were closed.
Some skippers fit a switch to disable the electro mechanical thingy that makes the blower engage ?
Just saying

There is no way he could be have been sticking to the speed limit if the superchargers were cutting in, 8 kph =5mph =4.3knts rarely more than 1200/1300 rpm on any AD/KAD twin engined boat on the Thames.

 

[Portofino]

How so? I'd agree with him. Maybe you should read past the first sentence.

You said this -
[“At the end of the day no matter what the opinions here are there is no manufacturer that will deliberately scupper their boat and reputation by putting in an inadequate engine, regardless of the back hand, unless Porto would have you believe that the "Nordic Schilling " practically bought the boat keeping the company profitable.”]

Why did they do it then ?
Move away from Perkins /Nanni for a SC KAD jobbie for mixed river / estuary use ? Do tell !

Clue ?️‍ £ / € / € ..

 

[SimonD]

I fitted the silencers off a KAD44/300. Made a massive difference to noise output. Ogura make the SC. It has an rev operting range that so long as it is not exceeded can run indefinitely. If I recall correctly that is 11k rpm. Obviously that is the SC rpm and not engine rpm. The SC is designed not to get you onto the plane quicker although that is a side benefit, it is designed so there is no turbo lag you get with a bigger turbo. It fills the gap it takes a smaller turbo to spin up and in addition helps a smaller turbo spin up earlier. i.e. your turbo will be making about 1 bar of pressure at 2500 rpm with the SC having given it boost but without the SC boost may only spin up to make 1 bar once you've reached 3k rpm on initial take off. Can you run without a SC or even turbo? Sure, if the pump smoke limiter is functioning properly it will sense a reduction in boost and retard the amount of fuel delivered accordingly. Opting for a smaller or finer pitched prop could absolve you of needing to run the SC at all if you dont need the torque to get over the hump. The previous owner of my boat disabled the the SC's and had finer pitch props on. The boat would leap onto the plane, wasnt fast, but could travel any speed within it's range effortlessly. The above being true for the 42 and 43 but not for the 44 and 300 where the SC becomes an integral part of ECU operations.

Many thanks for this. So, I have two choices: If, in practice, I spent long enough at the 'intermediate speeds' to make it worthwhile, I could replace the silencer to cut down the noise. Alternatively, I could switch out the compressor with no worries about 'excess fueling' as the smoke limiter would not let that happen. Brilliant! I think you've answered my question.

 

[oldgit]

There is no way he could be have been sticking to the speed limit if the superchargers were cutting in, 8 kph =5mph =4.3knts rarely more than 1200/1300 rpm on any AD/KAD twin engined boat on the Thames.

H,mm ,well it was me rocking to and fro as we proceeded between the locks using one hand to cling to the flybridge ladder and the other two to cover my ears.
The boat did not appear to be going that fast, assumed the folks gesticulating at us were waving in a friendly fashion.?

 

[Greg2]

May I ask why you concluded they were the wrong type of engine? Was it to do with the compressor?

Yes, it was. The Broom 38 is a very capable seaboat and the benefit of its SD hull is that it will sit comfortably at any speed, so being able to use the full RPM range is important. Losing a chunk to a wailing supercharger would be a notable downside IMHO. Another factor on that engine are reports of poor top end lubrication at low revs (displacement / river speeds), potentially with catastrophic consequences. Not an issue with the 43 as far as I am aware though.
.

 

[kashurst]

Running with the SC on for extended periods puts undue pressure on the spindle bearings and shafts of the other stuff connected to the same belts .The belt tension suddenly increases .A short 20 sec bursts is do able , but constant running ?? Bad idea .
This leads to premature failure of said items .

The bolt on nature of the SC in the development of the KAD series from its none SC base doner is the issue for prolong running .
The other component s on the belt we’re not specced for the additional lateral SC “on “ loads indefinitely.

There is possibly with some ( you need to do your own due diligence exactly which ? ) an issue with overfilling if you fit a switch or otherwise disable the SC belt.The rpm sensor tells the ECU once above the cut in - say 1400 rpm or what ever ,to feed more fuel in to match the additional air vol it thinks it’s gonna get .
Obviously if the SC is disabled then the fuel air mix becomes over rich , you are risking injector premature failure.

complete and utter drivel. If you are going to post technical information, please learn some basic physics, engineering, stop being patronising and some basic english grammar wouldn't go amiss either. Many engines in a variety of applications use belt driven superchargers that are run for long periods.

 

[Portofino]

complete and utter drivel. If you are going to post technical information, please learn some basic physics, engineering, stop being patronising and some basic english grammar wouldn't go amiss either. Many engines in a variety of applications use belt driven superchargers that are run for long periods.

Yeh designed from the drawing board up .
Comparing auto manufacturing none clutch belt tension jolting on components , durability to what VP evolved is a flawed .

The extra tension on the belt in a VP KAD set up if the SC s run continually strains the other pulley in the system spindles / bearings = premature failure .

Not so in a Merc etc as they were designed from a blank sheet for continuous running .

Sorry you lack he mental elasticity to differentiate.

A sign is the kads eat belts .Why ? When others do not ? What’s going on there ?

 

[Portofino]

complete and utter drivel. If you are going to post technical information, please learn some basic physics, engineering, stop being patronising and some basic english grammar wouldn't go amiss either. Many engines in a variety of applications use belt driven superchargers that are run for long periods.

Back up what you say ? I see like Bruce , a low ball insult go for the man not the ball over the grammar
Wondered how long you would take .At least it wasn’t your first post like Bruce’s .

post # 4 personally for you .
Post #8+10 for the SC disconnect supporters .

Enjoy guys .

Feedback Volvo Penta KAD 300 285 HP motor

 

[BruceK]

Low ball insult? Porto I was simply telling the truth. If you find that insulting you need to step back and take a good long look at your performance to date. We find it just as distasteful.

But to answer your question

Why did they do it then ?
Move away from Perkins /Nanni for a SC KAD jobbie for mixed river / estuary use ? Do tell !

That boat also came out with the AD41, they didn't move to 43 they evolved with engine development. I agree with Greg in that I'd also have chosen a Perkins Sabre given the choice. That by no means implies a 43 was inadequate, just a personal preference on what I feel should drive that kind of boat.
You do like to twist words to add to your argument but unfortunately I'm not playing that game. C'est la vie

 

[kashurst]

Yeh designed from the drawing board up .
Comparing auto manufacturing none clutch belt tension jolting on components , durability to what VP evolved is a flawed .

The extra tension on the belt in a VP KAD set up if the SC s run continually strains the other pulley in the system spindles / bearings = premature failure .

Not so in a Merc etc as they were designed from a blank sheet for continuous running .

Sorry you lack he mental elasticity to differentiate.

A sign is the kads eat belts .Why ? When others do not ? What’s going on there ?

Yet more misleading and technically inaccurate information. You really are not helping. Forum members on the mobo forum are often looking for help and good advice. Why do you post incorrect information and post links that support myths and gossip?
Correctly set up kad do not eat belts. If you or others have experienced this then whoever fitted said belts etc did it wrong, doesn't know what a torque wrench is or how to use it, or contaminated them with waxoyl or some other nonsense or fitted cheap copies.

Volvo Penta have been building engines for more than 130 years and sold them all over the world. The kad engines are probably the most successful marine engine ever produced. If you walk around any European marina 90% of the engines will be Volvo. Pretty much every sub 14m sports boat made before 2005 will have kads fitted plus a lot of sub 12m flybridges. There is a thing called product liability - a very big deal in the USA. If Volvo were not 110% happy with that supercharger design on kad and now D series engines do you seriously believe they would carry on with it?

Volvo, 130 years of global knowledge, thousands of qualified engineers, a world wide supply chain including Bosch etc al all think that design is ok. And then there is you.........

 

[SimonD]

Many thanks for the information on this. I'm happy to go ahead and decide what approach to take in the light of experience with the boat

Having found out a bit more about the boat in question, it turns out she's been used on the Thames from new, i.e. 23 years in fresh water, probably at low speed. So, I think we can assume the compressor has never run and the turbo hasn't been troubled much. Is this likely to have created any problems that will only reveal themselves when I get her in the sea and open her up?

 

[Momac]

Boating on Ye Thames.
Chum has a Faultline Brava 36 or 37 ( depending on the broker selling it) with pair of KAD 235 HP.
The constant racket and banshee howling of these engines along with the crunching lurch as the compressors cut in and out when the skipper desperately tries to maintain a constant 8 kms speed is less than relaxing !
Main memory of delivering the boat from Limehouse to Bray was trying to hang on as the boat surged back and forth and the racket from the engines while standing on the aft deck even though the patio doors were closed.
Some skippers fit a switch to disable the electro mechanical thingy that makes the blower engage ?
Just saying

I think you have no real experience at all of kad engines. If the boat in question was in and out of the supercharger range at 4.5kts it must have been seriously under propped or otherwise the superchargers cutting in way too early.