KAD44s swapped with KAD300s on Sunseeker Superhawk 34 - advice needed

Bradm

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Hi all,

We’ve just sold our boat and seeking a replacement.

I’m seriously considering a Sunseeker Superhawk 34 and there’s one example I’ve viewed with the following engine history;

  • From new in 1999 it came with KAD44s
  • In 2014 the engines were replaced with KAD300s, however one was manufactured in 2002 being a KAD300, and the other being a 2004 KAMD300
  • These engines in 2014 came out of a ‘project boat’ with only 15 hours.
  • They now have circ 160 hours

Whilst the hours are low, this S34 has suffered mechanically since last year, needing the turbos, elbows and superchargers being replaced amongst an array of other issues such as wiring, seacocks, alternators, water pumps, bow thruster etc. Approx £50k has been spent since August 2018!!

My question is, can you simply unbolt a KAD44 and replace with a KAD300, without doing anything to the original legs? Which is the case with this example?

Are there any issues running a twin engine boat with different engines, a KAD300 and KAMD300? I appreciate they both push out 285hp and are very similar, but they’re not identical.

Any advice would be greatly appreciated.

Regards

Bradley
 
The KAMD is the shaft version of outdrive KAD engine. The exhaust and gear selection will have been changed to enable the KAMD engine to be mated to an outdrive.

160 hours is low for a Turbo and Supercharger to require replacement. 15 hours on these engines over a 10 year period (2004 to 2014) seems a little suspicious to me. Was it on the water all that time? I guess the exhausts could have been the original KAD44 ones so that's understandable.

Seacock replacement on a 21 year old boat sounds right to me. Water pumps, alternators and bow thrusters don't last forever.

I don't believe that VP ever mated KAD300's to DPE legs but could be wrong.

All sounds a little bit Frankenstein to me. If I was interested in the boat I'd be interested to see who did the £50k of work (totting up the parts in my head only comes to £25k or so and none of them are super time consuming to fit). I don't think I'd want to pay top dollar for it particularly at this time of year when there will be others appearing on the market.
 
Many thanks Petem, my thoughts exactly, it doesn't quite add up.

The yard who fitted the engines in 2014 buys bankrupt stock, so that's where the engines originated.

As you say, those engines must have sat around for 10+ years doing nothing, then it hasn't helped with those engines only having done 160 hours from 2014. That certainly wouldn't have helped the turbos.

We know that the KAD300 is a perfect fit for this boat as that's what Sunseeker installed from factory, but what about the KAMD300 engine? Will this affect the performance of the boat with it running two different engines? Or if the exhaust and gear selection were changed will this engine perform the same as the KAD300 with no issues?

Whilst I have concerns, I have very little knowledge of engines, so maybe this isn't such a big issue and the reason for all the historial problems is due to the boat having sat around doing very little hours?

I've Googled but can't find the answer - what's the difference between the DPE and DPG drives? What issues do the DPE drives have volvopaul?

With purchasing a boat of this age I'd also buy a comprehensive warranty policy on the engines for 12 months.
 
Many thanks Petem, my thoughts exactly, it doesn't quite add up.

The yard who fitted the engines in 2014 buys bankrupt stock, so that's where the engines originated.

As you say, those engines must have sat around for 10+ years doing nothing, then it hasn't helped with those engines only having done 160 hours from 2014. That certainly wouldn't have helped the turbos.

We know that the KAD300 is a perfect fit for this boat as that's what Sunseeker installed from factory, but what about the KAMD300 engine? Will this affect the performance of the boat with it running two different engines? Or if the exhaust and gear selection were changed will this engine perform the same as the KAD300 with no issues?

Whilst I have concerns, I have very little knowledge of engines, so maybe this isn't such a big issue and the reason for all the historial problems is due to the boat having sat around doing very little hours?

I've Googled but can't find the answer - what's the difference between the DPE and DPG drives? What issues do the DPE drives have volvopaul?

With purchasing a boat of this age I'd also buy a comprehensive warranty policy on the engines for 12 months.

The KAD300 and KAMD300 are identical (same HP etc) other than the former being mated to an outdrive, the latter being mated to a gearbox and shaft . As far as I know, all you'd need to do to convert a KAMD300 to a KAD300 is unbolt the gearbox and bolt on an outdrive (and re-program the ECU which controls the actuators for the outdrive gear shifting).

The DPE drive was mated to the KAD44 which was rated at 260hp. the DPG drive was introduced alongside the KAD300 and is presumably stronger to cope with the extra torque / HP that the KAD300 generates.
 
Thank you again.

This has been invaluable feedback and also having spoken with a Volvo dealer, I'll be passing on this example.

The hunt continues. If anyone know's of a good Superhawk 34 coming up for sale please do let me know.

Many thanks again.

Bradley
 
Note that the KAD44 and KAD300 are identical other than a slightly different Turbo, a different Injection pump and some changes to the EDC system.

... as well as a different cylinder head, a different seawater pump, and mated to different sterndrives ...

Are they really identical twins, or more like siblings?
:)
 
Not to be negative but why have 2 different engine variants?
It sounds like a project boat even if its not why didn't the previous owner put an identical engine in if one had failed beyond repair.
 
Exactly, red alarm bells!

The broker now tells me, yesterday afternoon, that the gears in the outdrives were uprated to accomodate the extra HP from the engines. Nonetheless I'm ruling this one well and truly out.

Thank you for all your help.
 
Exactly, red alarm bells!

The broker now tells me, yesterday afternoon, that the gears in the outdrives were uprated to accomodate the extra HP from the engines. Nonetheless I'm ruling this one well and truly out.

Thank you for all your help.

Think you might have saved a chunk of cash and a giant headache there
 
Exactly, red alarm bells!

The broker now tells me, yesterday afternoon, that the gears in the outdrives were uprated to accomodate the extra HP from the engines. Nonetheless I'm ruling this one well and truly out.

Thank you for all your help.
Gears updated what a load of rubbish , broker knows nothing , that’s a lie . DPE is a 3 piece casing drive .
DPG is a 2 piece drive same lower case but updated upper case .
I’m wetting myself at that statement.
 
Many thanks Petem, my thoughts exactly, it doesn't quite add up.

The yard who fitted the engines in 2014 buys bankrupt stock, so that's where the engines originated.

As you say, those engines must have sat around for 10+ years doing nothing, then it hasn't helped with those engines only having done 160 hours from 2014. That certainly wouldn't have helped the turbos.

We know that the KAD300 is a perfect fit for this boat as that's what Sunseeker installed from factory, but what about the KAMD300 engine? Will this affect the performance of the boat with it running two different engines? Or if the exhaust and gear selection were changed will this engine perform the same as the KAD300 with no issues?

Whilst I have concerns, I have very little knowledge of engines, so maybe this isn't such a big issue and the reason for all the historial problems is due to the boat having sat around doing very little hours?

I've Googled but can't find the answer - what's the difference between the DPE and DPG drives? What issues do the DPE drives have volvopaul?

With purchasing a boat of this age I'd also buy a comprehensive warranty policy on the engines for 12 months.
With the mix up of engines and drives I doubt you would get a watertight warranty .
no one had mentioned insurance yet , no company would pay out for damage or failure to a bodged uk unprofessionally installed set up .
 
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