Ad31 v kad32

Bigplumbs

Bigplumbs

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Hello all

I am looking at Sealine S23's and S24s and I see that most have the KAD32 Engine but some have the AD31 engine and these tend to be a good £10K cheaper boats, What are the main differences between these 2 engines

Thanks

Dennis
 
The KAD32 has a supercharger, and 170hp instead of 150hp.
It doesn't sound like much of a difference, but having owned both ... it is!

KAD32 has more mid-range punch because of the supercharger, which makes it faster to get on the plane.
Also it revs a bit lower at cruise speed.
And it sounds better :p
But both are good engines.
 
20hp and a supercharger!

I've had both and can say that the kad feels like a much more powerful engine, especially in acceleration. This is of course all down to the supercharger providing oomph while waiting for the turbo to kick in. The ad feels a bit pedestrian in comparison, with quite a lot of turbo lag.

The plus side of the ad is no supercharger noise. This is important in a small boat, as sometimes the sea conditions will mean you want to run at reduced speed. The continuous supercharger noise at these slower speeds is quite tiresome.

Bottom line is whichever one you get, the other will seem preferable at certain, but different, times.

If £10k isn't a make or break amount, I would probably go with the kad. If that amount is the difference between being able to buy the boat or not. I would buy the ad.
 
CLB said:
20hp and a supercharger!

I've had both and can say that the kad feels like a much more powerful engine, especially in acceleration. This is of course all down to the supercharger providing oomph while waiting for the turbo to kick in. The ad feels a bit pedestrian in comparison, with quite a lot of turbo lag.

Very good reply and very helpful thanks very much

Dennis

The plus side of the ad is no supercharger noise. This is important in a small boat, as sometimes the sea conditions will mean you want to run at reduced speed. The continuous supercharger noise at these slower speeds is quite tiresome.

Bottom line is whichever one you get, the other will seem preferable at certain, but different, times.

If £10k isn't a make or break amount, I would probably go with the kad. If that amount is the difference between being able to buy the boat or not. I would buy the ad.
Click to expand...
 
Bigplumbs said:
Hello all

I am looking at Sealine S23's and S24s and I see that most have the KAD32 Engine but some have the AD31 engine and these tend to be a good £10K cheaper boats, What are the main differences between these 2 engines

Thanks

Dennis
Click to expand...

Whilst you are correct, the reason for the £10K isn't the different engine, it's because it's a completely different boat.

The AD31 went in the Sealine 240/S24, the KAD 32 in the S23/S25. The latter is a far more modern boat (as well as being physically newer of course, being the newer model). That's the real difference - hence the price gap.
 
I don't think the S24 was offered with an ad31 and certainly the s23 was offered with the kad32 diesel - or petrol engines.
http://www.britboat.com/boats/s24/engines
the s23 certainly would not have been offered with an ad31.
I used to have a S23, with kad32 , owned it 6 years, and would say the kad32 was adequate with two people aboard ( and enough clothes etc for a holiday) . I would imagine ad ad31 might struggle.
The earlier S24 is very similar size to the S23.
 
My 2001 S24 had a KAD32.
S240 (same boat) was offered with various engines, one of which was an AD31 with 150hp.
 
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My pontoon neighbour was showing me his S24 yesterday, that had a KAD32. Struck me that it was a lot of engine in not a lot of space and access to anything that was not at the top did not look easy!
 
dpb said:
My pontoon neighbour was showing me his S24 yesterday, that had a KAD32. Struck me that it was a lot of engine in not a lot of space and access to anything that was not at the top did not look easy!
Click to expand...

You'd need to be an anorexic person-of-diminished-stature (can you say "dwarf" these days?) to change a starter motor or a steering rack, but everything else was accessible enough.
 
dpb said:
My pontoon neighbour was showing me his S24 yesterday, that had a KAD32. Struck me that it was a lot of engine in not a lot of space and access to anything that was not at the top did not look easy!
Click to expand...

You are right on that point.

We have the S23 with KAD32 fitted and access is a bit of a pig to some parts of the engine. Service items are easy enough to get at though.

To the OP. I would personally buy the newer boat with the KAD32.

You are getting a newer package all round. We have friends with an S24 with an AD31. It does feel a much older boat and is really quite slow onto the plane and has a lower cruising speed.
 
CX54WEK said:
You are right on that point.

We have the S23 with KAD32 fitted and access is a bit of a pig to some parts of the engine. Service items are easy enough to get at though.

To the OP. I would personally buy the newer boat with the KAD32.

You are getting a newer package all round. We have friends with an S24 with an AD31. It does feel a much older boat and is really quite slow onto the plane and has a lower cruising speed.
Click to expand...

With the KAD32 what sort of speeds are you getting. I also see them with Mercruiser 4.2 ltr petrol which I think are 220 hp but of course are petrol. Again the petrol versions seem to be cheaper but of course I can get red diesel at half the price of petrol. Would you ever consider the petrol version

Regards

Dennis
 
Bigplumbs said:
With the KAD32 what sort of speeds are you getting. I also see them with Mercruiser 4.2 ltr petrol which I think are 220 hp but of course are petrol. Again the petrol versions seem to be cheaper but of course I can get red diesel at half the price of petrol. Would you ever consider the petrol version

Regards

Dennis
Click to expand...

We were offered a petrol one when we bought ours 9 years ago. Didn't even consider it as petrol availability where we are was at the time dire.

We are currently paying 75ppl for red diesel at the marina. Petrol there was £1.50 a litre prior to the pump being set on fire when a petrol boat went up in flames!!!

Top speed with the diesel is about 30 knots with a comfortable cruise at 25 knots.
 
Check the ad 31 is 150 , older ones are 130hp
Bigplumbs said:
Hello all

I am looking at Sealine S23's and S24s and I see that most have the KAD32 Engine but some have the AD31 engine and these tend to be a good £10K cheaper boats, What are the main differences between these 2 engines

Thanks

Dennis
Click to expand...
 
Bigplumbs said:
Would you ever consider the petrol version
Click to expand...

No.
Not at the price of fuel . With duty added at the 60/40 split red diesel is something like 95p per litre at the moment . Petrol at the marina £1.45. Plus the petrol boat consumes more quantity of fuel.
Also the scarcity of petrol at the waterside would limit our range and the search for petrol would spoil our holidays . I experienced this when we travelled with a petrol boat. Lugging jerry cans of petrol is no fun at all.

If your were to do just trundle up and down a river half dozen miles from the home berth and half dozen times a year than petrol would be okay.
 
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