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Message board > Engines > Diesel Engine replacement for a hardy seawings 234

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Message 1 of 4
Posted by member Keith Montgomery on Tuesday 4 July 2017

Hi, I own a 1991 Hardy Seawings 234. At the moment it is powered with a Volvo Penta 250A 146hp petrol engine. I am thinking up replacing this petrol engine with a suitable diesel.
I know there was a choice of diesel or petrol engine fitted when they originally were produced, the former being a volvo penta AD31
Just wondered if any HOC member has carried out this job as I would be grateful for any advice and help with this subject. I am told that there's the possibility of fitting the likes of a volvo penta KAD 32 with a 290 Duo prop leg.
Thanks Keith Montgomery

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Message 2 of 4
Posted by member Simon Kidd on Monday 10 July 2017


I don't know of any KAD32's having been fitted, but it would seem a well-suited engine for the task. I have seen a Mitsubishi conversion in 234 - though I doubt it provided any great performance. Check the overall dimensions of the KAD32 against the AQAD31 - just in case the height is greater with the KAD32 and it's worth checking the weights - the AQAD31 wasn't a light unit - so beware if the KAd is significantly heaver. I seem to remember the engine compartment of the 234 is very wide so the space taken by the compressor shouldn't be a problem.

A D3 160 or 190 might also be a good fit if you can find one, but most do prefer to KAD for its simpler mechanicals.
You may need to fit new engine bearers - it might be worth getting photos and dimensions of the engine bearers from an AQAD31 equipped 234 - as Hardy may have fitted difference sized bearers. (Fairline for instance used to fit completely different bearer designs between their Petrol and Diesel powered boats).

Best Regards


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Message 3 of 4
Posted by member Keith Montgomery on Monday 10 July 2017

Hi Sid,
Thanks for your reply, yes it would be well worth it to check the bearer centres for the AQA31 diesel on the 234.
A D3 190 would be the job but again you may be talking a retro fit with the old engine out, the transom hole filled and then cut to suit new D3 drive, if no conversion plate was available.
I see the Seawings 277 has a AD41 with duo prop drive at 200hp, have you any knowledge of those engines, I also like the layout of that boat.
Regards keith

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Message 4 of 4
Posted by member Simon Kidd on Friday 14 July 2017

Hi Keith.

I have surveyed and Sea trialed a Seawings 277 with the AQAD41P and we owned a pair of 41A's for years in a Fairline. The 41 is a nice engine - basically, a 31 series with an extra 2 cylinders at 3.6L capacity, in the 277 it's not a bad match at all, quite a nice setup for cruising in the teens and the odd bit of 26 knot hooning, she is not the fastest of sports cruisers but adequate. The P series of the 41 was the last of the line and tended to be a fairly clean running unit with a decent bit of "go", the earlier 41A's and B's were quite smokey units though none the less good workhorses. All these engines are older now, so an engineers inspection is strongly advised.


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