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S&S Swan General - Perkins 115 replacement swan 65 ketch
02 July 2014 - 10:01
Join Date: 30 June 2014
Posts: 1

Perkins 115 replacement swan 65 ketch
New poster, posting here;
we are looking to replace the original Perkins 115 hp slant motor on a swan 65 ketch.
Has anyone any experience as to what recent engines might fit this space including getting it down through the centre deck hatch way (hatch removed)?
Presently trying to decide whether a second rebuild of the Perkins or a complete replacement is best way to go.

02 July 2014 - 10:58
Join Date: 01 March 2007
Posts: 147

Hi Phil,

This is the same question I faced 3 years ago with my 47' - the Perkins still worked but carried huge hours as did the gearbox etc. I opted for new and went for the 75HP Yanmar and new drive train. We took the opportunity to re line/re wire at the same time - I am really pleased with it. It is physically smaller than the Prima M80 it replaced and slid thru the hatch fine. The clinch was selling the Perkins on ebay which more than paid for the labour with change left over.

Sarabande 47/029

03 July 2014 - 04:19
Join Date: 24 April 2009
Posts: 36

I just replaced my Perkins 4.108 with a Yanmar and am happy I did so. I was spending a lot of money keeping the old dear running, had to cancel a couple of cruises due to breakdowns, and got sick of worrying about it. Plus, I felt like there was nothing I could do to keep it from dripping oil. It was original to the boat (1976), rebuilt once, and we (and the prior owners) certainly got our money's worth from it but it was time to move on.

03 July 2014 - 16:02
Join Date: 02 January 2008
Posts: 1547

Hi all
I think it would be of interest here to provide some information about the rather peculiar engine installation on the early Swan 65's. Perkins H6.354M was mostly used, i.e. a horizontal version of the well known 6-cylinder engine, but laying on it's side. This engine is unusually low, and fits easily below the saloon floorboards.
A photo of this engine here below.
Unfortunately Perkins laid down the production of this version about halfway through the S65 series, later hulls mostly got Volvo TMD41 engines, which just fitted in.

Dear Jim
Would suggest there are several engines which fit, what are your preferences?
Assume that you intend to increase the power somewhat, here some considerations.
The propeller diameter is restricted and this limits the power it can absorb. Increased blade area helps, it would be advisable to go to maximum diameter and 4 blades, and to choose a suitable reduction ratio. If the existing shaft otherwise is in order it's strength needs to be checked against the new requirements.
If you need help with these things pls let me know
Kind regards


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