Engine type for Sunshine 38

[me1982]

We own a 1989 Sunshine 38 with a Yanmar 3GM30 engine.

We want to purchase a new engine, and would be happy to get a slightly stronger one.

Is there a way to know which engine models fits a Sunshine 38?

[Damir]

The best is that you stay with same type engine is easiest and best solution. All you must is adjust for new engine (shaft, blocks , batteries, water inlet, fuel tank and space for this engine. If you planning to change this is not simple job as you think. If is done correctly is ok but if not you running ok at sea you are in problem.

I have Sun shine 38 and i am satisfied with YANMAR engine

[dbostrom]

As damir says, changing engine models is a choice full of emergent problems. If the present engine will take the boat up to hull speed without excessive strain there's little or no benefit to be had from dropping in something more powerful. 

Depending on what you're trying to achieve it might be worth playing with the prop?

[Damir]

What bostrom say you can playing with the prop if yo have 2 blade to change with 3 blade and folding prop but if is to big will kill engine also wrong angle will do the same for every mistake boat must out to repair and readjust alo this job is for service not for amateurs. Wou know where you start but where you finish and expence come nobody know where will end. First try go get good workshop information and price also guarantee for this job

regards Damir

Read more: jeanneau.proboards.com/post/new/3486#ixzz3LNVS3ZQa

[me1982]

Thank you very much, both.
The main issue we have with the engine, is that in reverse the boat takes a very long time to respond (in comparison to many other boats).

What size propeller is recommended for this engine?

[Damir]

First you have to know that now you have a propeller on a boat that I'd go to a modification (perhaps you have an image of the propeller). Maybe it's a problem if the folding prop with two blades, one can observe vibrations  with three blades may not open completely. Try diver inspect propeler

The best and cheapest is to invite experts to review the propeller and by his recommendation, or decide what right now is looking for a serious company to make proposals propeller for your engine and boat

I have a propeller with three blades from the German company BOY-PROP from 1987 without any problems

Type S-3 16 "pich 13"
My prop is Nr1 / 189

Shaft diam 25 mm

their e-mail is [e-mail]
Fa. Boyens
Schnackenberg
Dompfaffenweg 38
22147 Hamburg
Phone: [phone]
Fax: [phone]
Mobil: [phone] + 49 (0) 171 7743078

Damir

[dbostrom]

Further to damir's good advice, it's apparently a quirk with some folding props that they sometimes hesitate to unfold when going into reverse so that's something else to check along the lines of "is it just stuck?"

As well, some folding props are not as effective in reverse as they are going forward.

So maybe the first thing to ascertain is, do you have a folding prop and if so what make and model, so you can scan for other people's experience with the same make and model. There are differences as much as 50% between forward and reverse bollard pull in a single design.

Here's a really excellent review (PDF) of folding props, done somewhat scientifically, describing a few quirks and other characteristics (including reverse performance) of 15 popular designs.

(fixed blade props also show differences in performance between forward and reverse but I don't have useful source of information for those)