re-powering a CSY 37

[Geof Filson]

My poor old 4108 needs to be replaced. two Yanmars at 39HP and 54HP have been recommended to me. Does anyone have any experience with re-powering and have advice on the matter?

Also if anyone in St. Thomas or area is interested in buying a 4108 for parts, this one has a newly rebuilt injection pump, newer starter, new salt water pump, good heat exchanger, new fuel return line, good Borg-Warner velvet drive transmission and for someone who wants to nurse it back to health, somewhat frozen block.

[Daq Hanssen]

With all that new stuff, why don't you rebuild the block.....?

[Warren Daniels]

I know that your engine is around 50 to 55 hp, if you wouldn't mind a little higher h/p engine, why not look into a Cummins 4b3.3 .  They are increadably rugged, they make 50 horse power at  1800 rpm and a max h/p rating of 65 at 2600 rpm.  The last one I looked at that would go in this walkthough didn't need a velvet v drive transmission.  Just a straight out shaft.  Saving weight and adding to fuel econ.  I know if I ever have change the westerbeke in this boat, I'll go with a cummins.   Low rpm means higher fuel econ and longer life for the engine. 
Warren

[Geof Filson]

I've rebuilt the block once and I am tired of fighting with it. The engine has always been cranky. I

 have to use a v-drive on the 37. I know that the 44 is a straight shaft.

[Warren Daniels]

Not always.  My present westerbeke transmission combination has a Borg Warner Velvet "V" drive in it. 
Warren

[bob lewis]

Geof;
I repowered my 37b hull #82( about 2 years ago ) with a Yanmar 50 HP non-tubro 4 cylinder
( model 4JH4-SE ). Had to put a 3 inch exhaust in, but not a problem. There was a lot of cutting down of the engine stringers, but again, not a problem.

Now all is fine. Smooth and quieter.
I don't see how you could use any more horsepower. Actually a larger engine at low power is not a good plan. The 50 hp of this engine gives me hull speed at 1800 rpm and full power at 3000 rpm is just a BIG waste of fuel. As the drag of the squatting stern won't allow much more speed. ( if you check the specific fuel consumption graph on any engine you are considering, you can determine the best rpm and horsepower output for fuel burn)
A Cummins will be heavier than a Yanmar and both require the Vdrive for a CSY37. The Cummins is likely taller and that is not a problem for Warren's 44wt BUT may not fit in our 37s.

( just for info - CSY put v-drives in the first about 20 hulls of the 44 wt - then used a straight shaft for the rest. Yes, any 44wt can be changed to straight shaft with just a little reworking of the stringers. )

Good luck and let me know if I can be of any help.

Aloha   Bob 

[Warren Daniels]

You could use a cummins 3bt engine.  It is 50 hp and only 3 cylinders.  It is quite short.  Research it and it might work for you.
Warren

[bob lewis]

Warren;
I went with a marine engine by a manufacturer which has worldwide support. After 2 years, I can't imagine a better choice.

Aloha   Bob

[Larry Scheer]

I put the 54 hp non turbo 4 cyl yanmar in GIGI CSY 37 in 2000. I kept the velvet drive. David Kummerle put a yanmar in last year with a yanmar v drive. Any advise needed just ask.