Repower Yanmar 4JH3E to a 4JH57

[Angus Beaumont]

Hi, Has anyone done this swap from a yanmar 4JH3E to a 4JH57? even better if you have done it in an Island packet 40.
I would be interested to know what alterations were required to the engine bed to make this change.
Thanks.

[grande4]

So happens that I have the same plans! I have an IP38. I'm at a standstill and living on the boat in Mex. Reparable but I want to replace. The dealer here is out for the holiday season. I've done a lot of sizing things up at this point. And,yes, I am at the mount brackets and securing the mounts in probable new place issues. Would a WhatsApp , US phone connection, or email be of more practical use here? Two basic questions; 1. Do the IP brackets I have (not Yanmar) fit the 4JH57 and can be used? 2. With a KM35P it seems that the mounts will need to move aft @ 2". Originally there are plates embedded in the fiberglass bed. Would these extend that far aft for new holes? Give me a reply if you see this and thanks!

[CassidyNZ]

As far as I know, all 4JH engines are the same “family” so have the same block and the same flywheel housing (onto which the engine mounts attach). So other than maybe exhaust connections and raw-water pipes, mounting points should be the same.

A quick call to any Yanmar dealer could confirm this except that some may throw a range of red herrings into the discussion to generate work for their workshop

[grande4]

The Yanmar dealer here in Mex. is apparently on vacation till next year. Yanmar is quite territorial so its hard to get much out of distant dealers so it seems. Given the designs to replace 4JH with 4JH it would seem logical that the block and flywheel would take the brackets from the previous engine. Being IP , not Yanmar, one wonders if there could be some interference, particularly in the front. To fit prop shaft position and the eng. compartment as well, a KM35P gearbox would seem to be in order and that looks like moving the attaching to bed bolts aft. A need to fiberglass in metal for the female threads perhaps. How to do that? And, yes, you have to be careful who you ask about what.... Thanks for the reply.

[CassidyNZ]

My Yanmar 4JH3E is mounted to the wooden engine beds with 100mm long 316 SS carriage bolts screwed directly into the timber. Been like that for at least 12 years that I know of and guaranteed a lot longer that I don’t know of and I’ve had the back set out twice to work on the engine. No sign of deterioration in either the beds or the bolts.

Sometimes I believe people over-think these things. Eight 3/8” carriage bolts are plenty sufficient to ensure the motor never moves. But of course if you believe that threaded inserts are going to be better, go for it.

[grande4]

The bed is fiberglass and threaded metal strips are glassed in and to match the engine mount machine screws, 3/8". No wood. No accessibility for putting nuts and washers on the end of the bolts. I can't move the position and put screws in fiberglassed material. Nothing to grab, just would break off brittle material.... If the original metal pieces extend aft far enough , 2+ in., then new threads could be made in the original pieces if it all lines up... No one available at Yanmar this time of year here or in Florida. Cheers!

[Angus Beaumont]

Good to hear you are also looking at this. I will pm you my mobile and we can WhatsApp. What I know is on IP’s the aft engine mounts are higher than other boats so you will have to remove the engine brackets off the old engine and use those on the 57. Other than that my engineer assures me there is not too much to do but I am not 100% convinced.

[sailorboy1]

I have a friend with a sister boat to my that has done the swap. It took some new custom motor mounts. In the total project this wasn't a big deal.

[grande4]

Angus, I'll look for a PM. Yes, it finally dawned on me that the brackets are Island Packet. And the bed on the 38 is raised a few inches before the aft mounts. The 40 seems to be also, then. And I use WhatsApp here in Mex.....