Motor swap

[NH Tooner]

I'm looking at an 87 Sundancer 270 with four-cylinder engines. Can I swap them for v6 or v8 with no problem as far as bolting them in


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[kevin27]

I think the engine mount grid was different. Sound like a big project. Better to find a boat with the engines you want.

 

[Rick K]

My neighbor did it. Monsterous pain in the ass. Then he had to swap drives, to match up to the engines. Not sure about the engine grid and all that, but I imagine that putting a V8 where a 4 once sat would require some mods or some new/different parts.

 

[keokie]

I would look into this. It may be very easy. I have done a number of engine swaps. Folks always tell you nothing will fit/work etc. Generally, you find things work very well. There is a good chance that the stringers on all the twin 270's were the same, and that the mounting locations are the same as well. I could be wrong, but I would verify that, before guessing it would be a problem.

 

[sdarc]

Go into the Sea Ray archives and see if this boat had V8's available. I would bet that there will be work needed for the upgraded outdrives.

 

[Sal A]

I swapped out a 4 cyl mcm180 to a 4.3 on a regal I had big pia had to glass in new mounting blocks. Boat sucked in so many ways after. Sold it 1/2 way threw the first season with the new engine for 1/2 what the engine cost. Buy a boat set up the way you want it too many deals out there

 

[270win]

I'd get one the way you want it...exponentially less expensive in the long run.

 

[keokie]

In general, I agree that buying the boat with the right power is best. However, when you start talking about buying boats from the Reagan era, there are some considerations. Like you could buy one with 350's, and then need to replace them and the drives. You can always piece meal repair, but you can never be sure how close you are to a catastrophic failure of 3 decade old machinery. This can end up costing you more in the long run. Then you have to add in the insecurity of how safe and reliable you are. A breakdown can have consequences beyond just monetary.

So... if you really want an '80's 270 (which is a great boat), and you want reliability, and maybe even current technology like EFI, new engines may be just the thing. If that is the case, you want to find a desirable example in terms of structure and condition that you can lowball due to undesirable power. Then use the additional funds for a contemporary re-power.

This would not be my first rec for how to own a boat, but if it fits you parameters. It can be a good way to go.

Also, twin 350's was a pretty common option on that boat, and they performed exceptionally well with them. It is likely, Sea Ray used the same stringer grid in all the twin 270's. That is why I say the conversion may be very straight forward.

 

[grande85]

In general, I agree that buying the boat with the right power is best. However, when you start talking about buying boats from the Reagan era, there are some considerations. Like you could buy one with 350's, and then need to replace them and the drives. You can always piece meal repair, but you can never be sure how close you are to a catastrophic failure of 3 decade old machinery. This can end up costing you more in the long run. Then you have to add in the insecurity of how safe and reliable you are. A breakdown can have consequences beyond just monetary.

So... if you really want an '80's 270 (which is a great boat), and you want reliability, and maybe even current technology like EFI, new engines may be just the thing. If that is the case, you want to find a desirable example in terms of structure and condition that you can lowball due to undesirable power. Then use the additional funds for a contemporary re-power.

This would not be my first rec for how to own a boat, but if it fits you parameters. It can be a good way to go.

Also, twin 350's was a pretty common option on that boat, and they performed exceptionally well with them. It is likely, Sea Ray used the same stringer grid in all the twin 270's. That is why I say the conversion may be very straight forward.

I have 1981 255 sedan bridge with same set up and the twin 350's were an option the front motor mounts will need to be changed. The transom assembly may need to be changed as well, depending on how new you upgrade to.

 

[Chris Nowell]

NH Tooner, what is wrong with the 4 bangers in there now that you have to get rid of them? I remember many years ago my Dad had a 28' Fairbanks with twin fours and I remember him yacking it up about how economical it was to operate and work on. With the help of the trim tabs it came up on plane better than one might think too, but it was propped with 17's. I imagine the twin 8's in a 270 would present quite a challenge when it came time to change plugs or drain the engine blocks and stuff like that. From looking at one in an ad there doesn't appear to be a lot of room to get a big forearm in between them to do anything.

 

[JVM225]

A friend of mine has swapped 6 cylinder motors in to 4 cylinder Sea Rays, and 8 cylinders in to 6 cylinder Sea Rays several times over the years. He buys boats with bad motors if he gets them real cheap, fixes them up, and uses them until he sells them.
Most recently he put one of the old V8's from my boat in to a 23' Sea Ray he bought cheap with a bad 6 cylinder in it. The motor I sold him was a real good running one, and he has just finished his second season with it. I re-powered because he other motor went bad, and just decided to do it all at once.
If a boat originally had the option of a different motor, it will probably mount up with no problem.
Where it gets expensive is you will need the matching ignition, exhaust, and drive for whatever motor(s) you put in there.
The ignition and exhaust difference is obvious, and the gear ratio in the drive itself is different.
When my friend did this last one he used my old motor which I gave him with the old ignition because my new motors came with all of that, and he used my old exhaust manifolds and risers because I got all new ones. I think he was nuts to take the chance on the exhaust, but so far it's worked out for him.
He did have to track down a good used V8 outdrive though.
If you really like the late 80's 270's but want bigger motors, it may be cheaper to just sell the one you have and look for another one with the motors you want.