Merc 470 swap out, need the experts

Hi folks, I am looking at a 19' 87 Four Winns Bow Rider that is in absolute beautiful condition with one exception, it has a very sick Merc 470 in it. The boat has a Alpha1 behind it, also in excellent shape.

Normally I give the 470's a wide pass and move along to somehing else but the boat really is in such good condition I am giving it another consideration. (I can buy it for $400 with trailer.)

I've been thinking a swap to a 4.3 V-6 would be nice and I understand I'm looking at new motor mounts, a "Y" exhaust etc. and I think I have most of that laying around but here is my questions if anyone knows.

I know the Bellhousing is an issue (I have some ideas on solving that) but is the transome plate also an issue? Is there something about the 470 that requires a special transom set up or no?

Yes, I know everyone, including myself, says its not worth it but this may be the rare case where it is. Any and all thoughts welcomed.

Re: Merc 470 swap out, need the experts

Bubba1235 said:

Hi folks, I am looking at a 19' 87 Four Winns Bow Rider that is in absolute beautiful condition with one exception, it has a very sick Merc 470 in it.

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I am going to ignore the request for experts. I have EXACTLY the same boat (love it) with a now healed 470. I looked into doing exactly the same thing and concluded that it was way too much time and trouble. How sick is it? Head gasket, or seized? If it is just the routine 470 stuff, head gasket, seals etc. you can fix all that stuff over a long weekend for a few hundred dollars, (and you don't even have to pull the motor), valve job (had hardened exhaust seats put in mine) another couple of hundred. I would not give up on the 470 yet, especially at that price. One other thing, the 4.3 will add 200 pounds to the stern of your boat. My non -expert advice .. GO FOR IT. Good luck.

Re: Merc 470 swap out, need the experts

Only real advantage i see is having an engine that you will be able to get parts for long time in the future.

Re: Merc 470 swap out, need the experts

zbnutcase said:

Only real advantage i see is having an engine that you will be able to get parts for long time in the future.

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That is true, however if you look at the demographics of the boats that 470's went into, they are all over 20 years old, some pushing 30. That means that more of the boats will be junked due to rot or whatever. So there should be a steady supply of 470's coming out of these boats that can supply parts, and rebuildable motors for a long time to come.

Re: Merc 470 swap out, need the experts

One other thing, the 4.3 will add 200 pounds to the stern of your boat

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...but depending on trim, can put 70-80 more hp to the prop.

Re: Merc 470 swap out, need the experts

180shabah said:

...but depending on trim, can put 70-80 more hp to the prop.

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Again true, but you need a fully dressed 4.3, and HP is expensive. Are you going to drop a $3000 motor into a 23 year old boat that cost $400 (including trailer), and spend half the summer doing it? I do not believe that would be a wise choice, more likely an older 175-190 hp unit to be cost effective. Not much gain for the added weight. Just my opinion. You probably could find a decent running 470 for $5-600 and starting Friday night be boating on Sunday.
Edit: Hmmm the hole sorta changes things. But how can you pass it up?