SWAP: 4.3 to 5.7..... woes?

I have a 2002 Glastron SX195 with the Mercruiser 4.3V6 w/ Volvo Penta SX drive. Here is the deal, I know of a 5.7 Mercruiser that has been completely torn down and rebuilt that is a COMPLETE motor for $1500. The guy says that it should be around 285hp +/-. Here is my question, How "direct" is this swap? Can you give me any clue as to what I'm looking at in regards to extra parts I will need for the swap, problems I might run into and of there is a fatal flaw I'm missing. I hate to pass this deal up but my 4.3 only has 93 hours on it and runs fine but the extra HP's is very tempting especially since its fresh; however, if i'm looking at lots of extra $$$ to do the swap its probably not worth it. Heck, I don't even know if I could sell the 4.3 for that matter.

I'd love the HP increase but at what cost..... this is where you guys come in.

Re: SWAP: 4.3 to 5.7..... woes?

I have a 2002 Glastron SX195 with the Mercruiser 4.3V6 w/ Volvo Penta SX drive

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Why are you looking for a Mercruiser engine, if you have a Volvo outdrive, why don't you do it right and put a Volvo and it's systems in?

Re: SWAP: 4.3 to 5.7..... woes?

The boat came stock with the mercruiser 4.3 and Volvo outdrive. I was hoping that being that both motors were mercruiser that everything would mate up other than the motor mounts. I thought I had read on here that it was a close swap but couldn't find the origional thread. The 5.7 is a mercruiser out of a 30' searay I believe. It has the exhaust on it already. Again it is supposed to be ready to go back in the boat with everything on it.

I am VERY new the the I/O's so can you explain why the lower unit would need regeared?

Re: SWAP: 4.3 to 5.7..... woes?

The boat came stock with the mercruiser 4.3 and Volvo outdrive.

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No, it didn't come that way from the factory.
That is like buying a Ford truck with a Chevy engine in it coming from the Ford plant.

Volvo and Mercruiser are two completely different companies.

I am VERY new the the I/O's so can you explain why the lower unit would need regeared?

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This is only covered in about 10,000 other posts, but in a nutshell. Props only work best within a certain pitch range. Usually 17" to 21" So to keep the pitch of the prop within those specs, the drives gear ratio needs to change with the torque and HP ratings of the engine.

Re: SWAP: 4.3 to 5.7..... woes?

Don S said:

No, it didn't come that way from the factory.
That is like buying a Ford truck with a Chevy engine in it coming from the Ford plant.

Volvo and Mercruiser are two completely different companies.

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I'd be more than ahppy to scan and send you the owner's manual showing the specs and graphics showing the mated pair from the factory. I don't doubt that you know MUCH more than I do about these topics; however, in this case, it came this way from the factory.

Now with that said, what does that do to the cost of the potential swap?

Re: SWAP: 4.3 to 5.7..... woes?

I'd be more than ahppy to scan and send you the owner's manual showing the specs and graphics showing the mated pair from the factory.

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I would sure like to see it, I will PM you my email address. Not allowed to post it on the forums.

Glastron does offer Volvo or Mercruiser as engine/drive options, but they do not mix engines and drives.

I think a picture of Your engine and drive would be helpful too.

Re: SWAP: 4.3 to 5.7..... woes?

Don S said:

I'd be more than ahppy to scan and send you the owner's manual showing the specs and graphics showing the mated pair from the factory.

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I would sure like to see it, I will PM you my email address. Not allowed to post it on the forums.

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Ayuh,... Post it Right here,...

I'd also Love to see what Don't exist...

Re: SWAP: 4.3 to 5.7..... woes?

Bond-o said:

Ayuh,... Post it Right here,...

I'd also Love to see what Don't exist...

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He may not know how to post it here, but I do. When I get the scans, I'll post them.

Re: SWAP: 4.3 to 5.7..... woes?

This, I gotta see!

You know, maybe in some alternate reality, a Glastron dealer could have sold a used boat that they bolted a "Mercruiser" engine into a Volvo driven boat(or vice-versa)

One would have to wonder why they would do that unless they had the "stuff" just lying around and neither the Volvo or Mercury "Rep" was around to see it before it went out the door............ (I wonder what THEY would say if they knew a dealer did something like that?)