Swap Mercruiser 5.7L with a 355 - Can this be done?

[kpkrol]

I'm having someone swap out my Mercruiser 5.7L engine with a 355 Chevy. This is coming off of a '91 Celebrity 200 bowrider. What needs to be done to do this? Can I use the heads, carb, etc from the Mercruiser for the 355? Anything else that I should do? <br /><br />btw: The crankshaft is moving an inch or two which is the reason for the replacement.<br /><br />Thanks in advance

 

[MooseHootie]

Re: Swap Mercruiser 5.7L with a 355 - Can this be done?

What do you mean about the crankshaft ? The 355 you talked about is a chevy 350 bored .030 over right? You need a marine cam and stainless headgaskets and brass freeze plugs, and marine water pump. Change that over from the engine you have now. If your 355 is a older model block that will be a problem too.

 

[kpkrol]

Re: Swap Mercruiser 5.7L with a 355 - Can this be done?

Thanks MooseHootie. The mechanic told me I had water in the engine which wore down the bearings on the crankshaft. Yes, it is a 350 bored to .030.If the old engine is a one piece rear main and the new engine is a two piece, does this matter?

 

[MooseHootie]

Re: Swap Mercruiser 5.7L with a 355 - Can this be done?

Yes the outdrive coupler is different that bolts to the flywheel.

 

[vinney]

Re: Swap Mercruiser 5.7L with a 355 - Can this be done?

If the coupler doesn't fit the flywheel won't either. The Starter different too.

 

[Bondo]

Re: Swap Mercruiser 5.7L with a 355 - Can this be done?

kpkrol,<br />Welcome to the iboats forums.........<br /><br />Everything stated by the fella's Is a Fact.........<br /><br />But,<br />All these Can be gotten Around..........<br />By Mixing,+ Matching various Chevy parts, your combo Can work.........<br /><br />For All intents,+ purposes, You're swapping a 5.7l Late model, for a 5.7l Early model(I just don't know Much Older Model)....<br /><br />The crankshafts have Either the 3 1/2"(early,2pc.seal) or 3"(late,1pc. seal) bolt patterns on the Flywheel end.....<br />The Flywheels are Either 153 teeth, or 168 teeth.....<br />Which means there's 2 Starters.......<br />Straight bolt pattern(153t), or the Staggered bolt pattern(168t).........<br /><br />Depending on Which Plant, Mercruiser was buying engines from, at the time yours was bought from Chevy,<br />You'll need a Flywheel with a 3 1/2" bolt pattern, <br />That Matches your Starter,<br />That Has the Clutch Bolt Pattern that Matches your Merc. Engine Coupler.........<br /><br />

btw: The crankshaft is moving an inch or two which is the reason for the replacement.

This is a Slight Exaggeration of Maybe .900, to 1.800 Thousandths...........<br />Right....??