marine or auto engine?

[legal size?]

On a used boat I,m looking at how can I determine if the replacement engine is a 5.7L Mercruiser or just a 5.7L GM (non-marine) ? Thanks

 

[Boomyal]

Re: marine or auto engine?

Tough one. There are a few differences but they would be difficult to determine just looking at it. Check the freeze plugs. If they are brass, that is a good start. <br /><br />Marine engines would have a little more clearance on the cylinder bore. That would be a factor of the piston manufacturers specification regarding the use of motor. The cam would be another indicator. Obviously very hard to determine by just looking at the motor. Marine cams tend to be very truckish, that is a low to midrange torque curve.<br /><br />You might also look at some of the peripherals like the carb, the distrib and the fuel pump.<br />They all of course could have been installed on an automotive engine but if they were not correct I would suspect the motor would not be either.

 

[Dunaruna]

Re: marine or auto engine?

Doesn't mercruiser use their own sequence of engine numbers as opposed to GM auto?

 

[Boomyal]

Re: marine or auto engine?

Originally posted by Dunaruna:<br /> Doesn't mercruiser use their own sequence of engine numbers as opposed to GM auto?

Don't think so Aldo. I know Ford didn't.

 

[MrBill]

Re: marine or auto engine?

Obtain serial number and cross reference on www.Mercruiserparts.com

 

[KaGee]

Re: marine or auto engine?

Hello Misfit, welcome to the forum.<br /><br />I found THIS to be useful.

 

[Northern Eclipse]

Re: marine or auto engine?

Take a look down by the starter and see if there is a metal serial # tag rivited to the side of the block. That is where Merc placed their I.D plates.

 

[Don S]

Re: marine or auto engine?

Originally posted by Dunaruna:<br /> Doesn't mercruiser use their own sequence of engine numbers as opposed to GM auto?

Yes, and Mercruiser does have a service bulletin that lists all the numbers that they use. It's bulletin number 2002-8 and is 16 pages long.<br /><br />Misfit<br />If you get the number as shown in the picture, I can check it against the list and see what it says, or you can get a copy from your local Mercruiser dealer.<br /><br />

 

[legal size?]

Re: marine or auto engine?

I Have serial# and engine code is VO2187MD. What does that tell me? And what kind of fuel consumption should I expect with this 5.7 on a 1984 22' Aquasport? And thanks everyone for your help.

 

[Dunaruna]

Re: marine or auto engine?

Misfit, this is part of the service bulletin that Don referred to:<br /><br /> http://www.marinemechanic.com/site/page135.html <br /><br />'MD' codes are at the top of the page.<br /><br />"what kind of fuel consumption should I expect?" - a lot.<br /> <br />Aldo

 

[legal size?]

Re: marine or auto engine?

Thanks again everyone for educating a newbie to the world of I/O. For now I think I've acquired enough info to make my decision.