Curiosity between Chevy inline six, and Mercruiser 165 MC1 inline six

[Weirdnerd]

I am always thinking when the time comes my 45 year old Mercruiser will develop problems, and I have been reading about some people who used a Chevy inline six engine as block replacement for many reasons ( Ie. cracked block, accident, corrosion, you name it).

What is the main difference between the truck engine and the marine engine?...pictures would be nice....I am all ears ( really , my ears are somewhat large)

I have heard about Brass freeze plugs, where are those?...also about some block overhang, but I can not picture it.... thanks for your patience.

 

[Bt Doctur]

basically you need the block with the "ear" to mount the front motor mount . Most car block did not have it

 

[Scott Danforth]

marine motor and truck motor both come out of the same plant. marine motor gets stainless cored head gasket and brass core plugs (they are not "freeze" plugs, they are core plugs)

from there, the starter and alternator are marine specific as they are spark arrested. the water pump on a marine motor is also a brass impeller vs cast-iron on a truck and the back cover is stainless on a marine water pump vs steel on the truck.

Marine cam has longer duration, and wider lobe separation than your typical automotive cam.

your GM based 165 hp mercruiser is a GM 250 cubic inch 6-banger found in many vehicles from the early 60's to the mid 80's. however if I was replacing it, I would get a 292 and fab up the right side mount

 

[Bt Doctur]

And properly rebuilt it can get up to 320 HP
http://www.enginelabs.com/news/dyno-video-straight-6-chevy-pulls-320-horsepower/

 

[Scott Danforth]

you can get more if you have forced induction. lots of inliner tech tips on inliners.org http://www.inliners.org/tech/info.html

 

[Weirdnerd]

So the ear on the engine block, water pump , cam and accessories...

That would explain a little, the previous water pump was rusted to a knob, took me a little to clean up the flange and replace it with the correct marine pump ( it was the first thing I looked into when I got the boat)

Technically if one has the time to replace the core plugs with brass and change the cam and water pump, the rest of accessories would be "plug and play"?

 

[Alumarine]

If the motor is from a truck the cam should be close enough I think.