I've done some basic searching and havent found any real answers to my question. What are the diffenences between a regular 6.5 TD and a Marine 6.5? I know that the marine injectors are direct upgrades for our engines but not much past that. What started this whole thing is I saw a rebuilt marine 6.5 for sale online but the seller wanted $13K. It was hoped up and I dont remember with what all (I had sticker shock when I was looking at it) but still, WTF? I didn't pay $13K for my truck. Why put that into an engine?

I was a Coast Guard Auxiliary and I learned something, can you believe it. All engine in boats the kind that is found in the enclosed area not the outboard must be setup for the marine environment. Since gas fumes (diesel is not a big issue but threat still exists) settles to the bottom of the boat and anything that creates spark like starter, alternator and etc could set it off. So those things are made to be closed so that no spark could get through. Another part is that the parts like the antifreeze plug on the block are brass so it will not rust out fast due to salt water. Above all, marine engine are soup up to generate more horsepower thus more money.

I was a Coast Guard Auxiliary and I learned something, can you believe it. All engine in boats the kind that is found in the enclosed area not the outboard must be setup for the marine environment. Since gas fumes (diesel is not a big issue but threat still exists) settles to the bottom of the boat and anything that creates spark like starter, alternator and etc could set it off. So those things are made to be closed so that no spark could get through. Another part is that the parts like the antifreeze plug on the block are brass so it will not rust out fast due to salt water. Above all, marine engine are soup up to generate more horsepower thus more money.

don't know what the frost plugs on my merc 135hp are made of but it utlilizes fresh water & antifreeze cooling. has heat exchanger so no salt ever in my engine. the alternator has a screen to shield against sparks. and when asked why the alt. was so pricey the dude says you put marine in front of a part name and it adds value to it. coulda cheaped out and went with regular alt. but fire on a boat is a bad thing. very bad.

Not all boats have exchanger. Mine did not have one but then I boat in fresh water.

Not all boats have exchanger. Mine did not have one but then I boat in fresh water.

i agree, my old 85hp johnson did not have heat exchanger but did not go out in the salt water either. even the heat exchanger merc sells are garbage. had a custom made one done up with a zinc anode inside as merc doesn't do that for the unit i had.

check peninsular's website, block is Hummer HD block. block setup and machine work to hold up to full load(auto engines do not hold full load constantly like boat)

but fire on a boat is a bad thing. very bad.
Look at the bright side. Eventually the fire would put it's self out.:joke:
I'll check peninsular's website. Thanks.