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Discussion Starter #1
Howdy all! I've been perusing the net and even this site for quite a while now and have yet to really get a definitive answer on my question so... I figure I'll just come out and ask it! I'm quite new to the idea of diesel but I'm learning as I go and trying to ask all the questions I can.

I've been hearing that the 4BT has been used not only as and auto/industrial engine but as a marine based engine as well. Across the net there are people that say using a marine engine in an automobile application is possible, even a desirable way to obtain one for use on the cheap. But they offer up no info on how the conversion may go. Then there is the other school that mention the need of tags/ID and HP ratings and the general fact that it can't be done.

So what is the actual verdict here? My reason for asking in that living up here on the North Coast of Ohio I have several marinas that service them and I can pick one at a very reasonable price. Should I or should I not persue this angle?? It's be going into a 73 CJ5 as a daily driver, not something that would get beat to hell.

Any advice would be greatly appreciated!! Thanks!!

Scuffy
 

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hi there. the main differences i can see with marine stuff is 1. they have endless cold water to cool everything, so you would want to back off the injector pump. 2. they may have a funky setup on the back of them, flywheel and housing wise. still if you can get good runners cheap i would grab all of them that you can.
 

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Can these parts be replaced at a reasonable price or adapted to run like the standard 4BT? Can a cooling system, radiator etc, be retrofitted?


Oh and thank you for your help!!!
 

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i am under the impression all the automotive bits will be able to be fitted. all the basic blocks look to be about the same. please don't let me frighten you off by any means. they may well have sae adaptors on them which isn't too bad.
 

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Some of the marine units are rated at up to 250 hp. For everyday street use I don't know how long it would stay together at those settings. On a marine application the motors run at a steady rpm for long periods of time. As said before, cooling water is unlimited for them. From reading here on the forum you will find that these motors run pretty cool so cooling may not be an issue. I would think the cam would be different on these high output engines, but that may be a good thing. The pumps may be different also. When you start buying different pumps and such the $$$ add up quickly. Lots of guys here are looking for the bigger pumps though, so again that may be a good thing. If you are after a 175 and up hp moter they may be the cheap way to go....
There are a lot of sharp guys here on the forum, however some have quited different ideas. Hopefully someone with much more knowledge than I will be able to answer your questions better.
How many of these motors are available??? Hmmmm??? How many hours? What condition? How cheap??? As you can tell you have me thinking.
 

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In general all the components are interchangeable with the base engine. The 250hp rated 4b marine engine had an inline pump with special injectors that were only used in marine applications. There could be several items to consider.. like a "water cooled" turbine housing... they are larger in size plus the additional plumbing. If you had access to a "scrap" 4b it would be helpful for the conversion.
 

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Since when is marine application stuff cheaper than auto application stuff? seems to me anything marine the price practically doubles...

There has also been a lot of talk regarding the reliability of the marine 4bts, if you find one on the cheap, there could easily be a good reason for the price difference.
 

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I sold my 110 hp 4BT from a airplane de-icer (originally powered a large hydraulic pump) to a guy who installed it into a boat. He had no issues at all.. It was a Bosch A pump which is common in equipment & such... I wouldn't worry about it too much. It replaced a Chevy 350... The "marine" 4BTs are higher power rated but that doesn't mean the 4BT you install needs to be....
 

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Marine application

The Marine application is pretty straight forward, generally an Sae#3 flywheel housing and a flywheel for a 10 or 11.5 inch over center clutch application....all standard stuff, an earlier note mentioned alot of water, yes they push a bunch thru them to help cool but the water pump is still the same....Keep in mind it will have a tighter governor in the fuel pump so the engine will be more responsive, it will have different compression ratio on the piston, but that shouldn't hurt either......the oil pan is an awesome piece of work, and it will handle angularity up to 30 degrees in all directions....Let me know if I can be of any help....Steve
 

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Discussion Starter #12
Wow!!! Thanks guys!! I didn't expect this much of a response, but let me tell you that it is much appreciated. Pretty much it just comes down to the fact I've got a buddy that can get 4BT's that have been pulled from boats that are getting scrapped or refurbed and at a minimal cost. I figured why let them go to waste! lol If I can get a few I'll keep ya posted!!
 
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