I have been looking for a donor pickup to pull the engine out of for a converting a gas powered boat. I have found resources for the marine exhaust manifolds and heat exchangers, but need to decide which year of engine would be the easiest. Up to now I have only been looking at the 1st gen trucks as I tought they would have less elctronics on the engine to worry about. I was wondering if the 94-98 12 valve engines were still mechanically injected. I know the injection pump is a different style, but from my reading it seems dodge didn't get heavily into electronic engine controls until the 98.5 model year. Any guidance anyone could give as what year of engines would be the easiest to convert would be greatly appreciated.<br><br>Thanks for your time, Marv

 

I believe That the 94-98 trucks have the P7100 which I believe is mechanical. If I am mistaken someone please correct me. I am guessing that the 1 gen. 12v would be the easiest. Hope this helps. -Anthony

 

Once you have the 12 valve engine out of the truck, you do not need the computer to make it run in a marine application. Hook up a simple key and starter button to energize the fuel solenoid and pulse the starter solenoid. Study the wiring diagram to see how this works. There is a &quot;Starter Relay&quot; which energizes the starter motor solenoid from the key in the truck. You may be able to eliminate this relay with a heavy marine starter button right to the stater motor solenoid. The &quot;hold in&quot; coil of the fuel solenoid gets power when you turn the key on, but you must supply power to the &quot;pull in&quot; coil when you are cranking and you should probably do this through a relay. The Cummins runs very cool and perhaps you should consider fresh water (antifreeze) cooling which eliminates many special marine parts. It is quite common for fishing and lobster boats to have copper tubing running bow to stern on both sides of the keel through which the coolant is circulated. A simple and inexpensive heat exchanger.

 

If you are going to be out in that boatin sub-freezing temperatures, which I doubt, you will need the intake heaters. These are controlled by the computer in the truck, but you can do it in a simple way. Use a separate button to activate them. Hold the button down for 30 seconds or so before you crank, like the old Mercedes. You could rig the manifold air temperature sender, which now feeds the computer, to a temperature guage to inform you of the need for heaters.

 

It sounds like the 94-981/2 engines with the inline injection pump is the best choice. Does anyone know if it is possible to convert a first generation engine from a rotary pump to a P7100, could they be swithched like other bolt on components or are the mounts a drive systems different.<br> As far as the cooling I have been looking at using some type of keel cooler and a closed system to protect the engines, but they are pretty expensive, I would have to build my own. I am also waiting to hear back from my uncle who is a retired sheetmetal worker, he thinks that we could design a system that would use the boats hull (its steel) as the heat exchanger and bond or epoxy some type of radiator to it from inside the boat, it seems like a pretty good idea and the heat exchanger would be better protected that an outside keel cooler, it would also get rid of several through hull fittings. The boat has two engines so I may set one up conventionally and experiment with the other. Anyway I need to figure out what to use for engines first. Thanks for everyones feedback

 

Hi, Yes you can convert from a 1st gen to make it a 2nd gen p7100 pump engine. You will need a gear cover,p7100 pump, gear, injector lines, fuel filter/ lift pump and pump bracket. The 1st gen head doesn't flow as well as a 2nd gen head, so you might want to look into changing that out too.

 

maybe you should find a Deutze engine and get rid of the entire water cooling problem.

 

Here is a link to what you want.<br>http://www.msea2.com/articles/marlin.htm