The Vermont Jeepgirl Guest Post

Going Green in 2014 By The Vermont Jeep girl.

When I started thinking about building a diesel powered Jeep I knew there would be several options for an engine. I researched several different potential diesel engine options. The number one diesel engine people talk about swapping in is the Cummins 4BT3.9 and I talked with some people that had swapped them into their Jeeps. A lot of people that were recommending this engine have never swapped one into a Jeep or even owned one. The two big complaints I heard from people that swapped in the Cummins were weight and vibration. We had a Cummins 4BT3.9 in a piece of equipment we owned. Although we liked the power and torque it produced we had some major issues due to vibration. In particular we had to have a spare starter as the vibration would crack the nosecone. We fabricated a support to the front of the starter but it would still crack at the nosecone. Our previous experience with the Cummins along with the prices these used engines are going for didn’t sit well with me.

 Another swap I read about and considered was one of the VW diesels. The GM 6.2 can also be swapped in using the same adapters used to drop in a SBC but again the weight is a major issue in Jeeps. Although some people are happy with them and the prices are reasonable I thought there might be some better options for me.

I also had read about the Mercedes OM617 5 cylinder turbo diesel. Although it isn’t a power house it did offer several advantages for swapping into a Jeep. Its light weight was also a desirable feature. While at the Bantam Jeep Festival in June of this year the folks from Koch Enterprises had a display booth set-up with the OM617 swap components they design and sell. They offer several different adapter plates that adapt the Mercedes engine to a variety of jeep bell housings. They produce an adapter that bolts to the OM617’s crankshaft that allows for you to bolt the Jeep flywheel in place. By using the Jeep bell housing and flywheel you also retain the stock Jeep starter. I really liked this and it was a major factor in selecting the little Mercedes diesel. At this point it was a matter of watching sales ads for a used Mercedes. The recommended donors are the 1982-1985 300D Turbo, 1982-1985 300CD Turbo, 1981-1985 300TD Turbo and the 1981-1985 300SD Turbo.

After months of looking we spotted a 1984 300D on Craigslist. It was a couple of hours away over the border in Massachusetts. I had just had emergency surgery the week before, it was snowing, and there was a winter weather advisory and… it was Friday the 13th! What could possibly go wrong?
This car had been fitted with a waste vegetable oil (WVO) conversion. If you are not familiar with these kits they allow you to run on diesel fuel or used vegetable oil! This was a clean little Mercedes, it had spent its’ life in Florida until just a few years ago. The owner was including a couple of 55 gallon drums for storage of the filtered WVO along with a pump and heater for the tanks. He also included several filters and other items for straining the oil. In addition to this he had spare fuel and oil filters and some specialty tools for the OM617. We struck a deal and once again thanks to our friend Cliff, we drove it onto his car dolly and transported it back home. .

Mercedes OM617 5 cylinder turbo diesel1984 Mercedes Benz 300D waste vegetable oil (WVO) conversion