The Drivetrain

Plans and Progress

The first thing we’ll be focusing on in this project is the drivetrain. What’s a drivetrain? It’s everything that makes the vehicle move. The engine, transmission, transfer case, differentials, etc. It’s everything that gets us where we want to go. And we want to go places where we don’t see many people.

We’ll update this page with links to individual blog posts as we make progress.

When we bought the ROV it came with the stock Ford 300 cubic inch (4.9 liter) inline six cylinder with a 1 barrel carburetor. The 300 is known as the “Big Six” in Ford circles and is one of the most reliable and most common engines Ford ever produced. It’s a good power plant for a camper or RV because they make tons of torque low in the RPM range. Parts for these engines are plentiful and inexpensive. Rebuilding them is also quite cheap compared to a gasoline V8 or any diesel engine.

The carb’ed engine isn’t great at elevation. Older carburetors are also known to be finicky and weren’t designed to tolerate the ethanol found in modern gasoline. So we’ll swap out the carb for an aftermarket fuel injection system. Thankfully Ford produced EFI versions of the 4.9L six so we can use a lot of factory parts in the conversion. The plan at the moment is to install an SDS EFI EM-5F injection system to control fuel delivery and ignition timing. 20+ years ago Mark had an SDS-EM4F on an 1987 Ford Thunderbird TurboCoupe 2.3L Ford engine installed a sandrail. Simple Digital Systems has been around a while. Their products are reliable and very easy to tune.

The transmission will be swapped out as well. The ROV came with a Ford C6 which is an an old-school, non-lockup torque converter automatic 3 speed. They are known for being bullet proof and inefficient. We’re going to switch to the Ford ZF S5-42 5 speed manual transmission. It has a .7:1 overdrive 5th gear which will help with the 4.10 ratio differential. The added efficiency isn’t the primary reason for the transmission swap. We want better off-road traction control that a geared manual tranny provides. The trans swap is planned to be the first major project.

The Pathfinder 4WD conversion has a poor front suspension design. That will be addressed as well. We like the updated design of the suspension found on Boomer the Camper Van We’ll borrow heavily from SpencyG’s work for a more capable front suspension.

We’ve gotten used to having locking front and rear differentials in our BJ45 Troopy. Lockers make driving in soft sand a much less stressful experience. So the ROV will get lockers too. Not sure if we’ll go the air locker route or some kind of e-locker. There’s plenty of time to make that decision.