Ranger Biodiesel Swap - Flywheel Adapter Fabrication Part 1

The crankshaft to flywheel adapter, bellhousing adapter, and engine mounts all needed to be custom-made for this build. I designed everything, drew up blueprints, and sent the bellhousing adapter design to a machine shop for fabrication. 

I decided to manufacture the crankshaft to flywheel adapter myself in my home shop, but first I needed to develop custom tooling in order to hold tighter tolerances necessary for a correct balance. 

To maintain correct centerline alignment, I first modified a machinable fixture collet with several concentric stepped ridges, that would perfectly correspond to both sides of the finished adapter. In this way, I could remove and reinstall the adapter multiple times and maintain perfect alignments every time. 

Next, I drilled a center hole and bolt pattern holes into the piece, and tapped them all with the correct sizes, to give me multiple methods of fixing the adapter to the plate during machining. With the fixture complete, it was time to start manufacturing the adapter.

 

Ranger Biodiesel Swap - First Start (Video Post)

 The first start and run of my Volkswagen 1.6NA swapped 1999 Ford Ranger. The process required several hours of bleeding air from the fuel lines and purging old diesel residue from the system, and now it runs perfectly! It's been approximately 20-25 years since this engine ran, and it was eager to clear out the cobwebs.

Ranger Biodiesel Swap - Spare Engine

I purchased a spare 1.6NA engine on Facebook Marketplace for parts, but ultimately saved a lot less than I thought I would. Unfortunately, it had been left out in the rain on a wooden pallet, and was completely full of water. I salvaged the cylinder head, intake, exhaust, vacuum pump, and lower timing cover, and scrapped the seized block.

The real prize was this lower timing belt cover, which is surprisingly hard to find and was missing from my engine. I shaved some ribs off the front to improve clearance with the alternator belt, painted the front of the engine block, and reinstalled all the parts.

Ranger Biodiesel Swap - Air Intake

I wanted to reuse the original airbox and filter, as well as reinstall the original MAF and intake air sensors for later data acquisition (and to avoid throwing codes!).

Luckily, the airbox is on the same side as the intake manifold, so the design is greatly simplified. I used a 3" to 2" reducing 45-degree elbow, a tee-fitting with a 1" port for the temperature sensor, and a 90-degeree elbow to the engine, all connected with short lengths of 2" OD Steel pipe. 

The hardest part was the intake manifold adapter, which has an oval inlet. I machined the oval port on a piece of 1/8" steel plate, formed one end of a 2" steel pipe into a matching oval, welded the two together, and trimmed everything to fit under the hood.

 

Ranger Biodiesel Swap - Exhaust System

 The original exhaust system was unusable, so I needed to fabricate a new one from scratch. For simplicity and low-budget, it's made from AutoZone slip-fitting exhaust sections, welded together at most of the seams, and attached to the original VW collector.

I left one joint unwelded in the center of the pipe, so that I can experiment with different muffler and catalytic converters at a later date. For now, it will simply be a 1.75" unmuffled straight pipe.

VW Exhaust Collector

Down Pipe

Mocking up the system

Welding the exhaust seams.

The original engine in this truck was a V6, which used a pair of O2 sensors (one per bank). Rather than weld an extra sensor bung to the downpipe, I spliced a single sensor to provide electrical outputs to the pair of connectors.

After assembly and paint, I attached the rear of the exhaust to a hanger with a rubber isolator. I left this portion adjustable, to facilitate future exhaust upgrades.

Ranger Biodiesel Swap - Alternator Adapters

 To simplify wiring, I decided to mount the original Ford alternator on the VW engine. There's no tensioner pulley for the serpentine v-belt, so I fabricated a hinged adapter and tensioning rod.

The first version of the hinged adapter was made from billet aluminum. 

Next, I turned an aluminum v-belt pulley on my lathe, to match to profile of the original VW pulleys.

Finally, I bent a steel bracket that curves around the outside of the alternator and bolts to the engine block. With an 8mm socket cap bolt and fender washers, I made a tensioner that pulls the belt tight, rather than pushes.

After installing the engine, I discovered that the alternator was hitting the steering u-joint and needed to be rotated higher. The aluminum hinge was at its limit of travel, so I made a replacement out of steel that allowed better clearance.