Ranger Biodiesel Swap - Flywheel Adapter Fabrication Part 2

 This adapter requires extremely tight tolerances to prevent vibration and misalignment with the flywheel, so the manufacturing process must be careful and precise. This is complicated by the design of the final part, which has alignment surfaces on both sides of the face, both radial and flat, and on inner and outer diameters.

Every time you remove and reinstall a part in a three-jaw chuck, it introduces a minute amount of misalignment in the part, especially in older worn machinery. In order to maintain accuracy through repeated removals, I manufactured the fixture collet (previous post) that has multiple precise ridges and two methods of retaining the part with bolts. These ridges correspond to ones that I will machine in both sides of the adapter, so that the piece will always be perfectly centered on the fixture no matter how many times it is removed and flipped.

The adapter started life as a 1-in thick round steel plate, and I drilled a hole through the approximate center the same size as the center bolt on the fixture. This allowed me to mount the plate in the fixture, and start machining the outer diameter and first face.

The stepped ridge on one side of the adapter is the primary alignment for the flywheel, so I machined the outer diameter to a tight tolerance against the inner diameter of the original Ford flywheel. 

Once completed, I flipped the adapter to the other side, aligned the ridge with the corresponding pocket in the jig, and locked it in place with the bolt. I then machined the opposite side flat and added another ridge for alignment in the other jig pocket. 

Once complete, I removed it from the jig and test fit it on the flywheel

The next lathe step required center boring of the adapter for the crankshaft alignment and transmission pilot bushing. This meant that the center hole would no longer be used for attaching the adapter to the fixture, so I first had to drill the radial bolt patterns. 

I mounted the adapter to a rotary table on a drill press with an XY cross slide, and drilled the inner and outer bolt patterns.

With the bolt patterns finished, I could then install the adapter on the jig without using the center bolt, and finish boring the inner diameters for the crankshaft alignment and pilot bushing

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 - 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.