A Mystery Prototype Engine

The White V4-106

Every once in a while you run across something really odd that requires a lot of research. In this case it was a mysterious two-stroke loop-scavenged V4 built by the White Diesel Engine Division of White Motor Company. If loop-scavenged diesels ring a bell, go back to the September 2017 issue of Diesel World where we discussed the Cerlist. The Cerlist was a two-stroke loop-scavenged diesel built under a license from AVL, the engineering company formed by Dr. Hans List. List was an Austrian engineer who perfected loop scavenging in both gas and diesel two-strokes and many loop-scavenged diesels built in their heyday of the ’50s and ’60s were List-derived.

When we were first introduced to the White V4 mystery engine in the collection of the National Automotive and Truck Museum (NATMUS) in Auburn, Indiana, we were convinced it was a List design. That proved incorrect, as AVL could find no record of issuing a license to White. More than a year later we were still clueless, but a review of SAE records turned up a paper dated 1955 with lots of clues, the most important of which was the designation, V-106. Then a good part of the rest of the story fell into place and we were able to find a bit of factory information on the engine.

According to a 1955 SAE paper, the White Motor Company began looking at compact diesels in 1951, mainly for their new Model 3000 cab-over trucks. They were open to just about anything, but a few years later had settled in on a European two-stroke system that combined elements of a Krauss-Maffei design with the Schnuerle port. Krause-Maffei was (and is) a German company with tendrils in many aspects of manufacturing but well-known for diesel locomotives. Adolph Schnuerle was a prolific German engineer with many patents in internal combustion technology, and most other loop-scavenged systems were derived from his work. Dr. List based much of his work upon Schnuerle’s, and that’s the only connection between the White engine and the List.

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It may actually have been Superior Engine Division of the National Supply Company that’s most responsible for the White V4. Some sources indicate that development of the two-stroke V4 began with Superior and fell into White’s lap when White Motor Company bought the Superior Engine Division in early 1955, calling it the White Diesel Engine Division. The purchase included Atlas-Imperial in California, which National Supply had absorbed in 1948, and Superior in Springfield, Ohio. This has yet to be clarified, and while White may have been looking for new diesels in 1951, the timing would seem to indicate White came into the loop-scavenged development later than 1951.

White called the engine series “V-106,” the V for the vee configuration and the 106 for the per-cylinder displacement.

White called the engine series “V-106,” the V for the vee configuration and the 106 for the per-cylinder displacement. A V4 and a V6 were developed and tested, displacing 424 and 636 cubic inches, respectively. The V4 was rated at 170 horsepower at 2,200 rpm and the V6 at 255. Part of a modular series, a V8 was also envisioned and would likely have produced 340 horsepower at 2,200 rpm from 848 cubic inches using many of the same parts as the V4 and V6.

It’s known that at least one V4 was installed in a White 3000 truck and there are indications as many as six trucks were tested with some version of the V-106. Marine and stationary applications were also envisioned and the engine in the NATMUS collection could be in that category, differing in many ways from the truck engines. It was installed into a crane used at the Springfield, Ohio, White Diesel Plant. When that plant was being closed and its equipment scrapped in 2001, the engine was saved and donated to NATMUS. It isn’t clear whether the crane installation was done originally for tests or later just to utilize a leftover test engine for a practical purpose.

The late-breaking news is that the NATMUS volunteer group gearheads got the V4-106 running in May of 2018 and you can view the video on YouTube. By the time you read this, the engine may well be on display in the NATMUS truck area, along with a collection of many other diesels. If you find yourself passing through Auburn, Indiana, NATMUS is well worth a visit!

DW-1811-VISM14-01 — The V4-106 is “square,” having a 5.13-inch bore and stroke and a 90-degree vee. The crankshaft has three 4-inch-diameter main bearings and 3-inch rod journals. The pistons are oil-cooled via spray jets in the gun-bored connecting rod. The ductile iron pistons carry three Keystone-type compression rings and two oil control rings. This is an industrial or marine version of a V4-106 since the exhaust is routed straight up (red arrows). The automotive applications routed the exhaust to the rear of the engine. Also, the air inlet is more or less pointed upward on this engine whereas on the automotive engine it was directed to the right.

DW-1811-VISM14-02 — First note the “White” script on the lower part of the head and everywhere else on the engine. The intake and exhaust are routed through ports located on the inside of the vee, cast into the cylinder blocks. The injectors are Bosch, as is the injection pump. The compression ratio isn’t listed in the available data, but cold weather testing showed the engine could start at zero degrees Fahrenheit unassisted. If we’re reading the graphs right, this engine consumed about 7 gallons per hour at full power and full load.

DW-1811-VISM14-03 — The V106 series was envisioned being built in both cast iron and aluminum. The aluminum V4 weighed 1,090 pounds complete and the cast iron version was 1,355 pounds. The V6 was 1,530 and 1,900 pounds. The engine was designed to fit low between the frame rails in automotive applications, hence the rather high motor mounts visible at the rear of the engine. This engine was coupled to the crane via a Twin-Disc brand coupling and likely installed in that crane in the 1956 timeframe. It was removed in 2000 or 2001, so that’s about 45 years in service. Not bad for a prototype engine!

DW-1811-VISM14-04 — The Mystery White is fuel by an American Bosch GVB inline pump. This type of pump was commonly seen on Mack trucks, but in looking for pump applications we didn’t find all that many for the GVB and none with this particular calibration. The prototype V6-106 used a six-port pump but the available information also mentions that Roosa Master rotary pumps were tested.

DW-1811-VISM14-05 — The blower is front-mounted and driven at crankshaft speed. That chute behind and above the fan pulley is the inlet to the blower, and judging by its size this engine obviously used a LOT of air. This engine also has a block-mounted water-to-oil oil cooler.

DW-1811-VISM14-07 — This is loop scavenging as seen in the Cerlist, and the White was similar. The white arrows show the intake. The V4-106 had three each exhaust and intake ports and they were open or covered according to the position of the piston. The black arrows show the exhaust ports, located higher up, and they are the first to be uncovered in the power stroke. By the time the piston has moved down to uncover both ports, the blower is pushing the last of the exhaust out via the positive pressure imparted by the blower. The shape of the ports is the “secret sauce” here so that the intake airflow scavenges the cylinder and doesn’t just blow directly out the exhaust port.

DW-1811-VISM14-08 — For contrast, this is the Uniflow two-stroke as used in the legendary GM/Detroit diesels. Again, this system requires a blower to push air into the cylinder. When the piston is at and/or near the bottom of its stroke, the blower pushes air in through the lower ports. Some of that is used to help push exhaust from the cylinder via the overhead valve(s). When the lower ports are covered by the piston and the exhaust valve closed, the engine goes into the compression part of the cycle.

It may actually have been Superior Engine Division of the National Supply Company that’s most responsible for the White V4. Some sources indicate that development of the two-stroke V4 began with Superior and fell into White’s lap when White Motor Company bought the Superior Engine Division in early 1955…