Ford T-Drive: An Abandoned Engineering Prototype

Timeframe: early ’90s

In the last 30 years, Ford has produced several experimental engine developments which were ultimately abandoned. Most have never been seen, much less detailed technically. T-Drive is one of them; another was the stratified charge V-8 (“PROCO”) engine of the 70s.

T-drive is an architecture consisting of a transverse inline engine, a transmission, and associated packaging. It was designed by Ford in approximately the 1990 timeframe and shown in several auto shows and to magazines. Ultimately it was abandoned due to several reasons. Ford instead went ahead with the “modular” V-6, V-8, V-10, and V-12 engine families and separate engine families for 4-cylinder engines.

The T-Drive engine was literally t-shaped – the transmission was located in the middle of the transverse engine instead of the end. This allows easy and compact placement in small spaces. Due to the tight spacing of the cylinder bores, engines were possible in a “width” of from 4 to 8 cylinders. T-Drive was designed from the start as a DOHC engine, state-of-the-art at that time. And because the engine design was entirely consistent (simply varying the number of cylinders in line) across the board, any new future technologies could be applied to the entire range of engines quickly and at minimal cost.

Engine output was never discussed. However, there are no reasons why it wouldn’t be exactly the same as a conventional engine. Displacement was apparently 2, 3.2, and 4 liters (4, 6, and 8 cylinders).

Ford Engineers:

  • Don Carriere, Principal Research Engineer
  • Ansel Flanery, Senior Research Engineer.

Advantages:

  • Family approach to a range of engines
  • Because of the size of the engine, and placement ahead of the axle centerline, front-, all-, or rear-wheel drive configurations could be engineered
  • Rear-wheel drive could have used variations of existing off-the-shelf transmissions (saving money)
  • Packaging advantages for “cab-forward” design
  • The transmission is located in-line with the midpoint of the crankshaft. This allows for a very low engine placement, and correspondingly low hoodline
  • Marketing: provide Ford with centerpiece engine technology, as Subaru has with it’s boxer engine family.

Problems:

  • Packaging, NVH, durability
  • Harmonics, torque pulse and gear rattle
  • Limited bore size (torque, breathing, valve area) and displacement
  • Engine weight over front axle-line, creating weigh-balance issues as in a front-wheel drive car
  • Front- or all-wheel drive would have required engineering variations on existing transmissions – which defeated the objective of saving money by using existing transmissions
  • Bulky transmission placement behind the engine – requiring specific design changes on existing front-wheel drive-based platforms (when one of the points is to be able to use existing transmissions).
DOHC inline-8. Because of the sheer width of the engine, the development car didn’t have room for a conventional braking assist system – note the two reservoirs hung off the strut brace.Judging from the patent text, this was at a minimum a front wheel drive car. It’s not known if there was a take-off for a driveshaft to the rear, making it an AWD car. The patent does allow for that.You’ll note that on both of these engines, there is a gap in the middle of the engine where the drivetrain take-off was engineered.
This is the most outrageous example of T-Drive: a I-8 Tempo Yes, a 4 liter 8 cylinder Tempo!
This is a FOX-chassis T-Bird, with a 6-cylinder T-drive engine. The engine is transverse, possibly leading to an unfavorable weight balance.
The rest of the driveline is conventional rear wheel drive. This car was probably built to demonstrate use of the near off-the-shelf driveline. Note that the engine takes up the full engine bay – note the radiator placement right next to the engine (normally much farther forward in a FOX T-Bird).

T-Drive Patents

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