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 engine of the 70s. We've finally found some information on T-Drive, a truly unique and innovative system. We'm still looking for information on the stratified-charge V-8, and while some information was published 30 years ago about it I haven't yet been able to find any information about it in my personal library. I remember seeing a picture of a room full of them, after being broken up with sledge hammers when the program was abruptly terminated.

T-drive is a system consisting of a transversally located 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 went ahead with the "modular" V-6, V-8, V-10, and V-12 engine families instead.

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. And 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 number of cylinders in line) across the board, any new future technology could be applied to the entire range of engines quickly.

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).

F ord 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

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).

This is the most outrageous example of T-Drive: a I-8 Tempo. Yes, a 4 liter 8 cylinder Tempo! Note the DOHC inline-8. Because of the sheer widtuh of the engine, t he 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 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 (normally very far-forward in a FOX T-Bird).

T-Drive Patents

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