Contour Zetec & Mustang Transmission
The Ford 2.0L Zetec engine is from a 1997 Contour with an automatic tranmission. The T5 transmission is from late 1980's/early 1990's 2.3L Mustang. Marrying the two may require a little more than Cupid's arrow, but the task is simplified by the fact that they share the same alignment dowel locations.
The 2.0L 16V DOHC Zetec
The Zetec donor engine was extracted from a Ford Contour SE built in November of 1997 and configured with an automatic transmission . The Ford Contour's family includes it's native brother the Mercury Mystique and the right hand drive european cousin known as the Ford Mondeo.
The pre-1998 Zetec engines are more desirable for power build-ups because they have a stronger bottom end, hydraulic lifters, and no Variable Cam Timing (VCT) which, at a minimum, can complicate things slightly. In the US market the pre-'98 Zetec is only available as an option for the 1995-1997 Contour model. In addition to the DOHC Zetec, the cost concious Contour consumer could opt for a more mild 2.0L SOHC, a still developing 2.5L Duratec V6, or the ever desirable SVT worked-over version of the Duratec V6 starting at 170HP from the factory.
In its stock form the Contour Zetec puts out 125HP with plenty of room for improvement. Other US market uses for the Zetec include '99-up Ford Focus and '99-up Mercury Cougar. The Focus version of the Zetec has some distinct differences, but the basic geometry is shared between all Zetecs (source of image unknown).
Ford's T5 Transmission
Taken from a late 80's/early 90's Ford Mustang, the Borg-Warner T5 transmission is one of the most common 'recycled' 5-speed transmissions available. It was used in a variety of makes and models so that finding parts for, rebuilding and/or replacing a T5 tranny is a simple task. The T5 is quite possibly the most cost effective gearbox available for the building of any project car... if you can make it fit. Here is a T5 identification chart showing various combinations used by Ford.
Mating the Tranny to the Engine
I plan to modify the T5 bellhousing just enough to add some new bolt holes and mount the Contour starter in the original location. There are some complications however, and I haven't solved every problem yet.
What it should take:
- a flywheel & pressure plate from a similiar (standard shift) Contour.
- a new clutch plate from a similar Mustang transmission.
- the crank position sensor housing from a standard Contour (Ford part number: F5RZ-6K341-A).
- a new pilot bushing from a standard Contour (Motorcraft part number: 82ET7-600-DASA.)
- a rebuilt clutch slave cylinder suited to the Locost (concentric) that will fit on the Mustang transmission (maybe from a Saab 900?).
- modifying the Mustang bellhousing by replacing the upper half with either a 3/4" aluminum plate or by fitting the upper half of an original Contour bellhousing.
Things we know:
- a Mustang starter won't fit in the Mustang location as the starter body will foul on the oil pan.
- the Mustang starter pinion gear won't fit the automatic Contour flywheel, and there is a good chance it won't fit the manual Contour flywheel either... so the Mustang starter probably has no value to us.
- the Mustang cable-actuated throwout bearing assembly will foul on the Locost chassis, suggesting a concentric slave cyclinder is preferable.
- the crank position sensor for an automatic is the same as the manual, but it's location is determined by a type-specific sensor housing that will need to be sourced.
- the automatic Contour does not have a pilot bushing.
- the automatic Contour flywheel is the same diameter as a Mustang standard flywheel, but the bolt patterns and gear teeth profile have not been compared.
- the Mustang standard flywheel does not have reluctor/crank position pick up points.
- there are equal number of crank position sensor pickup points (reluctor points) on the Contour's automatic and manual flywheels, so the automatic computer won't have any problem with the conversion to manual.
- the Contour's automatic starter does not throw out the pinion gear far enough to catch the manual flywheel. A starter from a manual Contour will be required to accompany the manual flywheel.
Things to worry about (TBD):
- complications when TIG welding the bellhousing, strength factors, etc.
- a pressure plate that must be replaced (at great cost. but a Cougar plate might be cheaper).
- not being able to find a suitable concentric slave cylinder.
The Research Process:
Removing the automatic flywheel
I was able to use a 24" torque bar with one hand while holding a screwdriver in the lower right with the other. Technically it was a nut-driver, but just about anything of the right diameter can be stuck through the flywheel and wedged against the oil pan to stop the crank from turning. You should note the orientation of the flywheel upon removal since the bolt pattern is keyed.
A two-piece dust plate is sandwiched between the block and the stock bellhousing. This is an encouraging find as a new dust plate of the same thickness can be fabricated to protect the final assembly. The plate is about .050" thick.
Contour Dust Plate
Crank Position Sensor
The sensor can be seen here inside the cam shaped housing. A single gold colored torx head bolt holds the housing in place. The black cylinder on the far left (inside the housing) is the actual sensor. It should be possible to replace this housing with one from a manual Contour to reposition the existing sensor.
There are 35 ribs on the inside of the flywheel that make up the crank position sensor "reluctor". These reluctor is detected by the crank position sensor to determine engine RPM. At the top of the photo, you can see that the 36th rib has been left out of the design, allowing the computer to detect what we can assume is TDC on cylinder #1. The same number of reluctor pickup points exist on the manual flywheel and only a new crank position sensor housing is required.
Comparison with T5
The Mustang bellhousing is shown here with the Contour Dust Plate lined up using the shared alignment holes. You can immediatly see the difference in starter locations, but what might be less obvious are the differences in the overall bolt hole pattern and that the starters are not the same size. Most importantly however, the dowel alignnment pins do agree along with one other threaded hole (9,3 & 2 o'clock in this photo).
Bolt Hole Misalignment
The critical bellhousing-to-block holes that to not agree are shown here along the top of the bellhousing. These are through-holes however, and it should be a pretty simple task to add stock material to the T5 bellhousing to accomodate the drilling of new holes.
il Pan Through-Holes
This photo details the lower two bolt holes where the Contour oil pan is bolted to the stock bellhousing. The left hole is drastically misaligned while the right hole is misaligned by about 1/4". Bolting the bellhousing to the oil pan is probably unnecessary so the alignment of these holes is not a factor.
The holes that do line up are threaded in the bellhousing. This is good thing because we know we can deal with the misaligned bolt holes by simply adding stock material to the bellhousing and then drilling through holes in the right spot; the accuracy of through holes is not critical as we don't need to worry about accurately cutting new threads.
More photos to come, comparing:
- the original (FWD) bellhousing vs. the T5
- the Mustang vs. Contour starters
- the automatic vs. manual Contour flywheels