Way back in 2008 I penned an article entitled "Four Play" in R&C chronicling domestic four-cylinder engines and converting them to rear-wheel drive. Check out "Four Play" here to read the full story. It generated more positive interest than any tech story for a while, proving there was interest in modern four-cylinder–powered hot rods. There have been additions to the choice of domestic four-bangers since then, notably Ford's EcoBoost turbo four (plus several Japanese killer four-bangers), but when I decided to put a four-cylinder engine in my lakes racer Model A roadster pickup, the Notso Special, I remembered that article, and was keen to use Ford's 2.0L Zetec engine—with a turbo.
The Zetec designation covers a number of Ford engines, including a 215ci V-8 used by the Benetton team in Formula 1 racing in the '90s, and has been offered in numerous cars in other countries since then, but the version I'm using is the Zetec –R, identifiable by its black plastic cam cover, and found in, amongst others, the Ford Focus from 1998 until 2004. It was also used in the Focus RS in turbocharged form, producing 220 hp. This engine is available in 1.6- and 1.8-liter variants, in addition to the 2.0-liter.
This engine is extremely popular for rear-wheel drive conversions, especially in the UK, as it shares the same bellhousing bolt pattern as crossflow, Pinto, CVH, and BDA engines, making it easy to convert using all-Ford parts, such as the Type-9 five-speed transmission, and clutches, flywheels, and starter motors from other domestic-to-them Ford cars. Oil pans from other models offer front or rear sump versions, depending on steering clearance.
However, I'm building my car in California, not the UK, and Type-9 gearboxes aren't exactly plentiful. (The Merkur XR4Ti being one of few sources, again not common in junkyards, even 20 years ago!) T5 five-speeds, on the other hand, are reasonably plentiful, and Quad 4 Rods, in Colorado, manufactures aluminum bellhousings to mate the Zetec and T5. The common trick when it comes to the parts inside that bellhousing seems to be to use the flywheel from an 1,800cc Zetec, with a 215mm 20-spline clutch to connect to the Type 9. That wouldn't work in my application, which also required a billet flywheel to meet racing specs, so Quad 4 Rods machined me a brand-new billet steel flywheel, reusing the original ring gear, and drilled to work with the Zetec's flywheel trigger sensor. I then went to McLeod Racing for one of their twin-disc Mag Force clutches and hydraulic release bearings to connect the engine to the T5 trans.
A quick word on the large subject of T5 transmissions: They've been used by Ford and GM in OEM applications for years, in everything from four-cylinder Thunderbirds and Mustangs, to S10 pickups and V-8 Mustangs and Camaros. Do your research as each has different gear ratios and overdrives, different shifter locations, and differing input shaft lengths and spline counts. V-8 versions have a higher torque rating than four-cylinder T5s, and there are World Class and Non World Class versions. Nothing to do with the strength of the transmission, Non World Class T5s use straight 50W gear oil, while World Class T5s use ATF as lubrication. A World Class T5 is easy to externally identify by the bearing race on the main case just below (and partially covered by) the input shaft bearing retainer. If it's a Timken tapered race, the T5 is a World Class.
As my car will be used for land speed racing, an aluminum bellhousing isn't enough to meet the rules or pass tech inspection, and a scattershield is required. However, obviously no one manufactures such an item for this application. In such instances, SCTA (Southern California Timing Association) allows bespoke scattershields to be fabricated from ¼-inch steel. A lot of work, but preferable to the alternative should the flywheel/clutch let go. Limited space in my car meant I probably made the process more complicated than a simple ¼-inch can over the bellhousing, but it solved the problem, and still allows acceptable space in the footwells of what is a small cowl section, especially once a cage is in there too!
GM's Quad 4 & Ecotec Engines And Ford's Zetec & Duratec Engines- Four Play
Notso Special Engine And Transmission Overhaul
Converting a FWD engine to RWD isn't rocket science, but does involve a little head scratching. The Internet is a great place for research, but do double check everything, as you can't believe everything you read there!
1. Unfortunately no longer available, I sourced my Zetec crate motor from Ford Racing, which included the exhaust manifold, flywheel, and fuel-injection harness, though I wouldn't be using the first two. This engine produces 130 hp and 127 lb-ft of torque, with a compression ratio of 9.6:1. It weighs 370 pounds dry.
2. While the Zetec was designed to be a FWD engine, Ford thoughtfully provided bosses on each side of the block, which made fabricating engine mounts a relatively simple task. I used 3⁄16 steel, with bolt-through cushion-type engine mounts from Speedway Motors.
3. The stock flywheel, showing the 36-1 timing holes to fire the crank trigger. This was sent to Quad 4 Rods for them to reuse the stock ring gear on one of their new billet flywheels. The flywheel only fits in one position, maintaining the timing.
4. Positioned at 10 o'clock when looking at the rear of the crank, this is the stock crank trigger that reads the timing holes on the flywheel.
5. This is the Zetec to T5 bellhousing manufactured by Quad 4 Rods. A very nice piece, all holes lined up, and those that should be threaded, were. It is supplied without any holes for a clutch release arm or hydraulic lines, meaning you can place them exactly where you want them. It also enables the stock (manual trans) starter to be used in the original location.
6. At the top is a T5 from a Thunderbird turbo coupe, judging by the large dampener on the slip yoke, with the shifter at the rear, a wide mounting pad, and a 10-spline input shaft. Four-cylinder T5s had a 3.97 First gear with a 0.79:1 overdrive and a lower torque rating than V-8 T5s. The lower T5 is from an S10 pickup, and has a 26-spline input shaft, the shifter farther forward (ideal in an early hot rod when you want it closer to a stock position) and a smaller, angled mounting pad farther back than the Ford trans.
7. With the Quad 4 Rods bellhousing bolted to the transmission, I began fabricating a scattershield from ¼-inch steel, mainly using triangles. The scattershield would bolt together with flanges at 12 and 6 o'clock to enable removal.
8. The leading edge of the scattershield was made flush with the front edge of the bellhousing. Later tabs were fabricated to bolt the scattershield to the engine block.
9. Here you can see the triangle construction. The scattershield had to fit tightly against the bellhousing halfway along its length in order to fit inside the transmission tunnel.
10. With the scattershield fabricated, and welded inside and out, a holesaw was used to drill the access hole for the hydraulic clutch lines to exit and enter. Here you can see the aluminum bellhousing is thicker than the ¼-inch steel scattershield.