Build catalogue
Ken Percival's 1972 TR6 V8 Conversion
britishv8.orgas published in BritishV8 Magazine, Volume XVII Issue 2, December 2009
Photo: britishv8.orgA 1972 Triumph TR6 rebuilt around a Ford 289 V8
Ken Percival transplanted a Ford 289 V8, originally built for his wrecked MGB, into his long-owned TR6, fabricating the chassis mounts, exhaust, cooling and a custom one-piece front clip along the way. The build favored simple, low-cost solutions such as a cable clutch and modified stock radiator over expensive parts, and the finished car is light, quick and still being refined.
Specs
As the owner states it.
- Engine
- 1965 Ford 289 "H.P." block with steel billet crank, converted to "4V" spec with hydraulic lifters, performance camshaft (specs unknown), Edelbrock Performer intake, Holley 600cfm double-pumper carburetor, K&N X-Stream filter top, Ford distributor with Crane pick-up and rev limiter, aluminum water pump, front-sump Canton oil pan with windage tray and racing pick-up
- Cooling
- Modified stock TR6 radiator with dual intake/exhaust ports and 4-row core; Flexalite 16 inch electric fan
- Exhaust
- 1965 Mustang HP iron exhaust manifolds into custom 2 inch O.D. system with dual inlet/outlet Dynamax muffler
- Transmission
- Borg Warner T5 5-speed (circa 1993) with 0.63:1 fifth gear, cable operated clutch, unmodified TR6 clutch pedal, Ford Racing lightweight flywheel, custom shortened driveshaft
- Rear End
- TR6 rear end with Quaife limited slip differential, 3.69:1 ring and pinion, stock TR6 axles
- Chassis
- Front crossmember cut 2.5 inches and strengthened by chambering, added 1x1.5 inch channel and second crossmember for motor mounts, A-arm and suspension tower mounts tied with 1/8 inch steel, roll hoop added
- Front Suspension
- Competition springs cut down 1 inch, Spax telescoping shocks, modified lower A-arms with spacers/shims for about 2.2 degrees negative camber and 4.2 degrees positive caster, Derling bushings
- Rear Suspension
- Competition springs and tube shock conversion, reinforcing plate added at top mounting point
- Brakes
- Aftermarket upgrades from Moss Motors
- Wheels
- Stock TR6 wheels
- Tyres
- Ohtsu 205/65HR15 front, 215/70HR15 rear
- Body
- Custom-made front-hinged fiberglass front clip, German-market TR6 turn signal lamps in grille
- Interior
- Mazda Miata seats
- Electrical/Instruments
- Autogauge tachometer, new temperature gauge and voltmeter
- Weight
- 2087 pounds
Parts used
What the owner names in the write-up, grouped the way the Parts page groups them. Where one of the shops we index lists the same thing for this car, it is shown underneath with a link to the shop.
Shop suggestions are being prepared. The owner's parts list is available below.
Engine 4
- Ford 289 "H.P." block with steel billet crankFord
Base engine transplanted from owner's earlier MGB build into the TR6
- Edelbrock Performer intake manifoldEdelbrock
Fitted to the converted 4V top end
- Canton oil pan, windage tray and racing pick-upCanton
Front-sump oiling system for the swapped engine
- Motor mount kit (for Ford 5.0 into 1953 Ford truck)
Repurposed crossmember and mounts used to locate the V8 in the TR6 chassis
Fuel & Ignition 4
- Holley 600cfm double-pumper carburetorHolley
Main carburetor for the 289
- K&N X-Stream filter topK&N
Air filter Ken strongly recommends
- Crane pick-upCrane
Installed in the Ford distributor; Ken later says he'd recommend a Pertronix instead
- Purolator fuel pumpPurolator
Supplies fuel to the carburetor
Cooling 3
- Aluminum water pump
Fitted to the 289 for cooling
- Modified stock TR6 radiator
Given dual intake/exhaust ports and a 4-row core to cool the V8
- Flexalite 16 inch electric fanFlexalite
Provides cooling airflow through the modified radiator
Gearbox & Drivetrain 4
- Borg Warner T5 5-speed gearboxBorg Warner
Circa 1993 unit with 0.63:1 fifth gear installed behind the V8
- Ford Racing lightweight flywheelFord Racing
Reduces rotating mass paired with cable clutch setup
- Custom shortened driveshaft
Made to suit the new gearbox and engine position
- Quaife limited slip differentialQuaife
Fitted into the TR6 rear end with a 3.69:1 ring and pinion
Suspension & Steering 4
- Spax telescoping shocksSpax
Front shocks paired with cut-down competition springs
- Derling bushingsDerling
Used in the front suspension rebuild
- Rear tube shock conversion
Replaced original rear shock arrangement, with a reinforcing plate added at the top mount
- Borgeson universal jointsBorgeson
Two used in the steering column for engine clearance
Brakes 1
- Moss Motors brake upgrade partsMoss Motors
Standard aftermarket brake upgrades fitted
Wheels & Tyres 1
- Ohtsu 205/65HR15 and 215/70HR15 tyresOhtsu
Front and rear tyres fitted to the stock TR6 wheels
Body & Trim 3
- Custom fiberglass front clip
One-piece front-hinged fender and hood assembly built by the owner
- BMW 2002 hood alignment roller and clip partsBMW
Used to align the custom front clip, with added metal guides
- German-market TR6 turn signal lamps
Mounted in the grille of the custom front clip
Interior 1
- Mazda Miata seatsMazda
Fitted in place of the original TR6 seats
Electrical 1
- Autogauge tachometerAutogauge
Added to the instrument panel
Other 2
- Ford exhaust manifolds (1965 Mustang HP)Ford
Chosen for quieter sound and less heat transfer into the cabin
- Dynamax mufflerDynamax
Dual inlet, dual outlet muffler for the custom 2 inch exhaust system
Photos
All 40 pictures in the write-up, in the order they were posted, shown from britishv8.org. A picture opens larger here, with the way through to the page it is on.
How it was done
Background and the donor engine
Ken had owned the TR6 since 1981 and had previously autocrossed it with its original engine, beating a much pricier Jaguar. The Ford 289 V8 had been running in his MGB since about 1996 with a C4 transmission and a 9" rear end. When the MGB was wrecked in September 2007, he decided to move the V8 into the TR6 instead.
Fitting the engine and chassis work
The conversion took about two months for the basic work, plus more time for bodywork, paint and electrical. The front crossmember was cut 2.5 inches for clearance and strengthened, a second crossmember carrying the motor mounts was added, and the suspension towers and A-arm mounts were tied together with steel bar. A roll hoop was also fitted.
Drivetrain choices
A Borg Warner T5 five-speed gearbox with a 0.63:1 fifth gear was fitted, using a lightweight flywheel and a custom shortened driveshaft. Ken kept the stock TR6 clutch pedal and designed a cable-operated clutch rather than going hydraulic, part of his stated approach of keeping things simple and inexpensive.
Cooling and exhaust
Rather than fit an aftermarket radiator, Ken modified the stock TR6 unit, adding extra intake and outlet ports and a 4-row core, paired with an electric fan. For exhaust he used 1965 Mustang HP iron manifolds into a custom dual inlet/outlet 2 inch system, chosen partly because they run quieter and keep less heat out of the cabin.
Suspension and handling
Front competition springs were cut down an inch and paired with telescoping shocks, and the lower A-arms were modified with spacers to dial in about 2.2 degrees negative camber and 4.2 degrees positive caster. The rear got competition springs and a tube shock conversion, with a reinforcing plate added at the top mount. Ken credits the negative camber setup for much of the car's handling.
Body and interior
Ken built an entirely custom front-hinged fiberglass front clip combining the fenders and hood as one piece, salvaged after a 1989 ice crash. Vents and a Mustang-style hood scoop were added, German-market TR6 turn signal lamps were mounted in the grille, and Mazda Miata seats went inside along with new gauges.
Result and future plans
Finished May 15, 2009 and driven about 3000 miles by that September, the car weighs only 2087 pounds and reportedly smokes its tires in first or second gear. Ken plans to fit 16 inch wheels with stickier tires, and is considering aluminum heads and a new camshaft, with weight reduction remaining an ongoing priority.
A summary in our own words. The full account, with all its detail, is the owner's: read it at britishv8.org ↗
Worth knowing
- A cable-operated clutch, built from a modified emergency brake cable, can be a robust and cheap alternative to hydraulics.
- In hindsight, a Pertronix ignition pick-up would have been preferred over the Crane unit that was installed.
- Careful, deliberate engine placement early on made it possible to keep stock pedals and use quieter Mustang manifolds.
- Modifying the stock radiator rather than sourcing a new one was a viable, cost-effective cooling solution.
- Salvaging used fiberglass fenders and hood can cost less than a single new steel hood, if you can find them.