Jim Blackwood's wicked blown Oldsmobile 215cid powered MGBOwner: Jim Blackwood
BritishV8 UserID: BlownMGB-V8
City: Florence, KY
Model: 1971 MGB
Engine: supercharged Oldsmobile 215 V8
Conversion by: owner
For more information, please read this article: Jim Blackwood's 1971 MGB V8 Roadster
Current EFI (Enderle-style intake & MegaSquirt controls)
custom triple throttle body
throttle position sensor
ethanol vapor intercooler
home-made plenum (fabricated in brass)
cam position sensor
custom radiator and fan shroud
custom headers and fender vent fan
wiring, relays, and circuit protection
Eaton M90 (Generation 4) Supercharger
Previous EFI (Mass-Air, Ford EEC-IV SEFI / TwEEcer controls)
cold air intake ductwork
throttle body and mass air flow (MAF) sensor
bumper splice hidden under over-rider
mechanically adjustable brake bias mechanism
pedal hangs between master cylinders, pivoting on a spherical bearing on a threaded rod...
side-to-side location of the pivot point determines relative piston travel and thus brake bias.
the large wooden knob is for brake bias adjustment
handcrafted wooden door trim
leather Mercury Marauder seats (seat-backs grafted to MGB bases and swapped-out lower cushions)
Oldsmobile 442 wing produces down-force for cornering
trim linkage automatically reduces aerodynamic drag at speed
(please also notice the back-up light and space-saver spare tire)
Jim Blackwood's 1971 MGB with Oldsmobile 215 V8
(as originally published in British V8 Newsletter, Volume 6 Issue 2, August 1998)
By: Jim Blackwood
City: Erlanger KY
Model: 1971 MG MGB
Engine: Oldsmobile 215 V8
How It Was Done
|Engine:||1963 Olds 215 from an F-85. Extensively modified with Olds factory turbocharger.
|Transmission:||late '70s Borg Warner T-50 (Monza?) close ratio gearbox was much better than the
wide ratio unit. The road race shift pattern takes some getting used to though.
(Reverse is to the left and up, where first gear is in most manual transmissions. -Ed)
Heated and bent the shifter and removed the stock chrome extension. Attached a custom
walnut T-handle made for my hand.
|Bellhousing:||D&D Fabrications. Offset dowel pins 0.012" to correct alignment between crank and tranny output shaft.
|Clutch Slave:||NAPA. Do not recommend this: created a box in the driver's footwell to clear the clutch fork.
Shortened gas pedal to clear box.
|Clutch:||10-1/2" diaphragm (NAPA for GM.)
|Flywheel:||D&D Fabrications light weight, 0.010" shim around crank snout.
|Exhaust:||owner fabricated 8 into 4 into 1 heavy wall turbo headers. No muffler or catalytic converter.
|Brakes:||1975 Mach 1 Mustang ventilated rotors and calipers on front, stock drums on rear.
Dual master brake cylinders with balance bar, adjustable from dash.
|Tires/Wheels:||Goodrich 265/50/14 on 7. Centerline Wheels, standard offset. Custom hubs on front and rear.
Front spindle bearing set up with American practice.
|Suspension:||Huffaker springs on front, lowered 1" de-arched rears with one full leaf added, competition
valving in shocks with light oil, Delrin bushings in A-arm, GT front sway bar, decreased toe-in to near zero.
|Cooling:||custom 5-core radiator 4" longer than stock, filler moved to tube at thermostat neck, steel flex fan
mounted to crankshaft, pressurized overflow tank, coolant line to turbo compressor housing.
|Rear End:||stock MGB. Axle flanges replaced with 5 lug 4-1/2" bolt circle (small Ford pattern.)
|Recommendations:||I like the close-ratio Warner T-50 transmission.
Use a hydraulic throw-out bearing set-up.
Learn to gas weld and make your own headers - it's not that hard. I had 80 hours in a set of
equal length (within 1/8") over-the-tire fenderwell headers dumping into glass-packs inside the
rocker panels. That's about a months worth of spare time. Also, it's possible to use the stock
starter by rotating the nose and an aluminum starter nose does exist. Some welding, grinding,
and drilling required. Geo Metro alternator is small, works well, and is easily mounted.