Mark Mallaby's 1977 MGB with Rover 3.9L V8 Engine and EFI

Mark Mallaby's 1977 MGB with Rover 3.9L V8 Engine and EFI

as published in British V8 Newsletter, Volume XV Issue 2, September 2007

Owner: Mark Mallaby
City: San Diego, CA
Model: 1977 MGB
Engine: 1990 Rover 3.9L V8 Engine and electronic fuel injection
Conversion performed by: Owner

This is my (almost) daily driver. Living in Southern California I do a lot of freeway driving. The smogged 1800 cc 4spd (non OD) could barely keep up in the slow lane! After a trip with my wife from San Diego to Napa, the poor old 4cyl gave way, spitting it's internals out onto interstate 15 a few weeks after the trip. (Coincidence? I think not.) This lead to us thinking about what was in store for the old girl. Built up 4cyl and an OD trans? Or Rover V8 with a 5 speed. We chose the later and have never regretted it!

The basic goal was to "build a reliable car with classic lines and enough power to get out of its own way". After buying the "How to Give Your MGB V8 Power" by Roger Williams and reading all the materials on the British V8 web pages and forums we think we have achieved that goal.

1990 Rover 3.9L V8 Engine and electronic fuel injection

Engine: stock 3.9 liter Rover V8 from 1990 Range Rover Classic with SD1 oil pan, timing cover and Buick 300 short shaft (AC) water pump.
Transmission: LT77 "D" five speed, flywheel, and clutch are stock units from a US-spec Rover SD1. The shifter selector remote section has been shortened about 2" to emerge in the stock MGB location.
Driveshaft: shortened SD1 unit with a conversion plate to match the diff bolt pattern, I chose this driveshaft because I liked the CV joints better than "U" joints and the tube is much larger in diameter.
Rear Axle: stock MGB with new 3.07:1 gears from Clive Wheatley. I recommend changing the rear ratio to everyone. You really don't get the full value of the conversion with the tall stock gears.
Fuel Injection: fuel injection is Range Rover 14CUX grafted into a US-spec SD1 ("Federal") intake manifold. The system works well without the need for machining the plenum (as would be required for a later-model plenum). The air cleaner is a K&N unit with custom cold air box. All aspects of the fuel injection are functional per CA law.
Exhaust: RV8 style headers from TSI with O2 sensor bungs. A 2-into-1 catalytic convertor feeds into 2.75" single muffler and resonator, to give a nice rumble but not so loud that it's annoying on trips.
Cooling: 3-row brass radiator (also from TSI) with a pair of thermostatically switched fans mounted in pusher (front) configuration. The fans are the auxiliary fans also from the Range Rover. An under body duct routes all air from the lower oval intakes to the radiator while the top shroud keeps all the air in and fingers out.
Body: the body is in "daily driver" condition, the parts for chrome bumper conversion were eBay items chosen for their aged "patina" that suits the rest of the car. I re-used the late model turn signal lamps because they cover the holes in the fenders and I had them on hand. I also left the over-riders off. I think the look is cleaner without them. The total cost of the bumper conversion was about $300.00 and was done in one weekend.
(I was bored.)
Interior: the interior is stock with LE steering wheel a new dash and wood kit being the only changes. The yellow lamp in the console in the above photo is the "EFI" (check engine) warning lamp.
Driving Impressions: my wife and I are really enjoying the completed car! We have about 5000 miles on it so far. At 70 mph the engine is turning about 2000 rpm. The power is effortless and the car is scary fast and very reliable. The car is also "green" - it passes California smog tests to 1990 standards and gets about 28mpg with the top down. (I would expect 30mpg with the top up). I love that the car looks like a "stock driver", yet we shock the hell out of some unsuspecting exotics here in Southern California. This is a great conversion. If British Leyland had made the MGB-V8 available in the US, they'd still be selling the brand in the US. It's a pity, really, that they chose the wedge-shaped TR8 instead.
WARNING: the Californian State Senate is not interested in modified cars meeting smog requirements. They are interested in removing old cars from California roads. California no longer has a smog exemption law. All cars built after September 1974 must meet emission standards for the year of manufacture. They are never exempt. Word to the wise: start (or finish) with a pre-74 body.

Rover SD1 oil pan, timing cover and Buick 300 short shaft (AC) water pump

twin Range Rover cooling fans

MGB LE interior

MGB in San Diego California

MGB roadster at the ocean

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