Lawrence Cotton's 1976 MGB with 1982 Buick 2.8L V6
(originally published in British V8 Newsletter, Volume 2 Issue 2)Owner: Lawrence Cotton
City: Thornhill, ON
Model: 1976 MG MGB
Engine: 2.8L V-6 from a 1982 Buick Skylark
How It Was Done
| Engine Mods: | intake manifold from a rear drive application such as an
Chevy S-10 pickup truck. Small remote coil. Distributor from
an S-10. |
| Transmission: | 1986 Borg-Warner T5 5-speed from a Camaro. A little metal
was ground away from starter drive bulge in bellhousing to
accommodate starter drive yoke. Yoke was ground down a bit.
Bellhousing is integral to transmission. Clutch fork pivot
was lengthened by 3/4" (This transmission is designed to
accept a starter on either side.) |
| Clutch: | 1986 Camaro. |
| Clutch: | 1986 Camaro. GM uses a plastic hydraulic line to feed the
plastic cylinder. Remove the metal end on the line and braze
it to a piece of brake line. Connect this to some flex above
cylinder head and mate to master cylinder. |
| Flywheel: | 1984 Citation X-11 4-speed manual. The amaro flywheel is
too big for a front wheel drive 2.8L. The X-11 flywheel
fits the crank, lines up with the starter, and accepts
the Camaro clutch. It is thinner and lighter than the
Camaro flywheel and as such increeases the clearance between
the throw-out bearing and clutch. The lengthened pivot
bolt alleviated this problem. |
| Exhaust: | S-10 pickup or Camaro 2 right (passenger) side manifolds
are required. |
| Brakes: | stock, with recent complete rebuild. |
| Wheels: | stock. |
| Suspension: | converted to tube shocks 15 years ago. MG-V8 bushings on front. |
| Cooling: | stock radiator with bottom tank turned 180 degrees and 1-1/4"
90 degree elbow soldered in at the front. 1-1/4" connection
replaced the stock size in the top tank. Radiator was
recored. There is no room for lower hose to connect to the
radiator on the engine side. It must come under radiator
(between radiator and steering rack), turn 90 degrees, and
cross over to passenger side connection. 14" electric fan was
installed. |
| Rear End: | stock with 3.9 gears. First gear is of little use of course.
Car is quite happy to snap off the line in second gear. |
| Instruments: | tachometer altered for 6-cylinders. A small brass elbow and
length of brake line connects oil sender (above filter) to
existing gauge. A mechanical Stewart Warner temperature sender
and 2-1/16" gauge replace the stock set-up. |
Comments and Tips
(1) This project was undertaken from a "cost conscious" point of view and subsequent function has often taken
precedence over form. Car parts and services, specialty parts in particular, are outrageously expensive in Canada.
(2) Do not confuse a GM 2.8 liter rear wheel drive block with the engine used in the conversion. Its one big
difference is that its starter motor lives on the passenger side. While it could be used, it would necessitate
custom headers. On the front wheel drive applications, the starter was moved to the other side to allow room for
the (troublesome) steering rack. What makes the front wheel drive type block so appealing is that the starter
motor, clutch slave cylinder, oil filter, water pump connection, dip stick, and alternator (custom mounted) are
all on the drivers side. Very busy indeed, but the passenger side is totally empty - except for the motor mount.
Therefore a rear drive type exhaust manifold fits perfectly in the normal position and the connection is to the
rear of the passenger compartment.
(3) An identical manifold is used on the drivers' side except that to make it mate with the unequally staggered
ports it must be reversed, the exit pointed upward toward the front of the car. Perfect! With a small belled stub
three tight 90 degree elbows (female at one end) and a 10" piece of pipe bent about 10 degrees (all 1.5" diameter)
the gases are routed up and over the water pump and down just in front of the passenger side motor mount. Midas
custom bent these pieces out of very heavy aluminized pipe in less than 20 minutes at a cost of $26. My concession
to the slightly circuitous nature of this arrangement was the use of 1.5" diameter pipe. The factory used 1.25"
pipe. I MIG welded (tacked) these together in place so as to get them perfect, and completed them out of the car.
(4) Simple brackets of 2" x 1/8" plate mount for the stock alternator out against the inner fender on the drivers
side. Later B's have a recess here. The aforementioned exhaust pipe must travel through the space between the
front and rear supports so keep this in mind when tacking up the Midas elbows. With the bank now exhausting beneath
the right side of the car, I towed the car to Midas and they clamped onto the forward pipe (the up and over one),
picked up the right right bank with a simple welded construction, came just behind the bellhousing and elbowed
across the driver side. Then turned back and over the rear mount crossmember and on to the stock resonator/muffler
system.
(5) Locating the pipe in the engine compartment is simplicity itself. Leave enough space between the crank
pulley and the steering rack to change the alternator belt. This will leave plenty of room for the small type
(remote coil) distributor at the rear.
(6) The rear motor crossmember is switched side to side and turned upside down. Cut the engine holdback bracket
off and weld a small extension on the back to pick up the single bolt for the T-5 transmission mount.
(7) The front frame mounts require two good MG (round type) engine mounts, some 2" x 1/8" plate and a bit of
imagination. With the powertrain in place and bolted up at the back, center it in the chassis. There are plenty
of threaded attaching points in the GM block close to the MG frame brackets. They are different on each side
as this is a front driver and hung more or less from the front. It is a matter of cutting, drilling, and welding
plates to bolt to the engine and to accept the MG mounts. On the passenger side the MG rubber mount bolts into
the stock frame opening while on the other side the tower on the frame is extended upwards. The rubber mount
attaches to this. This is in fact a blessing as the steering column intrudes into the bottom of the frame
bracket and makes tightening the motor mount nut a grim business indeed.
(8) When the engine hoist is released, the engine will sink a bit on the rubber mounts. To offset this, mount
the engine about 3/4" on the high side. Make sure the passenger side mount is at the bottom of the slotted
frame bracket. If it isn't, it will be when the hoist is released. PUT A PIECE OF OLD RADIATOR HOSE ON THE
WATERPUMP BEFORE MAKING THE LEFT SIDE BRACKET TO ENSURE PROPER CLEARANCE.
(9) The stock battery cable (+) is replaced (I lengthened mine, cheapskate that I am) so it will cross the
rear mount crossmember and connect to the GM starter solenoid. A fairly heavy cable was attached to this same
solenoid connection and run up and across the firewall to the fusebox area. I used an insulated post to
connect it to the brown wires that formerly attached to the MG starter. The three Lucas alternator wires
were lengthened and routed around to the new driver's side location.
(10) Air chisel the transmission tunnel beside the gas pedal to allow clearance for the starter. Take it out
back about 10", up about 7", and the floor out over to the frame (about 2"). When the engine bay is empty,
gently pound the driver's side inner fender well out in the area directly behind the shock absorber. This
will facilitate the exhaust manifold to exhaust pipe connection. Rather than try to bend the shifter, I opted
to enlarge the tunnel opening a bit toward the driver's seat.
(11) I initially made a v-shaped shroud and installed two 10" electric fans ahead of the radiator. This
cooled the engine all last summer. I have since removed these and installed one 14" high capacity fan
which does the trick and looks a lot neater. The heater is not connected - the water connection jumped with
a piece of hose. These connections are close to the up-and-over exhaust pipe so I've used a 3/4" 45-degree
elbow and a small nipple to keep the heater hose clear of the heat. The upper radiator hose is stock '82
Skylark slightly trimmed and insulated near the exhaust pipe. The bottom hose is a mix and match, the critical
piece being an "L" shaped length to attach to the pump and run forward under the radiator. The radiator shop
had just the one. A metal coupling and a standard 10" straight section extended it to the lower front
connection. The latter model radiator which sits further forward is probably a better bet if you can find
one. I couldn't.
(12) The stock front drive air cleaner is used. It is slightly modified to clear the different radiator
hose connection. Because it sits so low it clears the hood. Others I tried, including some speed shop
specials would not allow the hood to close.
Costs
| Transmission and clutch: | $600 |
| Motor: | $50 |
| Intake manifold: | $35 |
| Distributor: | $10 |
| Exhaust manifolds: | $30 |
| Drive shaft modifications: | $200 |
| Exhaust: | $226 |
| Temperature gauge and sender: | $75 |
| Radiator Modifications: | $200 |
| Radiator fan: | $125 |
| Miscellaneous: | $150 |
| Total: | $1717 |
