I spoke to Pete Mantell at Mantell Motorsport this spring as he was
doing a V8 conversion on a customer's MGB Since he had all the bits
ready to go, he was able to do a particularly apples-to-apples
Pete removed the MGB engine and four speed
(non-overdrive) tranny as a unit, and weighed them complete with
intake, carbs, exhaust manifold, starter, alternator, and even shifter
lever ---> 468 pounds.
(Obviously, an overdrive tranny would have weighed a little more.)
then weighed the replacement package: a fully dressed Buick 215 with T5
(5 speed) transmission, intake, 4-barrel carb, RV8-style headers,
starter, alternator, and shifter lever ---> 443 pounds.
Rover (or TR8) motor should weigh almost exactly the same as the Buick
motor except for just one or two components. Most obviously, many
people who use the old Buick 215 use original Buick flywheels. The
Buick flywheels can weigh up to about fourteen pounds more than
aftermarket flywheels. They came in different versions... heavier
flywheels for heavier 4-door models, etc. There are, of course, places
to shave some weight too... For example, I believe the Buick
(Delco-Remy) starter is about ten pounds heavier than an aftermarket
gear reduction starter.
The wide variance in reported weight
savings/increases is complicated by other items that tend to get
changed at the time of conversion. I could give many examples, but I'll
just give one here: The MGB (Salisbury) rear axle is plenty strong for
a 200hp, 2400-pound MGB but it typically gets replaced anyway if for no
other reason than to get a more appropriate gear ratio and/or a
limited-slip differential. A Ford 8.8 or 9 inch axle would typically
weigh more, whereas a Ford 8 inch axle might weigh significantly less
(especially if an aftermarket aluminum carrier is used.)
Quote: "Same for the Ford 5.0 w/ 5 speed combo. How about w/ all the aluminum stuff?"
know, aftermarket "small block Ford" aluminum engine blocks are
available if you've got the big bucks! That's a whole new can of worms.
The weight variation among Ford installations will inevitably be
greater just because small block Ford engines have been used in many
car models/years and also because there are so many aftermarket parts
available. Also, if you're setting up to produce more horsepower and
torque, you're somewhat more likely to select heavier driveline
components (tranny, axle, driveshaft, etc.) and probably even bigger
wheels and tires. One book recommends upgrading from 4 to 5 lug wheels
if you do a Ford conversion (to accomodate more torque). Personally,
I'm skeptical that's necessary, but that kind of thinking can add up to
a lot of scope creep and weight increase.