V8 Swap Into
A Mk3
By Karl Schluter -Low
Zep
****Do check laws in
your country before doing any of this work****
This swap has
measurements taken from my 1964 Zephyr 6 (New Zealand assembled, right hand
drive). View my car under My Mklll V8 to see other pictures of under
bonnet details and the accompanying write-ups for other details.
A V8 swap into
a Zephyr is a natural whether Chevy, Ford or Rover etc. Do consider a later
motor that is lead free. The Ford Windsor model is very similar in weight to
the Zephyr straight 6, more so if the V8 is fitted with an alloy intake,
headers and alloy water pump. The swap featured here has the motor sitting nice
and low as well. The centre line of the crankshaft and transmission should be
parallel at all times to the centre line of the car when looking down from
above. This helps maintain long driveshaft universal life.
With the dimensions
in this swap, the battery can remain in its factory position and the hand brake
can be slightly modified to still work in the factory design if original cast
iron exhaust manifolds are used. However, I do recommend going to a floor
mounted lever hand brake or Japanese or similar modified handbrake that pulls
out from the dash in the factory position. Cars factory fitted with automatics
have more room in the transmission tunnel, although this swap does not require
any cutting etc to the floor pan or firewall if using the C4 automatic or 4
speed top loader transmission, except for a small incision for the gear stick.
The factory column shift in factory fitted automatic cars can be modified to
shift the C4 transmission.
The factory
5/16ths-fuel line will work for most engines unless running a large 4-barrel or
fuel injection.
The cross
member measurements are in millimeters and are not to be taken literally, as
they will be different from car to car. I strongly recommend removing the
engine cross member for this work to check it thoroughly for cracks and to make
for a better welding job.
Wiring
When adapting
the wiring for a V8, the factory solenoid (with remote starter) can be reused
if the early V8"rat trap" starter motor is used. Use the factory Zephyr/Zodiac
6 sender units for the oil pressure and water temperature, installing these on
the V8 motor. Now is also a good time to update to an Alternator
.
Cooling
For a 289 or
302w motor the standard Mklll radiator can be reused provided it is in good
condition and you use a low temperature opening thermostat. I do recommend a
good flex fan and a shroud, even if just for safety reasons although a properly
designed one can help cooling. If your car has been recored with a cheaper 2
row radiator in the past, you will need to change to a 3 row (closer to the
standard radiator). If in doubt, check out a radiator shop. At the very least,
I recommend getting the radiator rodded by a good shop and pressure tested. The
factory inlet and outlet can be left as is on the standard radiator if the
right water pump is used, as both left hand and right hand outlet water pumps
are available. The top hose can be made of 2 x 90dg right angles of radiator
hose and a length of stainless tube. I also like to install a radiator
reservoir system to add water volume and hose life.
Driveshaft
and Differential
The Mklll
factory driveshaft can be reused with a larger V8 car universal installed with
matching yoke at the transmission end and a Mklll Zodiac universal at the rear
end with matching Mklll diff flange. I run the driveshaft all the way into the
rear of the transmission then back it out one inch and have that as the
driveshaft’s overall measurement. The inch free movement is to allow the
driveshaft to move in and out of the back of the transmission as the
differential moves under suspension travel. If in doubt about driveshaft
measurements, I recommend talking to the shop that is doing the work for their
advice first, plus also getting the driveshaft balanced. Now is also a good
time to make up a driveshaft safety loop, placed 6 inches back from the front
universal and mounted to the floor pan. I have successfully run the standard
Mklll diff however; both Borg-Warner diffs from Ford Falcons or Chrysler
Valiant’s etc can be modified to fit as well as Ford 8 and 9-inch diffs and
even Volvo!
Exhaust
With the cross
member in these plans, mounting the motor as detailed, extractors can be made
to fit, however, the steering box side (right hand drive) is very tight and is
made easier if the factory handbrake system has been installed elsewhere as
detailed above (at the start of this article). The top picture shows the
driver’s side (right hand drive) header system which is quite tight, but does
fit very well with careful work and trial fitting. The left hand side is
standard "off the shelf" 1970 Ford Falcon (or there about), so you
could pick up a set and modify them to fit a Zephyr. The system in the photos
has 1.5 inch primaries and 3 inch collectors. It’s not until the rest of the
motor is modified that you'll feel much effect with fitting headers to the
motor over the standard cast iron manifolds. A 5.0 liter V8 can be run quite
successfully with a single exhaust system; however, there is room for a good
performance twin system, mounting oval V8 style mufflers under the rear seat
floor pan area.
Engine Cross member
Below is the
left-hand side of the cross member extending from the block to the factory
cross member. The entire factory 6-cylinder cross member is used with just an
added on section with 90mm of tube to mount with the V8 engine mount.
Below is the
right hand side:
Both these
pictures are taken from looking on top of the car looking down into the engine
bay on their relevant sides. Again, the factory cross member upright is used
with just a built on section extending out towards the block with a 90mm
section of tube.
Factory
rubber V8 mounts
The mounts to
use are from the 1970’s Ford range and are very common. They are a through bolt
mounting design, meaning they have 2 outside flanges that mate to the modified
cross members 90mm tube with a through bolt. These mounts are easy to come by
and are easy to line up during engine work.
The swap
outlined here is for a front sump Windsor so if you are changing from a
different type of sump, you will require the matching oil pickup. American
Windsor’s with early Mustang / Fairlane are usually fitted with this sump. Most
Windsor’s are fitted with this style of sump regardless, unless fitted to a
Bronco or later model 5.0
litre fuel injected car.
This is a side
view of the gear box cross member, it needs an 80mm wide plate, 180mm’s long
(crossways) 8mm thick, welded to the front of the standard Mklll cross member.
2 transmission mount holes will need drilled in this plate once the motor and
gearbox are centered in the car. I have left the exact measurement out as it
can change from car to car, transmission to transmission. Not often done in
this swap but something I strongly recommend, is 2 triangle gussets be added at
each end of the plate. To further add strength to the cross member, modify the
cross member end mounts as seen in Gear box cross member mount fix .
Other points
of interest:
Along with this
swap, I recommend at the least the steering box be braced as detailed in Steering
box fix .
A strut tower
brace also adds strength to the strut towers and is an easy and worth while
strengthening aid Strengthening strut towers .
While the
engine bay is empty is also a good time to run new brake lines and convert to a
twin reservoir master cylinder Twin master brakes (Mklll) .
Disclaimer:
The advice and guidelines given in these articles are given in good faith.
The owners and managers of the Galeforce Zephyr site will take no
responsibility for any injuries or loss sustained while carrying out the
described tasks and procedures or any consequences arising. Please read
the Safety
First Article