The engine you choose is a personal and often emotional choice.
Many Americans grew up in Ford or Chevy biased households so will
be biased towards one marque or the other. Many people will want
to keep a Rover engine in the series LR at any cost and will stay
with the GM derived Rover V8. Some people like diesels, some
All the small block American block V8 engines and their V6 derivatives
can be made to fit within a series engine bay. Most American small
block V8's are very close in weight to the 2.25L Land Rover engine
so the suspension and handling characteristics are not affected
by the engine weight. When
evaluating the fit of an engine, remember to check for things that
hang onto the side of the engine at frame level (especially in the right side where the front propshaft is located) and clearance between
the oil pan and front differential. And
don't forget weight. There
are Diesel four cylinder engines that fit nicely but often weigh
in at twice the weight of a small block V8 and exceed factory spring
I'm not going to spend much time discussing Rover V8 engines.
The Rover V8 drive train has been engineered at the factory so
an engine swap is mostly a matter of modifying the bulkhead, mounts
and using factory parts. I
personally think that these are great engines for lightweight sports
cars but are not as good as the American V8s for use in big
heavy Land Rovers. They
are not as robust as the american V8s, parts are a lot more expensive
in the States, they are spec'ed for premium grade petrol and do
not get good fuel mileage. In several states fitting that new of
an engine into a Series Land Rover would require the Series Land
Rover to meet all emissions regulations in effect for the year
the engine was built. On the other hand, they are the easiest
V8 swap into a Series Land Rover since all the drive train parts
work together, are off the shelf and you can just state year and
model when buying parts for your conversion. Probably the
easiest way to make the conversion is to get a Range Rover Classic,
remove the body and install a Series body onto the Range Rover. This
has been successfully done a number of times.
For many people thinking about a V8, the choice boils down to
Ford and Chevy. Each has its advantages and each has its
disadvantages. The small block V8 Ford is a couple inches longer
than the small block Chevy . The extra length is clearance for
a front distributor mount. However the small block Ford is a little
narrower than it's Chevy counterpart and is an easier fit if the
stock Rover steering box is retained. Replacing
series inner wing panels with Defender inner wing panels provides
additional space site to side for a little extra space with the
larger of the small block engines (350/351).
The GM small block V8 will have it's distributor almost against
the bulkhead in an area that is difficult to access when the bonnet
is attached to the car. The Ford has it's distributor up front
and provides very easy access but makes the distributor more susceptible
to fan splashed water when wading. Ford makes a rubber boot that
goes over the distributor cap and does a great job of protecting
the distributor from splash.
The stock Chevy oil filter location is better placed for use in
a series Land Rover. It faces down at the left rear of the engine
for very easy access. The small block Ford oil filter sticks out
the left side at frame level on a Rover. The frame
prevents removal of a standard Ford oil filter. Ford
offers a 90 degree oil filter adaptor that puts the filter alongside
the engine instead of sticking straight out. This
actually puts the filter in a more protected area than the Chevy
the shorter Dodge 318 oil filter fits and works OK on a small block
Ford and can easily be replaced.
The oil pan must have it's deep part in the rear for maximum front
axle clearance. This is easily sourced in a small block Chevy because
the oil pump is at the rear.
The small block Ford has it's distributor driven oil pump at the
front so most Ford oil pans have the deep part at the front. You
would need to source an oil pan from a early small block Bronco
or Ford 4X4 pickup. This pan has the deep part at the rear. The
Rover's differential housing can strike this pan on extreme articulation
(I learned this on the trail). If you can, modify the front right
corner of the pan to effectively remove a 2 inch square cube from
the front right corner of the pan. Chevy has the advantage there.
The alternator is mounted high on a GM small block engine. Ford
tends to mount them low like the LR four cylinder engine. There
may be a frame clearance issue depending upon which stock mount
came with the Ford engine. However, alternator on a small block
Ford can be moved to a higher location to protect it from submersion
while deep wading and have more space at the frame rails.
The engine will be sitting close to the Rover bulkhead so exhaust
manifolds will need to exit down and not out the rear. The GM Ram
horn exhaust manifolds fit this application very well and is the
perfect solution. Ford exhaust manifolds most all exit the rear
and can not be used in their stock locations on the conversion. Thankfully Ford small block exhaust manifolds and be used on either side.
The early Falcon V8 left side exhaust manifold (single exhaust system) exits downwards between the last and second to last cylinder, or first & second depending upon which side you mount it. There is a more common Ford pick up exhaust manifold that exits in the same general area but is ngled very differently. You can make do with these if you mount the exhaust maifolds to the engine BEFORE fabricating the frame engine mounts to make sure that the exhaust will not interefer with the engine mounts. Exhaust manifold to engine mount interference can be a big gottcha if you install the frame mounts prior to installing the exhaust manifolds on a Ford. I ended up using the Falcon V8 exhaust manifold on the engine left side and a Mustang exhaust manifold on the right side. The Falcon manifold put the exhaust down pipe behind the engine mount providing lots of clearance for changing the oil filter. A left side Mustang exhaust manifold put the down pipe at the front of the engine allowing maximim clearance from the front propshaft and the starter motor.
Block hugger headers are an option for both Ford and Chevy engines that should be carefully considered before going that route. If you do use headrs get ceramic lined ones with the thickest diameter tubing you can find. Be cautioned though that steel tube headers, even ceramic coated ones run very hot and the Series engine bay is small and enclosed on 5 sides. Vapor lock is a very real problem with using headers in a Series engine bay. Especially at low trail speeds. I tried headers for a while and was plagued with vapor lock problems that insulating and moving fuel lines never completely cured. I also makaged to melt the clutch flex line on a long hot slow mountain trail climb. Putting an insulating tube over the rubber hose helped. In general I recommend against using steel headers in these engine bays. The headers only make a power difference in the higher RPMs. Header thermal wrap holds moisture against cool headers. Wrapped headers helps keep under bonnet temperatures down but often rust out the headers in 3 or 3 years from new.
The Ford engine is slightly lighter weight than the Chevy but
they are so close to each other and the weight of a 2.25L Land
Rover engine that weight is not a factor. Parts for both
are cheap and on the shelf at any North American auto parts store. I
think the choice is basically just individual preference. They
are both good reliable cheap engines.
Land Rover manual gearboxes will not hold up to American V8s so
you will need to engineer a drive train. 10 spline rear axles
will not hold up and you may find yourself dealing with leaf spring
windup in the suspension. Do your homework on engineering
the drive train and you can have a reliable trouble free conversion. I
have written a web page covering common
gearboxes and transfercases used in conversions. Hopefully you will find it of help.
When converting to a more powerful V8 a number of things need
to be addressed. The engine should be centred more within
the frame to provide adequate clearance for exhaust, left side
accessories and left hand steering. Installing the engine more
towards the frame centre line also distributes the side to side
weight more evenly.
In order to fit the larger American V8 bellhousing and to centre
the engine more within the frame, the bulkhead has to be modified
for more clearance in the bellhousing indentation. A small block
V8 will need a bulkhead indentation that is 3 inches wider to the
right and an inch higher clearance where the bellhousing passes
The bell housing clearance indentation needs to be modified to
allow centring of the V8 engine and space for the larger bellhousing. For
my bulkhead, a vertical cut was made near the centre of the indentation. Next
the welds that held the right side of the indentation to the rest
of the bulkhead were carefully removed allowing the removal of
the right half of the bulkhead indentation. A new
cut in the bulkhead was made three inches to the right of the edge
of the stock bulkhead indentation edge that carefully followed
the factory cut. The edges were formed and the right half of the
indentation panel was welded back into place along the new cut
three inches to the right of where it was previously positioned.
A three inch wide flat sheet of steel was welded into place to
cover the new three inch gap between the right and left sides of
the bell housing indentation. At this point the the bell housing
indentation looked factory stock but was three inches wider on
the right side.
The new edge of the indentation comes to the edge of the Kodiak
heater mounting flange. The heater did not need to be moved or
modified from it's original location. The end result as a
indentation about 25 inches wide. This is plenty for a small
block Ford or Chevy but a GM 6.2 V8 diesel will need an indentation
about 29 inches wide which will require taking a couple inches
off the already narrow left side foot well. The other option
is having the engine sit forward of the stock indentation and
use a Defender front radiator support and bonnet.
The Ford or Chevy bell housing needs more clearance along the
bottom edge of the bell housing indentation than the stock Rover
one does. The horizontal flange that goes into the passenger compartment
was cut out. One inch of metal was cut out of the bell housing
indentation along the top of this cut and the flange was welded
back into place. Basically the stock shape was retained but it
now sits one inch higher and three inches wider.
This completes the bulkhead modifications.
A couple of modifications need to be made to compensate for
the centring of the engine and to provide clearance for the radiator.
To start off with, the stock battery mount needs to be cut off
as does the stock four cylinder engine mounts. New mounts will
need to be welded into place.
If you are fitting a Ford engine it is a good idea to move the
radiator cross member forward an inch from its original location. You
just cut the cross member
away from the frame then reweld it one inch forward of it's original
location. The front tabs that the radiator bulkhead rest upon
are cut off one inch shorter and new mounting holes are drilled
one inch to the rear on the tabs. The end result is that the radiator
bulkhead remains in it's stock location and the fan to radiator
clearance picks up one inch. When the stock Rover steering
is retained the rod at the top of the steering relay is bent
rearwards one inch to maintain the steering geometry. But
it would be a good time to seriously consider going to power
steering. The front cross member usually does not need to be
moved when fitting a Chevy small block.
The cross member under the bell housing may require a diagonal
divot taken out of the top leading edge for additional clearance
of the front prop shaft. My Rover has the extended shackles and
front springs reworked for additional articulation so the divot
was added. Military 109 frames that were
factory fitted with long shackles have a divot in the same location. You
can cut a hole for the divot then weld in a curved metal plate.
The transmission cross member does not need to be modified. Since
the engine will be centred in the frame (engine centre 1 inch
left of frame rail to rail centre), the transfer case moves a couple
of inches to the right. This movement was compensated for by reworking
the transfer case metal mounts that are attached to the transfer
case. There is a bell crank that attaches to the frame for the
emergency brake. It had to have an arm bent to compensate for the
new lateral location.
The 109 has a cross member behind the transfercase that passes
the rear prop shaft through a hole. The hole needs to recentered
around the rear prop shaft. Cut the cross member off the frame,
then cut an inch cross section off the right side and rewelded
it to the left side. The cross member gets rewelded back into it's
original location. The only difference from stock is the hole is
moved an inch to the right.
This completes the frame modifications.
A new transmission tunnel needs to be fabricated out
of a sheet of aluminium. The new tunnel cover follows the same
basic outline of the stock cover but is one inch taller and about
three inches wider. If you use a Series Transfercase,
the lever with the yellow knob will sit on the top instead of
the right side (requiring shortening the length of the spring).
The floorboard on the right side needs to be cut down a little.
When I went to put the stock rubber floor mats back in my Land
Rover all I needed to do was cut a couple of inches off the
right side of the mat.
The tunnel mounting flange on the seat box needs to be reworked
for the new tunnel size.
That completes the interior & floor panel modifications.
I suggest doing some radiator research before specifying a radiator. There
are brass and aluminium radiators, vertical flow with the tanks
at the top and bottom and horizontal flow with the tanks at each
side. There are single pass radiators where the coolant flows in
a hose to a tank, down the tubes to the other tank and out. Then
there are multiple pass radiators where the coolant takes more
then one trip across cooling tubes. Best to do your homework first
so you have a decent idea of how different materials and construction
affect cooling. The engine, vehicle, climate & vehicle
use all affect the kind of cooling system that is best for your
puller cooling fan will require fan ducting, a pusher does not. A
mechanical fan needs to be directly behind the radiator core, the
spatial relationship between the engine and the radiator core is
unimportant if you use an electric fan. And you need to be concerned
about where and how you plan to mount the radiator. You can
just ask someone what they use and buy the same, but it may not
work the best in your vehicle for where you drive.
decide on a custom radiator you will have to figure out
all the dimensions, inlet & outlet specs as well as any mounting
brackets needed before contacting the company. Custom radiator
companies have experienced people who can walk you though pros
& cons of different cores to help you choose the best one
for your application but you need to tell them how much space
you have and where the filler & tubing need to be. Most custom
radiator companies also sell mounting brackets so you might want
to check out their offerings before finalizing a mounting method.
I have used both vertical and horizontal flow radiators with my
302 engine. The vertical flow looks the most like stock but needs
to be mounted behind the front cross member with the bottom tank
behind the cross member. If you use the mechanical fan there
is not much space between the cross member and the fan for a core
so you are pretty much restricted to a narrow core radiator. The
core size for a vertical flow radiator and mechanical fan is approximately
17 inches high by 24 to 24-3/8 inches wide by 1-1/2 inches thick.
The vertical flow radiator I had worked OK with my engine as long
as I did not work the engine hard on hot days. It was fine
for cool climate driving though. A thicker core radiator and an
electric fan to allow space for that thicker core likely would
have worked better on those hot days on long grades. I
replaced that radiator with a custom horizontal flow aluminium
radiator the second time my vertical core radiator needed to be
My horizontal core aluminium radiator
A horizontal core radiator can be mounted on top
of the front cross member providing more space for the engine length
AND allowing space for a thicker core. The height can be what fits
between the cross member and the underside of the bonnet. The
width is what fits. Some folks take a wide off the shelf
radiator and cut a hole in an inner wing so a tank can fit through.
The left side of my radiator rests against the power steering box
(with rubber pad between) and I have just enough space on the right
side for the bonnet prop rod assembly and for the passage
of the headlamp wiring. This radiator sits inside a rubber
padded U channel bolted to the top of the front cross member. The
2 vertical studs bolt to a flat plate that also attaches to the
top of the radiator bulkhead's shroud. I made 2 mistakes
with the specification. The overflow tube is pointed directly
to the inner wing with very little space for a hose. I should
have pointed it the same direction as the top hose. The
second is the bottom hose inlet. The frame is not horizontal
where it sits. A hose would fit better if it were parallel
to the frame and maybe pointed inwards a little.
Trial fit of the radiator. You can see the power steering box at
the picture right bottom and the bonnet prop mounting bracket
to the picture left. There s enough space to get the headlamp,
electric fan, horn & turn signal though below the bonnet mounting
bracket. With the bottom mount in place the top of the
radiator is even with the top of the radiator bulkhead shroud.
Here is what the radiator looks like from the front with the grille
off. The electric fan I used is from a V8 Mercedes. Mercedes
quality and only $15 at the wrecking yard. It is the largest
diameter fan that would fit my application. The fan is powered
through a relay. The repay is powered through a thermal
witch and a switch by the driver so the fan can be turned off
for a water crossing. While I was at it I also used the
horns from the same Mercedes, also powered through a relay.
Radiator hoses that fit can be hard to come up with unless you
are willing to use universal flex hoses. I wanted
to use molded hoses with smooth sides. I bought flexible
aluminium heater hose, shaped them into the shapes I needed then went to an auto parts store and
sorted though hoses until I found the right shape in the correct
diameters. You are very unlikely to find a correct hose
by looking through a book. Your best bet is to have a model
with the correct bends and be let loose at a wall of hoses to
search through and try to match up. I
never found a hose that was a match but I did find both of my
hoses as part of longer hoses. I
just cut off the parts of each hose that didn't fit the shape
I was looking for and ended up with correct molded hoses.
Car manufacturers generally use engines through a range of car
models. There tend to be high performance versions and economy
versions of most engines. You need to decide which
version works best for you. Performance versions tend to provide
lots of power at high revs at the cost of power at low revs. They
tend to require premium grade petrol because of the high compression. This
is very important if you are building a rig to make it through
very loose soil/sand /mud where you need aggressive tyres and high
RPMs to cut a path through the soil faster than you sink into it. But
most people drive trails at low speeds and don't road race
their 4X4s. For
most of us economy on regular fuel and maximum low RPM power is
the target. Most people over carburate their engines
when doing an engine swap for trail work. V8s built for economy
from the factory tended to have 500 CFM carburetors. Here's
302 Cubic inches
This chart shows engine airflow at a given cruise
for different engine sizes
From the chart above you can see that an engine pumps way less
air at cruise than most carbs are rated for. The larger carbs
allow for those short duration high RPM bursts and provide more
fuel for wide open throttle acceleration. A 500 CFM four
barrel is generally your best bet for a small block engine being
built up for trail work and economy cruise. Of course factory
fuel injection will provide better flexibility, reliability and
fuel economy but it provides a level of complication that many
people are not willing to understand and maintain.
Here's some data from an interesting chart I have come across
regarding choosing the diameter of exhaust system tubing to keep
back pressure from being too great for maximum efficiency. Larger
diameters than listed on the chart for HP is likely to decrease
low end torque. Too much back pressure can make an engine
15 - 200 CID
100 - 150
2" to 2-1/4"
200 - 250
100 - 200
2- 1/4" to 2 - 1/2"
2" to 2 - 1/4"
250 - 300
150 - 250
2 - 1/2" to 3 "
2" to 2 - 1/2"
300 - 350
200 - 350
2 - 1/2" to 3 "
2 - 1/4" to 2 - 1/2"
350 - 400
250 - 550
3" to 4"
2 - 1/2" to 3"
They also suggest specifying mandrel bends because the diameter
of the tubing is not changed in the bend. Regular tube bending
machines will decrease the tube diameter as much as 20% in a bend
making a 2" dia pipe flow the same as a 1-3/4" dia pipe. And
don't forget you want a high-flow performance muffler, especially
on 109s with the long exhaust pipe.
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