In order to fit a Rover V8 into a MGB bodyshell,
you need to make certain changes. These will depend on the bodyshell
you begin with - for example the later rubber bumper bodyshell will
need far less work than an early shell. All that you need to know is
well documented in an excellent book that I would recommend to
anyone starting a similar project.
How to give your MGB V8 Power ISBN: 1904788939
On this page I will try and describe the modifications I have
made and the thinking behind my decisions.
The Core Bodyshell
My core bodyshell is based on a post 1976 rubber
bumper MGB Roadster Heritage Bodyshell.
BMH or British Motor Heritage
Limited was established in 1975 to support owners and the
marketplace by putting genuine components for classic British cars
back into manufacture, using original tools wherever possible. Since
2001, when the company was acquired from BMW, it has been
successfully run as an independent company.
This shell was chosen as all the later shells had
a number of the modifications required for the V8 as standard
including different inner wings and bulkhead panels. However I did
not want a Rubber Bumper car in the end so the shell was converted
to accept Chrome Bumpers by the MGB Hive before delivery. The other
pre delivery modification was to have a height extension installed
in the transmission tunnel to accommodate the taller LT77 5 speed
gearbox (of SD1 fame).
It hadn't been primed when it arrived, hence the
wet looking paint!
Exhaust Header Holes
The standard headers on MGB V8's were cast
affairs that had to squeeze between the engine and the front chassis
rails. There are similar tubular ones available as a replacement
but in order to get the breathing as good as possible in this
installation it is widely accepted that the best route is to use
headers similar to those used by Rover on the MG RV8 in the early
90's. These are a 4 into 1 arrangement that goes through the inner
wing. The MGOC can provide a template as to where to cut the holes
and also the RV8 pattern strengtheners to put round the edge.
After some interest I have scanned the
templates and saved them as pdf's. Originally they are on A3 - the
line down them is the middle of the piece of A3 if that makes sense!
Template LH a
Template LH b
Template RH a
Template RH b
Right from the start of this project I have been
determined to have a twin exhaust system. Why, because that is what
V8's have! and I love the sound that V8 TVR's make - so that is what
I am aiming for.
Initially I feared that I would have to have a
bespoke system made up, but then the
produced one when they did
the MGB Supersports a few years ago. The only draw back is that it
won't fit with the fuel tank in its normal position. It is likely
that you could move the tank a couple of inches towards the centre
line as others have done - but I splashed out on an Aluminium tank
designed specifically to work with this exhaust.
The kit comes with all the relevant fitting kit,
but obviously the bodyshell needs mounting points adding and an
additional cut out in the rear valance.
Bonnet/Boot Hydraulic Struts
Little things to make life easier! Two on the
bonnet, one on the boot
Radiator Support Panels
When trial fitting the radiator I have
discovered that the radiator panels don't appear to have been fitted
properly by Heritage. Either
that or the work done by the MGB
Hive to convert from rubber to chrome bumper has created the
problem. They appear to have welded in a section from the bottom of
the radiator support panel to the main front leg that isn't there on
other chrome bumper cars. By cutting this link on one side I managed
to fit the radiator but was still not happy with it.
So I ordered two replacement panels to weld
into place. Whilst I was doing that I took the opportunity to add 3
holes to the left hand (near side) panel. As standard this is solid
with no holes whereas the right hand one has 3 holes. Given that the
air filter for the Hotwire system sits right behind the LH panel it
seemed logical that I should make the effort to get some cooler air
to it!. In or to have a professional looking job I purchased a
special tool to "bell" the edge of the hole from
RV8 Brake Servo
In terms of brakes I had intended to use the RV8
front cross member complete with RV8 brakes. So it seemed logical to
acquire an RV8 servo and master cylinder both of which were
available from the
I later decided to go with the Hoyle front end and I have got a pair
of 4 pot calipers from the
although they originate from
Coopercraft a Jag specialist. Not the lightest of calipers! but
I am sure they will be fine - I have just got used to handling AP
Racing calipers for Monaro's recently!
In order to fit the RV8 servo I had to remove a
plate from the inner wing as the servo is bigger than the standard B
item. But no problem with a spot rivet drill again from
In order to accomodate the LT77 (SD1) 5 speed
gearbox, changes are needed to the gearbox cross member. These are
detailed in "How to give your MGB V8 Power". I chose to cheat a
littel and managed to get hold of an RV8 Cross-member which was
designed to work with the LT77 or later R380 gearboxes. The only
issue then is that this needs to mount further back than the
standard B item so I had to drill new mounting holes. On the
origonal the bolts that hold the cross member in place go into a
tapped plate that is inside the chassis leg. One of my new holes
also went through this plate so I was able to drill and tap a new
hole. However the other hole missed the plate, but to move the plate
would mean either removing the chassis leg or opening the floor up
above the leg to move the plate. Neither seemed a good idea so I
drilled a large enough hole in the floor to be able to get a nut
into the hole and onto the bolt from the cross member.