On Tue, 10 Mar 1998 09:04:15 -0600 Mike Cousins
<mike.cousins@wsnelson.com> writes:
>..... I basically have 2 MGA's, a 1955 1500 and a 1962 1600 MkII and
I'm trying to make ONE good running car out of them.
>
>I'd like to use the frame from the 62 because it has the front disk
brakes and the wire wheel hubs.
Only very minor differences in the frames. The small bracket where the
front brake hoses attach to the frame are different because the hoses
have different end fittings disk vs drum brakes. Also the front frame
extension for the MK-II may (or may not) have the small indentations in
the top to accommodate a factory style anti-sway bar. All suspension
mounting points are the same.
>I'd like to use the body from the 55 because it looks to be in decent
shape. I'd like to use the fenders from the 62 because they are in good
shape.
Fenders are interchangeable, but, ..... The 1500 rear fenders have
mounting holes for tail lights. Tail lights on the MK-II are mounted on
the body below the boot lid. You would need to fill the holes on the
1500 rear fenders. 1600 front fenders have a slightly different mounting
for the parking lights, but I believe you can drill an extra hole in the
1500 fenders to accommodate the 1600 lights.
>I have an MGB 1800cc out of my '77 B (I'm putting a V8 in it) that I
would like to use for the MGA .....
Use the MGA engine mounts. Get an adapter bushing for the transmission
shaft pilot in the rear of the crankshaft. Use the MGA clutch disk.
The 1500 gearbox has a low starter position. The MK-II gearbox has a
high starter position. The 1800 3-main engines and very early 5-main
engines used the same starter position as the MGA-MK-II. The later 1800
5-main engines used a larger flywheel and different engine rear plate to
locate the starter accordingly.
You will need a flywheel from an early 5-main 1800 engine (1965-1967 GB
engine). The MGB flywheel has 3 locating pins for the clutch cover. The
MGA uses only 2 locating pins for the clutch cover. If you use the MGA
pressure plate you need to remove 2 locating pins from the MGB flywheel
and drill a new hole to install the locating second pin for the MGA
pressure plate. If you use the MGB pressure plate, you need to use the
clutch release bearing from the MGB, and use (procure) a release lever
and transmission front cover from an early MGB gearbox (1963-1967).
For mounting the starter you use the engine rear plate that goes with
whatever gearbox you use. When using the early rear plate with the
5-main engine, you need to bore out the center hole to accommodate a rear
crankshaft seal. There may be some additional issue with the rear plate,
but it is do-able.
If you're using the MK-II gearbox, you would want to also use the
transmission front tunnel cover and bulkhead plate from the MK-II, as it
has an added bump in the tunnel to clear the high mounted starter.
You will also need a water pump from an early 5-mail engine (GB through
GK engines 1965-1971), and the single groove water pump pulley from the
GB engine (1965-1967). This water pump is 3/8" longer on the front end
than the MGA water pump, and the matching pulley is necessary to align
the belt. You may need to shim the radiator forward about 1/4" for fan
clearance, differing stories here, tackle that problem when you come to
it.
You will need to use the water outlet elbow (thermostat cover) from the
MGA engine or from an early 1800 (G-GB) engine.
You will need to dispose of the air injection pump and plug the air
injection ports in the cylinder head (7/16" SAE fine thread set screws
work well). Other listers can give you more information on what's
involved in de-smogging your 1977 engine.
If you want to retain the air pump, all bets are off. You would need to
also retain the 1977 water outlet elbow that the air pump mounts on, and
the water hose comes out in the wrong direction for the MGA. You would
also need the 2-grove water pump pulley to drive the air pump, and it
would be exceedingly difficult to make all this fit behind the radiator
on the MGA.
Someone may also suggest that this would be a good time to trash the
single Stromberg carburetor in favor of the twin SU's (or some other
carburetor). All of the original MGA induction and exhaust system will
bolt right on to the MGB engine, and the MGA carburetors are the same
size (throat size) as the SUs that were fitted to the earlier MGBs.
If you consider using an MGB exhaust manifold, be aware that it will
interfere with the steering shaft. This requires a slight angle
machining cut on the mounting face of the manifold to move the bottom end
away from the steering shaft. Another fix may be to shim the left side
engine mount up a bit. When fitting the MGB exhaust manifold you need a
custom front pipe for the exhaust system. Opinions vary, but the MGB
long center branch exhaust manifold seems to be highly regarded.
Cooling capacity is also an issue. It would be a good idea to have a
radiator shop install a new 4-row core in the MGA radiator.
>Also, If I have to use the frame from the '55 1500, can I use the front
end parts (hubs, disks, king pins, trunnions, A-arms etc..) from the '62
on the '55 frame???
Yes, it all bolts right on. The one thing you need to change is the
small flange welded to the frame to accept the inner end of the front
brake hose, as the disk brake models use a different hose that will not
fit into the 1500 hose mounting bracket.
>Can I also bolt the '62 rear axle/spring assembly right to the '55 frame
??
Yep. Identical mounting, bolts right in.
>..... Most of the parts I'm looking at have 55-62 listed next to them,
which makes me think that they are the same for all models and completely
interchangeable. .....
Be aware of gearbox and drive shaft changes. Very early 1500's had a
gearbox with a rear sliding spline connection (1" 10-spline), an external
rear seal, and a drive shaft to match. Later 1500's also used a sliding
spline connection, but of larger size (1-1/16" 10-spline), an internal
rear seal, and a drive shaft to match (slightly different length as well
as the different splined front yoke). Very late 1500's and all 1600's
and MK-II's had a gearbox with an internal rear seal (different) and a
4-bolt flange to connect the drive shaft. Those drive shafts (2-piece)
have a sliding spline connection just behind the front universal joint.
Also, the very late model MGA MK-II gearbox has a rubber seal in the
front cover, and that front cover will fit on earlier gearboxes for use
with the MGA clutch. This part is not necessary for your conversion.
Okay listers. Have I overlooked anything this time?
Barney Gaylord
1958 MGA with an attitude
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