MX5 into MGB GT engine swap

[Not_Anumber]

Although the MGB engine bay is sufficiently capacious for even quite large V8 engines and the 4 cylinder MX5 engine fits almost as comfortably as the B series there are some challenges when it comes to the inner wing areas. These are narrower than those on most cars especially at the front.

Needing to make more space on the driver's side of the engine bay for an under-bonnet fuse & relay box from my donor car, one solution could be to relocate the coolant expansion bottle. Being a late B mine has a pressurised expansion tank which bears the main filler/ pressure cap rather than being a straight overflow vessel. One thought was to find a different shape tank that could be made to fit in the boxed section beside the radiator but im not convinced Id find something that would fit that shape.

Id be interested if anyone here had relocated their coolant expansion tank or replaced it with a different type.

[Not_Anumber]

The engine started on the first turn of the key. Early indications are that it has taken well to it's change of habitat.

The higher pump pressure uncovered a pinhole crack in the front to rear steel fuel pipe. This looks to have been caused by a scrape on something heavy thrown up from the road surface at some point in the GT's past which wasnt obvious with the lower pressure of the original SU pump.

The gearbox has to come out due to a seep from it's front oil seal. Otherwise everything else so far seems to be oil and coolant tight.

I was pleased at the noise it made particularly as it only has it's long 4 into 2 into 1 exhaust manifold on at present with no silencers yet attached. It was not as loud as i had expected so this may only need a single box system.

There will be quite a bit to do now on the wiring loom. i had loosely transplanted the whole MX5 loom complete and will now begin to unpick the tape to remove the wiring for items such as the airbag and ABS systems. There looks to be about as much wire in those 2 circuits as there is in the whole of the MGB loom so this should help to thin things down a bit.
Then I will start to combine the two looms, proceeding circuit by circuit.