NA 1.6 engine swap

Technical Area Engine, Transmission, Exhaust etc
2

The big ends went on my 1990 Eunos 1.6 manual MX5.  I decided to swap the engine as it was more convenient and cheaper.

I got a 1990 Eunos 1.6 auto MX5 and swapped the engines over quite easily leaving all hardware attached to the engines where applicable i.e. inlet manifold, throttle, spark plugs etc.  The alternator, pas and exhaust were swapped as was the flywheel but I did install a new clutch assembly.

I had to swap the throttle  assembly as the wiring loom had a different connector, apart from that it all seemed to go together quite well.  I fired up the engine and was quite satisfied with my handiwork when the engine spluttered and stopped.  I also heard a noise coming from the engine which is always there when it is running but I cannot find the source.  The automatic engine had no problems and worked without any noises so I am surprised that it has now.  I am able to start the engine but concerned that I may damage the engine if I run it too long.

My questions are:

Can I replace a manual engine with an auto?  What should I have considered before embarking on the project?

Will the timing be different between engines?

Are there differences with vacuum pipes?

 

Any advice greatly appreciated.   

3

The automatic has different cams to give it more low down torque but less top end power in order to allow the car to be more flexible at low speed and startup.

I cannot advise on the vacum pipes but the engine changes have been done many times.

4

Thanks for the info. Do I need to change the ECU to match the auto engine?

5

Probably not unless it is a much newer engine and you then have ammoboisers rearing their head.

6

Did you fit the spigot bearing in to the manual flywheel.And did you remove the spacer sleeve that was between the Auto “flywheel” and the crankshaft although it falls out generally when "flywheel is removed. Dont think new manual will fit over it anyway. What sort or nose and is it there all the time while car is running or does it go away when clutch is pressed.Need more info

7

I think I did fir the spigot and remove the spacer as you ask. I get the whining noise all the time when the engine is running and it increases in intensity with revs. Putting it into gear has no effect, it is still there. Not so apparent when ticking over at 1000 rpm. It started first time even with sitting idle for 6 months.