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MG MGA - why dizzy drive shaft

Why after the T series did they put the dizzy on the other side,using a shaft, as well as relocating the intake and exhaust manifolds to the other side, when the cam is still on the same side?
Len Fanelli

From Lindsay Porters B-series engine book. This is for B-series engines in general, not particularly MGA.


John DeWolf

I can understand the idea of having the fuel on one side of the engine and the electrics on the other, but they used the wrong side.
The starting point should have been to have the inlet and exhaust ports on the opposite side to the pushrods and then have the distributor and generator on the pushrod side.
Why?
Because with the present design you have head studs, pushrods, and inlet and exhaust ports all on the same side. This badly limits the port design. You finish up with very resticted porting options, siamesed ports, square ports etc. Put simply, a mess!
The Triumph engines have the ports on the opposite side to the pushrods and can have one port for each valve. The distributor and generator are then on the pushrod side. Simple.

The MG people always wanted 8 round ports and continuously fought with BMC management to be allowed to proceed with the Twin Cam.


Mick


M F Anderson

All I can think of, after reading Mick's post, is that this design results in a longer intake manifold run to the valve, which is often desired.
Len Fanelli

This thread was discussed on 18/01/2009

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