Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) +4 1990 manifold

many thanks John

shocking really... supplied by Morgan

I have to say Rob knows his stuff. On my T16 +4 h told me his race cat would not pass the MOT & refused the order.
But I can tell you his manifold & exhaust made a huge difference to the BL & MMC standard, the car was transformed.

Hi Ivor, I was lead to believe that the mild steel manifold was also supplied by Morgan

It might have been but that does not necessarily make it right.

All I would say is open up the discussion and don't assume that because it came from the factory that it is the best option.

I don't know the Rover engine but I don't like that manifold with that exhaust port shape.

Is the new gasket a good match to the exhaust ports.

Back in 1990 maybe the round tube manifold was all they could get and had gaskets made to suit.

If it was my car, I would research the manifold options before I just got a gasket to fit.

Given that choices may be limited in terms of the available manifolds, perhaps the best approach might be to get a custom gasket made that doesn't overlap the ports in the head but does provide as much sealing as possible around the new manifold.

My very limited understanding of gas flow suggests that the effect of the expansion into the larger diameter of the manifold pipes will cause a reduction in gas velocity but hopefully not too much unwanted turbulence so long as the port edges aren't interfered with by the gasket?

Certainly not ideal if one is looking for ultimate power, but if one is not looking to race the car one could probably compensate by simply dropping a gear and pressing the accelerator harder if one wanted a bit more oomph in any given situation