410 exhaust manifold

[livermoreb]

Thanks Bryn. All very interesting stuff. I am in London today, watching England being outplayed by New Zealand in the cricket match at Lord's.
I will check the carburettor number when I get back.
the manifolds you sent links for certainly look more like mine. I'll follow them up later too.
Thanks again
Bob

[Giles]

I think the driver side manifold has a central exit and the passenger side one has has a rear exit - and I think that was the case for the 407-410?

[livermoreb]

Originally Posted by Giles

I think the driver side manifold has a central exit and the passenger side one has has a rear exit - and I think that was the case for the 407-410?

That is certainly the case on my 410 Giles.

[Thor]

The manifolds on my 409 (with PAS) are the same, LHS has rear exit and RHS has central exit, and I recall seeing the same on other Bristols of the similar period. The RHS manifold has the central exit and the valve controlled by a bi-metallic strip which forces exhaust gas back across the inlet manifold to warm it up quickly from cold. All evidence, cars, and reports I have ever seen would say that all the Bristol 'Poly' engines had these features and the 4-barrel Carter carburettors, when they were built. In a comprehensive history of car engine design, I think the Poly engines would deserve an honourable mention for the good port and combustion chamber shapes allowed by the valve layout, without incurring the complication of the 'Hemi' double rocker shaft arrangement. It really is remarkable for a single cam 'V' engine.