Plenum Chambers (again)

[SimonR]

Having removed, cleaned and reassembled the carb on A335BWV, I've been wondering about the air system on my new (old) Maestro. The main question is why does the S-Series engine have a plenum chamber and the R-Series not?

There was a question about plenums do on the other forum, where Gareth answered:

It's all to do with fuel/air atomisation.
The inlet manifold does the same job, but with the plenum chamber it takes out some of the pulses in the air and smoothes it out before the fuel is added to the air in the carburettor, and then into the inlet manifold etc etc

So does that mean that the R-Series doesn't need the effect of a plenum? - or does it mean that in the years between the S and R engines the plenum chamber was more widely used in engines?

Would there be any value in adding a plenum to my R-Series engine and therefore changing the air system to the later version?

I must admit that this is all a mystery to me. :rolleyes: Still, it beats doing work I suppose!

[G Force]

Hi again. Not speaking from experience, but I would say the end would not justify the means. Practically speaking though whether it would fit under the bonnet is questionable, as it may stand too high and as the inlet would come from the offside fitting the air filter would be more complex than the S series.

Tuning air intake and exhaust systems is quite a complicated business and plenum chambers can be helpful in solving tuning anomalies during development, but probably rover used the plenum on S & O series to facilitate the re-location of the air filter assembly as a simple bend may have caused small running problems.

My guess is don’t bother mate.

Regards Gary;)