Interesting to see under "cars for sale" the P type engine with a cooling fan in the Netherlands post dated 14/04/14. Incidentally should such a late PB not have twin breather configuration
Robin, It's difficult to see how you can see the location of the second breather with the exhaust manifold in the way. However, you may be correct in that there is no evidence of the stud on the sump for the breather tube nor the tube itself. But yes, certainly all PBs should be a two breather block. I think it likely the engine number quoted is the original number, not the one currently with the car.
Does anyone know why Abingdon went to the trouble of adding an extra breather? The main offside breather should be much more than adequate.when racing we block off the nearside breather to avoid the agro of fitting an extra catch tank. Doesn't seem to matter.I've raced cars with PB and NB blocks and never bothered with the nearside breather.Tony.
I think that the reason must have been quite sustantial to justify the considerable cost of casting up an entirely new block. I have been told that it came from complaints made by the trials men, who found that the early PA blocks produced a great deal of oil frothing - which I suppose might have resulted in bearing failure.
Possibly high revs in first and second gears found the problem, rather than high speed in top, although having said that, the Works pushed through the build of the two breather blocks so that they could be fitted into the Q Types (with the possible exception of the first Q engine to be built).