Breather question.

[M25VAN]

I've got the sealed filler cap/rocker breather to carb setup but my slight concern with this arrangement is how well the cap seals. The ring on the filler neck doesn't have much of a flange on it and I had to pack out the sealing washer on the cap as when twisted on it was a very loose fit providing no seal at all.

[bmcecosse]

Perhaps the wrong cap for the rocker cover ?

[M25VAN]

I'll have to try another one but it was more the small area for the cap to seal on that bothered me. Maybe I will convert to Declan's setup.

[bmcecosse]

I think older rocker covers were designed for the metal cap - with external fixing. The later one for the plastic cap with internal fixing.

[panky]

I think I need a sit down, then go and buy one od Declan's £5 PCV's

http://www.ebay.co.uk/itm/321723245595? ... EBIDX%3AIT

[bmcecosse]

That's because it's a very rare and special BMC Works/Speedwell/Cooper S PCV valve...... There's one born every minute....or indeed more than one obviously, to bid it up like that!

[panky]

Must be a tuned big bore one

[panky]

I've got the crankcase vent piped through to the vac connection on the HS4 carb fitted to my 1098 with 12G940 head. It sucks like a goodun but I was wondering if a PCV would work properly if fitted in this line as I don't have a point on the manifold to connect to.

[bmcecosse]

There's no point. If you look at the carb - the suction port is blocked off by the throttle plate at idle.

[panky]

Ah I see, so that's why it hasn't been done. One thing though, if the oil filler cap is removed at idle there is a definite draw into the engine and it stutters and dies, I suppose because of the mixture weakening as air is drawn into the intake through the breather. The carb works well and the engine idles around 700 rpm smoothly, what do you think could be causing the high vacuum at idle.

[bmcecosse]

Hmm - maybe someone has opened up the hole in the carb? Anyway - the vacuum is good - and the engine idles ok - so no worries !

[panky]

Guess so, I'll leave well alone until such time I fit a manifold with the appropriate connection - thanks Roy.