Breather Valve seating

kemp1942 · Post by **kemp1942** » Fri Jun 11, 2010 10:44 pm

Thought I'd post this - couldn't get the breather valve vanes to lie flat on the breather holes on my spare engine that I'm putting back together.

Reversed the vanes, examined the 'seating' to no avail then tried a larger diameter washer and - bingo !

Something to remember

AlanBartlett · Post by **AlanBartlett** » Sat Jun 12, 2010 7:32 am

I always thought the vanes were not to lie flat, as allow the air esape freely to offer loose coverage of the holes? Any oil that escaped with it would simply drip down through the hole at the bottom?

kemp1942 · Post by **kemp1942** » Sat Jun 12, 2010 9:22 am

If they are 'sprung' open slightly as per the action of the washer in pic 1, then there must be a danger of air being drawn into the c'case without them being able to close. With them closed as in pic 2, the engine can still breathe 'out' - the pressure simply forces the vane to open slightly.

I think the problem is not just caused by the small diameter of the washer, but also by the fact that the hole in the centre of the vane and stiffener is too big for 7 HP - they are actually Bradford size but rather than have two lots of stock, the Bradford sized is used for both Bfd & 7