Thanks for that. I thought the malfunction of the valve would be a problem but it's over 10 years since the engine ran so I can't remember how it performed. I think I'll just blank it off and have done with it.I note what you say about the tappet chest breather. Regards John
Yup - got it. It's right at the back of the engine chapter. The valve is closed at idle and opens on high throttle openings. If the valve is open at idle it will mess up your idle mixture.
You need a new valve or block the hole in the inlet manifold to get it to idle properly. If you are going to vent the tappet chest to atmosphere put a long pipe on it so the oily smell stays away from the heater inlet
Haven't got my workshop manual to hand so I haven't got a picture to look at... but the spring and valve are probably there to close the pipe at times when it would cause a problem with running. I'll try to remember to have a look in the book when I get home.
Hi all, I'm close to firing up my SIV after its mechanical rebuild and on checking the breather valve on the inlet manifold I find it is missing the spring and the internal valve is 'chewed up'and as such is useless.The engine is a 1725 instead of the origional 1600,I know that earlier engines did not have the oil filler to inlet manifold breather connection and am wondering if the valve is necessary for good running etc.I know discharging crankcase gases to atmosphere is not good for the environment but I won't tell if you don't. Any thoughts would be appreciated. Regards John
Engine breather
Posted - 14 Jun 2011 : 16:30:56
and on checking the breather valve on the inlet manifold I find it is missing the spring and the internal valve is 'chewed up'and as such is useless.The engine is a 1725 instead of the origional 1600,I know that earlier engines did not have the oil filler to inlet manifold breather connection and am wondering if the valve is necessary for good running etc.I know discharging crankcase gases to atmosphere is not good for the environment but I won't tell if you don't.