Re: Re: Crankcase Breathing

[Mr. V]

I've just watched a live Q&A with Adrian Dodd implying that taking the breather off the redundant mechanical fuel pump window found on some blocks can cause the separator to be overloaded due to fling from the crankshaft. He suggests using the rocker cover, but that involves an inline separator which needs regular draining.

I moved mine from the timing case to the fuel pump window because I saw Philthehill did the same and I thought it was a good idea. It looks neat as well.

What does Philthehill think about the foregoing (as I reckon his knowledge and experience is equally valid)?

[philthehill]

I would disagree with Mr Dodd's comment in that oil fling from the crankshaft would overload the oil separator canister. There will be oil fling but in my opinion and experience the oil fling would not be sufficient to impact on the oil separator. The breather which has the same canister as the timing chain cover breather has a sufficiently large drain back passage that only the submerging of the breather would cause a problem. If the breather pipe is of a very small capacity then the vent may be overcome by the lack of drain back. I have never heard of any other negative comments as regards using the old oil pump aperture to mount a breather. Several tuning companies produce breathing kits to mount on the studs of the old fuel pump aperture.
As regards using the rocker cover - that is a very good vent but there is no need for a in-line separator. My engine has always breathed from the timing chain cover, the rocker cover and now the oil pump aperture into a catch tank. There is no in line separator from the rocker cover to the catch tank.
The main thing is to ensure that your engine is not a heavy breather and engines in good condition should not be throwing oil out via the breather anyway.

[Mr. V]

Thanks for that. I may enlarge the hole in the adaptor plate. At least I've got an oil resistant hose connecting the separator to the carb!