Re: Needing Air and Oil separation
Nater_Potater said:
Please expound on the rubber glove. Is it on the breather outlet? If this is 10 minutes after shutdown, what is filling it?
Very interested in your experiments!
Nathan
Hi Nathan.
You are correct, I haven't explained the glove very well.
I ran a 4-petal reed valve in the catch can (this can caught all the oil from the Combat breather tower). This system burst a party balloon when it was attached to the catch can air outlet.
I removed the reed valve from the catch can and fitted a $1 13gram steel ball to the Combat breather tower to function as a one-way ball and seat valve (see earlier post in this thread).
A piston ring replacement bottom end teardown came to fruition yesterday so a 37 km ring bedding-in ride resulted.
Upon return home, I removed the breather hose from the tower and fitted a elbow hose with a latex glove cable-tied to the other end. I started and ran the engine up to 3500 rpm and the glove inflated but did not burst.
I shut the engine off so as not to 'cook' the rings and left the glove in situ. Ten minutes later, it was still inflated as you can see from the photo so confirming that the steel ball seats well in the breather tower.
When dismantling the glove, hot engine oil had contaminated the inside of the glove (see photo) and compromised the latex integrity - if I had then restarted the engine, I am confident the glove would have then burst.
My modified Combat breather system now has:
- ball valving at the crankcases
- oil/air separation at the catch can
- vacuum extraction of catch can oil via a 'proper' low pressure/high flow filter (was a fuel pump filter) to the oil tank
- vacuum extraction supplied one-way by engine at inlet rocker cover and activated by the catch can float switch
- vacuum operates at 3 to 5 inHg [delete mmHg] (to be confirmed now that rings are renewed)
- vacuum extraction duration is controlled by a time-delay relay
- air venting to atmosphere via base of air cleaner box
- partial recirculation of blow-by gases to carburettor air intake (optimum volume to be determined at dyno re response to hobot)
The momentary push-on switch mounted near the ignition switch is for manual activation of the t-d relay.
Ta.