Additional blow-by gas line
My family's Honda Life once had this much of sludge.
The valve cover.
I wonder why the engine E07Z has built up so much of sludge. As I search the net, I find
there are many E07Z engines that have too much sludge like below.
I know an owner who changes the engine oil regularly within the intervals of Honda's
recommendation but his engine also suffers from the same problem. There must be some
design issue since it does not have a PCV valve and there is no connection at all between
the intake manifold and the valve case. It only has a single blow-by line but that is an old
technique derived from motor cycles. Honda's engine E series must be designed based on
the experience of motor cycle's engine design and it builds up the sludge faster than other
engines that have a PCV valve line in addition to another ventilation line.
I decided to do an experiment which make it possible to absorb the blow-by gas actively
to cylinder shown by a photo below. In order to achieve this, I set up a new additional line
like this. 
My idea is to connect the valve cover and the intake manifold via an orifice with an oil
separator in between shown at above photo. I got this idea fixing Daihatsu Mira the other day.
The glass bottle held by my hand is a home made oil separator. It was a bottle for strawberry
jam before. The top of the can is made of iron and I could solder two pipes. I also added the
silicon RTV there for a better reliability. I made a T joint that is used for the line between the
canister and the intake manifold. The internal diameter of the copper material is 4.5mm.
I intend that it does not disturb the passage of the vapor.
I drilled a small hole diameter of 1.5mm to it aiming to form an orifice and I connected
another pipe with solder that passes blow by gas via the oil separator. The line is connected
to the intake manifold and the vapor and the certain amount of blow by gas is absorbed to
the cylinder. The experiment is still going on and I still need to wait that it gets good result
or not but as far as I check the situation, things are doing well. The engine used to have this
much of whitened milk like oil below but now there is none. The red arrow indicates the point
where blow by gas is taken.
The valve cover side of connection is done at the oil filler cap drilling a hole with a modified
anchor bolt which is shown below. Remoning the center piece of the bolt, you can get a nice
path to get blow by gas in the valve cover through the cap.
The oil separator is now fixed as is below and the experiment is going on. So far so good.
