Whilst cleaning out the inside of my inlet manifold I could not help notice it was coated with glazed oil and soot.
I dont know if the previous owner had stuck a dirty manifold on or if the crap was from this motor itself, but none the less the crap was there and I dont want it to come back again.
If there is one good thing about carby cars (and indeed there probably is only one thing) it is that the inlet manifold stays nice and clean.
So I took myself for a path of discovery and looked at how all the different renaults I have achieve PCV.
The way i saw it.....
The fuego has a single outlet on the rocker cover going to a T piece which splits the line for a before and after the throttle plate.
No filters, catch cans or anything else.
The R21 has a different rocker cover design with a much bigger volume of air space in the baffled section of the cover. From this comes the same breather as the fuego, but a secondary small apature outlet with a yellow plastic cap that looks like a PCV valve (but is not a valve) going to the inlet side of the throttle, and the big hose goes to the filter side of the throttle and makes a big oily mess all over the throttle body.
I guess at idle the smaller aperture (yellow cap) hose sucks a draft through the large aperture hose, and at WOT.....?? the smaller hose would do nothing and the bigger hose would take the fumes and oil and redistribute them all over my now sparklingly clean inlet manifold.
Doing some reading on the net, and in particular the Toyota page,
I see that the fuego/R25/R21 system is called a fixed orifice PCV system.
I cant for the life of me see how at WOT the inlet piping creates a low pressure in the PCV line by venturi effect with the crude plasic nipple, but having said that I have not mesured its effect either.
My agenda is simple, although its application may not be.
I want PCV but dont want oil in my inlet.
Sounds simple enough, but how do I achieve this??
Should I use the fuego rocker cover, and simply put a sealed catch can full of steel wool in the line between where it splits into two and clean it out every month or so??
or is there a more modern solution that is both environmentally responsible and does a good job of venting the fumes from the crankcase??? ($400 for an vapour pump is a bit steep at this stage in my budget)