Without all the people who approve of the pcv valve jumping down my throttle I have a few questions. What gaskets have you always seen blown out? Oil pan? Are we sure its not just poor dirty assembly? Has anyone had a pressure/vacuum/compound gauge on the block to verify with 2 breathers that huge pressures are even present? And even at WOT we wont have any vacuum worth mentioning, but a car where the rpms fluctuate and de-accelerates every shift we have excellent vacuum. Personally I cant even see gaskets being pushed out, if anything maybe oil past seals. How does a pcv pull moisture from oil from a machine? I've had 302's with Vortech T-trims pushing around 20 psi of boost and had the PCV remove with just breathers and no problems.
And what I really cant understand is with a pcv valve the whole idea is to have a sealed engine compartment and in theory keep the crankcase in a vacuum if its possible or at least try to. So if the system works why would you have a breather on the other valve cover? If the pcv valve works now we are sucking in dirty air from the other valve cover directly into the engines oil.
I will say this if your engine is covered by a top and its just the family cruiser then I agree with a pcv valve to keep oil fumes/mist away from everything. If you are building a max effort engine then no pcv. If I had a max effort engine I wouldnt want to use my engine's intake and combustion chamber as a garbage dump for excess oil and fumes.
Does anyone here really think that a PCV valve can move enough volume to keep the pressure in the crankcase lower than it would normally be with two breathers?
The PCV valve will literally ONLY do anything at idle... Period... End of story.
The vacuum levels will be so low at WOT that it will not do a damn thing.
Much rather see MOPAR style breathers (with the hose fitting built into them) with hoses routed to the flame arrestor/scoop, or to evac tubes in the headers.
Mercruiser probably builds more marine engines than anyone on the planet and they do not utilize PCV valves.
The PCV valve is an engineered vacuum leak designed to pull excess crankcase pressure from a tight engine under the condition of freeway driving in an automobile that has an approximate manifold vacuum
greater than 12" of vacuum. I can assure you, your jet boat does not do that.
PCV's do not work on a jet for the same exact reason a vacuum advanced distributor does no work.
LO, sorry if you disagree... I respect your opinion but have to bow out this time.
GT
