Smoke out of the breather?
- Thread starter my66coupe
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6Stang7
New Member
Mike
Do you have a PCV system on your engine? That smoke is crankcase fumes, which are coming up from the oil pan, through the drail holes in your heads, and out your breather. I suggest getting a PVC system on your engine if you do not already have one, as the benifits are well worth it. I really dought it's from your rings not sealing, but do a compression test just to be sure.
-Shaun
Do you have a PCV system on your engine? That smoke is crankcase fumes, which are coming up from the oil pan, through the drail holes in your heads, and out your breather. I suggest getting a PVC system on your engine if you do not already have one, as the benifits are well worth it. I really dought it's from your rings not sealing, but do a compression test just to be sure.
-Shaun
I have one, its on the passenger side valve cover, The smoke is coming up from my drivers side breather. I did a compression check recently, Im getting 125 PSI all around, because of cam overlap. I can manage 175 with really loose rocker arms, Im most sure its not my rings. Any ideas? Can I switch sides for my PCV? My other side doesnt smoke like the driver..
Mike
Mike
i saw a pcv system the other day that did not attach to your carb, it attached to theback of your header and worked on a vacuum. Seems like that would be a better setup than having it sucked through your carb again. SOmething to think about.
I dont understand how some people can get away with not using a pcv system and some people cant
I dont understand how some people can get away with not using a pcv system and some people cant
pabear89
Active Member
my66coupe said:
Check for a plugged or inoperative PVC valve.
the drivers side has the breather element and air is supposed to be drawn
thru the element down thru the pan and back thru the pvc valve to the intake.
PB
allcarfan said:
In my friends' shop this is how they did the PCV on a 85ish mustang with a 351. The PCV was connected via the rubber hose down to the end of the header, on both sides. I think it's illegal on a street car, but...
Ah Ha! I found a page with some information.
Attachments
There is a certain amount of "blow by" from every engine's crank case, the amount will vary according to the ring gap, cylinder wear, compression.etc. A little blow by is normal. Those exhaust scavenged PCV systems also use an anti-backfire check valve between the hoses and the exhaust pipes. You can also do as I did and mount a late model smog pump to your motor that has a tube inlet that normally draws air from the airfilter, but instead can be re-routed to pull a vacuum on the crankcase. I ran the exhaust hose from this back out along the frame on my Ranger to a homebuilt muffler ( they're noisy little f---ers otherwise) mounted behind the back bumper.
I don't know about parasitic... But you do have to vent the gasses some how. Either breather or pvc. If not you start blowing seals. The first to go is you intake bead. Especially if you only run RTV and not the cork. I once had a pvc with no breather and autozone sold me the wrong pvc. I blew out the back of my intake bead the first time I hit 6 grand. Talk about embarassing, driving down the street with a smoking car. 
Blown4.6
Founding Member
Hmmmmm, I when I bought a new airleaner, it didn't have the pcv hookup/s; so, I just put 1/2" tubing onto each breather (mine have little snorkels) and run it down and out of the engine compartment. I can't see how this would harm the engine.
TurboDoctor
Founding Member
When your getting blow by do you also get oil build up?? I would put one push in style breather and one pvc vavle. Watch the push in breather and see if the spounger inside collects oil.I had a 302 that had horrible blow buy and it would coat the air filter in oil in about 3 days, long story short scared cylinder wall.
If you're referring to why I did this to mine, this PCV system is the hot ticket for race motors now. Ford Racing sells the smog pumps to mount on race motors, to pull a vacuum on the crankcase, this free's up about 7-8 HP cause the pistons are working against vacuum. I had the smog pump layin around along with 20 ft. of used heater hose ( the exhaust for the smog pump) from a 93 E150 Van that I salvaged from a friends wreck. (along with the 5.0 roller motor and AOD trans too) I figured , what the hell, I'll put the pump to work. My accessory drive setup on the Ranger's 5.0 is from an 88 Crown Vic and I was only utilizing only one set of the 2 pulley drive. I mounted the smog pump from the right head, fabbed a stiffener bracket for it and it's driving off the other crank pulley.allcarfan said:
it frees up 7-8hp, but by adding another pulley and extra weight, the gain is nominal yes? no?
Sounds kind of complicated to me. Why cant it be as simple as two breathers? Or a breather with a neck on it that goes to my airfilter?
I just dont know about the air out of the valvecovers going into the car or aircleaner...doesnt seem 'healthy'...unless i am misunderstanding something.
Sounds kind of complicated to me. Why cant it be as simple as two breathers? Or a breather with a neck on it that goes to my airfilter?
I just dont know about the air out of the valvecovers going into the car or aircleaner...doesnt seem 'healthy'...unless i am misunderstanding something.
6Stang7
New Member
mustangman70 said:
I donno about that, I would have to see a dyno chart showing an engine with one, and without one. I think; however, that you would get better performance with a PCV system. The reason is that crankcase fumes build up in the engine because you have no PCV system to suck those fumes out, which will create crankcase pressure. Now, you have this built up of pressure in the crankcase that your pistons must compress EVEN MORE when they go down on the intake and power stroke. The piston moving down will cause the volume available in the crankcase to get smaller, so you're taking X amount of crankcase fumes, which are already under some amount of PSI, and compressing it more because your piston moving down is reducing that amount of volume. The amount of force it takes to do that is a parasitic loss. So I see a PCV system as giving you more performance. A friend of mine had a Chevelle that would not idle correctly unless he had a PCV system on it. Besides, crankcase fumes are corrosive and will cause bearing wear, so it's a good idea to get a PCV system for just that fact.
-Shaun
pabear89
Active Member
allcarfan said:
Gain would prob be seen in the higher rpm bands,
It used to be that simple in the older days, engines had draft tubes.
The tube was mounted in the back top of intake or block area and
ended up behind and lower than the motor, with a angle cut on the end to
make a vac draw when air passed by it.
Smog laws and engnrs have found that the crankcase needed to have bettert flow and less pollution in the air.
PB
still concerned with pulling that air from the valvecovers/crankcase compared to using 'fresh' air.
Any opinions?
Any opinions?
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