• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Fiesta ST Forum and Fiesta ST community dedicated to Fiesta ST owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Fiesta ST Forum today!


Will a BOV adapter reduce intake valve carbon?

Messages
475
Likes
227
Location
Dublin, OH
#1
I recently installed an OCC on my new 2017 FiST and after just 1000 miles, I had accumulated maybe a couple of ounces. My question is whether the volume of air passing through the PCV valve (and into the OCC) will be reduced, along with a reduction of oil vapors, if I install a BOV adapter that allows boost to vent to the atmosphere, instead of venting into the crankcase with the OEM setup? Any thoughts?
 


Messages
145
Likes
46
Location
Lenexa, KS, USA
#2
The recirculation system is upstream of the PCV system, changing it wouldn't change the PCV flow. Also, the stock system recirculates back into the inlet side of the turbo, which does have a path into the valve cover but I don't think I'd call it venting into the crank case exactly.

Here's a thread that explains how the PCV flow works pretty well:
http://www.fiestast.org/forum/fiesta-st-performance/481-oil-catch-can.html
 


Last edited:

Bluedrank

Active member
Messages
676
Likes
252
Location
Winter Park
#3
Nope.

It sounds like you want a catch can with a VTA option like the damon motorsports one has. BOV will not do what you're thinking it does.
 


TyphoonFiST

9000 Post Club
Premium Account
Messages
11,496
Likes
7,986
Location
Rich-fizzield
#5
How does it not reduce carbon? It's reduces oil blowing through and introducing cleaner air into the intake.

Sent from my SM-N950U1 using Tapatalk
 


TyphoonFiST

9000 Post Club
Premium Account
Messages
11,496
Likes
7,986
Location
Rich-fizzield
#6
Nope.

It sounds like you want a catch can with a VTA option like the damon motorsports one has. BOV will not do what you're thinking it does.
Or you could also get a vent to atmosphere oil cap...I have one...with a one way check valve....works pretty slick.

Sent from my SM-N950U1 using Tapatalk
 


Messages
145
Likes
46
Location
Lenexa, KS, USA
#7
How does it not reduce carbon? It's reduces oil blowing through and introducing cleaner air into the intake.
There are 2 paths from the crank case into the intake track, one to the intake tube before the turbo and one at the intake manifold. Most of the PCV flow happens under manifold vacuum on that second path. The only time PCV flow going into that first path is under boost and if you're under boost, the BOV would be closed most of that time anyway.

So, yes, you could vent a very small amount of the PCV flow out of a blow off valve in the short time between the BOV opening and the manifold pressure dropping into vacuum but in practice, the majority of the PCV flow goes either directly into the manifold or into the turbo's inlet while it's producing boost.
 


OP
apex1
Messages
475
Likes
227
Location
Dublin, OH
Thread Starter #9
The reason for my original post in this thread is as follows. Whenunder high levels of boost and you lift your foot off the throttle, the boost pressure is vented. In the stock set up, it is vented through the diverter valve into the crankcase. So there is a blast of pressurized air into the crankcase. Where does it go? Does it cause a puff of air that has picked up oil vapors to vent through the PCV valve? I do not know the answer, which is why I pose the question. If the answer is yes, would venting to the atmosphere prevent that? Perhaps the answer is no. But that is why I asked the question.
 


Messages
365
Likes
87
Location
-
#10
The reason for my original post in this thread is as follows. Whenunder high levels of boost and you lift your foot off the throttle, the boost pressure is vented. In the stock set up, it is vented through the diverter valve into the crankcase. So there is a blast of pressurized air into the crankcase. Where does it go? Does it cause a puff of air that has picked up oil vapors to vent through the PCV valve? I do not know the answer, which is why I pose the question. If the answer is yes, would venting to the atmosphere prevent that? Perhaps the answer is no. But that is why I asked the question.
That's not how it works though. Someone else already mentioned it. It vents to your intake, after the maf, before the turbo. Not your crank case.

Sent from my SM-G930W8 using Tapatalk
 


M-Sport fan

9000 Post Club
Messages
14,000
Likes
6,700
Location
Princeton, N.J.
#11
That's not how it works though. Someone else already mentioned it. It vents to your intake, after the maf, before the turbo. Not your crank case.
^^^Yes, I HOPE this is how it actually works, as I do NOT want that much extra pressure introduced into the crankcase, which has too much pressure already for my tastes. ;)
 


Similar threads



Top