Hi people,
I don't own an s2000, but plan on to. I noticed that the s2k has to crankcase air hoses that routes back into the intake stream.

Has anyone taken these things off the intake tract and just stuck a breather filter on instead? I race and build a few older Toyota engines/cars, and one of the things I always do is remove that hose cause I hate to get the intake manifold all gummed up with oil over time.

So, will removing these hoses and plugging up the holes in the intake manifold throw any check engine lights and cause the engine to run rough?

Just something I've been thinking about....

Thanks!

Mikhal
http://www.geocities.com/ae82power

 

I wouldn't make such a mod to a newer car without researching it thoroughly. In modern cars, they control the negative pressure in the crankcase to reduce venting of various gasses into the atmosphere. In some cases, it might even have a detrimental effect on performance, due to changes in the composition of the intake charge. At the very least, you'd probably see an increase in NOX emissions, due to increased cylinder temps.

Depending on how well the engine compute can respond to unexpected inputs, it would most likely think that the PCV valve was clogged, and may register that as an ECU warning.

Tim

 

I wouldn't want to disconnect it, since the manifold is actually drawing cool air through the valve cover. If you are concerned about gunk, install a catch can.

 

Mine has a breather filter on it and it works fine.

Chris

 

Are you using TWO breathers, or do you still have the PCV valve / hose hooked up? With the PCV valve / hose hooked up to the manifold, there will be hot ventilated gases going into the engine ONLY when there is allot of vaccuum (not WOT). I don't see how there could be any performance benefit to changing this, since there will be no flow when at WOT.

 

Greg, don't tell me you think that drawing cool air through the valve cover improves performance... I don't want to get into the "the manifold acts as a heat sink to the head" debate again.

The crankcase needs to be vented in order to prevent blowing seals out of the motor. The PCV system is designed to limit the amount of exhaust and fuel vapor that would normally be leeched into the atmosphere should it just be "vented." I'm not certain, but it should also provide for a little more resistance to popping seals out of the motor since it keeps the crankcase at a vacuum and not atmosphere or a little above.

On a car with FI, it's a wise idea to install a catch can to remove oil vapor or even run two breathers and eliminate it altogether. This would have a limited, if any effect, on a NA F20C.

From my experience, not very much oil gets blown through the PCV system into the manifold- Honda did a pretty good job of baffling the valve cover (unlike most of their other motors).

 

[QUOTE]Originally posted by marcucci
[B]Greg, don't tell me you think that drawing cool air through the valve cover improves performance... I don't want to get into the "the manifold acts as a heat sink to the head" debate again.

 

What do you think about the situation where some blow smoke out of the exhaust, likely from oil travelling the forward vent tube going to the intake runner? Typically this happens on the track where hard braking right handers occur. This is not the PCV system, and I agree with you that the PCV does not pass any oil, if at all.

 

I don't believe this is coming through the PCV- I think that it's oil getting past the rings.

After serious track time, I notice my oil REEKS of fuel. It's also jet black. I don't see any consumption, but it stands to reason that there is some. I did used to have people say I burned some, but since I have stopped overfilling the crankcase I have yet to hear such.

My guess is that it's getting past the rings. When I had my manifold off, I noticed almost no oil in it.

 

[QUOTE]Originally posted by marcucci
[B]I don't believe this is coming through the PCV- I think that it's oil getting past the rings.