Doing away with PVC recirculation crap!

[davidf]

While cleaning the throttle body this morn. I noticed it was very gunky and I hate the fact that it goes back through the intake/valves/combustion, so I want to know from you Honda experts if it is safe to plug the 2 ends on the suction side of the intake and run 2 hoses from the valve covers to let the crankcase breath into the atmosphere. I'm sure most is about emmissions but we do not test here. I figure if it's not sucking the hot crankcase fumes back down the intake, the car might actually run more efficient. Any professional input is greatly appreciated.

 

[Sulley]

Cars were set up that way until the '60's. I do know that the PCV is the single most effective item of emissions control equipment added to engines, if I remember correctly is cuts overall emissions from an engine by well over 50%. The other nice thing is that they don't really affect driveability as the other early smog equipment did. You do have to clean things now and again.

Earlier engines had a breather tube, usually mounted to the side of the engine block. I believe there was some engineering as to length and what the draft of the passing air at road speed would do as far as drawing vapor out.

My airplane has an breather tube setup and if what you are planning is anywhere close to as messy, you'll wish you kept the PCV hooked up.
The oil/grime/dirt buildup is amazing.

I think the biggest problem will be finding somewhere to vent the open line, so that it doesn't circulate or get drawn back onto the car or into the engine compartment and ultimately cause a huge mess.

 

[OneRedNSX]

just put in a catch can. catch all the gunk in the can and the vapors still get recycled...

 

[OLDMNSX]

david,
First, a few questions I would ask are:
1. How many miles does the car have on it?
2. When was the last time the throttle body was cleaned?
3. What kind of oil are you using, how often do you change it?
4. How old is the PCV valve?
5. Have you run a differential compression test to check for excessive blow by through the rings into the crankcase which produces excessive vapor into the throttle body?

Unless you run the tube clear out the rear of the car the airflow will just whip that vapor all around the engine compartment. I agree with the previous reply, it will make a mess. This will also make your car smell like oil vapor when it is sitting still while running. I am sure your wife or girl friend will be quite impressed with your modification.

Remember if you clean the throttle body use "Throttle Body Cleaner" not carb cleaner.

Brad

 

[Briank]

There is no good reason to mess with the PCV system. It connects after the throttle body so it does not add to any throttle body deposits and the last thing you what to be smelling is that oily blow by smell.

Might you be running a K/N or other oiled element air filter?

 

[scooternsx]

The rear bank pcv hose runs into the intake pipe(before the throttle body) I say go with a catch can.. you can T both lines into one and run that to one of the nipples on the catch can, run the other to the intake nipple.. no more gunk in the TB.

 

[Briank]

There is a reason it’s called a positive crankcase Ventilation system. The rear line supplies air to the crank case and the PCV valve draws the fumes out of the engine. T'ing them together will render the whole system inoperative. If the PCV side has a problem you can get blow by gases coming out the rear bank into the inlet side of the throttle body. :wink:

 

[nsxtasy]

I'm sure most is about emmissions but we do not test here.

Just because you won't get caught, doesn't make polluting a wise idea. Shame on you!

 

[drew]

The car runs more efficiently WITH the PCV, not less. It also keeps your engine cleaner and it has an added benefit less emissions too.

There are ONLY downsides to removing the PCV system.

I used to deal with a lot of 60's cars...it was introduced long before emissions were an issue.

 

[davidf]

Ok guys I'm convinced. I'll leave it alone. Thanks for all the responses. :smile:

 

[enkrypt3d]

How often should you clean the TB? I didn't know this was one of those required things... my NSX has about 71K on it now. Not sure if its ever been done.

What would be the process to do this? I imagine you just spray the TB cleaner in it and go?

 

[davidf]

Cleaning the TB is a simple job. At 71K you should do it once and be done with it. My car actually idles better now.:smile: