Vent tube on Driver and Passenger side valve covers for crank case pressure relief

[nikkodnp]

Hi everyone,

Car is a 89 5.0 LX with a T5 and 168,000 miles. There is a Steeda firewall catch can installed from the rear PCV then back to the upper intake on the rear.

Ive been searching the internet for days now and have yet to find anyone who has tried or questioned this.

Basically i installed a king cobra clutch kit around 5 years ago, along with a new rear main seal, flywheel and all clutch related bearings. Ever since then its still been leaking and ive sort of just lived with it. Recently my clutch started slipping with chatter, which ive attributed to oil getting on the friction disk. Ive verified this after changing my clutch the other day and finding oil slung all over the bell housing.

Im currently under the assumption that the rear main seal wasnt necessarily bad, but instead the engine just has too much blowby. This time around i installed a crankshaft repair sleeve but it appears to still be leaking.

My idea. Has anyone ever tried putting a vent from the driver side valve cover, (not breather) similar to the vent on the passenger side fill neck? I want to drill and tap a small 3/8 hose fitting on the driver side somewhere with rocker arm clearance and T it to the vent tube on the passenger side which will connect to the hose fitting on the throttle body.

The question. With a properly functioning PCV, will there be any adverse side effects of running a vent tube from both valve covers? I’ve seen SN95 mustangs with this driver side vent tube but with a passenger side PCV.

I know the best alternative would be to rebuild the engine, but id like to get some input from the community about this idea.

 

[Tob]

I yanked the TFI/fuel injection systems and redid the crankcase system. I run a PCV valve in the passenger side cover that runs to the base of the intake plenum.

On the driver side I run a breather that allows the crankcase to draw air in when needed.

 

[nikkodnp]

Thanks for the input. I live in CA where i know a breather wont pass the visual.

I want to know if there will be any issues in running dual vents to the throttle body in my fuel injected setup. Im looking at drilling and tapping a 3/8 in NPT barb on the driver side valve cover.

 

[Tob]

Have you tried a higher flowing PCV valve? Ford has a number of them that look identical but have different flow rates.

 

[nikkodnp]

I havnt tried another PCV valve, which would you recommend?

I think the PCV valve would be closed at WOT, so with the crankcase pressure at its highest it needs to be relieved through the valve cover vent(s).

One vent may not be enough, thats my reason for adding a secondary vent on the driver side.

 

[Mustang5L5]

Problem is if adding the additional vent creates additional flow or releifs pressure, than the ECU may not be able to adjust. The inlet is post-MAF, so care needs to be taken to avoid adding additional combustible gas.

I don't know the answer to your question, but the above would be my concern.

Is this a stock engine? Have you done a compression test on it or taken vacuum readings?

 

[nikkodnp]

The engine has a cobra intake, stock heads, stock cam, stock bottom end. I havnt done a compression test on it, but there is no noticable smoke coming out the back other than a puff when shifting at high rpm’s.

It sounds like it may be worth a try with a 3/8 NPT/ Hose fitting, tapped into a safe spot on the driver side valve cover.

I am interested in swapping the PCV valve as this could help when not at WOT. I’ve heard of people using a turbo Supra PCV, or even the SVO PCV. Would this be ok on an N/A motor or does this only apply for boosted applications?