EJ20H Heads - PCV system

Heads, valves, pistons, rods, crankshaft, etc...

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skid542
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EJ20H Heads - PCV system

Post by skid542 »

I think this is a redudant question and I've read through a few threads including Vikash's classic PCV thread. I'm finalizing my engine bay and and ready to do the PCV system. I've got EJ20H heads so they only have the one vent per valve cover and my block has the forward crank breather vent pluged to allow the coolant crossover pipe to work.

I'm using a rotated turbo setup and the newer style stock 45 deg. intake box.

The plan is -

Tap and install a 1/2" nipple directly into the filter box, post filter, one nipple for each valve cover vent. This makes routing super easy and fairly clean.

I will have a T-fitting to tie the rear crank breather vent to the PCV valve. The other end of the T-fitting will go to a fitting I will place in the small length of pipe leading to the compressor inlet. I haven't quite figured it out yet but I will make this fitting have a small venturi effect.

So, at this point I should have fresh air available to the valve covers and have a vacuum being pulled on the crankcase - either by the venturi or the PCV.

This sound reasonable?

*One last question - any reason why the PCV valves at the generic auto-part stores wouldn't work or should I go OEM?

Thanks in advance. I'll have a new teaser pic mid week - the engine bay is starting to look pretty :).
Lee

93' SS, 5mt swapped, 182k, not stock...
96' N/A OBW 5sp, 212k, Couple mods... RIP
99' N/A OBW, 4eat, mostly stock.
Legacy777
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Re: EJ20H Heads - PCV system

Post by Legacy777 »

Are you keeping this car MAF based? If so, you need to route the breather vents post MAF so that the air that is drawn into the motor is metered.

In the threads you searched.....what were the comments regarding valve cover vents always being a source of fresh air? Is there a situation that may cause part of the blow by gasses to exit through the valve covers?

Either way....if you're keeping the car MAF based, you need to move those 1/2" nipples post MAF.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
skid542
Fifth Gear
Posts: 2857
Joined: Fri Dec 26, 2003 6:37 am
Location: North Idaho

Re: EJ20H Heads - PCV system

Post by skid542 »

Josh, the threads I was reading through does indicate that there may be blow by through the vent covers and we know that there is also oily residue sometimes.

However, I am not keeping my car MAF based. The MAFT Pro, my fuel control piggy-back, allows me to run a true speed density setup. So I'm not worried about sending blow by gases over a hot wire :) - good comment though for anyone else reading this thread and for future information.


Otherwise though - sound like a logical plan? I'll be picking up the fittings tomorrow to do the work.

Also, is the PCV valve a standard enough item I don't need to get an OEM and the NAPA brand will work?
Lee

93' SS, 5mt swapped, 182k, not stock...
96' N/A OBW 5sp, 212k, Couple mods... RIP
99' N/A OBW, 4eat, mostly stock.
Legacy777
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Re: EJ20H Heads - PCV system

Post by Legacy777 »

Yeah.....sounds ok then. Only issue I could see is the oily vapor dripping onto the filter. If you have a paper element, that may cause you problems over a period of time.

A NAPA PCV valve should work fine.
Josh

surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT

If you need to get a hold of me please email me rather then pm
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