Engine oil in air intake

[iaksa]

Hi everyone,
Recently I notice some problem with my car and found engine oil in air intake (M90 with Richwood 7 psi kit). I think oil coming in air intake from small hose from bottom of engine (I will check where is connected) and it is connected to "P" on throttle body.
Is anybody now what need to be connected to "P" , "R", and "E" when engine is modified with M90 Richwood kit. Also what is connected when car is stock.

Hope somebody will help.
Iaksa

 

[cribbj]

I can't help you with the stock hose routing, however I'd suggest that if you want to keep a closed crankcase ventilation system on your car, that you modify it like this:

1. Completely remove your PCV system and plug off its connection at the intake manifold

2. Run a hose from each valve cover to a baffled type "catch can".

3. Run a hose from the outlet of the catch can to your intake, after the MAF (if you still have one), but before the supercharger.

If you have a fairly high mileage engine, it will have some blowby, and the supercharger is going to increase that blowby a lot, hence the oil in your intake.

The catch can will catch the oil before it gets into your intake. You definitely do not want to be sucking oil into a high compression supercharged motor, because oil increases the chances of detonation.

We often find this problem on high mileage MKIV Supras which have been converted to big single turbochargers.

 

[iaksa]

Thanks

Thank you very much.
So, let me see if I understand all instruction correctly because I am not too experienced.
- plug off connection at the intake manifold (back side of M90 - close to M90)
- plug off connection at the bottom of throttle body where passenger valve cover vent goes
- connect passenger side valve cover vent and driver side valve cover vent (using PCV valve) together with T connector - connect to IN of the "catch can"
- OUT of the "catch can" connect to intake, but after MAF and before TB

Is this like you explained ?
Please correct me if I am wrong ?

Can I use like Lextreme "catch can" from Home Depot ?

Thank you again for your help.
Iaksa

 

[cribbj]

That will work as you described, except for the PCV valve - there's no need for it anymore.

Be sure that after these mods, the M90's bypass valve still has a connection to the Richfield manifold. I'm saying this only because I don't know how you have your hoses routed, but the bypass valve must always be connected to the manifold.

Sorry, I don't know about the Lextreme Home Depot catch can. Periodically you'll need to be able to drain this catch can as it will fill up with oil, so put a drain in the bottom of it.

 

[iaksa]

Thanks

Yes, I have M90's bypass valve (comes w/ Richwood M90 kit), also I have right now hose connected from driver side valve cover vent with PCV valve, and hose from passenger side valve cover vent to the bottom of throttle body. All those hoses I will reroute like you explained with " catch can". One short question: What should I used instead of PCV valve just to connect a hose ?

Thanks,
Iaksa

 

[XR8tt]

The PVC is possibly not holding boost ? Either get a PCV from a engine that is turbocharged / blown.. From a 2J etc ??
Or get a one way valve from any make of car were they have inline one way valve for break booster.. I get mine from Nissans...
You may have to double your engines crankcase breathing by adding another vent ...

 

[cribbj]

One short question: What should I used instead of PCV valve just to connect a hose ?

Thanks,
Iaksa

Put new PCV grommets in the valve covers, then you can put double ended brass barbed fittings like these into the grommets and connect your hoses to the other end of the barbs:

​

I would use at least 3/8" ID hoses so they won't restrict the venting of the blowby. If you run small hoses like this, you really shouldn't tee them together, they should go to the catch can separately. Try to keep them as short as possible, too.

For highly boosted Supra's these hoses are often -8 AN or -10 AN (1/2" or 5/8")

If you want to spend some money and get some bling, you can weld AN fittings to your valve covers and run SS braided hose from them to the catch can. They'll cost 10x as much and won't work any better, however.

 

[iaksa]

Thanks again

I will definitely go with your design.
After notice some oil round baypass valve and M90 (I have boost and LED A/F gauge in car), also notice that driver side of V8 going lean at 6-7 psi. Like you said "oil increases the chances of detonation" - that 's what happened. Few weeks ago engine lost valve cam plug on driver side - probably building pressure during long driving under the boost.
Anyway, I will also change ignition wires, Supra injectors, new distributor caps and rotors, new spark plugs.

I really appreciate your help.

 

[XR8tt]

Double check your not boosting crankcase ??
The valve cover to thottle body should be disconnected OFF throttle body and vented to air cleaner via an oil seperator. Even if there was a one way valve on this breather it will be closed on boost as well as PCV ....
If you welded or fitted extra breathers on valve covers, make them as high as possible to prevent oil in blowby..Check tune !!! Maybe too advanced and building too much cylinder pressure....My tune has heaps retard as torque comes on then advances again in upper rpm...

 

[iaksa]

Double check your not boosting crankcase ??

Like I said I am not experienced, but I am going to be one day ). Let see if I am understanding a basic. I have a 1UZFE '93 w/ M90 and Richwood manifold w/ baypass valve. On pressure side of M90 I have just boost gauge and nothing else. So just Richwood manifold can be under boost - right ?. Driver side valve cover vent w/ new PCV is connected to M90 intake (low pressure side) and passenger side valve cover vent is connected to throttle body - I think oil coming from this vent (passenger). So sequence is: air filter - MAF - TB - M90 intake - M90. If I understand, in my current configuration, engine crankcase is not boosted - right ?.
I guess my question is where to connect OUT of catch can hose:
1)between MAF and TB.
2)in front of Air Cleaner like David (Lextreme) did.
3)connect to the bottom of throttle body where was before connected.

Basically option 1) and 3) are same - right ?
Thank again for help.

 

[XR8tt]

This is what should be checked?? Obviously on a boosted engine the throttle body is getting boost...
Quote::
and passenger side "valve cover vent is connected to throttle body" - I think oil coming from this vent (passenger).
------------------------------------------ ---------------------------

I would say boost is going though this vent back to crankcase...????

Options
[1]
Either fit a one way valve nrear throttle body and fit a "T" piece off to air cleaner ot vacuum side of blower...

[2]
IMO it would be FAR easier, just disconnect and seal throttle body vent tube and connect to air cleaner or vacuum side of blower....

In the past we just fitted filters to breather were it vented to atmosphere !! But we can't do that these days...
Tho it could be done as temp measure...

 

[cribbj]

XR8tt, his TB is on the suction side of the blower, not the discharge side, as you'd have on your TT setup. This is the way all of the Richwood setups are done.

Hence his TB isn't under boost, nor should that line from the valve cover to the TB. I was suggesting that he run both those valve cover lines to a catch can to avoid aspirating and burning any oil in the engine.

If he's running a MAF, the outlet line from the catch can should be brought back to the intake system AFTER the MAF because that blowby air has already been metered once by the MAF. If he brings that line in ahead of the MAF, it'll make the MAF give false readings.

 

[XR8tt]

Ahh yes you are right!! Centrifugal and turbo systems tend to blow through t/b...
Yes all air entering engine should be metered..Unmetered air can cause all sorts of tuneing issues..
This is were a pic is worth a 1000 words...
I was told the Mazda RX8 / Subaru WRX have an electric vacuum pump to scavenge crankcase.. I must check them out !!

 

[iaksa]

Thanks again,
When I finish this small project I will let you now with some details.