Blowing oil under boost

[cobra04649]

I have a 331 stroker with a powerdyne race rebuilt that i had tuned today.
When i took it to the tuner i had the throttle body discharge tube ( the one that went to oil filler neck vent) blocked and the oil filler neck vented to outside air thru hose. My tuner uncapped throttle body cap and ran hose to oil filler neck vent pressurizing my crank case. His explanation it has to be done this way to control idle (iac is brand new). It had (b4 i got there)blew the pvc so they zip tied it to intake to keep from blowing out then on a run to 5000 it pushed oil thru valve cove and main seal. and under regular driving am getting puddle under car. I have a non vented oil filler cap and vent in neck. How should this be?

I am running about 9 lb at 5000 and 475 rwhp and 530 rwtq

 

[MCRParts.com]

I have a 331 stroker with a powerdyne race rebuilt that i had tuned today.
When i took it to the tuner i had the throttle body discharge tube ( the one that went to oil filler neck vent) blocked and the oil filler neck vented to outside air thru hose. My tuner uncapped throttle body cap and ran hose to oil filler neck vent pressurizing my crank case. His explanation it has to be done this way to control idle (iac is brand new). It had (b4 i got there)blew the pvc so they zip tied it to intake to keep from blowing out then on a run to 5000 it pushed oil thru valve cove and main seal. and under regular driving am getting puddle under car. I have a non vented oil filler cap and vent in neck. How should this be?

I am running about 9 lb at 5000 and 475 rwhp and 530 rwtq

This is all wrong. Take the tube from the throttle body to the oil filler neck off IMMEDIATLY!

Recap the throttle body, vent the oil fill to the air box and toss on a breathable oil cap.

the pcv cap should be capped off too.

Sounds like you knew more than the tuner
The holley systemmax is a great blower intake,and it comes with the pcv hole already cast over.

 

[cobra04649]

Thanks for the input. Kinda what i thought.
I also was told to maybe vent the oil fill to after meter pre supercharcher. I dont have a air box just an open filter. Also can i just put a oil breather in pvc?? Tuner said he had configure this way to get idle. Im worried if i change it it may throw off tune. hope not!

 

[just4bob50]

Hey buddy, glad to see my old blower is working so well for you. As others reply you will see that what we talked about, is the correct way to set it up. ( Also stated by MCRParts ) Good luck. and I want to see the dyno sheet at work on Monday.

 

[vristang]

The tuner is a hack.
Not knowing better than to pressurize the crankcase is inexcusable for a 'professional'
Do you feel comfortable releasing the name of the shop? To warn others not to go there?
(I have been screwed over by a shop that I trusted before, so I know exactly how you feel. The only thing that made me feel slightly better is that every chance I get, I warn others to never use that shop)


You cannot drive the car the way it is. It will mess up your rings.
If you have to retune (at a better shop), then so be it.
I know that is bad news to hear after the cash you just shelled out. But that is the best advice for where you are now.


A breather on the pcv would be fine. Also, if you can get a breather on the drivers side valve cover that would be even better. With higher combustion pressures you will have more blowby, which means higher pressures in the crankcase. This is expected.
If you can get the 2 breathers on there (pcv and drivers VC), that would be nearly ideal.

The inlet hose on the passenger VC can either be capped off, or run it from between the MAF and SC, as you mentioned.


Good Luck and let us know how it goes,
jason

 

[just4bob50]

I would also post this question in the power adder section for more feedback.

 

[BLOWN 5.0 FOX]

yes- if the tuner was stupid enough to pressurize the crankcase, i would not trust his tuning capabilities either!!!

It would be an injustice not to share the name of the shop. If they are doing this to all fox's that come in the door , that sucks and alot of people will be doing rear mains over and over again!!

 

[cobra04649]

thanks Jason for ideas. I started with blocking off tb and venting filler tube neck to filter area but leaving filler cap on and pvc connected as it use to work fine. but now idle is low (600) and may have drivability problems off idle. (have not taking for drive or brought tempature up). Do i need to retune whole range since capping tb. also was thinking about running oil filler vent to pre metered air. any thoughts? And is there a chance of getting oil in intake?

 

[vristang]

thanks Jason for ideas. I started with blocking off tb and venting filler tube neck to filter area but leaving filler cap on and pvc connected as it use to work fine. but now idle is low (600) and may have drivability problems off idle. (have not taking for drive or brought tempature up). Do i need to retune whole range since capping tb. also was thinking about running oil filler vent to pre metered air. any thoughts? And is there a chance of getting oil in intake?

You may just have to re-adjust the Idle. There is a procedure for doing that, so that the ecu knows what is going on.
I'll see if I can find a link in a minute...


It would work to run the oil filler inlet hose to pre-metered air, IF the pcv is removed. Removing the pcv will mean using breather caps on the valve covers and/or the pcv hole in the lower intake.

If you remove the pcv and don't put the valve cover inlet on the intake tube, then there won't be ANY way to contaminate the intake with oil.

It seems there are a lot of options, so you get some creative freedom here
Just make sure that the crankcase pressure has adequate vent points (2 would probably work), and there is no chance for boost to get into the crankcase.


Let us know what you sort out,
jason

 

[millhouse]

If you decide to run a line from the oil fill neck it MUST be in a non pressurized area. With a super or turbo setup this means at the inlet side of the compressor. This is the only area you have which sees vacuum at all times. Having some vacuum on the crankcase will promote better ring seal (especially under boost) to a certain degree. Now, if you already have blown out your rear main seal you will need to replace that ASAP. If it leaks at all there is a good chance the blowby will continue along the path of least resistance.

 

[cobra04649]

So far i capped the tb and ran the oil filler vent to intake pipe b4 charger and warmed it up and set manual screw and seems to idle at about 950 (ok with me). but have not driven it to get into boost or see if idle is ok. I want to go thru idle procedure checklist but i have a painless 5.0 efi harness and dont see timing spout anywhere and dont see it in paperwork either. Kinda remember wondering where it was when installed harness.

 

[cobra04649]

I just set idle manually and it runs great! drivability is better than ever. And No More oil leaks. I did talk to tuner. He seems to think my tune will still be ok. Any thoughts??

 

[millhouse]

You may find that your injesting a bit of oil through the supercharger with the new setup (the stock setup did too, you just don't realize it). You can throw an inline oil/water seperator which does a mighty fine job to combat that.

 

[MCRParts.com]

Glad we could help ya out a little with this one.

 

[coming4you]

???

you guys are saying to run a Hose from the driver valve cover ( nipple ) To where ???? Im confused .... Im asking cause i have a S trim on a 331 myself but i have that nipple on the valve cover capped.... A breather cap on the valve cover... But im still using the pcv valve ... I didnt know you should cap that as well... IF so what do you plug the hole in the back of the intake with ?

 

[vristang]

If you still have the pcv in place, and aren't using a check valve, then the boost pressure from the intake will purge directly to the crankcase.
This is very bad for ring seal.

On the intake side of the pcv, you can use a nipple vac cap, probably similar to what you have on the oil filler neck nipple.
For the pcv hole in the lower intake...
some folks have used a breather cap, but you could cap it off with just about anything large enough to fill the hole...

One way or another you have to keep boost from getting into the crankcase.

If you want to run the inlet hose from the valve cover, then it should pick up fresh filtered air from between the air filter and the SC.

jason

 

[millhouse]

With the PCV system it's all or nothing. If you plan on keeping the PCV valve you need to replace it with one suitable of holding back boost. The turbocoupe PCV valves do a great job with this and can be found at your local Ford parts counter. The auto parts replacements are not even close to OEM spec…and the don't even look alike. They (unlike the OEM's) will not keep boost out of your crankcase.

Now, as stated before the line that goes from the throttle body to the valve cover must be removed when using forced induction. The pressure from the super/turbo will push into the valve cover in turn pressurizing the crankcase. What happens next is oil blowing out the dipstick tube, valve cover gaskets or blowing out the main seal.

After eliminating that line you now have lost your main source where you would normally pull vacuum on the crankcase. You need to in some way adequately vent the crank. If you put a filter on the oil fill neck and leave the PCV intact you have just introduced a vacuum leak into your system. Non metered air can now freely enter the crankcase and in while not in boost can find it's way back into the intake VIA the PCV valve. By connecting the valve cover to the supercharger inlet you are able to pull a vacuum on the crankcase when you need it the most (under boost). This promotes ring seal which in turn should keep blowby to a minimal. The downside is you are likely to pull small quantities of oily mist into your supercharger. As previously stated, the stock setup draws it into the intake anyways….so this is not a foreign route. What the oil does though is slightly increase your risk of detonation (oil lowers the octane rating of the fuel). A inline oil/water separator that you can occasionally check and empty if needed works quite well to combat the problem.

You can eliminate the PCV altogether by either venting it to the atmosphere or plugging it, but you need to make sure you vent the crankcase adequately. A single breather typically is not enough so many throw an additional one at the old PCV location. With that setup however your likely to get an oily misty residue over the entire engine compartment. You will also need to periodically clean the filters as they will get clogged with oil.

 

[just4bob50]

you guys are saying to run a Hose from the driver valve cover ( nipple ) To where ???? Im confused .... Im asking cause i have a S trim on a 331 myself but i have that nipple on the valve cover capped.... A breather cap on the valve cover... But im still using the pcv valve ... I didnt know you should cap that as well... IF so what do you plug the hole in the back of the intake with ?

I always ran a PCV valve with my charger and dont no of any one who doesnt. My set up was identical to yours. I was going to run a line from the vent tube on the oil fill neck to my power pipe after the MAF, but never felt the need to with the breather cap. I also always used a Motorsport PVC from the Ford dealer. If you put a clean piece of tube on the top of the PCV valve and blow into it you will see that boosted presure cant pass. The valve only opens up under vacume. Infact if you have an old vacume line running to your PCV it wouldnt be a bad idea to replace it also as I have seen where the vac. lines blow off the PCV under boost, and that is because the valve is closed under boost. Good luck.