excessive blow by problem, solved

[jeff1234]

Hello all, Recently I got my "85 Shelby back on the road with a fresh turbo and an upgrade to TII. I took it for a ride and much to my dismay when I got up to 11 PSI smoke started to poor out of my tailpipe and engine compartment. (I didn't have a pcv system hooked up) Thinking my turbo had problems I called Chris at TU and he helped me understand that blowby was preventing turbo oil from returning to the pan and forcing it out the turbo bearings. We cant have that now can we.
What to do, the car hadn't been using oil before and now it was very embarassing to have this problem. I realized that the open valve cover port was causing part of the problem and had to do something about the blowby. This isn't a good time to rebuild the engine but I thought I had a solution that would cost less than $20.00.
I took a metal tube that lots of turbo Dodges had and cut it off at an angle on one end and removed about a quarter inch of the other end. I got under the car and eyeballed where I would put it on the manifold pipe and outlined it with a magic marker. I then cut an oval hole in the pipe a few inches down from the turbo outlet. I got an ordinary 1/2 npt X 3/8 npt threaded black iron bushing and using my die grinder removed the internal threads to fit the pipe inside it. I welded the pipe inside the bushing and screwed on a check valve from a 1987 Chevrolet Caprice with a 307 "Y" engine. This is part of the air injection system and dosn't allow exhaust to flow back into the air injection system. I re-installed the manifold pipe with a length of 5/8 ID heater hose and screw clamp. I attched the other end to the emmisions outlet on the valve cover which has a straight outlet.
This created a pan evacuation system. It creates a vacuum because the flow of exhaust past the opening for the tube welded into the manifold pipe scavenges any air flowing out of the valve cover opening. The tailpipe is open so no significant positive pressure is created at the check valve. When the engine is running and you have the hose off the valve cover a very small pulse is felt at the hose. When you open the throttle very good negative pressure is felt.
There's nothing new about this system, fuel dragsters use it to scavenge high internal crankcase pressures and it helps with ring seal. I thought it would work but I wasn't sure.
I took the car out for a test and yippee, no more smoke. Additionally the engine seemed to idle smoother. Its not clear if this can cause problems down the line but at least for now I can avoid a rebuild which I dont have money or time for.
The pictures will tell the story and if you have the tools, its pretty easy to do.

[turbovanman²]

Nice, Ondonti has been running that setup for awhile. Jegs has kits for like $30, :thumb:

I want to run something similar but scared I'll be blowing oil thru my exhaust, :(

[glhs727]

great idea, especially using some misc. parts!

but for other people, we sell the vibrant e-vac kit for $33
Each kit includes a Male E-VAC fitting (which features an integrated Male 10-AN bung for major cost savings), an M18 angled O2 bung and an M18 x 1.5 male threaded plug.
later,
Cindy

[DBB mini]

I am running the jegs exhaust evac on my van. I still need a check valve to hook it up properly but the jegs kit is easy enough to install.

[DBB mini]

great idea, especially using some misc. parts!

but for other people, we sell the vibrant e-vac kit for $33
Each kit includes a Male E-VAC fitting (which features an integrated Male 10-AN bung for major cost savings), an M18 angled O2 bung and an M18 x 1.5 male threaded plug.
later,
Cindy

I like that. How did I miss that? Is it on your web catalog?

[badandy]

Many of us have been using this setup for YEARS. I ran the Moroso kit on Whitey which had an all stock 150,000 mile bottom end at 24 lbs. boost without any blowby issues. I love the setup but for some reason some have mixed results :confused2:

[shelbymopar89]

This is a good idea, should it be put downstream of your wideband o2 if you are running one? I would think so, anybody know anything different?

[badandy]

This is a good idea, should it be put downstream of your wideband o2 if you are running one? I would think so, anybody know anything different?

Definately downstream of Wideband or else crankcase fumes will cause inaccurate readings.

[t3rse]

I love the setup but for some reason some have mixed results :confused2:

because of improper installation...

[badandy]

because of improper installation...

:o I was trying not to be so blunt as we both know in the past how steadfast those that did not have the proper results swear they did everything perfect...and I didn't want to get into that debate again.

[t3rse]

:nod: :thumb:

[shelbymopar89]

so is there a trick to installing it correctly?

[TurboII]

now what exactly does this kit do. I've read and heard about these but don't know how they work over the other vacuum source.

Joey

[t3rse]

if you don't get the nipple far enough into the stream (and it needs to be at a high velocity point) then it won't work correctly...also getting the angle right is key...what it does is pull a venturi on the crankcase which puts it in vacuum and suck the nasties into the exhaust stream

[DodgeZ]

http://boostedmopar.com/forums/showthread.php?t=108

[TurboII]

if you don't get the nipple far enough into the stream (and it needs to be at a high velocity point) then it won't work correctly...also getting the angle right is key...what it does is pull a venturi on the crankcase which puts it in vacuum and suck the nasties into the exhaust stream

No sh!t that sounds awesome!

[jeff1234]

Hello all, Here's an update. Labor day weekend I had the car out beating the living hell out of it and having fun. I am amazed at the power this car puts out. My best G-Tech before the TII change over 15.5 @ 91 MPH. After, the best G-Tech was 15.1 @ 101.5! this was with 11 psi. I realize that the G-Tech scores the quartermile differently than the drag strip, but this is still an impressive change. Apples to apples, if you get my drift.
Anyway back to my update. On that day the car started smoking again so I suspected that the check valve had failed. I pulled the hose off the valve cover and sure enough the pulses at idle were weak and application of throttle showed a weak vacuum signal that disappeared quickly. Apparently I need a different more durable check valve. I think what caused it to fail was a high cycle rate on the diaphragm in the check valve. Its my belief that the pulses I could feel at idle are there all of the time even though they are not detectable. The diaphragm in the valve is rubber I was told and so it probably vibrated to death.
In the end, I dont think I will replace the valve at this point and I am going to address the real problem which is worn out rings. I have a couple of common blocks so I am going to rebuild a 2.5 for next spring. I still like the idea of that evac system and will probably upgrade the valve.

[turbodaytona87]

Definately downstream of Wideband or else crankcase fumes will cause inaccurate readings.

Does that negatively effect the vacuum potential? My wideband is about 18 inches away from from the swingvalve connection.

[badandy]

Does that negatively effect the vacuum potential? My wideband is about 18 inches away from from the swingvalve connection.

Does what affect vacuum potential?...are you asking if the evac being downstream from the wideband effects vaccum potential? I don't see how or in what way it could. If you are asking that the further down the evac connection is made effects vacuum?...I would say I'm sure it does but by how much I have no idea without testing it.

I have mine installed in my mid pipe which is not quite half way in the exhaust system. On a previous car I installed it in the downpipe (pre-wideband days).

[SUPER60omni]

I have the simple method....... stock PVC in stock 3 way elbow. PVC valve in top hole and the bottom hole I clamped a piece of pipe for a junction to attatch a piece of heater hose and ran to the ground (or just after the K frame). NEVER had a blow by issue at 35+psi + Nitrous. I have a solid motor tho with little to no blow by. Once and a great while after a hard run down the highway on a long 4th-5th gear pull it will leave like 3 drops of oil from the hose, but its dry 99.9% of the time.

[turbodaytona87]

If you are asking that the further down the evac connection is made effects vacuum?

That's what I was asking. I might have to try this out, my current system doesn't seem to be working.

[john1320]

I have the simple method....... stock PVC in stock 3 way elbow. PVC valve in top hole and the bottom hole I clamped a piece of pipe for a junction to attatch a piece of heater hose and ran to the ground (or just after the K frame). NEVER had a blow by issue at 35+psi + Nitrous. I have a solid motor tho with little to no blow by. Once and a great while after a hard run down the highway on a long 4th-5th gear pull it will leave like 3 drops of oil from the hose, but its dry 99.9% of the time.

Same setup on my old (RIP) 89 Tona @14psi, daily beater.
I still plan on plumbing the scavenge kit on the Charger, for a better wear on the rings. (makes me feel better?)
Turboscotty used those kits on his 25psi Turbo Scamp, and his circletrack car.
Both behaved well, and you know how much you rev the piss out of a circle-track 2.2!:clap:

[johnl]

They work. You might want to check how much vacuum you are pulling when you're in the boost. In theory too much crankcase vacuum could interfere with the oil pump's low side pick up. Supposedly, maximum benefit is at about 15# of vacuum. Haven't done it, but I imagine that you can regulate the amount of vacuum with a Grainger valve. Just tee it into the hose between your gulp valve and the valve cover/crankcase to bleed atmospheric air into the vacuum line. There are vacuum relief valves sold that bleed air into the valve cover but for a street car the air sucked into the VC should be filtered. Putting the bleed in the vacuum line avoids that problem; any dirt just goes out to the exhaust.

[Dusty_Duster]

Why not just run the valve cover port through a catch can and then to the intake before the turbo?

[johnl]

Why not just run the valve cover port through a catch can and then to the intake before the turbo?

Because catch cans fill up. That said, you can put a one way check valve in a drain line from a catch can and have that drain line connect back up to the crankcase.

[Dusty_Duster]

Is the actual PCV valve required if using a catch can and running the vacuum line to the intake before the turbo?

[Force Fed Mopar]

Is the actual PCV valve required if using a catch can and running the vacuum line to the intake before the turbo?

Yes :thumb:

[Force Fed Mopar]

stock PVC in stock 3 way elbow. PVC valve in top hole and the bottom hole I clamped a piece of pipe for a junction to attatch a piece of heater hose and ran to the ground (or just after the K frame).

How much harder would it have been to make a hole in the intake tube and run it to there, like factory? Seems better than having it blow oil all under you car :)

[t3rse]

Because catch cans fill up. That said, you can put a one way check valve in a drain line from a catch can and have that drain line connect back up to the crankcase.

If your catch can is "filling up" your motor is on the way out. Mine is very small and has yet to fill up (even a 1/10) with a few hundred miles. I did have it get half full once when I was tuning and has it so rich fuel was making it past the rings....

[turbovanman²]

Because catch cans fill up. That said, you can put a one way check valve in a drain line from a catch can and have that drain line connect back up to the crankcase.

You don't want the trapped oil/crud going back into your engine, its nasty stuff.


If your catch can is "filling up" your motor is on the way out. Mine is very small and has yet to fill up (even a 1/10) with a few hundred miles. I did have it get half full once when I was tuning and has it so rich fuel was making it past the rings....

Exactly, my worn engine would fill it once a week, when it was new, it would take months to even get a drop in there.