Crank Case Vacuum Exhaust Scavenge Testing 

I really like tests like this with actual data to backup findings.

I built a pan-evac system for my 67 big block camaro back inthe 90's. the venturi setup in the header is important to get right, and you need to use the one way check valve, its just a air injection smog valve. My setup pulled a LOT of vacuum and made it very hard to remove the oil fill cap with the engine running. Mine pulled a bit of oil since i didnt have a good enough baffle system, and in retrospect i should have had a good catch can inline with it.

I think you will see an even greater affect the higher the engine is revved, and the more free flowing the exhaust, like if you remove the mid pipe in your exhaust how you mentioned. The more and faster the exhaust gas is moving past the angled bung, theoretically, the more/harder it should draw through the hose. I've seen this used in the big drag racing and mud bog engines for years. A lot of guys call it evacupan. In that application they are typically open header and the angled bung is welded into the collector. They almost always have a one way check valve to prevent anything going back up the hose into the engine, but I've seen several dyno tests and on those big inch high revving engines they were actually pulling a vacuum on the crankcase at high rpm. The more exhaust that was flowing past the bung the greater the pressure differential and thus more/harder it would pull from the engine. Your application is slightly different because your intake air is pressurized while they were naturally aspirated so you may have more blow by than they did. Great video man. Looking forward to seeing more testing. Do you have a link for the bung you used?

Looking forward to followup testing results! Great stuff

Something to keep in mind... its important to note key on engine off crankcase pressure before each test of different configurations. Ideally you'd be driving the truck, stop and shut it off and key it back on check your crankcase pressure at that moment and start datalogging before starting the truck and driving and do this with each variation. Atmospheric conditions may even be different from in your garage vs outside the door. When dealing with only a few kpa difference, its almost necessary to back it up with several runs and compare the averages between different configureations. I guess that was a long winded way of saying I like what you're doing, keep doing it!

Great Information. I was using a hose off the passenger valve cover to the front of the turbo and it made a huge difference. I do like your idea better.

I always wondered about those. Glad you had some improvements with it.

I've been wondering the same thing Ryan. I used to see the bungs all the time on drag cars. Seems to be a simple addition which might prevent oil from leaking. I would put it after the O2 sensor.

This is awesome. I did a bunch of fabrication work for a friend of mine and he requested we setup one of these as well. We didn’t do any before or after testing because it was added when we originally put the car together but with a 500hp 4 cylinder it doesn’t ever have crank case pressure issues. His setup utilized a check valve at the exhaust fitting as well to prevent backfeeding exhaust or pressure spikes from backfires and launch control and what not. I might try this with my twin turbo truck now that I’m thinking about it again. Same as you mentioned I have a few oil leaks likely caused by a bit of pressure

Keep it up Ryan deffinitly different results than I had and I'm thinking it has a bit to do with flow with the twins as I'm still single but have a fender dump so may try again. Good job.

Stands for reason if you boost high, your going to pump up the crankcase pressure, and then you risk high engine stress, oil leaking seals and diminished returns. Negative crankcase pressure de-stresses the engine so it's not working against itself. It's also giving you a mild turbo effect on the underside of the pistons on the induction stroke. David Visard wrote about this/common knowledge in drag racing circles a million years ago. For even more gains run an actual vac pump. Nice video.

Thanks for the test! Im going to do this mod too.

I tried these with a 5.3 single turbo exhaust dumped at rear end ...I made sure the angle was right etc....at idle it was pushing exhaust out the 10an hose....I have since changed to a front fender dump and was thinking of trying the kit with the check valve.Good video!

The more parallel the bung is to the exhaust pipe it is being welded into the better. If it goes in on an angle, the benefit will be less. The velocity of the gases going past the bung will cause the evacuation and negative pressure. A check valve helps as well especially if you are going on the street and going at low speed and idle.

PQY Universal Stainless Steel E-VAC Scavenger Kit Includes T304 SS E-VAC Fitting just went up based on the Ryan recommendation. They're a million $$ now lol

Needs a diverter one way check valve at the top of the exhaust probe and the probe needs the open angled outlet facing to the rear . In my N.A. trials and a friends JDM right hand drive modified turbo Supra.

I've actually considered putting one of these on my car as well. It's only a 1.8 4 cylinder but has double the factory power and with the bigger turbo I'm putting on it I'm hoping to get to 350+.

On the old school header evac system they used a mid 80’s mopar type of egr back flow check valve

we are here

I'd really love to see you compare these exact results to changing location of the vacuum to your turbo inlet to see if that would possibly be any better.. I'm running a 5" hood stack, which is a tight radius 90° directly off the back of my s475/96 t6, and barely have enough room for the filter on the front but if the results speak for themselves like these just did I would try to incorporate both.. was also told to get an ls3 valley cover where they relocated a pcv there and running that to the intake may be beneficial, along with what your doing from the valve covers

Connect them together, unless you have access to an extra crankcase entry. You'll need at least one crankcase entry point, to allow fresh air in.

I commented on your Blaser build page on FB the proper check valves

If you weld a pipe half way down the tail pipe at a 45 degree angle from the exhaust pipe toward the tail pipe. You will get the benefit of the air rushing out from both sides of the exhaust manifolds. Better and more suction

The old school evac fittings had a little can on it that is a check valve.

Luv it... I have similar setup making 1Kawhp,big single. Mine smokes a bit so very unterested in results...dyno results would be awesome!

Have you tried this setup with one of the moroso or Ford check valves? I have it routed with a stock pcv setup off the 3/8” nipples on each VC going to a T and then into a catch can. and the catch can out going to behind the TB with a one way, so It pulls vacuum all the time its not under boost. The oil fill caps(yes, both banks) with the baffled 12an bung on each VC is ran to exhaust scavenge for under boost. I think the moroso valve is necessary on the exhaust scavenge, so the vac side can pull vacuum properly. The banks need to be as equal as possible. An easy test is to place a vacuum hose into the dip stick tube and into the cab. Use your thumb to monitor the vacuum on the crank case. Your data log method is pretty slick

Over whelmed ! That was a awesome idea. And if you were able to pull more vacuum from the crank case , how's that affecting your boost?

Excellent test! I think adding the one way valve would add some more vacuum as well, love to see y ou test that. I've done a similar (vac/boost gauge ran into car) A to B test on my LS turbski Mustang and found I had to seal off the catch can and just run the scavenge setup. The only "problem" I had was at high rpm it would draw too much vacuum. Found they sell little vacuum relief valves.

If you had a PVC valve in a valve cover or equivalent. Then PVC to catch can, catch can to intake... The boost to improvements in performance probably came from blocking the vacuum leak that fed the PVC valve. Yes you need crankcase ventilation. Using intake vacuum dose influence AFR. Easier to keep stable without random holes in the system.

I always wondered about these

GREAT video. Your testing protocols are very good. One issue I don’t think I saw in any of the comments or in your video is regarding the how you determined the proper positioning of the scavenge tube relative to the exhaust flow? I saw how you drilled the hole, welded on the bung and then screwed the scavenge tube into the bung. But did you pay close attention to which direction that small slot is facing in the exhaust stream once the scavenge tube is fully screwed in? If so, which direction is that small slot facing?

excellent test, i've always been told this wouldn't work but this is great. i'd expect reversion cause more instability but maybe the turbo is damping the pulses?

Watching all of this.

I know this is old, but I hope you eventually figured out you need the rest of the parts for the system. You really need the check valves for the pulses.

Would love to see a follow up video with the other Syphon fitted. Unless you already tried this, and it's blasted you into orbit?

That's very interesting

I would love to see a follow up video

Most kits have a pcv one way valve in them, look up the summit kit or Moroso kit youll see what i mean, this is more for open header style motors that are na or supercharged from my understanding but with enough flow i coukd see it working on a turbo setup

Add 4 of them and get rid of the catch can! 🤪

👍👍👍

I wonder if the angle of the fitting makes a difference? Mine seemed to be more angled into the exhaust.

So how would you set it up with a catch can to make sure it's still venting properly

👍

What did you end up using for the permanent hose? Any temperature issues?

Any update on adding the other side and/or taking the can off?

I believe the spikes are exhaust reversion ?

Don't remove your mid pipe. The only problem that you run into with running two of them is you at high RPM can pull oil into your exhaust. Which can make smoke out the exhaust. Be Blessed and Be Safe 😇

Any update on the scavenging testing?

Is the scavenge directional to make a venturi?

N/A people run 2 of those scavange tubes. Obviously one on each side. I would be affraid of it pulling oil into the exhaust under hard boost and putting it under your tires.

Just tried on my car and it blows exhaust into my valve cover lol. its a 4 cylinder turbo straight piped from the turbo so there's no collector.

They do work not near as good as a vacuum pump. Most effective around a foot from the exhaust exit.

Ran a header crankcase evap system like that, on both headers, 30 years ago. Ended up going to a vacuum pump system, was better and cleaner.

You didn't proove it, but I bet this straight thru muffler scavenged better than the 40 series mufflers ever did.

The Moroso crankcase evacuation kit/system has a one way valve included that should ease your fear of blowing exhaust pressure into your motor. Cool test though. What if you hooked up the system to the catch can so it would be under a slight vacuum? Should make the catch can very efficient.

I study gas dynamics for NASA. I have one of the fastest 2 strokes in the world.

This was a test, but is the goal to hook these up to the catch can vent so you can still use your oil cap & what's sucked into the exhaust is less oil & more blow-by? I've seen a different exhaust evac system on lots of derby cars with 80s emissions era check valves from the exhaust air injection system. Like the SUM-120180. No experience with it, but hey, one way valve.

where can i find these for purchase?

You ever get around to installing the second one?

Im gonna stick one on the other side of a loud valve. Why not 🤷‍♂️

I would like to use an ehaust Scavenge sysyem, but I am concerned about the temperature of the evacxhaust welded bun in the exhaust melting the fuel hose to the catch can. Any ideas?

did he leave the catch can side open??? The system needs to be air tight. The only "air" in the case should be blow by ...

Hey man did you weld it in before or after your wideband? Or do you think it doesn't matter either way?

Did you end up using both? Did you end up using them long-term? -Mike

Is it normal for my catch can to smoke? This is my first turbo build

U would have a much better effect if u tap into the turbo to pull the blowby gasses out. The exhaust ones work yes. But using the turbos to pull the crankcase pressure is ideal.

Is your catch can vented?

Nice info doesn't seem worth it back pump maybe a safer option

moroso check valve.

2:50 Fi Audio, I miss them!