The Official Crankcase Evacuation thread for Turbo Hondas / PCV / Catchcan /

[2point2]

i love you man.

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[Frozen E]

subscribing until I can find a place to print this thing out at. to you for a great writeup.

[ImAcracker]

Originally Posted by ScottEK

I appreciate the time you put into putting this together

Me too.

[dasher]

Originally Posted by Tony the Tiger

I am wondering if your test car is running a catalytic converter? If you put the slash cut tubes before the cat, you will end up with pretty bad vacuum (and sometimes positive pressure) at the slash tubes. I had mine relocated to after the catalytic and it got much better results. Reason for this is that the catalytic converter is a highly restrictive portion of the exhaust, and anything before the cat will generally build up pressure as load increases.

No Cat, slashcut is 12" from turbo , 3" exhaust with moroso spriral flow resonator.

You are correct! You will achieve some nice results after the cat because the inherent restriction the cat induces ....

I'll respond later to other posts ... too many tonight at the bar...

[dasher]

Originally Posted by Bailhatch

How does that gauge read vacuum?

Using Dwyer Instrument's simple, frictionless Magnehelic movement, it quickly indicates low air or non-corrosive gas pressures--either positive, negative (vacuum) or differential. The design resists shock, vibration and over-pressures. No manometer fluid to evaporate, freeze or cause toxic or leveling problems.The Magnehelic differential pressure gauge is the industry standard to measure fan and blower pressures, filter resistance, air velocity, furnace draft, pressure drop across orifice plates, liquid levels with bubbler systems and pressures in fluid amplifier or fluidic systems.

[dasher]

Originally Posted by Tchleung

dasher, what do you think about this setup?

http://www.honda-tech.com/zerothread?id=935871 You can add catchcans in the appropriate spots easy.

This Idea could work, but is not worth the hassle in my opinion.

Some concerns of mine:

1) You would need to use 2 separate catchcans. 1 in-line between the crankcase/Intake
and 1 between the crankcase/Intake manifold.
2) I would run a check valve after the PCV valve because the PCV valve may leak under boost when the Intake manifold pressurizes.
3) In High vacuum in the Intake manifold the PCV valve would be slightly open thus the vacuum generated would be minimal in low load conditions(this is good).
4) You should also run a check valve(not PCV) in-line between the crankcase/ intake because in low load conditions the vacuum created in the intake manifold could possible draw air from the intake.

The advantage this setup has to offer over simply using a slash-cut tube in the Intake (preturbo) is that it will provide some additional vacuum at idle and low load conditions.

The disadvantage is that you will still contaminate your intake charge; now even more so because you have vacuum being drawn directly to the Intake manifold instead of trapping most of the contaminants in the Inter cooler piping and Inter cooler . Consequently you will get more contaminants in your Intake manifold also.
Another disadvantage is that this setup is more costly and complex than the other method because you have to run 2 separate catchcans. PCV valves also tend to fail more often than regular check valves

[dasher]

Originally Posted by Tony the Tiger

If you put the slash cut tubes before the cat, you will end up with pretty bad vacuum (and sometimes positive pressure) at the slash tubes. I had mine relocated to after the catalytic and it got much better results. Reason for this is that the catalytic converter is a highly restrictive portion of the exhaust, and anything before the cat will generally build up pressure as load increases.

The theory I have to explain our data is that an exhaust slashcut evacuation method is also dependent upon exhaust pressure waves and pressure differentiation between the crankcase and exhaust and not just the Bernoulli effect.

Placing the slashcut before the cat is a bad idea because the cat is so restrictive and creates a large amount of pressure which will sometimes fight its way up the evacuation line. After the Cat their is no such restriction.

I could probably get better results to mimic yours if I placed my slashcut slight further down the exhaust and after my resonator. The moroso spiral flow resonator is not a true straight-through resonator and is slightly more restrictive.

[sleeprhatch]

Finally a concrete write-up on this sh!t!

[Tchleung]

Thanks for the insight dasher!

[Setsuna F Seiei]

subscribing

[turbosi03]

Originally Posted by dasher

Your asking about using 1 port on the back of the block of a B series engine instead of 2?

All this means is that their will be less ventilation. Won't be that big of a deal, but slightly worse. With an open breather setup you want as much ventilation as possible.

I remember a thread a while back were someone was suggesting using only 1 of the 2 ports with on the rear of the block to cut down on it siphoning oil. I never had this problem using both ports and without the use of anti-siphon tubes in those fittings.

that might have been me... I used one port on the block for my open air catch can setup. along with my valve cover breather... and thats actually what the engineers at Z10 told me. they said the one closest to timming belt works more as an oil return, while the other side acts more like a ventilation chamber... they said thats why the stock PCV can is located on that side.

they also told me you don't want to run an electric vacum pump for street use. forgot the reasons, but I think it had to do with pump being on all the time...

either way great write up!!

[dasher]

Originally Posted by turbosi03

that might have been me... I used one port on the block for my open air catch can setup. along with my valve cover breather... and thats actually what the engineers at Z10 told me. they said the one closest to timming belt works more as an oil return, while the other side acts more like a ventilation chamber... they said thats why the stock PCV can is located on that side.

I never experienced these problems with that vent sucking oil in the evacuation tube. Has anybody else had that problem and tried both methods using both 2 ports and 1 port to test the difference to verify this with other cars?

[ZhaGg]

Sorry if this is a stupid question:
when using the "intake slashcut" method, am I supposed to route both the PCV AND the valve cover breather to the compressor intake?

[1.8EG-T]

Very nice write up. What is the most complete kit for the b series motor out there? I have a catch can, but it only has one port

[shifty35]

I like the electric brake booster pump idea. Seems like rigging a linear amplifier running off the map sensor voltage would be a great way to linearly increase vacuum with load. Just some heavy duty semiconductors...

[AspectIndustries]

Damnit! I need more time to read this thread, sounds like something useful to know and to need. for my car.

Some cliffs notes on whats recommended? LOL!@

If not, fine, ill read..later on when i got time.

[dasher]

Originally Posted by ZhaGg

when using the "intake slashcut" method, am I supposed to route both the PCV AND the valve cover breather to the compressor intake?

With this method I would route 1 or more lines from the back of the block to a sealed/no open breather element catchcan inline between the crankcase and Intake(pre-turbo). The Breather Line on the valve cover should preferably have a small filter attached to allow for a secondary source of breathing. For engines were the PCV valve/line is located on the valve cover also you would use this same method: PCV Line-catchcan-intake(pre-turbo) and a small filter on the breather port. You should remove the PCV valve and find another non-restrictive plug instead. No check valve is needed with this setup.

Any catchcan would work inline. The Moroso catchcan can be also used without the breather filter. If your catchcan is not baffled then add surface area inside the catchcan to trap more contaminants.

[dasher]

Originally Posted by hybridrex

Very nice write up. What is the most complete kit for the b series motor out there? I have a catch can, but it only has one port

Endyn has a nice complete kit if you want to use the open breather setup. I would not recommend using the drain-back feature. Drain the contaminates manually and make sure they don't re-introduce themselves to your engine.

Be a little more daring guys and try the slashcut exhaust method and slashcut wastegate method in tandem. I do! My lines running from the back of the block to my Moroso catchcan are mostly sucking in fresh air now. My oil stays cleaner and my car feels great.

[dasher]

Originally Posted by shifty35

I like the electric brake booster pump idea. Seems like rigging a linear amplifier running off the map sensor voltage would be a great way to linearly increase vacuum with load. Just some heavy duty semiconductors...

That is one solution I played with, along with others....

Have fun toying with this idea. I know I did. Then I began to realize that it is important to "Keep it Simple" when it comes to pulling vacuum from the crankcase. One mistake, one fluke, one electrical problem and your engines toast!

[dasher]

Originally Posted by hybridrex

I have a catch can, but it only has one port

Solutions:

1) Weld/Jb weld in a second port in the catchcan.
2) Only use one fitting on the back of your B series block.

[mamaboy]

dasher,
moroso offers a vacuum pump for $450 i believe. just tap your valve cover and run a belt to the crank pulley and attach a catch can to the pump. i was looking into this option. i stated before in a previous post about how v8 guys do this all the time to help reduce crankcase pressure and help seat the rings. other options include obtaining a air pump from a gm that was used to introduce air into the exhaust stream for emissions, but rather using that as a air pump to draw out the HC's from you crankcase.

[dasher]

Originally Posted by mamaboy

dasher,
moroso offers a vacuum pump for $450 i believe.

Custom only. Time + money.

http://www.moroso.com/catalog/...17200

I'm sure if you are creative you can remove your Ac compressor, modify a custom bracket, pulley and belt and try and tune it so it pulls an appropriate amount of vacuum. Seems like alot of work to me.

You do not want to run their original race pump either(part numbers 22640 and 22641) because they are only made to spin up to 6000 RPM maximum.

When all is said in done your money would be much better spend at z10eng because they will prove you an off the shelf setup or custom one that includes a lot more than just a vacuum pump.

[D.Dappa]

Originally Posted by dunkd

thanks for explaining this...

same here man !

[PrettyLude]

subscribed

[haysr]

I read a article in Hot Rod on this topic last year. They found a vacuum pump on a Ford Taurus. They where able to get 5 hp out of a v8 with the mod. I told my brother to look for the article since I didn's save it. He told me drag cars use vacuum on their cars. They weld a tube at 45 degree angle on the exhaust pipe and run a line up to there valve covers. The exhaust flowing by the tube creates a vacuum. It would be linear.