Ok just so we can keep Bret's build thread clear of banter and continue to educate the rest of us on what seems to be a vital but commonly misunderstood system of Forced Induction and Naturally Aspirated vehicles alike, I started this thread.

Let's post in here from now on concerning theories, real world experience and any helpful information concerning Crankcase Evacuation Systems on Forced Induction Vehicles.

Maybe mods will sticky this thread if it turns into valuable information.

 

Very good Idea Mike, I will be watching this thread hoping to suck up as much info as I can from the pros!

 

Clown I am with you on this one what is the world coming to.... So guys let see it here....

 

I'd like to learn more about maintaining a 14" to 15" crank case vacuum.

I have a 4 stage belt driven dry sump pump/system on a FI LS2.

Any concern the crank case vacuum could get above 15" and if so what is the best way to monitor & maintain?

 

I am going to install an RX can and filter, I think it will be fine for mine, but I have a basic SC setup. The guy that promotes the RX CC's on here seems to know a lot on the subject and has had some good info on some past threads, so maybe he will reply.

 

Thanks all. I was just answering the posters question to me but this is much better.

Here is a recap of the problems facing those with large cobe/big power FI builds.

Please ignore anything I put in directed at another as it does not apply, I copied and pasted alot so as to not have to re-type it all. I can't type worth a dang anyway and my spelling & grammer are barely passable:

Understanding oil contamination from combustion byproducts




Most think of crankcase ventalation and evacuation as an eviromental issue, and just address releasing the excess crankcase pressure that is part of any big cube or FI build.

The evac system is not for the environment....it is to keep the engine alive and wear free as long as possible. Your not alone and 99% of car owners never think about it or realize whats happening over time. And yes, most will drive 50-75-100k plus miles and never know the damage gradually being done.

My qualifications?

over 35 years building race and performance engines.
Mechanical & Automotive engineer by trade
Graduate of the Reher Morrison Racing engine building school (one of the most respected in the world and a GM R&D contractor).
Owner and driver of drag teams with multiple Divisional, National & World championships in both NHRA & IHRA in several classes (this is where every minute detail in an engine matters)
And I tear down and build most every kind/brand of motor imaginable (except diesel) on a weekly basis.

So here goes:

Every motor has a certain amount of blow-by, the bigger the CI & the more boost the more blow-by (with everything else assumed is equal and no piston/ring/cylinder issue).

Most only look at the crankcase pressure portion and deal with that and that is only a small part of the crankcase evac systems function. The most important is the flushing & removal of the harmful combustion products before they have a chance to condense & settle into the crankcase oil.

These consist of:

Unburnt fuel
Carbon monoxide
water vapor
carbon particles
and several other harmful compounds that when mixed in the crankcase produce Sulfuric acid and as that accumulates past a certain PPM the bearing surfaces, wrist pins, and crank journals begin to be etched and start to damage. This is gradual of course so that’s why like you, most never realize whats happening.

The other very harmful byproduct is the very abrasive carbon particles (near diamond-like in abrasiveness) that many are to small to be caught by the oil filter and accelerate wear as well.

If you have a good cross flow of filtered fresh air entering one side of the crankcase (best is through a flow controlled breather), say the pass side oil fill cap, that fresh air will travel through the pass side valve cover, around the rockers, down the pushrod valley, through the center of the crankcase, (now on the LS6/2/3 valley cover with the fixed orifice it exits there drawn by vacuum so 1/2 the engine is still stagnant with foul compounds...especially the drivers side rocker area) up the drivers side pushrod valley, past the rockers and exits the rear of the drivers side valve cover flushing and pulling the compounds out BEFORE they can settle and condense into the crankcase. Now with out that flow the compounds settle and mix with the oil every time the engine cools. When started and run to operating temp the volatile of those are "flashed off" and again could be evacuated but if just venting with breathers, ONLY the excess crankcase pressure will exit and very little of the harmful compound mix goes with it and once the abrasive carbon particles mix with the oil they are there to stay reducing the protection your oil provides. Now if changing your oil after every track event then this is not an issue. But with a street driven car it is and I can tell you to just look at how dirt your oil gets as far as coloration when you eliminate the evacuation portion of a PCV system, but that tells very little. Send in an oil sample to a good analysis lab and the report back will verify everything I'm saying. The over the road trucking industry does this as a rule, and we do with our race engines as well looking for metal content that tells us a bearing is going away before we could ever detect it and knowing to freshen before a catastrophic failure.

Now back to the LS engine. Any built, big cube, or FI motor cannot breath using the valley cover fixed orifice as it is far to restrictive and excess pressure is a given. So we never use the valley cover vent tube but draw from the rear of the drivers side valve cover.

Now we come to the issue of FI builds that pressurize the intake manifold. Turbo or front mount centri SC systems, the problem with the OEM style system is as soon as you are under boost and the intake is under positive atmosphere you are pressurizing the crankcase directly via the vacuum nipple that evacs under non boost.

The only true solution for street driven cars is a oil separating crankcase evac system that will provide proper, continuous evac while operating under non-boost via the intake vacuum, and as soon as it senses pressurization a check valve senses this and closes blocking any chance of crankcase pressurization. Then as this happens a secondary valve opens and uses the suction/vacuum of the head unit to continue evacuation while the separating can traps & removes all the oil in suspension allowing only the gasses that do not effect the energy released per explosive event (you do NOT want ANY oil entering the intake air charge or residue/varnish forming on the compressor wheels throwing them off balance).

No oil caused detonation, no shortened engine life/increased wear, and the best of everything you need for the motor to perform properly & last as long as possible.

This thread shows others using it with the issues solved. READ it in detail and every step these owners did to solve the issues and the end result:
http://forums.corvetteforum.com/c5-f...olution-2.html

So build your own if you like (it is not hard) but the system works and works like a dream but if you have a piston/ring/cylinder issue you need to tear down and correct it.

Stevie, lots of good and correct info in your post but the race teams (no drag teams...they use belt driven vac pumps or in TA or TF just the hoses going to large cans as oil is changed every run as well as motor tore down.) do not return the raw contaminated oil to the crankcase.....it is filtered and cleaned vis a mini centrifuge type separator (see: Alfa Laval for the industrila diesel versions).

Below is a Maserati in the shop right now that we just did a full engine rebuild on and this motor is from the late 50's LeMans racing and you can see even then in road racing they were using oil separating systems. This early model did vent to the atmosphere and DID return the oil to the crankcase as they did not have the oil analysis we do today and were unaware of the damage the contaminates would cause:



Below is one of our top dragsters (runs high 6 seconds at over 200 mph and 60's .9 range). The motor is a 622ci and we run on alky. The vacuum pump is used to evac the crankcase and to increase HP. We use low tension rings and try to maintain a 14-15" vacuum (any more and the oil starts to pull off the wrist pins & crank journals) controlled by a adjustable vac relief valve installed in the opposite valve cover as the vac pump pulls from providing the same flush & evac I described in my other post.







4DRUSH, I assume your using the 4 vane Moroso pump? It is quite effective and as the vanes wear the parts for replacement are readily available. We always keep shafts, vanes, and bearings in the race trailers for this purpose.

The 4 vane is a good match for FI as it has quite a bit more capacity than the 3 vane. Here is a link to the type of adjustable valve we use:
http://www.jegs.com/i/Aerospace-Comp...C-RFV/10002/-1

We prefer Aerospace Components as they are a sponsor of our race teams in the past but the Moroso does very well also.

You are going to want a crankcase vacuum guage (can be plumbed into the valve cover on the opposit side as the pump pulls or to the valley cover nipple) so you can mointor it down track at WOT when the pump is turning max RPM. Then adjust the valve so you don't exceed 15" vac. It is a sealed spring loaded unit with a lock nut so thats pretty easy. The other part is your motor needs to really well sealed to not have unfiltered air sucking dust/dirt directly into the crankcase. For a street driven car you can also add a moroso or specter type mini filter to it so that air is always filtered. If you do not have a relief valve then you risk engine damage from the oil being pulled off of the wrist pins & crank journals. Pulling less than 10" is not very effective in removing the harmful combustion by-products but it is still the best solution to all the issues described above. I also added pictures of a few of our alky drag motors to show the vac pumps and relief valves.

The issue with the belt driven pumps is longevity. We have tried electric ones but they fail even faster and do not have the capacity the belt driven units do.

Now, and agin, thanks for a civil thread to discuss this. Anyone reading this is free to buy or do what they choose....I am just sharing a lifetime of knowledge gained in the performance & race industry and on the track where it counts. I am not very active here but there are a few other racers that know me personally and can vouch for my credentials. I am a paid engineer & tech consultant of Colorado Speed and have also a lifetime of designing & developing products for the aftermarket performance industry.

I also urge any that are serious about real performance to read David Rehers "Tech Tips" here: http://www.rehermorrison.com/blog/?p=638

Read years of them for knowledge that can't be bought....I trained there under Darrin Morgan, one of the worlds best when it comes to flow, velocity, and induction. He is right there with Tony Mamo and other greats in the racing industry. Even though I have been bulding race & performance engines for over 35 years, I still learn more every day from paying attention to the true geniuses like these guys. When I close my mind and decide to become ignorant is the day I give up. I am sure I will learn more in the years to come as well and will share it with any caring to learn.

We are no longer as active in racing as we had been in the past due to the economy and other factors as I age (mid 50's now) but still crew & support our family drivers and others from our teams in the past. We won the NHRA Super Gas World championship this year in Pomona and Peter & Emily will both be running the full season again in 2012. We still support multi time LSX/NMCA world Champion Edgar Perez as well when we can as well as several other drivers.

So, lets make this a POSITIVE thread and shoot some questions my way. This subject is probably the most misunderstood system on engines today.

 

We can data log crank case pressure with your new engine management Jay.

(or any other additional sensor we choose for that matter)



Excellent thread MVP, this should get cleaned up afterwards and become another sticky when completed.

 

I run the RevXtreme Crankcase Evac System. I did it to get rid of the oil mist under the hood and it works great. I have not run full tilt with the setup yet, but I have pushed to atleast 850rwhp post the install and everything works as advertised. My setup is in my signature..

 

Thanks for the tip Bat Car.

I think we met at the last CC National in S.C., the year it was rained out.
(you let me store my jack & street tires in your trailer) ??

 

 

Cool Doug!! Technology is amazing today with the data available.

Yes, that was me. Sorry we didn't pay our weather bill that race!!

 

I didn't have much in the way of problems using the supplied A&A fittings and hoses making 750rwhp. I really don't care for PCV at all though. These cars get oil in the intake stock. It is not worth the hassle imo.

I ordered a catch can off ebay with 2 3/8" ports on the side, 1 on the bottom, and a breather for the top. It is baffled at the top. I am going to run a 3/8" fitting off the stock, baffled hole on the driver's side, and the same off the top of the oil cap on the passenger side.

I don't see any reason to over-think this. I have more thought into just about every other part of my build than this. If I have issues with the can filling up too fast I will just consult with people who I know personally who have RESULTS to show what works. I'm not interested in what SHOULD work since that rarely turns out to be the correct path on these things. I'll just go with something proven. I would have stopped at 550rwhp on a stock shortblock years ago if I liked to listen to people who theorize on the net constantly...lol

 

No theory here.....this is on thousands of cars and NO oil ingestion into the intake period. A few have already chimed in. The results are proven and have been for years. So your dead wrong. I didn't criticise your build, it looks awesome except for your not having a clue about crankcase evac. Stay with your "EBay" set-up and cut the corners you want, but to make false statements helps none of the members that truely want to learn.

Oh, and whenever your ready to race, the little girl is ready to kick your but.

Happy new year!

 

Has anyone got a mech pump to work with the the ECS or A&A kit short of losing accessories?

 

It's funny. You mention over 30 years experience, etc, etc, but I'd peg you for an 18 yr old kid based on what you type.

I'm not concerned with your opinion on my build in any way...lol. I value your opinion that much.

Are you telling me their is a woman with a faster car than mine? OMG, I must prove I have the biggest e-dick in the world and accept your challenge. I couldn't GAF if you paid me to.

 

The benefit of vacuum pumps on higher HP cars is no theory. They're THE best, and most effective system for crankcase evacuation PERIOD.

PS Happy New Year!!

 

Might be possible on the driver's side, clearing the rack would be a problem. The drive system is already designed.
Would need to move battery to rear for the oil tank.
Deleting the ac would make things easier.

 

Lol. Good for you. I do this in my spare time as a hobby.

 

I agree. They are not always mandatory though.

 

I had the RX Performance catch can and blew out my rear main seal.... i changed over to -10 lines straight off the valve covers to a vented Moroso can- no issues.

Explain.