PCV Ideas...
Thread Starter
Teching In
Joined: May 2014
Posts: 39
Likes: 0
PCV Ideas... Hey guys...
getting close to getting my 300zx LS1 swap completed. One thing I need to do is figure out PCV routing. The pcv hose that was on the motor when I bought it is shot, and a new one is a hundred and ten bucks, which seems silly when I could probably make one for 30 or 40.
Does anyone have a "how to" on re-routing or customizing the PCV setup?
Thanks.
getting close to getting my 300zx LS1 swap completed. One thing I need to do is figure out PCV routing. The pcv hose that was on the motor when I bought it is shot, and a new one is a hundred and ten bucks, which seems silly when I could probably make one for 30 or 40.
Does anyone have a "how to" on re-routing or customizing the PCV setup?
Thanks.
Do a catch can setup... Here's a few nights of reading for ya.
https://ls1tech.com/forums/search.php?searchid=25797751
https://ls1tech.com/forums/search.php?searchid=25797751
suggest you read some articles online about PCV if you don't know the purpose,
picture from this ls1tech article,
https://ls1tech.com/forums/conversio...t-66-nova.html
the goal is to simply suck air/blowby out of the crankcase but you need to have clean filtered air going back in. so you want the hose that has the air going into the crankcase pulling from either behind the air filter and there is sometimes a port for that on the air lid behind the air filter, or have some kind of breather filter on it. Also, depending on the throttle body it might have a nipple to pull fresh filtered air from, and it's located before the throttle plate so it's not intake vacuum, and in this case it's also air that's been accounted for by the MAF which is ideal.
the other hose that sucks blowby out of the crankcase from other port on valve cover goes to the pcv valve to regulate suction then connects behind the throttle plate to intake manifold vacuum. where and how you choose to route hoses doesn't matter, as long as you accomplish the basic purpose of PCV. but you want to double check and suck from a valve cover port that is baffled or won't obviously suck oil directly.
and for hoses you can buy a 20' role of cheap 3/8" fuel hose or whatever fits the nipples on the valve cover and make your own, no need to buy pre-formed oem "PCV breather hose".
picture from this ls1tech article,
https://ls1tech.com/forums/conversio...t-66-nova.html
the goal is to simply suck air/blowby out of the crankcase but you need to have clean filtered air going back in. so you want the hose that has the air going into the crankcase pulling from either behind the air filter and there is sometimes a port for that on the air lid behind the air filter, or have some kind of breather filter on it. Also, depending on the throttle body it might have a nipple to pull fresh filtered air from, and it's located before the throttle plate so it's not intake vacuum, and in this case it's also air that's been accounted for by the MAF which is ideal.
the other hose that sucks blowby out of the crankcase from other port on valve cover goes to the pcv valve to regulate suction then connects behind the throttle plate to intake manifold vacuum. where and how you choose to route hoses doesn't matter, as long as you accomplish the basic purpose of PCV. but you want to double check and suck from a valve cover port that is baffled or won't obviously suck oil directly.
and for hoses you can buy a 20' role of cheap 3/8" fuel hose or whatever fits the nipples on the valve cover and make your own, no need to buy pre-formed oem "PCV breather hose".
Last edited by 1 FMF; Jun 6, 2014 at 02:36 PM.
I'll be the '04 LS6 PCV nutswinger for this thread 
If one is going through the hassle of an engine swap, then removing the external PCV system is another easy step. Yes, it's easy -- and one can still install a catch can if they desire.
If one is going through the hassle of an engine swap, then removing the external PCV system is another easy step. Yes, it's easy -- and one can still install a catch can if they desire.
can you post some pics, diagram, or explain?
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Here is a how to if you're interested in doing it:
http://ls1howto.com/index.php?article=18
But read this first
http://ls1howto.com/index.php?article=18
But read this first
Originally Posted by The Bat Car
.....
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.
...
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.
..
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.
..
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.
.....
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.
...
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.
..
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.
..
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.
Last edited by My6speedZ; Jun 9, 2014 at 11:56 PM.
So if I understood what Bat Car was saying. Is that with the LS6 valley cover hose connected at the intake and the passenger side hose connected near the throttle body that we still need a connection at the rear of the drivers side valve cover to proper evacuate the drivers side valve cover area?
Last edited by RedFirehawk; Jun 19, 2014 at 07:39 PM.