modifications to the pcv system?

[lostforawhile]

hey does anyone know the clearance between the back of the oil pan and the crank throws? one of my pet projects is getting rid of that dam leaky hose at the back of the oil pan. you really need a PCV system,it keeps your oil from turning to sludge,but it could use some modifications. on the original vapor inlet,it's just a welded piece to the pan with a small metal baffle on the inside of the pan,really a 90 degree piece of steel spot welded on. what i was thinking was running a pipe thread bung on each end of the pan, on the back, running these to a t, and going into the oil seperator with a welded on pipe thread piece. this would enable braided line, that should solve the oil soaked dripping line crap. plus it would pull vapor from both ends,making for better scavenging. the more blowby you get out of there,the cleaner your oil stays. well both blowby and water vapor combustion byproducts. the other thing i was going to do,and i've seen this done on other cars, at the top of the oil seperator,before everything gets sucked into the engine through the pcv valve, run an oil water seperator,like you run inline with an air compressor, to take all the crap out of the line before it gets burned in your engine. all you would have to do is open the drain on it when you change the oil. i've seen that kind of setup done before and once you see what it catches,you will never want it burned in your engine again.

[Demon1024]

i like it. send me one.

it sounds good man. i believe you'll pull it off too.

[lostforawhile]

i like it. send me one.

it sounds good man. i believe you'll pull it off too.

probably going to be a one off,but i will post detailed info so others can copy it if they need to. should be able to be done by anyone with a welder and some time. I'll make my own steel pipe thread bungs but they can be bought pretty cheap also,places like msc industrial supply.

[cygnus x-1]

I had an oil separator between the PCV valve and manifold vacuum port for awhile, and it caught a surprising amount of oil. It was fairly clean, but the engine was newly rebuilt. It would be nice if the separator box could be replaced with something that did more separating.

C|

[lostforawhile]

there is a lot of oil vapor that is whipped up by the crank and the entire rotating assembly, the seperator can't get it all out, thats why i'm adding the second seperating filter. they make systems for airplanes that will attach in place of that box,and do the same thing, but they are expensive. all the crud that doesn't get caught goes right into your intake along with the combustion byproducts. was supposed to be for clean air,yet it gets burned in your engine? i never understood why the crap couldn't be captured and disposed of in the first place, i mean you need to get it out of there for your oil's health, but there has to be a better way then reburning it. it could simply be added to your used oil at drain time, the oil is full of it anyway.

[Tdurr]

vent it to ur exhaust. prob solved. lol

[lostforawhile]

not as effective, you need a good regulated vaccume source such as manifold vaccume through the pcv valve. reed valve in the exaust works but not as good.

[cygnus x-1]

That crud that gets into the oil is I think mostly unburned hydrocarbons from the combustion process. Ideally these would be either burned during combustion or oxidized by the catalytic converter. So releasing them back into the air is really not a problem since they were supposed to go there in the first place. Primarily PCV is to keep sludge from building up in the crank case. The extra oil that gets recirculated is really just along for the ride and should be ok for release back into the pan. It's the gases we want to remove, not any whipped up oil. The oil filter should take care of the oil.

C|

[2ndGenGuy]

I built a catch can for my 81, and it grabs a surprisingly high amount of milky goo. It's like an oil and water mixture. I was under the understanding that a lot of that is moisture that's boiling out of your crankcase, like condensation from when the engine cools and heats up. Definitely seems like good stuff to get out of the engine! That's why I think it's bad when people don't have at least one source of vacuum pulling vapors out of the case. Whether you catch it in a can, or reburn it in the combustion chamber, as long as it's not in your oil and bearings, I think it's a good thing.

[lostforawhile]

That crud that gets into the oil is I think mostly unburned hydrocarbons from the combustion process. Ideally these would be either burned during combustion or oxidized by the catalytic converter. So releasing them back into the air is really not a problem since they were supposed to go there in the first place. Primarily PCV is to keep sludge from building up in the crank case. The extra oil that gets recirculated is really just along for the ride and should be ok for release back into the pan. It's the gases we want to remove, not any whipped up oil. The oil filter should take care of the oil.

C|

yea the extra filter before the pcv just catches all that and lets you manually drain it into your used oil it can be recycled with it,much better for your engine then it being reburned in it again. the pcv would operate normally just the crap would be captured before it goes back through your engine. i was going to build a double pickup off of the oil pan for better scavenging of the unburnt crap floating around. more you can catch,the less goes into your oil. those unburnt hydrocarbons also form acids in the oil, this makes the oil break down faster and promotes corrosion in your engine, the oil filter won't stop them, if you add an extra seperator it gets them out of the system. there is quite a bit of research on this and people who have done it, i'm just figuring out how to add one to this car.

[cygnus x-1]

those unburnt hydrocarbons also form acids in the oil, this makes the oil break down faster and promotes corrosion in your engine, the oil filter won't stop them, if you add an extra seperator it gets them out of the system. there is quite a bit of research on this and people who have done it, i'm just figuring out how to add one to this car.

That's true about making the oil acidic. And also as 2GG said part of what gets pulled out is water vapor. If there was a way to pull out only water vapor and gases it wouldn't be so bad returning it back into the intake. My biggest annoyance with PCV is that it usually makes the intake oily.

C|

[2ndGenGuy]

yea the extra filter before the pcv just catches all that and lets you manually drain it into your used oil it can be recycled with it,much better for your engine then it being reburned in it again. the pcv would operate normally just the crap would be captured before it goes back through your engine. i was going to build a double pickup off of the oil pan for better scavenging of the unburnt crap floating around. more you can catch,the less goes into your oil. those unburnt hydrocarbons also form acids in the oil, this makes the oil break down faster and promotes corrosion in your engine, the oil filter won't stop them, if you add an extra seperator it gets them out of the system. there is quite a bit of research on this and people who have done it, i'm just figuring out how to add one to this car.

I would just put a gravity separator in there. You can use those water / oil separators they use for air tools too. Seems to work great for me. Just a can with two lines in the top and a divider down the middle so that the pressure can still flow, but the changes in direction of the flow will capture most of the moisture and nasty oil. Like a baffle I suppose. I just put it inline between the breather port and the manifold. You are probably safe putting it after the PCV valve I would assume. I made mine by soldering a can of mandarin oranges which were yummy, and then soldering a couple barbed fittings on it. You can probably use some sort or aircraft can if you want and your fancy AN fittings too. Like this thing: http://www.theoldone.com/components/breather/

If you don't want it going back into your intake, there are bungs you can weld onto your exhaust system that use the scavenging, and are supposed to really work well. I've seen them used along with taps using manifold vacuum as well for extra pressure release and venting.

My catch can is on sort of a "circuit" since for some reason my EK1 has some major blowby and it causes massive oil leaks when the pressure isn't relieved. I've got the breather going to the catch can with a 3/8 line, simply to fit the breather. Then I use the standard size vacuum lines, and run one out of the can. This goes to a Y fitting which has a one-way check valve on the two lines that split off. One goes to the intake manifold vacuum, and the other goes to carb vacuum.

So what happens is under throttle, one valve closes, and vacuum comes from the venturis. And when the throttle is closed, the other valve closes and vacuum comes from the manifold. So under any throttle position, there will be pressure relieved from the crankcase. This keeps my engine from blasting oil out the seals, at least for now until I decide to tear down the engine and possibly re-ring it.

I'm pretty sure this is how the stock system works. Even on the LX-i, you've got the tube going from the valve cover to the intake pipe, and the tube going from the engine block to the intake manifold. No matter throttle position, you have ventilation. It's the main reason why a little breather filter on your valve cover isn't a good idea. The flow through the valve cover goes both directions. It's the big difference between PCV and just a regular crankcase vent. But I'm tired and rambling at this point, since I spent about 348139483 hours researching PCV and crankcases and stuff a little while ago, I just decided to puke up everything I learned.

[lostforawhile]

I would just put a gravity separator in there. You can use those water / oil separators they use for air tools too. Seems to work great for me. Just a can with two lines in the top and a divider down the middle so that the pressure can still flow, but the changes in direction of the flow will capture most of the moisture and nasty oil. Like a baffle I suppose. I just put it inline between the breather port and the manifold. You are probably safe putting it after the PCV valve I would assume. I made mine by soldering a can of mandarin oranges which were yummy, and then soldering a couple barbed fittings on it. You can probably use some sort or aircraft can if you want and your fancy AN fittings too. Like this thing: http://www.theoldone.com/components/breather/

If you don't want it going back into your intake, there are bungs you can weld onto your exhaust system that use the scavenging, and are supposed to really work well. I've seen them used along with taps using manifold vacuum as well for extra pressure release and venting.

My catch can is on sort of a "circuit" since for some reason my EK1 has some major blowby and it causes massive oil leaks when the pressure isn't relieved. I've got the breather going to the catch can with a 3/8 line, simply to fit the breather. Then I use the standard size vacuum lines, and run one out of the can. This goes to a Y fitting which has a one-way check valve on the two lines that split off. One goes to the intake manifold vacuum, and the other goes to carb vacuum.

So what happens is under throttle, one valve closes, and vacuum comes from the venturis. And when the throttle is closed, the other valve closes and vacuum comes from the manifold. So under any throttle position, there will be pressure relieved from the crankcase. This keeps my engine from blasting oil out the seals, at least for now until I decide to tear down the engine and possibly re-ring it.

I'm pretty sure this is how the stock system works. Even on the LX-i, you've got the tube going from the valve cover to the intake pipe, and the tube going from the engine block to the intake manifold. No matter throttle position, you have ventilation. It's the main reason why a little breather filter on your valve cover isn't a good idea. The flow through the valve cover goes both directions. It's the big difference between PCV and just a regular crankcase vent. But I'm tired and rambling at this point, since I spent about 348139483 hours researching PCV and crankcases and stuff a little while ago, I just decided to puke up everything I learned.

does yours have a pcv system or does it have the little seperator in the aircleaner? a lot of those suffer really bad crankcase pressure with that system. thats what causes all the blowby problems and other problems. there are a lot of ways to convert one to a true PCV system. that will solve most of those issues. many older import cars without pcv's had the same problems. it's really not an emissions system as it is a system to remove blowby and moisture from the crankcase. it really helps your oil to have one. i was going to use one of those compressor seperators on the firewall. i modified the factory box on the back of the engine to threaded fittings. the top of it gets an aluminum 90 degree angle, that goes to the seperator with braided line,it comes back with the same,goes 90 and up to the pcv valve hose. i already figured all this in with my new manifold . on the bottom it will split into two braided lines, one goes to each end of the pan. the factory hose connection on the pan will go and be welded up. it will scavenge from each end of the pan. the original line is 1/2 inch or so,so i split the two lines into two smaller lines, you want to keep the opening size in the pan the same, even if you have to split it into two different hoses. it's made to pull a specific amount of vaccume. too little and it doesn't work,too much and you can get oil sucked into the system. i kept the openings the same size on the box itself. the pcv valve on the datsun part of the manifold,is about the same as the original one, so it should work the same. only difference is it's metal and it screws into the manifold. the metal ones can be soaked in solvent and last forever. i also ran a piece of heavy walled tube through the breather box, it's threaded on each end, and i'm going to run bypass coolant through it. if you keep that box hot,it helps to keep the blowby and the water vapor in a gaseous form,that can be pulled out of the system. if not, a lot of it condenses on the upper part of the box and goes right back into the engine.

[lostforawhile]

i hope my post showed up,stupid database errors. the oil seperator on this car really sucks. it has nothing but a metal plate over the bottom part of it, the center connection to the engine goes straight to the pcv valve. any vapor or oil mist it picks up there,goes straight into your engine. i was thinking that the pcv system may also be a major cause of idle problems in carbed cars. it would be on the FI cars too but the idle controller can compensate for it much better. the entire system is basically a big controlled vaccume leak off of the manifold. if you have a valve cover leak,an oil pan gasket leak, if the pcv valve is bad, or one of those brittle hoses that go to it are bad, you just developed a large vaccume leak right off of the manifold. the pcv valve is basically a one way valve, it's supposed to regulate vaccume, but it also prevents flames from shooting into your oil pan,in the event of a backfire in the manifold. it's a check valve.

[lostforawhile]

[lostforawhile]

wow the site is actually working again

[lostforawhile]

ok sec gen guy is going to send me a pan, will be pretty easy to modify off of the car. looks like everything will fit. i had modified a FI thermostat housing for AN fittings,so i drilled the ground bolt hole out,and tapped it 1/8 npt,this is one side of the coolant that will heat the box. on the other side of my new manifold,where the coolant comes out of the block,added an aluminum t and some other fittings,this is the other side of that coolant passage. i used much thicker round bar stock then i needed to,to make sure there was no chance of leaks. using -4 braided line and fittings. since it's smaller then the original bypass hose, coolant will still flow through the bypass correctly. thats important,because my vaccume thermo valves and temp sender,are installed on the back of the new manifold like original.

[2ndGenGuy]

Yeah the old E-series motors only had the breather. No PCV system. I am tempted to try making a PCV system or somehow make the crankcase breathe a little better. Tapping the oil pan is one way to do it, but I'd be afraid of oil sloshing.

The PCV on the ES works just like on the A20, but it flows in reverse basically. With the PCV valve in the valve cover instead of in the intake manifold. You're right about a bad valve making carb'd cars idle poorly too. A bad one will basically turn it into a bad vacuum leak. Usually sticking open.

[lostforawhile]

[Rendon LX-i]

Thats a pretty good little setup you got there lost. As of now im just running a Ebay catch can and its working great. Pcv-catchcan-pre intake turbo. I had my valve cover (T) to the pcv line then to catch can it was sucking way to much oil. Or should say turbo was to strong of a vacum source. So i just put a 3/8 hose from valve cover to ground works great. I seen alot of HMT crew using the stock catch can which is black box by adding a fitting like you did works pretty good. I want to complety elimanate the PCV system and doing a good catch can install...As for now im using this setup to get me by. But nice work lost.

[lostforawhile]

Thats a pretty good little setup you got there lost. As of now im just running a Ebay catch can and its working great. Pcv-catchcan-pre intake turbo. I had my valve cover (T) to the pcv line then to catch can it was sucking way to much oil. Or should say turbo was to strong of a vacum source. So i just put a 3/8 hose from valve cover to ground works great. I seen alot of HMT crew using the stock catch can which is black box by adding a fitting like you did works pretty good. I want to complety elimanate the PCV system and doing a good catch can install...As for now im using this setup to get me by. But nice work lost.

if you can try to maintain a pcv system, you can always build a system with a reed valve in the ewaust instead of manifold vaccume. the pcv really helps keep your oil clean

[Rendon LX-i]

Question.....an i just take off that hose that inbetween the oil/water separater or w/e....Reason beening When im on boost i build up alot of crank pressure...so i need to release it. SO if i just run from the pan port to the catch can and vent it...OR connect it to preintake turbo..>BUT ideas guys ideas.....i need to get this done...really pissing me off

[lostforawhile]

Question.....an i just take off that hose that inbetween the oil/water separater or w/e....Reason beening When im on boost i build up alot of crank pressure...so i need to release it. SO if i just run from the pan port to the catch can and vent it...OR connect it to preintake turbo..>BUT ideas guys ideas.....i need to get this done...really pissing me off

the problem is you will lose a lot of oil, that seperator shouldn't cause any pressure buildup, it's just an open baffle. it's much bigger then the port on the oil pan.

[Rendon LX-i]

so what should i do then lost...SHould i take out my pcv valve WHICH is a pain to get out and gut it or.............shit idk...i mean its working but im getting oil shooting out of my valve cover under boost i mean always on boost going up the hills....IDK......

Not only that but my catch can is not catching shit...my turbo is sucking it all up LOL..so im reburning it as you should say

[lostforawhile]

here's a good thread on turbo hondas and pcv on honda tech he spent about a year figuring all this out http://www.honda-tech.com/showthread.php?t=1199935