pcv system how and why you need it.

[@northfloridafungi9336]

this video was a lifesaver. I could not find any info on the system you explained. You are the only youtube I have found to explain the valve pcv breather/oil sep. I had mine set up way wrong. Rerouted the pcv line from the head back into the cap. With a new understanding, your set up totally makes sense. Fixing mine now. Thanks man

[@EfurdGarage]

Thanks. And im glad it helped

[@bentleynut1648]

A quick video but very well explained and extremely useful to me. My car was missing the pcv valve and was not connected to full vacuum at base of carb. It only had a breather on the other side connected to the air filter. As a result it was getting oily around the breather and didn’t look right. The car also has plenty of soot on the plugs and the oil appears thin.....so they may both be consequences of the pcv being previously deleted. I am putting the system back in place now and will change the oil. Hopefully the car runs better then. Thanks for your help

[@EfurdGarage]

Thanks. And yea after you fix the pvc and change the oil, take a look at everything. It could be related but may not be. Could be lack of pcv making another issue worse. But thats a good place to start

[@lxrdjaay]

I don’t have one installed on my 454 bbc & couldn’t figure out where the small oil leak was coming from. This helped. Thanks.

[@EfurdGarage]

Glad it helped

[@Odin2411]

Props for actually replying to people and helping. Unfortunately correcting my pcv didnt help. Im fouling out plugs with oil every time it revs over 2k

[@EfurdGarage]

Thanks. But as far as the pcv if its oil fouling then its another issue. You have to make sure your covers have baffles some aftermarkets do not. Did this start before or after correcting the pcv

[@Odin2411]

Happened as soon as the engine was put back together. 94 engine with an unnamed intake and holley 600 carb.

[@Odin2411]

Stock valve covers though

[@EfurdGarage]

@@Odin2411 ok. Is there oil in the hose that runs from your pcv to the carb? and if so how much?

[@Odin2411]

No, but its struggled to run for more than 2 minutes since i hooked up the pcv. Ill be putting fresh plugs in tomorrow. Its possible they were still too fouled for the pcv to matter

[@beachboy4106]

Cheers Mate, this is really useful, I have a 1974 454 bbc in my 1980 Z28, the engine has loads of modifications, like Edelbrock RPM intake manifold, and Edelbrock performance heads, new pistons, and MSD electronic ignition, and new Holly Classic 750 carb. I was noticing oil spots when I parked up at the shops for a short while, and after a burnout or two on the way home I would notice a small puddle of oil form overnight on the garage floor under the rear of the engine. Since all the engine gaskets were good the oil seemed to come from the valve covers, so I replaced the old tin ones with cast Edelbrock Elite, and still had oil around them. Then a friend told me about Positive Crank Pressure, and I think it is this causing the problem. I have two breather caps ( one on each valve cover), and the oil seems to trickle from them when I drive the car hard. I think the oil was running along the ridges along the top of the valve covers and dripping down the back near the oil filter. I live in the UK, and love the Camaro.. over here its quite unique and get lots of attention! Could you advise me about the best way to deal with the problem. Thank you, and keep the videos coming , they are especially useful to us in the UK with limited knowledge of you awesome American steel beasts :)

[@EfurdGarage]

Yea, you said you had 2 breathers but did not mention a valve. The pcv system uses the engines vacuum to pull the excess pressure out of the engine. The valve keeps anything from going back into the engine. Valve covers usually have 2 size holes so you need to see which you have and get a pc valve, now a stock pcv is small and some after market covers have a large hole, but you can buy grommets to take care of that as well. as far as looks they make many of the pcv that look like breathers. Pcv to carb is the best way. Now with vacuum breaks some carbs only have one large vacuum port so you may need a spacer and add a fitting in to use both. Also make sure your valve covers have the baffles installed inside

[@beachboy4106]

@@EfurdGarage Thank you so much mate, after reading this and looking again you are right. I did not know about PCV until today. My breather caps were basically a cap with some kind of air filter built in. But with no baffles under the covers, and the pressure inside the engine it has been spraying oil out under hard driving.. I will keep one breather and buy a new one with PCV valve and I can connect it to the front of my Holley carb as there is a spare port next to the brake vacuum hose. If this still sprays oil then I will have to also consider baffles for the Edelbrock Elite rocker covers. Let’s hope I can get all these little problems fixed before the end of lockdown 😀

[@EfurdGarage]

@@beachboy4106 you got it down. The breather filter is just to help keep anything from getting in the engine. The baffles will help espically with keeping the pcv from sucking up oil. Baffles and pcv should get you right where you need. I dont know how much vacuum your engine makes but if your running vacuum breaks you should have enough

[@amongus6061]

Hell yeah bro just like everyone else in the comments I couldnt find jack about what I needed and you nailed it with this vid

[@EfurdGarage]

Awesome i glad you found what you needed. Thank you!

[@jdwht2455]

Good basic explanation. If I can expand on it a bit by saying that you need a baffle in the valve cover to deflect most of the oil and that the PCV valve should be about 3/8" above that baffle. Next, you may need to experiment with different PCVs to get the right flow. I finally gave up after 5-6 different PCVs on my fairly mild 302W in my '31 and bought an adjustable M/E Wagner PCV to stop the oil carry over fouling my carb and intake valves. Voila! Finally! It works and no more carry over

[@EfurdGarage]

I always run baffles, tried it once didnt go well. no baffles probably work best on an evac system. I have never had an issue with using a stock pvc and baffel getting to much oil most of my engine run about 18lbs of vacuum at idle or less. But you got it working and thats what counts

[@davidcraft4909]

I personally feel like an engine idles smoother without the pcv hooked up, but it is absolutely necessary to hook up the pcv. If you block it off then you will most likely have oil seep out of every gasket, oil pan, timing cover, valve cover. I cannot confirm this for sure but I'm pretty sure I popped the front seal out of a 454, the one that goes into the timing cover and seals on the balancer, from not running a pcv and just having one large vent in the valve cover. So yeah, good info for letting people know how important it is,

[@EfurdGarage]

True you wasting engine vacuum with it, but it is needed.

[@brianphillippe1694]

well explained. As always very clean engine / engine bay. yelm WA

[@EfurdGarage]

Thank you Much. And i cant stand a messy engine bay it drives me crazy

[@bretthair4249]

What about the heater hose? Is there any way to have that set up with these kinds of air filters

[@EfurdGarage]

Are you referring to the pre-heat tube that runs from the exhaust manifold to the factory air cleaner?

[@joeasbury974]

Another very important thing the PCV does is evacuate water vapor when the engine comes up to temperature. If you don't have a pcv and a thermostat hot enough to vaporize the water (180 anyway) it will build sludge in the engine. This is another reason not to run engines briefly or take short rides that don't heat the engine fully.

[@EfurdGarage]

True. alot of people dont think about it and just drive short jolts.

[@JoeHynes284]

i agree, don't think it does not for lubrication, i think it was the first piece of emissions equipment ever installed, the rerouting to the intake part.

[@EfurdGarage]

it was kinda a first part of emissions because it does burn off the fumes out of the engine, but it does pull out the pressure from inside the crankcase, which keeps oil from blowing out the valve covers breathers, and from blowing gaskets. I have had a bunch of people here in town that remove it and they all end up with oil pushing out the breathers and leaking around gaskets after the pressure building up. even drag racers use a evacuation system to pull the pressure out of the engine during a pass

[@TheReill83]

Awesome I appreciate you sharing.was getting oil up my distributor shaft causing me to loose power because of the high pressure to my top end not having any were to go.

[@EfurdGarage]

Glad it could help

[@gamwsas]

i am getting oil on my distributor too because of that.

[@buggzo]

Thanks for the upload! Do you have a link to those aftermarket versions? I need both the breather and pcv

[@EfurdGarage]

i do not currently have a link, sometimes i find them on ebay other times summit racing. just avoid the "pcv" that is a breath with foam as it will suck up into the carb, make sure it has the check valve

[@IsaiasMoreno.]

I recently bought a 90 gmc 350sbc. The guy I bought it from said he had just fully rebuilt the engine. But I noticed that when it warms up and pressing the gas it would smoke blue. I also noticed that the breather and pcv are on the same side. The opposite valve cover has a push in sealed oil cap. I see oil coming out of the exhaust where the oil cap is could the be because the pcv and breather are not installed on opposite side to provide adequate fresh air to the engine

[@EfurdGarage]

yes if the breather and pcv is on the same side all it is doing is mostly sucking fresh air in the valve cover. get them on opposite sides and see how it does

[@bige4618]

Thank you, awesome video!

[@EfurdGarage]

your welcome, Thanks for watching

[@house9850]

Fantastic upload thank you, quick and concise. I have a 350 v8 chevy g20 i just inherited, and leaking, smoking valve covers. I wanted to replace the gaskets but there is so many hoses and stuff on there i was like wtf. I think its California emissions crap i have to keep.

[@EfurdGarage]

It depends where i am i can make it simple. and clean up alot of that stuff. but it depends if your in California then there might be some thing you have to keep

[@cormacgillis7805]

I'm doing the valve covers on my 1993 5.7L g20 now, if you're talking about everything in the way on the driver's side, it's AC hoses.

[@house9850]

@@cormacgillis7805 youre probably right thanks for the heads up. I was just disappointed an 83 still needs to be smogged here in the no fun state of California. I'm going to take another crack at it next month when the weather cools down outside.

[@marko6394]

Does it matter which side the PCV valve is on and which side the breather filter is installed or will it work both ways?

[@EfurdGarage]

Will work on either side

[@JamesAutoDude]

Where do you get that breather and that valve that goes on the valve cover?

[@EfurdGarage]

usually summit racing or sometimes ebay but you got to make sure they have the check valve

[@chrisknight8709]

You helped a lot, and I loveeee the gto man 🤙🤙🤙

[@EfurdGarage]

Glad it could help and thanks

[@YousifClassicCars]

So the breather cap is removable and is considered as the oil cap, right?

[@EfurdGarage]

yes, most after market covers do not have a spot for the twist off oil cap. so yes you remove teh breather and add oil there.

[@Spudderr]

Do you see any benefit with the large chrome style valve vs the small oe style? My 283 really starts stinking of oil after about 3000 rpm and I’m trying to band aid it was thinking the larger style may breathe better

[@EfurdGarage]

are you talking about the valve cover or pc valve. Pc valve you wont see as long as the one on there is clean and good. The valve covers can depending height has less to do with it, but the baffles inside have alot more control such as how open they are and how close to a rocker they are.

[@Spudderr]

@@EfurdGarage was referring to the one like you have on the 350 in the start of the video with the hose running to the carb

[@EfurdGarage]

@@Spudderr o well no. Thats just a billet aluminum fancy one. It has the same pc valve inside of it like stock. Just looks better.

[@traviswebb625]

Trying to finish up a Chevy 454 rebuild. I put a basic PCV valve on one side, and will look for a breather for the other side. Is the PCV valve the one that connects to the carb? Does the other side/breather need a line hooked up to it as well? If so, where does that connect?

[@EfurdGarage]

The pc valve will connect to the carb at the large vacuum port. most carbs have 2 one in front and back. usally the front is used for pcv and the back brakes. the other side is fine with a breather cap.

[@traviswebb625]

@@EfurdGarage Thanks!! Great video! I need someone to decode the vacuum system for me, to put it in laymen's terms, so this was helpful!

[@EfurdGarage]

@@traviswebb625 Glad it helped

[@midnightraiin4035]

i want to do this setup. my question is my main seal is beginning to leak, if the causation is crankcase pressure. at this juncture if i resolve excessive pressure is it likely main sesl pressure drop will cease oil leak. every time i turn around im fixing something. in the last 2 months i rebuilt the carb and chnged master brake cylinder. this is all a learning curve.

[@EfurdGarage]

it may not fully stop the leak but it should slow it down. But if it is light it could stop it. But the pc system is a must have regardless. there is a reason they installed them and still have them to today.

[@midnightraiin4035]

@@EfurdGarage thank you. i will get right on it

[@northernwoodsman]

How did you get a breather style valve? Evey other one I see just looks like a stock one.

[@EfurdGarage]

There are several company's that make them. Summit racing sells some. Jeggs. You can find some on ebay but you want to make sure you are getting one with a check valve in it and not the ones with foam

[@northernwoodsman]

@@EfurdGarage yeah, some are just breather. Thanks!

[@jtrigueros2418]

On carburetor cover the lil hole bottom for the old breather what do u do ? Cap it?

[@EfurdGarage]

If you are talking about the stock air cleaner you could keep it stock and run the pipe up or cap the hole in the air cleaner and put a aftermarket breather in the valve cover. Some after market air cleaner lids come with the nipple so you can run the stock pipe but you can leave it plugged to

[@takingrisks7538]

Does it matter which side you place the filter cap and the breather?

[@EfurdGarage]

On a set up like a chevy no. I usually put the valve where the hose will be shortest

[@rodolfofuentes3687]

What are the sizes of the lines ?

[@EfurdGarage]

3/8

[@yenkofarm7440]

Thanks for the tip- My breathers have low mileage, but they're around 20 years old- Should they be replaced periodically, or is there a way I can test their effectiveness?

[@EfurdGarage]

If you can blow through them. It wont allow 100% air through but it should allow about 60-70% air. Some breathers have a removable bottom and you can change the filter. The cheaper ones you just replace

[@juanchoman9824]

Does it matter what side the breather is on? My is on right side back.

[@EfurdGarage]

it dosnt, as long as one side is vent/breather and the other side is vacuum if lits like the chevy. i usually put my breather in the back and pcv valve in front so its a shorter hose to the carb

[@estebanjuarez93]

The PC valve u have is in the breather?

[@EfurdGarage]

Yes. Aftermarket pcv for looks.

[@MikeJones-ky1cu]

350 SBC 30over 670 avenger carb. No brake booster. Just a drag car. Car runs like crap when I cap off front vacuum port for PVC. When I plug up PVC still runs bad. When unblocked and port is open car runs great. Why?? The only vacuum that is not plugged is vacuum advance. Do I need to run PVC.? Can I run the carb with that cap off? When vaccum port for pvc is capped off engine knocks and makes my eyes water.And it wont even rev up. With cap open revs up fine.

[@EfurdGarage]

first yes even drag cars run a pvc, most when they do not produce enough vacuum will run a crankcase pressure evacuation set up. Since it seems to run best with a "vacuum leak" and your eyes water. it is very possible your to rich that the fuel pressure is too high, the needle and seat are worn out or gunked up, the float level is wrong, or the float itself is bad. Most people who run drag cars will run full advance and no vacuum advance. also it would seem to me that a street avanger would not make a good carb for a drag car. what cam are you running?

[@MikeJones-ky1cu]

@@EfurdGarage Not sure on cam size. I gave the information to Holley and they paired me up with that carb. Carb is brand new. The timing is 180 degrees off. Not sure if someone just threw this distributor In there and sold it to me. Instead of distributor rotor facing number 1 cylinder its facing 180 at 11 aclock instead of 4 a clock. And the smoke only burns eyes and engine starts thumping when vaccuum is plugged off or put PVC back on. It does have a summit crank. All new plugs and wires. And I am getting 12 volts from hei distributor 12g wire.

[@EfurdGarage]

@@MikeJones-ky1cu I will say it's hard to diagnose something without seeing it in person but it sounds like there could be some issues. I would set the timing right first. And go from there. Really you want a carb to work with the cam so not knowing that is kinda a handicap, I know I was recommended a 750 but went 850 and still could go a little more. But it shouldn't run better with the vaccum leak so regardless there is an issue and I have even had carbs fail out of the box. What kind of pump are you running

[@Switchblxde7]

what if i had two PCV Valves and two breathers? Maybe it wouldn’t be necessary, but would it damage my engine?

[@EfurdGarage]

Well it would almost be like running no pcv, since you would have one i each valve cover,( unless its like the pontiac) and one breather in each. then mostly you will be pulling air through the breather on each side instead of the crankcase. If you ran the 2 pcv on one cover and 2 breathers on the opposite the pcv vacuum could end up fighting each other, as well as extra vacuum pulled from the manifold

[@jessemendoza2991]

What are you running it off of? The carb or a carb spacer? Would this also cause condensation to build up, without a pcv setup? Thanks

[@EfurdGarage]

I run them off the carb as long as it has the provision. But if not they make spacers with it since some where like that from the factory. Most condensation issues is from not driving it long enough to heat up enough to dry it all out, but the pvc would help with that as well

[@jessemendoza2991]

@@EfurdGarage Thank you for your response.

[@Tom-wq2mz]

May you give me some information on the GTO Pushrod pan. I've got the same block in my Catalina 400. So it uses a Valley pan. My distributor is getting oil inside fouling out the ignition module. I checked my valley pan and it is loose. I was told because the valley pan was loose it's created a oil leak because of improper positive crankcase pressure. Any truth in it. Thank you

[@EfurdGarage]

well as currently my 64 gto is almost completely stock non-numbers matching. crankcase pressure can cause oil to get places if your pvc system is not pulling enough pressure out. i got plenty of silicon around the edges of mine. But it almost sounds like you have a crack in the distributor somewhere. honestly once the distributor is in place its hard for ( im not going to say impossible but pretty close) oil to go underneath the disy where the pump meets it and all the way up. The distributor dosnt go through the valley pan it is right at the edge. and the base of the cap is slightly elevated from the pan, so i dont see it sucking it up and in. if you got a leak i would make sure the pan isnt warped and silicon it done good. then check the distributor for crack. there may also be a seal in the dissy ( i have never took one apart.) I would look at the distributor as the issue myself.

[@deanwitt7903]

Awesome video thanks . Two questions though . Would this not cause the piston tops to become oiled up in time ? Also I have a 389 Pontiac with road draft tube . Is it ok to leave the road draft tube to function as normal and add a Pcv to one valve cover to manifold vacuum ? Reason being at open throttle there be no vacuum but crankcase can still vent through draft tube ?

[@EfurdGarage]

thats the old style which they went to the pvc for a reason. it wouldnt cause oil build up unless there was something major wrong with the engine because the fuel and combustion would take care of it other then the carbon build up. yea if you add pvc you want somewhere for the pressure to escape wince wot there is no vacuum, so the pressure could still escape through the tube at wot and cruise speed and idle the vacuum is taking care of it

[@deanwitt7903]

@@EfurdGarage perfect answer , just what I was going to do but just needed confirmation I was on the right path . Thank you .

[@EfurdGarage]

@@deanwitt7903 thanks for watching

[@deanwitt7903]

@@EfurdGarage Another question sir ? I have a duel plane manifold though so is it going to be a problem to achieve vacuum from all cylinders if I drill for a pcv .?

[@EfurdGarage]

@@deanwitt7903 should have a large vacuum port on the carb for that. if not i would try to get a spacer and add a fitting in it for vacuum so you dont have to drill into the intake. it is best to drill into the plenum so you have vacuum from all ports. if you have room

[@Workfourit]

I got a Cadillac 429 with blow by smoke, would this help reduce the smoke brother ? Thank you

[@EfurdGarage]

If you dont have 1 it will help plus you really need one if you dont. You have to get rid of that crankcase pressure.

[@Workfourit]

it does have a PCV valve but not a system like you have in this video. Could you please tell me what brand you got, and in my situation do you think it would help ? Much appreciated

[@EfurdGarage]

@@Workfourit is yours using a vacuum source? Or how is yours setup?

[@tedslife7086]

I have a 496 stroker can I keep my line from my PCV to the front connected to the Edlbrock Carb and on the back of my intake manifold I left a capped ported area can I run a line to that to my other side valve cover breather for a better flow ?

[@EfurdGarage]

one side should be vacuum for pull like whats on the front. you need a fresh air side which you will need a breather. running another vacuum to the other side will create vacuum fighting each other, it also wont be a positive flow. But also you never want to run pcv off a single runner always a full plenum/carb, runnign off 1 intake runner can cause the plug to get oil fouled since if any oil is pulled it will be pulled to 1 runner rather then distributed across all

[@mexdrago3009]

Does it matter which side has the pcv valve?

[@EfurdGarage]

On a set up like a chevy with pcv on one side and breather on the other. It dosnt matter. I like to make it where the hose is shortest for the best look

[@theshark2804]

Ok i was thinking of running a oil catch can. I dont like the idea of sending oil back into my fuel system

[@EfurdGarage]

Catch cans don't pull vacuum they are just there to catch excess oil that is usually caused by blowby at high rpms when the PVC is not working, bad rings, or boosted applications for the most part. PVC dosnt really put oil into it, sometimes just a little depends on your baffels if you have them in your valve cover or if you have bad rings. Sometimes I have a little in the hose but it would be a few drops nothing major. If you do suck up oil unless it's alot you won't notice.

[@nate8867]

You should be fine if youre not boosted and a carburetor should clean off the intake valves anyways. Could also just vent to atmosphere if you think global warming is a hoax :P

[@MrMedicAdnan]

PCV on valve cover with 1/2" hose going to Catch Can inlet and the outlet of Catch Can going to your Carburator vacuum port. That way your crankcase is vented properly and no oil will ever make it to your intake. Get a clear Catch Can so you an tell how much blow by you have which will also tell you how healthy your engine is.

[@sillygily4435]

Every pcv valve system I see runs the breather to the intake as a hose. My engine I just bought off a guy has no pcv valve and only one breather. Is it ok if I just drill a hole and install a pcv valve on one side and keep the breather on the other? Or do I need to run a breather to the intake?

[@EfurdGarage]

By intake do you mean intake runner? Because intake runners pulse and you get the best constant vacuum from the plenum/carb. The only issue with just drilling a hole in a valve cover is no baffle to help keep or slow down sucking of oil. so you really need a cover with a baffle

[@sillygily4435]

@@EfurdGarage Yessir. Got it figured out now. I think im just going to get new valve covers because I don’t have a drill or a way of making a baffle. And valve covers aren’t really too expensive.

[@danielpeters408]

Thanks for the video 👍🤙

[@EfurdGarage]

Thanks for stopping by and watching

[@noampitlik2332]

It was helpful. Thanks.

[@EfurdGarage]

glad it was helpful thanks for watching.

[@kountrycustombuilds]

I have a 94 k1500 and there is a vacuum hose to the back of my tbi and a pcv on the front.....is this the right way to run it or should I change the vacuum on the back?

[@EfurdGarage]

@@kountrycustombuilds usally there is one vacuum on the back and its smaller its for the map sensor. The front is for pvc.

[@kountrycustombuilds]

@EfurdGarage ok, yes. I'm sorry, I misspoke. The one I'm talking about is connected to the collar for the air filter and goes to the valve cover on the driver's side. If I put a breather on the valve cover there should I just plug that hose?

[@EfurdGarage]

@@kountrycustombuilds yes if you put a breather in the valve cover just plug the hole or get an air cleaner spacer its like the collar but no holes

[@neeko7878]

Can you put the breather on the drivers side or the passenger side? Mine looks like yours but my buddies is the reverse

[@EfurdGarage]

Either way works. Pcv on one side and breather on other it dosnt matter which side.

[@jasonthompson3135]

Hi sir great video with great info my apolgy as I'm new to this I have a question if you dont mind I bought a 64 impala none ac car or power brake booster on car oringinal brake cyliner from a guy last year has a 327 motor 350 tranny with rochester 2jet carb no air filter on carb car runs good no overheating theres two hard lines with rubber hoses attached to them each one is small one is big coming from under the distributer not hooked up to anything the carb has a valve thing on the right front and a inserted screw on the back of the carb also there's a valve on the intake manifold also behind the carb not hooked up to anything there's two breathers or pcv valves on each side pass and driver side of the valve covers not connected to anything I also have a vented oil cap on the oil filler tube blows a little white smoke at idle from the dual exhaust and small amounts of smoke comes from my oil filler tube also valve covers leak a little oil here and there sorry for long questions could you help me on this one as to how to properly route things I bought a aftermarket air filter for it sort of like the one in your video maybe could not find the original one Thanks

[@EfurdGarage]

the line off the distributor is i recall is a breather vent tube and is old school. the small one may be running to the transmission since it is a 350 turbo and they have a vacuum canister at the rear of the trans. back in the day they didnt have a pcv setup and eventually learned they needed one. there are a few way to go about this. you can put a pc valve in one valve cover then leave a breather in the other. and block off the tube from the distributor. you dont wanna pull with vacuum from the distributor because you will suck up alot of oil. the line from the transmission should go to a full vacuum source, a port with vacuum at idle usually its put on the port in the rear intake runner.

[@jasonthompson3135]

@@EfurdGarage Thanks alot on that another question or so sir what hose would I hook up to the air filter and also would I need to time the motor to top dead center and or the distributer as I've only drove the car a few times within this past year The guy I purchased the car from said it sat for about two years off and on just small drives around from his house and work maybe a few blocks at times the car has year old spark plugs and wires they still look clean I do have a timing light thing along with other new parts I've bought for the car I appreciate your knowledge

[@EfurdGarage]

@@jasonthompson3135 you dont have to have a hose to the air cleaner if you have breather caps and no open holes. a hose to the air cleaner was a way of making sure there was a filter. so if you have valve coevr breathers, a pc valve and block off the one in the rear or put a breather on it no need for a hose. But you can get an after market air cleaner base with a spot for a hose and its just a standard rubber car hose. you will want to bring #1 piston up on the compression stroke

[@jasonthompson3135]

@@EfurdGarage ok thanks alot I appreciate that you helping me and others will come back to you with great grace indeed looking forward to your other knowledge and content your straight to the point and make it way easier for guys like me to understand

[@EfurdGarage]

@@jasonthompson3135 your welcome and i appericate it. Thanks for stopping by and watching

[@robertjackson7590]

Should a Carb engine backfire the PCV valve checks pressure to the crankcase so it won't blow seals out of the engine.

[@EfurdGarage]

Im not sure exactly what you are trying to say. But i think what i am understanding to answer is. The pcv valve will keep the carb from backfiring into the engine, the valve is a check valve that lets the engine pressure out and nothing in

[@robertjackson7590]

@@EfurdGarage Correct, the "check" valve checks the flow in one direction. It will only allow flow to the vacuum side then the PCV part regulates the flow at different vacuum levels. The engine backfiring can also blow the Diaphragm on Vacuum Modulators on the older transmissions. They used an orifice to stop that problem.

[@Black-Dragon-Media]

Could I run 2 PCv valves on my sbc. It’s a 10066036. I have the drivers side running to a port on my edelbrock performer intake. Can I connect the passenger side to the front of my Holley 580 vs carb?

[@EfurdGarage]

i personally wouldn't, as there would be no where for fresh air to come in, i would run the pcv to the front of the carb and breather on the other side. i wouldnt run the vacuum from the intake runner. Now if you have the aftermarket air cleaner base with a nipple you could run a hose without the valve.

[@salty6849]

So I have a question. I have a crankcase breather tube, it runs to the back of my TBI I believe. I am going to change out the air filter I have now for a Edelbrock air filter. So then how do I get rid of or put in its place?

[@EfurdGarage]

if you are talking about the one that runs from the valve cover to the back of the stock air cleaner, you can just put a breather cap in the valve cover or some aftermarket air cleaners bases have a provision you can knock out and keep the tube. just make sure you keep the one with the pc valve connected

[@salty6849]

@@EfurdGarage well I'm not sure where it ran to originally. Cause I've never seen the stock air filter lol. The guy I bought it from has a pretty horrible "after market" intake. I'm wanting to put one in right. The engine is a 5.7 350 the hose comes out of the valve cover and into the back of the TBI. You can't take that out I'm assuming? Or is it still what your saying to do?

[@EfurdGarage]

@@salty6849 what year is it? you have to have one vacuum source from the valve cover to usually the throttle body or air intake

[@salty6849]

@@EfurdGarage it's 1994 I'll get a better look at it tomorrow and see if I just made a simple mistake and looked at to fast or what. But the intake I wanna install has a knock out for the breather hose, I'll have to check into that to. I might just be having a major brain fart right now

[@EfurdGarage]

@@salty6849 being a 94 its much like the old small blocks. so you have the pc valve in the valve cover then goes to the front center of the throttle body. the other from the factory was a tube that went to the side of the air cleaner, i think what you are calling an intake is the air cleaner the intake sets under the throttle body. you can use the knock out on the air cleaner base or just use a valve cover breather in the valve cover. i installed a 94 tbi in an s10 you can see on the videos how i did it

[@LKRS111]

Is it okay to delete a pcv system, on a 350 sbc that's close to stock and just put a breather on both valve covers ?

[@EfurdGarage]

no, it isnt. it will build up to much pressure in the valley, you will have oil coming out of the breathers, use more oil by the pressure going past the rings and burning, and eventually blow out gaskets. . now drag races get rid of it but they still use something else to pull out the pressure weather its a pump or exhaust, but you have to have something to eliminate that pressure, a closed system will not be good on a motor

[@americanjoe7679]

It's not gonna build up pressure with a breathe on both valve covers

[@EKonMaster]

I didn`t hook my line because i didn`t know it would make a difference, so it should be suck to help the process, good to know thanks

[@EfurdGarage]

no problem

[@marko6394]

I have white smoke coming from the passengers side valve cover vent. What would cause this? Should I connect a valve and feed a tube to the intake manifold?

[@EfurdGarage]

Should have a hose from a cover to carb/ intake and a breather in the other or if running stoxk air cleaner a hose to the air cleaner

[@marko6394]

As-is, the intake filtet is on the driver's side cover and the passenger's side has an oil fill cap/breather combo, which is where the smoke is coming from. No smoke from the other side. Why is this?

[@EfurdGarage]

@@marko6394 ok so you do have a hose on drivers side. Passngers side you have a breather cap. You have white smoke from the passngers side. Sounds like not enough vacuum, what are you useing on the intake side a check valve set up or the chrome cap with the fitler martial in it? And is it to the intake or carb

[@marko6394]

@@EfurdGarage The intake (driver's side) is just a small filter, and the passenger's side has a chrome cap with vent (not sure if there is any filter material). This is a classic GMC truck (50's I believe) that my nephew is rebuilding, and I'm just trying to help any way I can. My knowledge of engines is limited, but I do know a few things. As to how one valve cover draws air in and the other expels it is a mystery to me. He has no hoses connected to the carb or air filter, so no ventilation system at all at this point.

[@marko6394]

Here's the only pic I have at the moment drive.google.com/open?id=0B9wd6vLJATnjUUd5S2FReV9vQVdnd20zcl9lSzU4dUZKRElr, which shows the vented cap on the passenger's side. I can grab a screenshot from a video I took (and maybe post the actual video) to give you a better idea of the existing setup. It's literally a small filter on the driver's side valve cover like this one (www.summitracing.com/parts/knn-62-1490?seid=srese1&gclid=Cj0KCQiAxrbwBRCoARIsABEc9sjwjj9YnsV6cbs-knaZm7MGaDJAJKLASwsnrmXvcCV7AZXNBVmjy7saAoD7EALw_wcB) and vented cap on the passenger's side, which is where the "smoke" is coming from. It dissipates relatively quickly, so it could be condensation (or maybe a bit of coolant). I don't believe it is burning oil. No smoke from exhaust. By the way, we measured about 15" of vacuum at the rear port on the carb (Holley) and could not get it higher than this by adjusting the air/fuel screws.

[@westogarage]

what are you using for your q jet spacer?

[@EfurdGarage]

an old helix power tower spacer that i have owned for many many years. i have some phenolic ones for some, but i am still running that one to this day

[@luismontemayor5713]

Hi i have a 383 but sb.. with a 4 barrel carb (brawler) and i cant find where the pcv goes connected to i really need help Oh and in the front of the carg it has a bigger inlet im assuming that it could be there

[@EfurdGarage]

yes usually you want to run it right to the front of the large inlet on the carb. There should be a large one in the back of the carb for brakes. if not they make spacers with a port.

[@luismontemayor5713]

@@EfurdGarage good morning thank you for replying back yes I have one from the booster running to the intake.. Thank you for the info

[@EfurdGarage]

@@luismontemayor5713 as far as the booster it should be ran to the back of the carb or the plenum, not an intake runner.

[@luismontemayor5713]

@@EfurdGarage mmm I'll have to check That.. Thanks again

[@andreg8192]

Can I hook up the PCv valve to the manifold intake?

[@EfurdGarage]

You can but i would recommend going to carb or a spacer with the port

[@andreg8192]

Efurd Garage the previous owner hook up the pcv valve and the brake booster on a T. Is that right?? I know the brake booster has to have its own line right?

[@EfurdGarage]

@@andreg8192 it is best for the breaks to have there own line.

[@andreg8192]

Efurd Garage so where can I hook up the brake booster and pcv valve. The previous owner have them hook up on the back of the carburetor into a T fitting.

[@EfurdGarage]

@@andreg8192 usually a carb will have 2 large vacuum ports one for breaks the other for pcv. If not you can always add one in the plenum of the intake or a spacer. in fact i did one not to long ago where i added a fitting to a 1" spacer since the carb only had 1 port. i believe you can buy them with them already too. typically the manifold port which is just in a runner off the back is best for vacuum to the transmission.

[@thehulkamaniabrother2.089]

Maybe I'll put that back on my 396. I just took it off the other day lol the valve covers I put on didn't have the right rubber grommet piece. I do have a breather on one side and it was blowing out steam because there is water in the oil I later found..Dammit!!!

[@EfurdGarage]

@@thehulkamaniabrother2.089 well could be condensation that happens. But yea i would put it back for sure

[@thehulkamaniabrother2.089]

@EfurdGarage oh the oil looked like coffee so I got some new oil and the wrong filter today at napa. I thought it was a canister style filter but of course it's a regular screw on one.

[@crowvelle]

I had a crankcase breather that leaked oil everywhere. Is a baffled filter enough to prevent this, or would I need a catch can?

[@EfurdGarage]

a baffled breather would help, but if you are using a good pvc and thats still happening sounds like you could have bad rings creating extra blow by. if baffled dosnt help (which i always try to get baffled valve covers) i would go with a catch can

[@rcristo1411]

I have gmc 5.0 but I don’t know where is connected

[@EfurdGarage]

if you have one should be in the valve cover if not you need to have it

[@voted_wotb]

I just replaced the hose and valve on my 305 but now my truck stalls out when idling.. any ideas??

[@EfurdGarage]

the vacuum changes when you have the pvc hooked up, have you idled the carb up a little? 600-800 rpm idle would be good. Of course if you have a vacuum leak it will do that as well

[@waltzaremba9737]

Hello I really hope you can help. I have a 68 camaro rs it’s a bbc 427 worked with vacuum headlights the port in the carb i have going to my brake booster the one in the intake I have to the headlights what should I do to run a PCV?

[@EfurdGarage]

what carb are you running? really you should have the breaks off the large port on the carb and if you only have one large port like some holleys do it wouldnt hurt to have a small spacer with and added fitting to run vacuum off of for the breaks or pvc.

[@waltzaremba9737]

It’s a quick fuel 850 I believe the build took a long time but I had it built for my set up a spacer hmm okay

[@EfurdGarage]

@@waltzaremba9737 I. Running a 850 quick fuel brawler on my big block as well, it's in my 80c10. I drilled a hole and tapped it in the spacer so I could run a fitting to run the pcv.

[@waltzaremba9737]

Efurd Garage ok if I run that set up what ports should go to what?

[@EfurdGarage]

@@waltzaremba9737 I would have to look later but I believe my breaks are off the spacer port, PVC is off the carb, and you should be ok with manifold for the headlights. But really I don't think it will make much difference if you swap PVC or break since those should have about the same amount of vaccum

[@eddymarkle]

Thanks man.

[@EfurdGarage]

Your welcome. Thanks for watching

[@Ricky-manic]

I see I dont know if mine was was replaced all I know it looks like oil and seeping the center valve cover bolts on my sbc 🤔

[@EfurdGarage]

a bad valve will cause it to build pressure and seep somewhere and that somewhere could be those bolts if they are not snugged down enough

[@AlmostSlammed]

I just replaced a blown motor and reused my top end, I’ve been leaking oil through my passenger rear valve cover bad and it starts to smoke once it gets up to temperature. All bolts are snug, could this be pcv related? Mine has a pcv valve on each cover, no breathers

[@EfurdGarage]

AlmostSlammed if it's through the breather yes it could be. You only need one pcv, with two there fighting each other and wasting vaccum possibly not even allowing it to work correctly, I would try one pcv and breather, as long as you don't have bad rings you should be fine after that

[@MrRickarriaga]

My block 350 chevy was leaking oil and we changed out everything. And so po it breather cap and PVC and no more leaking

[@joshuagarvey9362]

I am confused.So many misleading videos.I am trying to install A catch can On my old 68 Camaro with A 400sbc.1 video says run A line to each valve cover to each side of he can.This video says to run one to carburator and the other to the can watch goes back to valve cover?

[@EfurdGarage]

Well adding a catch can wont do much espically without a vaccum source to pull. Unless your engine makes no vaccum or your making tons of boost there is no need for a can. If you have blowby thru the pc sysyem there is an internal issue. If you look at most drag cars. Espically with older style engines they use the headers as a way to pull the crank case vapors. Running from both covers to a can and thats it will only allow the vapors to build and create the same issues as not running a pcvalve. You could run from the pc valve to a can then to the carb or vaccum source. If its stock or mild then its best just tp run a breather in one cover and a pc valve in the other then to carb.

[@joshuagarvey9362]

Efurd Garage understood thank you somuch.Motor is A 406 Sbc full roller.Compression is 11.5 to 1.Cam is pretty big with A LOB at 108 so my vacuum will be limited.My issue Is I just built this motor and fired it up.My oil pressure was 80 psi.Kind of high.When in warmed up it dropped down to 65 psi.Still high.Been doing some reading and A PCV hook up might help.So I purchased A catch can being worried about the oil coming out, precaution.

[@EfurdGarage]

@@joshuagarvey9362 being fresh with break and oil and tight tolerances you can have higher oil pressure. if your running baffeled valve covers you wont have to worry much. without something pulling the crankcase pressure out you can have oil leaking, alot of the worst causes is caused by bad rings where compression in the cylinder goes past the ring and pushes into the crankcase causing the oil to go the only way it can out. if you got about 12lbs of vaccum you should be fine with a pvc on a street car, if you have 10lbs or lower the breather to exhaust would work as the exhaust pulses can pull and act as vaccum.

[@joshuagarvey9362]

Efurd Garage understood.I did not check vacuum yet just was worried about oil pressure right off the back.Still have break in oil in it.I am going to fire it up again and time it,adjust float bowls and check vacuum and million on there things to check lol.Ty ty so much.

[@EfurdGarage]

@@joshuagarvey9362 no problem thanks for watching.

[@jessejameshurtadoiii9916]

I have no Damn clue on how to connect the pcv valve or vent hose as nothing is connected, any problems this way???

[@EfurdGarage]

If you have a older v8 like the ones shown just like that. Just put a valve in the valve cover run the hose to the large port that always sucks on the carb. And it is bad not to have one connected

[@jessejameshurtadoiii9916]

@@EfurdGarage yeah the hose for the vent and pcv valve is just sitting there not connected the vent hose is just blowing smoke

[@EfurdGarage]

@@jessejameshurtadoiii9916 the vent hose would go to a stock air cleaner if you dont have one a chrome breather cap will work in the valve cover. As far as the pcvalve just run rubber line usually fuel line will work from it to the carb and it wont smoke out the vent as much. Carb should have spot for the hose if not you may need a spacer with one

[@jessejameshurtadoiii9916]

thanks for the Help it's not smoking at all and the line you mentioned was plugged and I couldn't see it but another question, what can I do when i go to give it gas it seems kind of sluggish like it doesn't have much power after 1st and second gear for a 5.0 I assumed it would have better get up

[@EfurdGarage]

@@jessejameshurtadoiii9916 as you said vent hose blows smoke with the pvc hooked up it will pull from the engine and the vent hose would be for fresh air. As for sluggishness there could be alot that could be affecting that. 5.0? So a ford i assume? Or chevy?

[@codymarschinke9383]

Was wondering what went there lol. I need to get a breather

[@EfurdGarage]

Yea cant tell you how many times i send the hole just open to the elements

[@mooosestang]

Having a pcv hooked to your carb isn't going to pull more blow by out the motor than would normally be pushed out by the piston motion. What it will do is feed all that blowby and oil back into the intake. Racing motors don't run pcv valves.🤣 a breather on each valve cover is plenty to release the blowby pressure.

[@EfurdGarage]

wrong. wrong and wrong. do some research first. What is it doing on the carb a vacuum port, pulling excess crankcase pressure so you dont have blowby. If you knew anything about race engines you would know they either run vacuum pumps to pull the pressure out or they use a header evac style system that pulls pressure out. A breather on each side is not enough unless its not running. Even modern engines use a system such as the tube going into the air duct for vacuum. the valve is just a check so pressure dosnt get back in in case of backfire. But hey i guess you know more about cars then the ones that build and race them all the time

[@mooosestang]

@@EfurdGarage Some very high horsepower race motors need a vacuum pump sure, but not the vast majority of people just bracket racing 10 second cars. Dont' be such a cocksucker. The pcv is just for emmisions dick.

[@Chevyssboy138]

I put one on my 283 and it stopped my oil link and made my car idle higher lol

[@EfurdGarage]

@@Chevyssboy138 idle does change with the vacuum. Just make sure to use your favorite tuning screwdriver 😆

[@Chevyssboy138]

@@EfurdGarage I did I went around the block and then lowered it so it’s back at 720rpm

[@Chevyssboy138]

@@EfurdGarage and it don’t smoke anymore or run ruff

[@EfurdGarage]

@@Chevyssboy138 good, obviously some of us believe stock is bad and modify cars. But sometimes the factory did do things that were needed like the pvc even racers use some kind of evac system to remove crankcase pressure. Glad it is doing good for you!

[@Veterangarage]

Good video. Hey get that glass fuel filter off your engine. They will leak and cause a fire. Use a clear plastic one that doesn’t break or loosen on you.

[@EfurdGarage]

Thanks. But thoze glass filters are not an issue. Been using them on my daily drivers and other builds for over 15yrs. Make sure the seal is good, properly tightened, and if your hose clamps are tight they dont have room to loosen