Hi, I have recently found that I am sucking oil through my pcv valve. I had thought it was for a while, and then today I put an inline fuel filter with clear hose on it and sure enough, after a short 4 mile trip there was already oil in the clear inline filter.
I am wanting to put a catch can on the firewall or somewhere, and I just want to see if my idea will work, or if anyone else has a better idea.
My idea is this: Run the hose from pcv valve to a mason jar, through an elbow fitting in the lid of the jar, and then have and identical elbow also in the lid of the jar with a hose going back to the carb, with possibly a foam filter in the bottom of the jar to soak up the oil to try to avoid the oil being sucked back up through the "carb" fitting.
Feel free to suggest other options or ideas for a catch can. I really do not want to spend $125 on a Moroso custom catch can if I can make one for a few bucks.
are your valve covers equipped with baffles so the oil droplets flying around off the rockers are not sucked directly into the PCV valve..
do you happen to own a dwell meter that has a Digital tachometer it took me a LONG time to find this .. but at idle.. when you block the PCV flow.. the engine idle speed should drop between 50 and 70 RPMs. if it drops less than 50.. you need a larger calibration in the PCV valve.. if it drops more than 70 RPMs.. you need a smaller PCV calibration.
about 20 years ago.. almost all the parts providers changed the PCV catalog system.. many sell PCV valves by EXTERNAL shape.. not calibration.. if you get too much pcv flow it will suck the oil droplets and vapors right out of your valve cover and cause your engine to consume oil between 300 and 500 miles per quart..
you did not mention or post images of your set up.. there are oil filler caps that have PCV and or crankcase breather grommet holes in them with course usually stainless steel wool like a chore boy inside.. to trap the oil particles before it gets to the PCV valve.
are you running a filtered crankcase breather in the other valve cover or other end of your valve cover..
got a vacuum gauge that also measures pressure.. 30 inches of vacuum and 15 pounds of pressure... usually used to adjust carbs. hook the hose to the engine oil dipstick tube with the dipstick removed of course.. place the gauge on the windshield and go around the block.. making sure that you are NOT building any crankcase pressure or crankcase vacuum.
got pictures of the outside of the valve covers and the inside.. ... grommet hole size..
have you felt around with the grommets out with a bent piece of wire to see how much clearance above the rocker arms you have..
Wayne,
Do you have access to some form of calibration chart? I've never been able to locate anything like that, nor have I found anyone tht can provide it.
OP,
If your setup is stock in terms of build, pcv location and line routing then you might have an engine issue causing this. If you're engine is not stock in terms of pcv operation, then you need to answer Wayne's question about your motor and setup.
Wayne,
Do you have access to some form of calibration chart? I've never been able to locate anything like that, nor have I found anyone that can provide it.
nope... i have been planning on scrounging a flow meter and hooking it up to a a vacuum cleaner if i can get it to build 15 or 17 inches of vacuum.. i may have to use 2 in series to build enough vacuum .. some kind of fine adjustable valve in the vacuum cleaner hose. heck.. they are brush motors.. i might be able to use a router speed control to change the speed of the vacuum motor.. so i can bench flow test a bunch of them at different vacuum ratings. its not rocket science unless you hit the throttle.. then it becomes ROCKET RIDE.. wheeeee!!!
its still easier to just make sure the electronic idle speed control is disabled for the test on engines equipped and block the end of the valve.. conventional carbs don't have electronic speed control but many cars newer than 1983 may have it.
OH.. i forgot a test.... at idle.. unplug the PCV valve from the end of the hose... or start your engine with your finger over the end of the hose without the PCV connected... at idle the engine should die or almost die with the massive vacuum leak you have created.. this tests the ability of the port to flow... and the hose..
lastly.. here is a tip that everybody will want to copy and save.. even if you take a cell phone photo of the list below so you always have it with you.
Armor Mark brand /Goodyear brand/PCV hose
AZ Part Number: 50290 goodyear Part Number: 65185 Size: 11/32 in.
AZ Part Number: 50291 goodyear Part Number: 65186 Size: 15/32 in.
AZ Part Number: 50292 goodyear Part Number: 65187 Size: 19/32 in.
these work for PCV and for power brake booster vacuum connections for the most part.. these are stiffer than fuel hose and won't collapse under vacuum.
you can see tiny changes in the calibration washer ID in these images i linked..
there are also internal valve and spring changes you can see the bottom of the internal part has different stamping letters also..
Here is a picture of my current set up. Breather on passenger side, pcv on the drivers side.
when I pull the pcv out there is a piece of sheet metal directly under it inside the valve cover, very little clearance between the bottom of pcv and this sheet metal piece. I can't remember exactly what it looks like inside so I will pull a cover off and post a picture. I will also do the test with the vacuum gauge on the dip stick tube.
If this is pulling oil through you're either driving really hard all the time so huge amounts of blow by are generated, or if a daily driver it's a good sign that there are mechanical problems developing from the ignition or cam being out of time or the cylinder walls or rings are damaged or worn out.
While a catch can will reduce the mess it doesn't solve the root cause. The design you propose will work but the problem with jar of glass or plastic is the potential fire source a all metal solution would at least be safer.
Here is a picture of the baffle inside of the valve cover. It is just a small piece of aluminum in there. Could I stuff some steel wool on top of it? Or should I just invest in some OEM covers?
I also assembled a catch can today. I'll let you guys know how much oil shows up in it.
ntrue,
From looking at your pictures it appears that the oil residue under your valve covers has a tad bit milky appearance. If it is, then that's identifying something. The question is what the 'something' is. Perhaps you engine is not running hot enough. The idea being that the engine heat will change the water droplets (which are normal from condenation) to turn to water vapor and be evacuated via a properly functioning PCV system. Or, and more of a concern, is that you have an engine issue that's first sign is what you're seeing. Hence, the reason for me reposting Bogie's comment from early on this thread.
IMO, no 'stockish' and street driven SBC needs a catch can to grab excess oil/water mixture out of the crankcase if the engine is in a good state AND tuned properly. If this issue has recently developed, then I'd by looking for the solution to the cause rather than the symptom.
To give an example, which I prefer not to but will help identify what I'm saying, my son's SBC with a turbo with BIG ring gaps sucks less oil in through the check valved PCV than yours by a BUNCH. It also has a catch can attached to a vac pump that turns on when in boost that we are yet to drain out more than 3-4 tablespoons of oil from in 1000+ miles of driving between drains. I think you're at the point of putting a bandaid on a gunshot wound - hopefully not, but that's what it looks like in those pictures.
It is a daily driven truck. I drive about 200 miles a week give or take a few. I don't think it is a blow by/engine issue because even idling it still sucks a few small drops through. I think it is more of a valve cover baffle/improper pcv valve issue.
If these are factory covers it is highly unusual to have this type of a problem. In my personal case my shop truck has a sort of L31 in it with over 400,000 miles on the clock it doesn't pull oil through the PVC system.
You may want to pull the covers to check the vents and clean them.
Like Bogie said, you may have some other problems internally so it wouldn't hurt to check that out.
To keep the oil from migrating through your PCV valve cut a piece of maroon (coarse) ScotchBrite to press into the hole for your PCV valve. You may have to remove the cover to make sure it is secure. Usually a couple of tie wraps will work. This will cause the oil to collect on the ScotchBrite and drip back into the engine rather then get pulled straight out through the valve.
If you decide to go with a catch can look for those spun aluminum drink bottles at Goodwill or the thrift stores. They are cheap and the top can be drilled and tapped for a "T" fitting for your lines.
Mark
if you eventually get one off.. flip it over and with the valve cover arranged so the bottom of the image is the exhaust port side of the valve cover..
some may have baffles screwed in.. that you might be able to create replacements for by creatively bending new baffles...
upper side ---\_M____M____ lower side. M is the mounting pads.. you want to protect the shield area by blocking the entry into the intake side of the baffle.. this is if your baffles are removable.
somebody mentioned RED SCOTCHBRITE pad... NOPE that has abrasive particles in it.. you will want to use something designed for it... you could use stainless steel or brass chore boys...
you can get breather elements replacement materials right from the parts store. but these are really not designed to survive inside the valve cover..
you might want to scope out these and see if they will fit thru your grommet hole..
CST part number 8075 fits 72 to 85 dodge V8s..
stant part number 10075
if your opening has keyways... =O= the ford version might work also..
stant @10071 the size if 1 5/32" on this you could also pull the locking strip and reinstall it with the valve cover off.. so you can get it thru the ROUND hole without the grommet..
oh.. if the push in versions go in TOO DEEP.. stick either a thick Oring on them or a grommet so it won't go as deep thru the mounting grommet..
hint... you may need to retain these.. so they don't fall off.. and i am talking creative ways to do so.. annoying ways to do so... an external snap ring around the raised area so it cannot slide out thru the grommet... yep.. you have to install the breather in the valve cover with the valve cover off. . this negates the ability of easy removal to refill the engine oil thru that opening.. it won't stop some assistant from getting a massive grip on it and yanking it out of the valve cover with the grommet.
I put an oil-air separator on my SB Ford after finding way too much sooty carbon build up on heads, pistons and valves. You just have to drain it occasionally but it will pick up oil carry over. This one is very small and, if I recall, came from Jeg's:
.
There are many others listed from low end dollars to way high if you do a search.
My crate engine had only a couple thousand miles so it was virtually new - just needed an inspection after a throttle hang up (broken motor mount twist) and wa-a-a-y to many unloaded rpm.
Here is a picture of the baffle inside of the valve cover. It is just a small piece of aluminum in there. Could I stuff some steel wool on top of it? Or should I just invest in some OEM covers?
I also assembled a catch can today. I'll let you guys know how much oil shows up in it.
Don't use steel wool... Use ScotchBrite as I suggested earlier. ScotchBrite is not metal, if any of it breaks down and gets into the crankcase it won't hurt anything.
Pull the cover off and cut a few pieces of ScotchBrite to stack in there. Make it tall enough so the pad is compressed about a 1/4" when you bolt the cover back on.
Mark
A thought.....
Stock height valve covers will deflect oil back down onto the rockers.
I think the tall valve covers are allowing an oil mist to develop over the rockers
and this is getting sucked into the engine.
If you want to keep the tall covers some kind of deflector is needed, stud girdles do this.
Do you live in a emissions/test state if you do not your going to like this old trick.
It works as a separator and will cost you next to nothing.
Take a glass soda or beer bottle with a metal screw on cap.
Remove the cap from the bottle.
Drill two 3/16 holes in the metal screw on cap. Install a rubber grommet at the bottom grove
Stick 2 3/16 lines through the holes so they run 3" below the cap. Put some gasket sealer around the hose. Heating up the hose before pushing it through slightly undersized holes will lend to a tighter seal.
Run a 3/8 line to a copper adapter that tapers down to 3/16 od. Put some spring clamps on the line to seal them. Run the 3/8 line to carb and pcv valve.
Screw the bottle into the cap twisting the bottle not the cap.
Set the bottle cap above the valve cover. I have used coil holders and set the bottle on a fender or firewall well before. A bent coffee can with a rag at the bottom works in a pinch.
It might cost $5 if it cost anything. But it works and will give you a very good idea on just how much oil your loosing. You can get elaborate with it. But it is designed as more of a tool to diagnose the condition of the engine saving you money if it does need repairs more as any kind of permanent component.
Nailhead, I thought the same thing as far as the milky appearance, so I looked at the oil that was around the rocker arms in the heads and then drained a little from the crank case and it isn't milky at all. I believe is was just moisture inside the valve cover because I had just ran it about 20 minutes prior to taking the cover off, and it was only 17 degrees outside yesterday. So going from hot to cold caused some condensation.
I am going to get some factory valve covers and see if that eliminates the issue, if it does I would say that's the problem was due to the covers having not so great baffles. If it does not, I will look for a deeper problem.
Thanks for the help everyone!
Nailhead, I thought the same thing as far as the milky appearance, so I looked at the oil that was around the rocker arms in the heads and then drained a little from the crank case and it isn't milky at all. I believe is was just moisture inside the valve cover because I had just ran it about 20 minutes prior to taking the cover off, and it was only 17 degrees outside yesterday. So going from hot to cold caused some condensation.
I am going to get some factory valve covers and see if that eliminates the issue, if it does I would say that's the problem was due to the covers having not so great baffles. If it does not, I will look for a deeper problem.
Thanks for the help everyone!
If the oil and coolant weren't to operating temp for any amount of time, then that is definitely what that could be from. I'd check it when ambient temps get warmer after a drive or two as it takes a couple drive cycles to get that out. Hopefully it will be gone.
FWIW,
I got rid of some Edelbrock valve covers because they had a similar ineffective baffle. Bought some Proform baffles that have an excellent stock type baffle.
Used another method on an old Camaro. Had a stock cover adapter connected to the air cleaner base like someone mentioned earlier. Didn't have a PCV, but the vacuum inside the aircleaner was enough to remove all the blowby without causing a lean condition by connecting directly to carb port. May have to use carb cleaner spray now and then, but I didn't have a problem. May not be best for performance, but work very well for me.
ssmonty
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