318 with blow by

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72swingerwoman

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im getting blow by on my pcv valve i shook it last night make sure it was working properly but i think i might of shook it loose so that is it seemed to be free moving instead of stuck. but im looking for if anybody knows know the compression for the 318, i want to test the cylinders make sure they are up to par but i cant find what the number should be?! guess im just trying to figure out how big of a spring project ill have when i give the motor a make over.

thanks.
swingerwoman.
 
80 psi would be fine for a good worn 318.
Evidence of blowby would be oil in the frying pan (air cleaner) ?
If the pcv valve was clogged up you can bet the rubber tube and carb tube is clogged as well. Lay the rubber tube on the ground and beat it with a hammer. Dump the carbon deposits out (or just replace it). Use a 1/4" drill to clean the metal tube at carb base by hand. Twist the drill in , pull it out, wipe it down, repeat.
My 73 318 has 302 thousand miles on it now. Replaced timing chain once, stem oil seals once, oil pump once. distributor once. Carb rebuilt twice.
 
80 psi would be junk IMO. I would be looking for readings above 110psi. Closer to 130/150 would be good readings. Below that, maybe issues. The pcv valve will always sound a little loose. If you were to blow thru both ends, one direction (from inside valve cover end to hose end) should not allow any air past, and the other direction should allow air easilly to pass. Take off the oil filler cap, and see if any vapor is visible escaping. If there is a bit visible, you have blow by. The compression test is a great tool. Write down the readings and post them.
 
I would have to agree that 80 psi is too low, you would be lucky for a motor to even light cylinders at 80psi.


Chuck
 
Yeah well they do wear out. Mines hitting between 80 and 90. I can grab the belts and turn the engine by hand but it gets great mpg and I might drive it from now on.
 
RedFish said:
Yeah well they do wear out. Mines hitting between 80 and 90. I can grab the belts and turn the engine by hand but it gets great mpg and I might drive it from now on.
Click to expand...
It has been experience that when a cylinder hits south of 90 that it will not produce power. After the rpm is increased and the piston speed increases it will fire. But at an Idle? I use a MINIMUM of 110 before I give it her last rights.
 
So here's a quick PCV system test (first buy a new valve and hose, $10 or so). On the valve cover opposite the PCV valve you have a hose running to the air cleaner. With the engine at idle, plug this hose with your thumb. You should feel vacuum build after 1-2 seconds. If your idle speed picks up once this vacuum builds, your intake valve guides are worn and leaking, acting like 8 little vacuum leaks. On a high mile 318, I would expect this, especially if you use a little oil, no biggie. BUT if the engine blows your thumb off the hose and builds pressure not vacuum at idle you have massive blow-by. Your rings are probably stuck, broken, or seriously worn out.
 
so i put my finger on the pcv valve hose, it does not suck it is a blowing that is does there is no vaccum at all on this hose, so if there should be i dont know whats going on. i changed out the pcv valve when i posted this, and it seemed to fix the oil going threw the tube, i thought but i just dumped the tube out full of oil once again. my oldest brother thinks and says that is how they run, but for some odd reason i dont buy it! im going to do a compression test here on thursday on it. is there a difference on where the pcv valve should be located on the cover, mine is driver rear side? should it be located in the front? i am lost.. i do have new valve covers to put on it, but i was going to do that next spring when i fix the oil pan leak, i dont know if maybe its the valve covers also, i dont know how much difference there are in them. they might have a small leak on them also.. so not sure how much that will play a part in the whole effect on this issue also. but i will do compression test and see what that shows... thank you for the insight.. to all...
 
and i do have plenty of power, i think its running good when i get on it.. i just dont understand all the oil blowing out of the pcv tube
 
If the pvc tube is blowing something is screwed up for sure. Compression test will tell.
 
If you are using some sort of aftermarket valve cover without a baffle, your PCV may suck oil. But, if the crankcase is building pressure, your rings are shot (and the engine will leak oil like a Lycoming). Do two compression tests, dry and wet. The wet test follows the dry test, shoot about a teaspoon of oil into the spark plug hole and retest. If the compression number is higher, this confirms worn rings.
 
im confused on baffel? what is? is that an air breather?
i wish i understood motors better.
if i have bad rings and and maybe whatever else can go bad during that, how much engine power does one usually loose, or can you not notice the change in power, and are there any other signs of burnt or bad rings, and maybe more...that will help me figure this out easier also... but crossing fingers ill get the comp test done tomorrow..
and this question might make you guys laugh.. but im not afraid to get laughed at soo.. is there any way for oil to get into the headers for some odd reason im getting smoke off the other side motor i dont see the oil on the headers but its getting smoked off?? i know my covers leak a tiny tiny bit.. but i just dont ever see oil where the smoke is coming off of just curious if it can be an internal thing?
 
72swingerwoman said:
im confused on baffel? what is? is that an air breather?
i wish i understood motors better.
if i have bad rings and and maybe whatever else can go bad during that, how much engine power does one usually loose, or can you not notice the change in power, and are there any other signs of burnt or bad rings, and maybe more...that will help me figure this out easier also... but crossing fingers ill get the comp test done tomorrow..
and this question might make you guys laugh.. but im not afraid to get laughed at soo.. is there any way for oil to get into the headers for some odd reason im getting smoke off the other side motor i dont see the oil on the headers but its getting smoked off?? i know my covers leak a tiny tiny bit.. but i just dont ever see oil where the smoke is coming off of just curious if it can be an internal thing?
Click to expand...

If your not getting vaccum on the pcv valve, pull it off, see if your getting vaccum at the hose, if not pull it off and see if your getting vaccum at the carb port. If your still not getting vaccum, the port in the carb is gummed up, pull the carb off and clean the guck out.
 
i never put the pcv valve hose on the carb since it was spitting out oil, i wasnt sure if the oil was going to gunk up the carb, since i put a new carb on it here a few months ago.. the valve cover, or valve, which ever it suppose to suck is blowing instead, i can see the steam or vapor coming out of the hose, then after a while comes the oil spitting out of it... i had it hooked in the the air filter which now i need a new one of since its full of oil. i will be doing the compression test i hope tomorrow. to see what the cylinders are doing.should i switch maybe where the pcv valve is located move it the front port hole instead of the back one? or doesnt that matter at all? a few guys at work told me that its suppose to blow, but im taking the word of the guys on here, since you guys are mopar junkies... and im a learner but i think im going to get ready for the day and go buy a compressor checker thing today so im ready to do it tomorrow!
 
cylinder 1-- 125
cylinder 3-- 135
cylinder 5-- 130
cylinder 7-- 125

cylinder 2-- 140
cylinder 4-- 140
cylinder 6-- 130
cylinder 8-- 140

i cant express how much of a pain in the butt, cylinder 5 and 7 was to do... not even looking forward to getting the plugs back in, starting to not like headers. lol.....that is dry... i didnt want to do another wet test for 7 i should of did one for 1.. but 7 took me almost an hour to get the tester plug, and hose attached.. the plugs from 7,6 and 8 were black compared to the other plugs that still looked almost new.they are a month old or so.
 
Your compression looks okay to me ! No way should you have this issue under normal circumstances.

As someone else asked before - are you using aftermarket valve covers, ie not stock steel ones ? Aftermarket valve covers do not have an oil baffle below the pcv valve on the rocker cover in most cases. Usually there are bosses on the under side of the cover that can be tapped and a flat plate of metal attached to them.

A cheap and dirty way to check is to pull the pcv from the cover and stick a screwdriver down into it and see if it falls down more than about 1/2 to 3/4 of an inch, also take a flashlite and shine in there. If you see something that looks like a plate then its baffled. If it does not appear to have anything under it, pull the cover to inspect.

Ive seen valve covers from moroso that will not allow you to install a baffle you end up using a special grommet that has a baffle of sorts built in to them. I personally do not like these style covers, and would suggest using cast AL valve covers, they always have a way to attach a baffle from the underside.

You also need to check the hose attachment on the base of the carb as someone suggested for vacuum. If its blocked then clean it out.
 
So your PCV valve is not hooked to the carb/intake?!? That's your problem!!! The PCV valve hooks to the throttle body with a 3/8" piece of hose. This allows the engine to suck and burn all the fumes from the crankcase. Take a look at the factory setup, or post a picture of what you have. You should have a PCV valve in one valve cover and a breather in the other (to let air in) . The Mopar style breather connected to the air filter, but took in unfiltered air and has an internal filter. The reason it hooked to the air filter housing was to keep the engine compartment clean.

One side benefit of a properly working PCV system is drastically reduced oil leakage. The engine isn't trying to force oil out everywhere.
 
the oil that is getting let go out of the pcv will not hurt the carb then? im more worried about i guess plugging up the carb with the oil coming out of it, i dont know much about the whole carb thing and where the port lead to, but if that vaccum port wont get hurt by the oil getting let in there i will get longer hose and hook it up. i have a breather on the other side of valve cover, passenger side. pcv driver side.

thanks for all the help guys.. im assuming that the compression was good then?

i have put on a edlebrock carb and air filter so that is the only thing that is different right now on the engine. i have never heard of Erson, i believe is the valve covers that are on there now.. i have gotten edlebrock valve covers for my birthday waiting to put them on when i pull the engine next year to fix my oil pan leak. i changed out the holley that the guy put on since it ran bad, only to find out that the carb was not tight i could move it about a quarter of an inch when i went to take it off, i probley didnt need a new carb but im not a holley fan anyways.

IMG_0975.jpg
 
Aha !

Do as C 130 tells you !

Erson is cam maker, used to be independant now owned by holley or someone like that.

The valve covers are the stamped steel aftermarket types like the moroso ones I described before. I'll bet there is NO baffle in them. When you hook up the pcv you will get alot of oil being sucked into the carb and burnt = blue exhaust smoke.

Put the edelbrocks on there (assuming they are cast aluminum) and make sure you have a baffle under the pcv inlet. If your new edelbrocks are stamped steel then you will have the same problems as the erson covers. As I said before there is a type of grommet for these steel covers that has a baffle built into them. Hole size is probably 1.22", any car parts store should have them.

By the way your oil pan leak might get better once the pcv is working right.
 
OK, the Edelbrock has a PCV port on the front center of the carb. Big hole, hooks directly to manifold vacuum, shouldn't plug up with oil. If it does, think what else this oil is plugging up!

I'd bet those valve covers aren't baffled. The factory valve covers were pretty well designed, and raised the PCV up higher, and baffled it. But then again, chrome always makes you go faster.
 
Ok, the Ersons are cheapie valve covers, and I dont think they have a baffle on them. A baffle is a flat of steel on the inside of the cover, that keeps oil flying off the rockers from entering the PCV ssytem. PCVs have two sides. The engine side that gets pressed into the grommet, and the hose nipple, that runs to the carb. The valve should be pressed into a grommet in the cover, and the hose runs directly to the rear of that Edlebrock carb. There should be a 3/8 hose nipple fitting in the back of the carb. If you pull the PCV out of the valve cover with the engine running, it will be sucking at your finger when you place it over the engien side (that's the end that gets stuck in the valve cover). You are filling the hose with oil because the baffles are not there, and the oil is getting sucked thru the valve. The valve is designed to control air, not fluids. So, the fix is good baffled valve covers, and normal installation of a breather on the opposite side. Your compression readings are fine. And I agree about 5 and 7...that last valve cover bolt on the left is a fun one too...
 
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