Air coming through the valve cover

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B717

B717

How wide is Home Plate?
FABO Gold Member
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What would cause air to come up through the valve covers. new rebuilt 318 have been driving it for about 1000 mile now. coming home the other day got on it just a bit and noticed blue smoke coming into the car. any ideas thank
 
Blow-by. That is, compression leaking past the piston rings. At 1000 miles it's possible that the rings haven't seated yet, but I've never had it take anywhere close to that long. What pistons and rings were used in the rebuild? Wall clearance, end gap etc...
 
C130 Chief said:
Blow-by. That is, compression leaking past the piston rings. At 1000 miles it's possible that the rings haven't seated yet, but I've never had it take anywhere close to that long. What pistons and rings were used in the rebuild? Wall clearance, end gap etc...
Click to expand...
Agreed, sounds like blow by compressing the crankcase. I had a similar problem after overheating my 318.
 
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C130 Chief said:
Blow-by. That is, compression leaking past the piston rings. At 1000 miles it's possible that the rings haven't seated yet, but I've never had it take anywhere close to that long. What pistons and rings were used in the rebuild? Wall clearance, end gap etc...
Click to expand...

Pistons are Icon Forged Flattop w/2 Eye Brows
comp ratio 9.50

comp cam cl 20-223-3
Hydraulic
Duration 268/280
Lift .477/.480

sent pics of the build sheet
thanks
 
540slant6 said:
Agreed, sounds like blow by compressing the crankcase. I had a similar problem after overheating my 318.
Click to expand...

I'm running an electric fan wondering if it's doing the job. don't have any coolant over flowing.
 
I broke in the engine with comp engine breaking oil 10w30 and changed it with 20w50 vr1 racing oil asked the shop that rebuilt the engine they said should not be a problem.
 
That's a clean looking engine! Would you consider using steel fuel lines to your carb since rubber lines are a fire hazard?
 
H22A4 said:
That's a clean looking engine! Would you consider using steel fuel lines to your carb since rubber lines are a fire hazard?
Click to expand...

Funny you ask they are on back order should be here in one week. just put a 650 edelbrock thunder series.
 
That looks like strait vacuum into a breather. the breather hose should go to the air cleaner, the opposite valve cover should have a pvc valve and hose going to the bottom of the carb. How does it run hooked up that way?
 
Hey that's maximum idle air bypass, don't you know? Goes good with a 268.lol
And double filtered, too!

Hyup, your installer/tuner has some 'splaining to do!

I would get rid of that plastic fuel filter too. If it ever pops you could be in for a major meltdown!
And I would swap out that 20/50 racing oil, for some 10W30 street oil.
 
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Yeah man, really clean engine bay!!

That passenger side front valve cover "fitting" should be a PVC valve plumbed just like you have it going into the carb.
 
spl440 said:
That looks like strait vacuum into a breather. the breather hose should go to the air cleaner, the opposite valve cover should have a pvc valve and hose going to the bottom of the carb. How does it run hooked up that way?
Click to expand...
It ran ok never really good always felt unbalanced and now i know why. thanks for the feed back
 
AJ/FormS said:
Hey that's maximum idle air bypass, don't you know? Goes good with a 268.lol
And double filtered, too!

Hyup, your installer/tuner has some 'splaining to do!

I would get rid of that plastic fuel filter too. If it ever pops you could be in for a major meltdown!
And I would swap out that 20/50 racing oil, for some 10W30 street oil.
Click to expand...

I was told I needed an oil with high zinc. you suggest regular conventional oil then add zinc to it? sorry for the amateur questions but learning as i go. fuel lines are on the way

thanks for the patience
 
Well a 268 is pretty big for a teener, and it's gonna want some bypass air alrightee.
Ok so first things first get a PCV and grommet plumbed in there and a decent breather on the other side. There's nothing wrong with the oiled filter you have on there now, except a few hours after installing it on a running engine, the oil will have all been sucked out of it, and the filter will now start to pass dirt. And whenever you go WOT, blowby will flow backwards through the filter and puke oil-mist all over your valve cover,and then the dirt will stick to that. So, if the breather on the passenger side passes air in both directions then use it and shelf that little one on the passenger side. Ideally the new breather should be plumbed to inside the filter house,between the filter and the air-horn. I know, I know , that's a PITA. So What you can do is install an exit hose on the breather nipple about a foot long and point it anywhere except down.Then the blowby will mostly leave it's oil in the filter or in the hose where it can drain back. But make sure both access points in the covers are baffled inside. The breather will require maintenance.
After this,the engine will require a retune.You can follow along here;
340 camshaft question, yea another one.

As to the oil; you can still find cheaper hi-zinc oils out there. They are labeled as diesel oils now, or Heavy Duty truck oil. But it was more the viscosity you chose that I was against. 20W50 is mighty thick. I tried 15W40 once and my pump blew the filter right off the pad and spewed oil onto the hot TTI headers. That coulda got ugly in a hurry. There are different schools of thought as to adding a Zinc package, I can't expound on that except to say that I have run it with any old cheap-azz oil since 2004 and for maybe 60,000Plus miles with no adverse effects. There are much better arguments for oil types, I'm sure.
Here is one;
More Than You Ever Wanted to Know About Motor Oil
 
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66fyssh said:
Yeah man, really clean engine bay!!

That passenger side front valve cover "fitting" should be a PVC valve plumbed just like you have it going into the carb.
Click to expand...

looking through some pictures of the engine before the rebuild it had a pcv on the passengers side.
thanks for you time
 
AJ/FormS said:
Well a 268 is pretty big for a teener, and it's gonna want some bypass air alrightee.
Ok so first things first get a PCV and grommet plumbed in there and a decent breather on the other side. There's nothing wrong with the oiled filter you have on there now, except a few hours after installing it on a running engine, the oil will have all been sucked out of it, and the filter will now start to pass dirt. And whenever you go WOT, blowby will flow backwards through the filter and puke oil-mist all over your valve cover,and then the dirt will stick to that. So, if the breather on the passenger side passes air in both directions then use it and shelf that little one on the passenger side. Ideally the new breather should be plumbed to inside the filter house,between the filter and the air-horn. I know, I know , that's a PITA. So What you can do is install an exit hose on the breather nipple about a foot long and point it anywhere except down.Then the blowby will mostly leave it's oil in the filter or in the hose where it can drain back. But make sure both access points in the covers are baffled inside. The breather will require maintenance.
After this,the engine will require a retune.
Click to expand...

Ok thanks for the help I'll make some adjustments and let y'all know something. now for the oil you mentioned getting of the 20w50 and going with 10w30 I was told I needed a oil with a high zinc. any suggestions
thanks again for your time
 
Don't be in a hurry to drop the oil that is in there now, it's good stuff.
Rotella T comes to mind, for the next oil change. Read up on it.


I put some links in post#19 for ya
 
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AJ/FormS said:
Don't be in a hurry to drop the oil that is in there now, it's good stuff.
Rotella T comes to mind, for the next oil change. Read up on it.
Click to expand...
Thanks again
 
AJ/FormS said:
Don't be in a hurry to drop the oil that is in there now, it's good stuff.
Rotella T comes to mind, for the next oil change. Read up on it.


I put some links in post#19 for ya
Click to expand...
Why would you drop the good synthetic oil for a low to no zinc diesel engine oil?
 
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