My breathers are leaking

[Mikeeal]

I have Trick Flow (no baffles) valve covers. I drilled em and put in cheapy Kragen style push-in breathers. While running and afterwards, they leak pretty good. I originally thought it was the seal, but upon further inspection, it's definitely coming out of the holes on the bottom of the breathers. Do I need to figure out a baffle system or is there a breather I can get that will not allow this to happen?

Thank you kindly!

[Scotty_S-15]

Yeah, you probably need to fabricate some baffles.... the rockers are probably slinging a ton of oil up there. Got enough clearance inside the valve cover to squeeze baffles in there?

* Got a good PCV system working?
* Sure there isn't a blowby problem?
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[stroker1]

Additionally to scottys points, you may need to consider putting risers on the breathers if all else fails. They would need to be fabricated kinda like the oval track valve covers. You may be able to get your local muffler shop to help you expand the pipe. Try to find some aluminum tubing the right size and tig it on to the valve cover. That's an old school method used by old timer roundy round racers here in NC. This is where NASCAR originated. These old timers got pretty creative back in the day with not much technology. Especially poor old tabacco farmers and boot leggers that ran dirt track on saturday nights.

BTW, I would consider this LAST. Just wanted to throw this out there.

[Mikeeal]

No PCV system Scotty, should I?

I don't know what blowby is, I will research now.

I will keep that in mind stroker, my exhaust guy wouldn't have a problem doing that for me.

[spacecadet]

If you don't have a PCV system hoked up I would definitley suggest it. All motors have some blow bye. IF the motor has too much blow by then it will over pressurize the crank case and will cause the seals to leak. It will also cause oil to escape from the breathers. The pcv system vacumes the fumes from the crank case. It keeps the crank case pressure down and elimantes the gassses form the cranks case.

As for the valve covers, it may be easier and cheaper to buy a new set of valve covers that have the baffles in them alredy. Speedwaymotors has a bolt in valve cover baffle, that might help you out.
Space

[HATFIELDSCHEVY]

before pcv systems they ran a hose from breather cap to air filter. they sell the breather cap with hose outlet then run to air intake with a breater eleament should be very easy to hook up.

[355V8S10Tahoe]

I agree you need the PCV system, just pull one of your breathers and put a PCV valve in with a hose running to the base of your carb and you should be fine... On the other hand if you start burning oil you should look into some baffles... I have no baffle tall valve covers and a PCV system with no breathers on the valve covers, I ran a hose for fresh air to one valve cover from the base of my Edelbrock air cleaner and a PCV valve in the other valve cover, any blow by gases are burned in the engine with the incoming fuel... Here is a picture when I was building mine, you can see the two hoses...

I would also like to add that I also have a restrictor insert in the fresh air hose from the air cleaner, this keeps the flow down and creates more vacuum in the crankcase... Without it you run a better risk of pulling oil in the intake... I've had no problems with it and no baffles!

[chevycountry88]

Reading about your problem, that's to good lookin of a truck to be riggin, with all the money you' ve already put into it. My suggestion in order to eliminate the problem and the hassle, would be to buy a good set of valve covers and gaskets instead of fabricating a set. I'm doing a V8 swap in a '88 S10 with a '78 model 350 with a 4 bolt main. The valve covers I ordered were the low profile Edelbrock valve covers from Jegs for $81.99 plus handling charge part # 350-4248. You can also get the Elite push in breather part # 350-4204 for $26.99, I also purchased the T-bar valve cover hold downs (4 per pack) and the short style chrome clamps (8 per pack) for $4.99 part # 7209899 & the gaskets I'm using are the perm align valve cover gaskets for sbc $31.99 also comes with the rubber bushings for the pcv. I know this is a little bit of money to spend. It would be better to spend a little cash to eliminate your problem instead of spending a lot to replace your engine.

[Scotty_S-15]

You asked what blow-by is..... That's the gases that "blow-by" the rings. The less the rings seal, the more blow-by, but even a good engine has a little blow-by. That's why the crankcase of a normal engine needs to be vented in some manner, otherwise positive pressures will develop in the crankcase. And as you might imagine, when you go wide open throttle, high RPMs, you can get substantial blow-by.

Being a little redundant, 'cause I think this is pretty much what 355V8S10Tahoe just said....?

A normal PCV system has:
* A PCV valve plugged into one valve cover, plumbed to the carb base fitting, which sees manifold vacuum. This draws out any nasty corrosive gases that build up in the crankcase.
* A breather on the other valve cover to allow fresh air in to replenish the air being drawn out by manifold vacuum. On stock system, this vent is plumbed to the air filter, so filtered air is being drawn into the crankcase.
* Simple as that. But even if you have a push-in breather (air intake) in the valve cover, it should be baffled, because under WOT, high RPM, low vacuum conditions, it is not unusual for the blow-by to go back out that vent.

Another plus for using a PCV system, especially on a street driven, high mileage vehicle, is that it keeps the crankcase much, much cleaner, preventing huge amounts of mung & crud to build up as was the case is the early 60's and previous engines.
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[355V8S10Tahoe]

Thanks Scotty, that pretty much sums it up, I must say I have a nice clean set of valve covers this way and you don't have to spend a hole bunch of money for a good PCV system either... A possible rubber grommet, PCV valve and some 3/8 hose should be all he needs to get, unless not having baffles turns out to be a problem... It wasn't in my case...

[OTHCUSTOMS]

I HAVE THE SAME PROBLEM AND I HAVE BAFFLES, i put breathers that accept a hose and i put mr gasket catch cans.. every so often i have to empty out the catch cans

http://store.summitracing.com/partdetail.asp?autofilter=1&part=BSP-21120&N=700+115&autoview=sku

http://store.summitracing.com/partdetail.asp?autofilter=1&part=STF-5115&N=700+400210+4294877892+115&autoview=sku

[harleyboy]

here is some thong I found on yahoo.
Remember now, the air is supposed to flow from the air cleaner's Kotex pad thorough that hose and into the valve cover, circulate around the crankcase and get sucked out via the PCV Valve. When the blow-by becomes so excessive that the PCV Valve system can't remove it, it has to go somewhere! Else the crankcase pressure would become excessive and the engine would explode. The place that it goes is back thorough the hose to the air cleaner - THE WRONG WAY!!! Of course it carries any oil in the valve cover back with it and that's what you mop up two or three times a month or week if it's really bad. Bottom line?? It's time for a new box of kotex or an engine overhaul, whichever is cheaper. (there is one other solution - see below)

If you do find oil in your air cleaner it may well be that your PCV valve is stuck closed and is therefore not sucking the blow-by out of the crankcase but rather, it is blowing back into the air cleaner. Make sure to check the PCV Valve before overhauling your engine!!
for more info heres the site.
http://www.misterfixit.com/blow-by.htm

[mkmsports41]

Blow by was a big problem when I raced cars. We were always turning these "stock type engines around 7000rpm. Of course we did not have any pcv system. We used tall valve covers with breathers and baffles. Still would have blow by. One trick I used was to take the breather out and put small portion of a rag in there. Some people even used like a brillo pad which seemed to work the best. However I didnt b/c brillo pad is made from metal. Another alternative which l liked, but never did, was using a JAZ catch can. Drain it every often and everything is good. Also, several guys will weld a fitting in the exhaust and let it be burnt. JMO

[355V8S10Tahoe]

I would like to add to what harleyboy said... If you have a working PCV system and the intake manifold vacuum in your crankcase being pulled through the PCV valve is being overcome by blow-by, you have a serious blow-by problem...

[Scotty_S-15]

I would like to add to what harleyboy said... If you have a working PCV system and the intake manifold vacuum in your crankcase being pulled through the PCV valve is being overcome by blow-by, you have a serious blow-by problem...
Exactly. Providing your PCV system is working properly, and you're getting oil in the air cleaner, the motor is probably "one tired puppy". This is common with high mileage engines.
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[harleyboy]

mikeeal how many miles do you have on the motor,(if you said before sorry).