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Old 02-17-2013, 11:58 PM
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High rpm oil leak

So I decided to do a little spirited driving and when i hit 5.5k i had a massive oil leak from the driverside of the engine (350 sbc Gen 1 pre 1979 block)

I don't know if it's from the dipstick or the breather or both

but I lost like over a qt of oil and my engine compartment is drenched

I'm running a pcv valve system

what could it be ?

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Old 02-18-2013, 12:10 AM
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Do you have a breather on the opposite valve cover as the PCV? What was your oil pressure when you were 'spirited'?
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Old 02-18-2013, 01:21 AM
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I used to get oil out the drivers side valve covers too. went on the headers at high rpm.smoked like I blew up the engine.Didnt smoke at all when I drove down the return road. I eventually got different covers
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Old 02-18-2013, 06:32 AM
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Exhaust back pressure can pressurize the oil pan and cause oil to be pushed out of the engine through open breathers at high RPM. If you have a functioning closed PCV system, you should not have any breathers that are open to the atmosphere. Do you have a good dual exhaust system?
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Old 02-18-2013, 07:16 AM
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Is it wet all the way in the front or just from the dipstick back?If it is wet in the front it could be you did not put the bolt in where the fuel pump rod passes.In front of the engine on both sides of the crankshaft pulley there are two 3/8" holes in a vertical position. The top one on the passenger side has to be plugged with a very short bolt or oil will leak especially at higher RPM.Make sure the bolt is too short to reach the pump rod and bind it.
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Old 02-18-2013, 07:31 AM
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high rpm oil leak

mouse is in error,with a pc valve you must have a breather,if pc is on right valve cover the breather on left.you must have circulation ,if not you will also have a mosture isue. other posibility is oil not draining back to base as with out proper venting you hve a vacume in the base and valley which will slow drain back in a big way.recently had a isue with a young fellow that put ductape over breather that fell off,wiped out the bottom end as engine was running low of oil in base as not draining back,
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Old 02-18-2013, 09:55 AM
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I didn't get a read on my oil pressure when I was accelerating hard

Just to be clear I do have a pcv valve and a breather on the opposite side

the oil leak is definitely just out of the driverside( where my dipstick and breather are) and thats where the headers/fender/ and that side of the hood got drenched in oil
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Old 02-18-2013, 12:33 PM
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This is more about questions to pose to others that know the theory around oil backing up out of a breather.

For one thing if the PCV valve was partly blocked or the wrong one for the engine and didn't flow as well, couldn't that cause pressure to build in the crank case even if the engine is sound but being pushed to its limits.

Also a worn engine or if the fitment of rings in a new engine just not holding back the blow by well enough.

Put that together with a thicker viscosity oil that drains back slower and lets say a high volume pump was used and heads that have smaller passages to drain all that oil at a high rpm in such a short period of time, couldn't that back up the system as it were as well ? ( and dangerously running the pan low on oil ! ).

Just thoughts
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Old 02-18-2013, 01:12 PM
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Oil coming out of dipstick

Had same problem when I changed intakes from one that had an oil filler tube on it to one that didn't. Found out that this oil filler tube was also the breather and when I was dialing in the timing (and doing some high rpm runs) I had oil shooting out of the dipstick tube.

Too much pressure in the crankcase causing the oil pressure to have to go somewhere so was coming out of dipstick tube.

Changed the oil filler cap on the other side valve cover with a breather; verified that my PCV valve was working and not no problems anymore.

(Note: Still working through determining exactly what PCV valve to use as they have different flow rates and such and there is so little info on it)

Hope this helps.
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