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new engine blowing out oil.
I've just been for a run (about ten miles) with my new engine, it seems there is an awful lot of oil (enough to smoke on the exhaust and get me worried) coming out of the pcv valve one one bank and about the same amount coming out of the breather on the other, whats causing this? I have filled it with the correct amount and grade of oil. Oil pressure is good, no noises from the engine.
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simon,
How new? |
It's likely blow by from the rings
creating crankcase pressure, which is blowing out some oil... my problem on my new 514 was the stupid stock dipstick tube, I replaced it with a ss braided/billet unit from Jegs with an o-ring on the dipstick handle, and went with a PCV on the passenger side and a breather on the driver's side.. the oil seepage almost vanished, and since I now have 3 k on the motor, rings nearly seated, it has totally vanished.
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'bout ten miles
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In other words
It's likely normal. Be sure NOT to use synthetic oil for the first 3,000 miles minimum. I may go 5,000 miles just to make sure since just recently have my rings and other things finally felt "seated" and my horsepower has gone up.
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Simon ,
its way to early to be concerned with blow bye, your rings are not seated yet, so you are getting oil in the combustion chambers and combustion in the crankcase (blowbye)Give your self a couple hundred miles before you get concerned....do keep an eye on your oil level.... good luck KK |
Your valve covers have baffles? Many aftermarket covers do not, and that can contribute to an oily mess.
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I'm in exactly the same situation right now. 125 miles on the car. I'm wondering if I have the right breathers. Some with baffles might help? No PCV setup on mine.
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Cowtown...
See my post above for the solution.. worked great for me as soon as I did the mods..
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I've decided to get another pcv for the other rocker cover and connect them both to a couple of tubes venting under the car. I'll give it a couple of hundred miles before I make any rash judgements.
Thanks for the help guys. |
Another idea...
Go light on the loud pedal for the first 500 to 1,000 miles... the harder you drive her the more oil is gonna blow out ;) :3DSMILE:
OH, and are you SURE your PCV is fully working?? |
I'm trying to drive as gently as possible, without revving too hard or straining the engine at all. Yep, from the amount of oil that's being thrown out, I'd say the pcv valves working fine !!
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Simon,
Blow-by is very normal for any fresh engine, the rings need to seat and the "break it" period needs to pass. If you have a higher lift cam, the amount of vacume you are pulling may not be enough to remove all of the gases from the crankcase ( at the beginning ). If it is spitting oil out the cover holes, i'd worry. Run the engine for 500 miles and check the blow-by again, it should be almost non-existant. Keep in mind, this works off vacume. If you put your foot in the carb, you have NO vacume to speak of. Actually, I am going through the exact same process right now and after three hours, the smoke is much less. Just my $0.02 :3DSMILE: |
Quote:
Excessive blow by will cause the breather to puke...... normal until the engine is properly broken in. Good luck Simon..... glad to see you have a running engine now, it's been a long journey right? - Jim - |
sussed it???
I must explain, I didn't plug my pcv valve into the vacuum inlet on the carb, I just left it open (c'mon, I've been off the road with the cobra for months now, I was impatient. I even have my new MSD ignition sitting on the passenger seat !!) so I was concerned about the oil coming out of the pcv and breather (the breather oil was dripping on the hot exhaust!). Of course pcv stands for poitive crankcase ventilation so what I neede to do was SUCK the blowby out of the engine (I hope/pray thats all it is)
I've connected it up now and it doesn't seem to be coming out of the breather at all (haven't been on a run yet) so keep your fingers crossed for me guys. :) |
Simon
As noted above the PCV system is supposed to be a sealed system. However, a couple of other things you might consider checking. If you don't have a sheet metal baffle inside the valve cover under the oil filler or PCV valve hole oil can get thrown up by the rockers and exit the PCV and / or oil breather / filler. Also, the first engine I built (many years ago) I didn't make sure that the ring end gaps were offset from each other when I installed the pistons. I had a couple where because of the way I installed the rings the end gaps were almost perfectly lined up. This caused a lot of blow by and in the end I had to pull all the pistons and make sure the ring end gaps were offset correctly. Once offset and reinstalled the blow by was virtually eliminated. Hope you find the problem... |
Simon,
Glad to hear you are up and running again - too bad you missed all the warm weather, you must like driving your Cobra in the cold. Just plug the hose from the PCV to manifold vacuum and you'll be fine (should be a fitting on the carb. below the butterflies or if not on the manifold). The only oil you should be getting is a mist (after a while), which will be pulled through the inlet and go out through the exhaust - you won't even know about it. :D If I remember correctly, you had no PCV on the last engine????? Good to see you Sunday. GUMBALL UK |
That's right...
My stock Ford Racing 514 valve covers did not have ANY type of baffling at all ! So, instead of the trouble of replacing them with an aftermarket set, I used Mr Gasket rubber baffle/grommets.. you can get them from www.jegs.com I put a small wafer of breathable but stiff foam in mine also for more baffling.
Others here are totally correct.. correct PCV routing is essential..I did not realize your PCV was not even attached to the intake :confused: ;) |
Ford Racing Crate Engine
BiB,
Must be Ford Racing does something diffferent with their crate engines. I built my 514 from their short block but installed the Ford Racing aluminum valve covers. They come with sheet metal plates and screws that mount them to small bosses inside and just under the breather/PCV holes. So far, they work great. Sounds like Ford Racing cuts corners on the crate builds. Surprise, surprise.... :-) Chuck |
Fishy
Soon will have the covers off for the first time and we will see what we will see.. I wonder if it's a part I can order from Ford racing or Jegs...gonna find out right now, cause there ain't nuttin' visible in there now :confused:
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