427 FE S/O blowing oil out of one breather cap

[Flygirl]

Any thoughts about this?

Seems to happen above 3000 RPM. Fifteen minutes on the freeway and a few secondary road blasts caused a few ounces of oil, clearly under pressure, to blow out of the right breather cap and puddle at the base of the rocker cover.

Last time that happened to me, my I-4 Pinto Runabout (don't laugh) had a stuck valve which broke and damaged a piston.

But on this engine, it was happening only on the right side. Could it be some issue with the valve train on that side of the engine?

Engine seemed to be running on all cylinders, no smoke evident on acceleration or deceleration.

Is this one of those FE things? There was no PVC system installed, but as I understand it, that would only handle normal blow-by, not anything to this extent.

You guys know more, what do you think?

[Grubby]

Do you have a PCV? If yes, then I would bet rings not sealed or broken piston or rings. If no PCV, I would add one and see if it improves the problem.

John

[Flygirl]

No PCV. I've been advised that a leakdown compression test might reveal more.

[DanEC]

If the right valve cover doesn't have a baffle under the breather that could explain why oil is blowing out - that's about the only reason I can think it would blow out it and not the left bank breather too. Blowby from the crankcase should vent out both sides equally. I guess it's possibly you have some wierd, excess top-side oiling issue on only one side, but that sounds pretty unlikely.

[olddog]

Pull breather cap and look into hole with a light. If you see rocker arms, there is no baffle, and that could be the only problem.

If you see a baffle, I would think there is some serious blow by or perhaps the drain back wholes are blocked and oil is filling the entire valve cover at higher rpm.

[Flygirl]

Don't think there was a baffle, hoping that's in fact the issue.

Regarding blow by on that side only, thinking this through more. Even if the valve guides or seals were seriously bad on that side only, wouldn't the pressure be relieved through the drain back holes? I didn't think of that until now.

The oil expelled was in the shape of a number of small droplets, if that helps any.

[Gaz64]

Originally Posted by Flygirl

Don't think there was a baffle, hoping that's in fact the issue.

Regarding blow by on that side only, thinking this through more. Even if the valve guides or seals were seriously bad on that side only, wouldn't the pressure be relieved through the drain back holes? I didn't think of that until now.

The oil expelled was in the shape of a number of small droplets, if that helps any.

Oil blowing out the breathers is from piston ring blowby, nothing to do with guides.

All comes down to the engines' condition, who assembled it, and how well the heads drain.

Me personally, I run my breathers from the crankcase. The rocker covers are sealed, no blowby flows out the rocker covers, hence no airflow up through the cylinder head drains.

A leak down test is in order; but if your oil consumption is ok, a redesign of your breather system may be an easier solution.

[Jeff Frigo]

Did you buy this car, or still looking at it?

[FWB]

oil coming out the breather is usually alot more mundane than major engine damage. A valve bad would pop thru the carb. piston ring blowby would include smoking out the exhaust.

with the advent of aftermarket rockers and FE oiling mods, chances are there is too much oil getting into the valve covers via rocker oiling. coupled with a valve cover without a baffle makes for oil puking out the breather.
do you have factory rockers or aftermarket. solid cam or hydraulic.

[lovehamr]

Agree with FWB. As far as crank case pressure being relieved through the oil drain back hole goes, I can't see that as being a problem because the CC and heads are so open. You could totally plug the drain back holes and the oil would still drain back through the openings at the intake and heads. The valve guides would stay submerged which would cause smoking at some point but CC pressure still wouldn't have a problem leaving and properly baffled VCs still wouldn't puke it out like the OP is saying. I would look for something less innocuous than a broken motor and run the PCV with a baffled VC and good PCV valve. If that didn't help, then I'd look elsewhere. JMHO

[priobe]

check the valve covers for the baffle.

Then you can determine if you have a bigger problem. Depending on the valve covers used and the rocker arms sometimes the baffles are removed to gain extra clearance.

This is typically found in the cast aluminum covers. I dont believe the pentroof covers have this issue.

The oil will find its way out of the beather leaking the oil. This is common.

[elmariachi]

Originally Posted by lovehamr

I would look for something less innocuous than a broken motor and run the PCV with a baffled VC and good PCV valve. If that didn't help, then I'd look elsewhere. JMHO

Bearing in mind that the OP is trying to buy this car long distance, the amount of inspection by the OP in a Piggly Wiggly parking lot and the ability to make PCV changes and then run the car for any period of time to confirm/deny, is limited. This car needs mechanical inspection by someone experienced with FEs.

Just my 2 cents.....

[KirkV]

I had this problem in my 302 on higher rpm's and put a filtered vent on the filler spout side and a PCV on the other side valve cover and no more oil pucking. I do plan on removing the valve cover on the PCV side and installing a baffle, as soon as there is time.

[trularin]

Just a bit more info.

Is this a newer engine?
Has it had its first oil change?
Did this just start to happen or has this been going on for a while?

Ring seating is a primary reason there is blowby on new engines.

For those not so new, a simple compression test if a leak down is not available may give you some indication of which cylinder may have a bit to much wear or stuck ring(s).

Additionally, a plug check may also lead you to a cylinder that is challenged.

[Flygirl]

Originally Posted by Jeff Frigo

Did you buy this car, or still looking at it?

Still looking at it.

This engine is in a car currently for sale, so I have no trend information.

Originally Posted by FWB

do you have factory rockers or aftermarket. solid cam or hydraulic.

Solid lifters, aftermarket rockers.

Originally Posted by Gaz64

A leak down test is in order; but if your oil consumption is ok, a redesign of your breather system may be an easier solution.

I agree, but as a potential buyer I'm not sure how to proceed yet. Oil consumption unknown, as I said no trend information unfortunately. Did see the spark plugs, and they didn't appear to be oil-fouled.

__________

Appears more and more like internal problems. Has now been inspected by an experienced mechanic with significant FE expertise.

The question is, how bad the problems are.

No indication of blue smoke out exhaust either under acceleration or prolonged deceleration while holding it in gear.

Info on the engine: Has 1,200 miles on it total over the last 10 years. A decent amount of air can be felt being expelled from the breather cap, more than just blow by.

I'm still interested in the car, but afraid that we'll tear into the engine and discover something really bad, possibly forcing us to re-engine the car with something less desirable than the 427 s/o. Oil freshly changed so no way to do an effective oil analysis.

On the other hand, perhaps a lower selling price might free up cash to freshen the 427, and I'd end up with a really sweet, very period correct Cobra...

Do I want to take on that risk? That's the question.

Another question: Could another induction system, perhaps Webers, have washed the cylinders with fuel and damaged either the bores or the rings? That could be a potential explanation.

[Dimis]

Originally Posted by Flygirl

On the other hand, perhaps a lower selling price might free up cash to freshen the 427, and I'd end up with a really sweet, very period correct Cobra...

Do I want to take on that risk? That's the question.

I'm thinking YES!!

If is just mechanical... take the plunge!

There are no guarantees that a perfectly tested engine wont kick the bucket anytime soon anyway.

So negotiate the price down.
Push the mechanicals as hard as you feel comfortable during your ownership.
If they don't break then you're the winner.
If they do break, well then that is NOT a bad thing either

Take the money you saved & make it yours! Built the way you want with the bells and whistles that tickle your fancy, and you have new engine (& mechanicals) to enjoy, then sell off any left over parts to recover some of the cost

Its a win win either way.

As long as the chassis is square and straight - mechanicals and consumables can be mended.

I'd say, it's all about the negotiated price.


PS: If we are talking about that black ERA listed in here PhotoPost Classifieds - ERA 427sc - Powered by PhotoPost Classifieds
Then I'd give it a go. Just for the record, I do NOT know the owner, but have emailled them for details on the car. Specifically year of build, as I was keen on it. But year of build wont comply here in Aus


PPS: Make sure your over analysis doesn't cause your paralysis when making decisions

[DanEC]

Originally Posted by Flygirl

Another question: Could another induction system, perhaps Webers, have washed the cylinders with fuel and damaged either the bores or the rings? That could be a potential explanation.

Yes, it's possible but it just falls in the area of speculation unless the heads are pulled to inspect the bores. With the low mileage on the engine it may be the rings have never seated in - more speculation. I have an old big block Corvette that consumed about 4 quarts of oil on the highway on the way home from picking it up. I changed the oil and it dried up and hasn't hardly used hardly any in 20 years - at least for a big block Chev anyway.

[RICK LAKE]

Flygirl Here are a couple of checks
Valve covers, does either valve cover have a baffle? Some valve covers only have a baffled in 1 side. This is the one that needs to go on the right side of the motor and have a PCV hooked to it. Some valve covers have neither side with a baffle. You can still hook a PCV to it if there is an oil fill hole or make and drill your own. They sell a groment that seals, fills the hole, and stops oil leaks. Valve train tins, they sit under the rocker stands and help guide the oil back to the block. Some guys run them, I don't because of the ERSON rocker arm setup. Oil in the heads, I flood my heads to the pushrod holes. If you have good valve stem seals, no extra oil will get down the stem and give you the blue smoke cloud when starting the motor. This oil also helps cool the valve spring down under hard loads and driving abuse.
You are helping by filling in with more info. If the rebuilt motor has only 1,200 miles on it, IT'S not broken in. The rings are not seated to the cylinder walls, valves are not totally sealed to valve seats, even if lapped in. This motor needs from 3-10K miles until everything is broken in and a couple of oil changes along the way without any synthetic oil being used until 7-8k miles.
It sound like you have a car that has sat and the owners got tired of owning it. Bottom line is if you like the car and have driving it a couple of times, buy it. If unsure walk away. Horses and cars are alike, Horse checks out with a vet job, get him home and find he has a fractured leg bone. 6-8 weeks to wait and see. Some make it, others are put down. Cars are the same. It's a box of chocolate. Rick L.