Engine Still Burning Oil- What next?

[mike herbert]

Anybody that has driven behind me on the tour de vin or Snakes to the Lake knows what I'm talking about.

I have a 427W built by a reputable builder down south. It has Probe forged pistons and AFR 185 heads, roller rockers and hydraulic lifters. I have Wayne Presley's stack intake manifold on it.

The motor has about 2000 miles on it. When I first started the motor for break in, the fuel mixture was extreemly rich. I burned about 1/4 tank of gas in 30 min run time. I later leaned it out but didn't want to mess with it on the initial start up.

From the first day it was burning oil. I assumed the rings would seat and it would go away. Well, 2000 miles later it's still burning oil.

It goes thru a quart every 250 miles. It's most obvious after I let off the gas on hard accelleration. Smoke seems to come out both sides but it's kind of hard to tell when your looking in the mirror.

I spoke with the engine builder a few times and he thinks the seal of the intake manifold isn't tight with the heads where intake meets the heads in the valley and is sucking oil in thru there. I replaced the intake gaskets twice so far. The last time I changed them, I looked at the old gaskets and there was a crease along the whole length of the bottom of the gaskets so I think they're seating fine.

While I had the intake off, I noticed a fair amount of thick oily buildup in the top of the valve in every cylinder.

So far, the only things I can think of are leaking valve guides (brand new AFR Heads?) or maybe I washed the cylinder walls on that initial start up and the rings never seated.

Anybody got any recommendations on what I should do next or does anyone know of a good shop in the east bay that can look into it?

[Zoom This]

Mike,

My 418W stroker has been using as much oil also. I replaced the intake gasket last year and that resolved a lot of my smoking during the downhill high vacuum (read copious amounts). However, I still use a quart every 250-300 miles. Rings have been excluded and the culprit is in the valve seals and/or guides. I have Edelbrock Victor Jr heads that have been using this oil since new. Car has 9800 miles on it now.

Several weeks ago I drilled and tapped my intake mainfold for a dedicated vacuum port for the brakes. As I was cleaning out the manifold runner as carefully as possible to remove any residual aluminum shavings down in the runner, I slipped my shop vac hose, with a 3/8" adapted clear hose, slowly down the runner. As it got close to the valve, it sucked up a small amount of oil! This is not mormal! Bottom line is that I will need to pull the heads and have them rebuilt with new seals and guides. May as well CNC port 'em while they're out. The motor itself runs great. strong and does not blow blue smoke out the exhaust during acceleration, but does puff a little while going downhill for a period of time. Good luck with your fix and I hope this helped.

[Hotfingrs]

I had my engine rebuilt last year, and after I had it done, it burned oil. When I go to the drags and check it after a night of racing, I'm usually down 2 qts. This is about 90 miles time. Prior to rebuild I was using Royal Purple 21 oil. I switched to Pennzoil 20w-50 racing and kept using it, because it's way cheaper than putting in RP the way this thing was burning oil.

About a month ago, I was going to the drags, and wanted to change the oil. The Pennzoil is so dark and heavy, I wanted to put a light colored oil in, so I could see how fast the oil changed color. I put in Quaker State 10w-40, only because they didn't have what I wanted. Nice golden color going in. Went to the drags, made my runs drove home. Checked the oil level the next day and it's on full. The engine builder's theory is that the other oil was too heavy and the rings didn't wipe enough off, so it was burning it.

I don't know if he's right or not....Only know I don't burn oil anymore. Next change RP will go back in and see what happens.

[Zoom This]

Hmmm.....wish I had that kind of luck. I've tried many different oil blends and weights, from 70w racing oil to 20-50w to 10-30w, even tried a pint of STP as an experiment. Nothing stopped the oil consumption, ruling out my rings and the discovery of oil in the intake port, per my earlier message. Until I get the heads worked on, I am using 10-30w dino oil. By the way, the oil consumption has always followed my gas consumption. Heavy on the throttle, heavy on oil use. Light on the throttle, like on the freeway and the motor will use ONLY 1 quart for about 450-500 miles.

Lesson learned, always have your new heads checked for guide clearance and proper seal installation before installation on the motor.

[DAVID GAGNARD]

Do you have a PCV system on the car????????? If so check it and make sure it is working properly,if not,you may want to put one on it and try that..........eaiser than taking the motor down and checking the heads...........

Also,you may want to do a "compression" test,run all cylinders,write down the readings,than,come back and put about 2 good squirts of engine oil in each cylinder one at a time and run the compression test again.........if the compression goes up,than it's your rings............

David

[Gasman]

Mike, I learned the hard way, running rich is the worst thing you can do to a motor. At exactly 2000 miles my 427 was using a quart of oil every 50 miles. Very embarrassing to say the least. The cylinder walls were scored from the gasoline washing the oil off the cylinder wall. I had to sleeve two cylinders and replace the rings, cam and bearings. I hope your damage is not so severe. At the very least, I'm afraid a ring job is in your not to distant future.

[HighPlainsDrifter]

Hi,
Sorry to say but your rings didn't seat.
Rings initially seat in the 1st 10 minutes of running.
Hastings Rings says;
You check fluids and timing,then drive it in 2nd or 3rd gear , 1/2 throttle 2,000 to 4,000 rpm to 2,000 rpm on and off to set the rings. Do this about 6 or 8 times and the rings will be set, drive the car normally after doing this.
Your engine needs a re-ring and hone, then do that to break the rings in correctly.
Perry.
BTW; Blowby past the rings goes up through the guides and intake valve during overlap and into intake manifold so there will be oil there.

[coyled]

Mike, run a leak down test first to see if the rings are seating properly. The oil rings could still be bad, but this will eliminate ring seal issues. Make sure your pvc is not sucking oil into the intake. Spray carb cleaner around the intake ports to see if there is a leak there while it is running. Make sure that there is not too much oil going to the top of the valve covers or that the oil that is up there is draining back properly. Too much oil there sitting on top of the guides or valve seal will make it easier to suck more oil through. Lastly, and most likey, the guides and or seals are bad. These are just a few thing to check first and save some head aches later. good luck, Scott.

[mike herbert]

I pulled the PCV and still burned the oil.
I pulled the passenger side headers off last night and found 3 of them to be black on the inside, the other one looked like it was burning clean.
I also pulled the spark plugs on that side and they actually didn't look too bad. All of them were the same color of a little bit browner than light grey.
I'll do a compression test tonite but I don't have a leakdown tester. Does anyone have one that I can borrow over the weekend?

[mr0077]

Mike, having deposits on the back (stem) side of the valve and smoke on deceleration (high intake vacuum condition) has just GOT to be a leaky intake manifold, loose valve guides or bad guide seals...you just can't get oil or deposits there any other way that I can think of (except for a PCV sucking oil, and you would have an oily PCV hose and/or valve in that case). And you've pretty much eliminated the leaky gasket. A remote possiblity would be a leak/crack in the intake manifold that would allow it to suck oil, or maybe pushrod holes in the head?
I would suggest changing the seals first (fairly easy), and if that doesn't fix it, welllll...you know what's next. I don't believe it is your rings.

[Dennis Kelley]

It sounds like you have an enormous vacuum leak. Is you PVC connected to your intake. I hope you get it fixed but it does not sound good. with 2000 miles on the motor I would have to wonder it you may have to pull the motor and go through it. If it ran that rich its probably ruined the bearing with gas in your oil. How did it run that rich? I thought fuel Injection was suppose to be more precise than a carb. I have AFR heads also and the quality of the heads is second to none. I thought blue smoke on decelleration was because of the rings? I had a 302 that smoked when the PVC hose came off but thats a dam lot of oil for a new motor.

later Dennis

[Rick 427 Cobra]

Compression tests for rings is a waste unless the rings are basically missing. Leak down test is the gold standard test for cylinder sealing. There has been a lot of talk about oil consumption and overly stroked motors because of the piston pin/ring proximity. I won't go there. Do the leak down test first, then look at other things.
Also, I would be slow to think about massaging the AFR heads. They are awfully good out of the box and unless you very good you could be going in the wrong direction.
Tony R had a problem with cylinder wall wash out due to his fat injection set up too.

[mike herbert]

I did a leakdown test last night on 2 cylinders before I got yelled at by someone else who wanted to eat.

Compression on all cylinders was between 160-175#.

Leakdown on cylinder #1 was 36% with most of the air comming out of the valve guide area.
Cylinder #3 which was the one the looked good with light grey in the header had 5% leakage with know real noticable air comming out any particular area.

Is it safe to spray a little soapy water in the area that leaks or is that going to cause problems later?

[blykins]

Valve guide or valve seal?

How do you know it was coming from there?

[mike herbert]

You could feel the air comming out around the valve springs, I'm not sure if its a guide or a seal. That's why I want to spray the soapy water to get a better idea.

[blykins]

Well, that's a good indication it's not the rings...

[Tony Radford]

I had the exact same issue with my stroker when it was new. I was consuming a quart every 100-200 miles. I let it go for 3,000 miles (watching the level very closely of course). It wasn't smoking and ran great. It ended up that my Demon carb was too rich and caused my rings to destruct, probably during run in. I was told that the rings were basically gone. This has happened to a number of folks I know. There are very few things that can cause that level of consumption. In my case, they didn't pull the motor. It only took them a day to replace the rings and another few hours at the dyno shop to get the A/F ratio right.

[mr0077]

Mike, a leakdown is run with the valves for the tested cylinder closed (and the piston at TDC ideally), to test for leakage...The typical check is to pressure up a cylinder, listen for a hiss (air leakage) at the oil filler (indicates ring leakage into the crankcase), tailpipe (exhaust valve leak) or carburetor air horn (intake valve leak). Air flow at the valve guides probably means the valve wasn't closed, but there still shouldn't be any air flow there...could the air have leaked past the rings, into the crankcase and out the drainback holes so it seemed like it was coming from the springs? That would be a heckuva leak around the rings. I STILL don't think it is rings (they smoke on acceleration, or all the time, not just deceleration).

[Gasman]

Ken, Beg to differ, my rings were toast and the motor ONLY smoked on decel.

[mr0077]

Hmmm...Gasman, never heard of such a thing, wonder if anyone can explain how that would happen...maybe the rings were so bad that they allowed oil to get sucked into the chamber during decel? Were the oil control rings good? What condition were your guides in when you overhauled the motor? maybe it burned oil (or not) due to the rings all the time lightly) and the guides laid down more smoke on decel?
I guess anything is possible, anyone else have Steve's experience?.