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Help on recent 383 rebuild burning oil

13K views 33 replies 12 participants last post by  y2k600f4 
#1 ·
Purchased in car with about 50-100 miles on it that had a freshly professionally rebuilt 383. I drove it home 300 miles, dumped oil put new filter and quaker state 10W30 (3/08). I drove it approx 200 miles in the last 6 months (busy fixing little things); and it is burning oil some oil. Pulled a plug, it is black and wet and I get lots of gray smoke with black specks all over my bumper and garage floor; lots of black soot in tailpipes. Oil was low when changed recently, put in again quaker state 10W30. I figured the rings were not seated yet, but after talking to others they informed me they should of seated already….I thought somebody could give me some insight on this board. I have not began to trouble shoot (compression test, leak down test etc); I don’t have the tools but I am willing to get them. Any help would greatly be appreciated. The following is what I know about the engine build.

All new parts which include the following (this is all I know)

Summit Cam sum-1106
Chrom moly +100 push rods
Holley 4160 750 Carb
Procomp Aluminum Heads 190cc/64cc
Performance products 52026 crosswind intake
New Eagle bottom end; externally balanced (.040 overbore, Flat top +5cc pistons)
Felpro 1003 head gaskets
Felpro 1205 intake gasket

Thanks.
 
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#2 ·
y2k600f4 said:
Purchased in car with about 50-100 miles on it that had a freshly professionally rebuilt 383. I drove it home 300 miles, dumped oil put new filter and quaker state 10W30 (3/08). I drove it approx 200 miles in the last 6 months (busy fixing little things); and it is burning oil some oil. Pulled a plug, it is black and wet and I get lots of gray smoke with black specks all over my bumper and garage floor; lots of black soot in tailpipes. Oil was low when changed recently, put in again quaker state 10W30. I figured the rings were not seated yet, but after talking to others they informed me they should of seated already….I thought somebody could give me some insight on this board. I have not began to trouble shoot (compression test, leak down test etc); I don’t have the tools but I am willing to get them. Any help would greatly be appreciated. The following is what I know about the engine build.

All new parts which include the following (this is all I know)

Summit Cam sum-1106
Chrom moly +100 push rods
Holley 4160 750 Carb
Procomp Aluminum Heads 190cc/64cc
Performance products 52026 crosswind intake
New Eagle bottom end; externally balanced (.040 overbore, Flat top +5cc pistons)
Felpro 1003 head gaskets
Felpro 1205 intake gasket

Thanks.
Depends a lot on the rings and if the wall honing and ring materail were matched.

Chrome rings if used need a coarse hone and still can take a few thousand miles to seat. If they were missmatched with a smooth hone used for moly rings they may never mate.

Moly rings if used need a smoother hone finish but usually break in and seat quickly. But if matched with the coarse hone wall for a chrome ring, very often the moly coat is "sanded" off and the rings will forever push oil into the combustion chamber.

Life just isn't as simple as in 1960 from a ring materail and cylinder wall finish standpoint. But, also, only driving 200 miles in 6 months isn't exactly the kind of use that seats rings of any sort. Molys on a smooth wall will do it, but for chrome you've got to get a bunch of heating and cooling cycles and maybe even a little wailing on it a few times to drive 'em home. Plus that little use isn't good when trying to break in a flat tappet cam. If you've lost a lobe and lifter you will also have oily problems on the plugs and in the exhaust.

Bogie
 
#3 · (Edited)
Bogie,

Thanks for the informative post ! I looked at the bottom end kit and the Piston Ring Facing Material is Plasma moly (Perfect Circle Rings). I don't know how the honing was done, but I will try to find out (if I can). I am assuming the Plasma Moly should of seated already if the honing was smooth....and if it is course than I am looking at a tear down :( Thanks again and if you have any other tips on how I can perform a proper break in I would would love to hear it.
 
#7 ·
oil burning

I am thinking this is a small block chevy? This is a common problem that happens with some intakes and gasket not being matched properly.If the block has been decked or the wrong port gasket used ,there will be a vacuum leak in the valley and oil will be sucked into the intake and coat the spark plugs much like bad valve guides. Pull intake and see if the cylinder head ports are oily.
 
#9 · (Edited)
I checked the specs on your cam - Duration at 050 inch Lift: 234 int./234 exh. What RPM did you run it at during break-in? What ignition system are yourunning and how much initial and total advance?
I kept the RPMs around 2-3K (normal operation) during the 300 mile trip and 200 or so miles of basically city driving in the last few months.

The ignition is New HEI
I'll have to look into the timing...

I am thinking this is a small block chevy? This is a common problem that happens with some intakes and gasket not being matched properly.If the block has been decked or the wrong port gasket used ,there will be a vacuum leak in the valley and oil will be sucked into the intake and coat the spark plugs much like bad valve guides. Pull intake and see if the cylinder head ports are oily.
This is a possibility and thanks for the tip. I want to do a little more investigation before I start "tearing" into things.

Could be those terrible "Pro Comp" heads. Those are about the worse head you could put on a motor. Probably leaking oil around every valve guide.
I am aware of the reputation of these heads :( Unfortuneately I did not choose them and it is a very well possibility this is a cause of the oil burning or intake or rings.

It would be a good idea to change the plugs and get a little more run time on it.What you are seeing out coming out the exahust might be excess fuel thats not getting burned completely. Make sure the carb. idle circuit is set correctly andavoid prolonged idling.
I think I read on another post that a carb running rich effect oil burning ?

I guess the first thing I will do to troubleshoot is to make sure the carb is dialed in properly and than do a compression check. Thanks for the tips everyone.
 
#10 ·
burnin the midnight oil..

It sounds like you need a leakdown tester.. then you could definately tell if the problem was in the heads or not... harbor freight tools has them if i remember correctly.. and if they have it its usually pretty cheap too.. not a bad tool to have around anyway.... so it wouldnt be a total waste...

Let us know what you find.
 
#11 ·
It sounds like you need a leakdown tester.. then you could definately tell if the problem was in the heads or not... harbor freight tools has them if i remember correctly.. and if they have it its usually pretty cheap too.. not a bad tool to have around anyway.... so it wouldnt be a total waste...

Let us know what you find.
Thanks, I think I will get one before this weekend they are $30. I will post results ASAP.
 
#12 · (Edited)
No to highjack this thread but I'm experiencing oil burning from my just rebuilt 327. Rather than start a new thread I hope you don't mind me asking my questions here.

I have yet to do any tests to try to figure out the source of this problem but am hoping it may be (partially) due to the fact I still seem to be running way rich. How much of a factor could this be? I'm only seeing blue smoke from the divers side and its not constant. It does show up a little time to time during city driving but man does it seem to plume smoke when I get it onto the highways. Is this pattern any sort of an indicator???

Thanks,
Ced
 
#13 ·
y2k600f4 said:
I kept the RPMs around 2-3K (normal operation) during the 300 mile trip
and 200 or so miles of basically city driving in the last few months.

The ignition is New HEI
I'll have to look into the timing..
When running a camshaft with 230+ degrees duration, combustion at low RPM
(under 3000 or so) is very poor. If the tune up isn't just right plugs foul very
easily.

How does this relate to poor ring seal?

On a good running engine, combustion completes before the exahust valve
opens or shortly there after. When the tune up is not right, combustion never
completes, this results in fuel/carbon in the cylinder further contaminating
the next fresh charge. This fouls the plugs making a bad situation worse.
This fuel/carbon in the cylinder is not good for the rings, especially when
they haven't seated well.
 
#14 ·
When running a camshaft with 230+ degrees duration, combustion at low RPM
(under 3000 or so) is very poor. If the tune up isn't just right plugs foul very
easily.

How does this relate to poor ring seal?

On a good running engine, combustion completes before the exahust valve
opens or shortly there after. When the tune up is not right, combustion never
completes, this results in fuel/carbon in the cylinder further contaminating
the next fresh charge. This fouls the plugs making a bad situation worse.
This fuel/carbon in the cylinder is not good for the rings, especially when
they haven't seated well.
Thanks for the explanation on how a bad tune effects cylinder rings.

In my case I am pretty sure the carb is dialed in properly and timing is correct; but I plan on checking the carb and timing.

My issue is excessive burning of oil and I want to first investigate the rings by doing a leak down test. Then I will be checking the carb and timing. I just don't know where the oil is going ? Several people have posted potential problems and the list is getting longer :(
 
#15 ·
y2k600f4 said:
Thanks for the explanation on how a bad tune effects cylinder rings.

In my case I am pretty sure the carb is dialed in properly and timing is correct; but I plan on checking the carb and timing.

My issue is excessive burning of oil and I want to first investigate the rings by doing a leak down test. Then I will be checking the carb and timing. I just don't know where the oil is going ? Several people have posted potential problems and the list is getting longer :(
The rings are a major thing the leakdown test picks up.

Bogie
 
#16 ·
y2k600f4 said:
Purchased in car with about 50-100 miles on it that had a freshly professionally rebuilt 383. I drove it home 300 miles, dumped oil put new filter and quaker state 10W30 (3/08). I drove it approx 200 miles in the last 6 months (busy fixing little things); and it is burning oil some oil. Pulled a plug, it is black and wet and I get lots of gray smoke with black specks all over my bumper and garage floor; lots of black soot in tailpipes. Oil was low when changed recently, put in again quaker state 10W30. I figured the rings were not seated yet, but after talking to others they informed me they should of seated already….I thought somebody could give me some insight on this board. I have not began to trouble shoot (compression test, leak down test etc); I don’t have the tools but I am willing to get them. Any help would greatly be appreciated. The following is what I know about the engine build.

All new parts which include the following (this is all I know)

Summit Cam sum-1106
Chrom moly +100 push rods
Holley 4160 750 Carb
Procomp Aluminum Heads 190cc/64cc
Performance products 52026 crosswind intake
New Eagle bottom end; externally balanced (.040 overbore, Flat top +5cc pistons)
Felpro 1003 head gaskets
Felpro 1205 intake gasket

Thanks.
fuel pump leaking fuel into the block, not on the ground. holley carb ...power valve blown during startup by pumping the throttle, not the acc.pump leaks fuel in the vacumn port for the power valve and the power valve stays open all the time and that is fuel/oil delutement. gas does not seal the rings. sysmtom. oil gets black in a few days...that is powdered metal....black oil also it starts hard cause' the float bowldrainsinto the rngine/oil/intake manifold...on the plugs, etc.
 
#17 · (Edited)
y2k600f4,
Your missing my point. I don't know where the oil is coming from, may be rings
may not. There are lots of places to get oil in the engine.

My point is it's spitting carbon out the exahust, that same gunk is fouling the
rings. A leak down is in order, but before I'd jump to conclusions, I'd put a good
set of plugs in it and put some heat in the cylinders, run the RPM up several
times (with a load) and give the rings a chance to seat before pulling it apart.

adams specialty engs and I are thinking along the same lines.
 
#18 ·
adams specialty engs and I are thinking along the same lines.
I appreciate the info and suggestions !!! I don't think I missed the point (however maybe I had a poor choice of reply's ?) and I know noone really knows about where the oil is coming from but I really appreciate the informative info on the possibility of a fuel problem not allowing the rings to seat properly (if that is a problem); gives me some where to start. I will take your advice and swap out the plugs and get some heat and load on the engine. In the meantime I am going to pick up a leak down tester and see where that takes me. Thanks for expanding on the potential problem. I am no way in a rush to tear into the engine, and I hope that is not what I need to do :( .
 
#19 ·
Update

Ran the engine to temp....pulled plugs (took a while due to headers) and did a quick compression test (going to do again). All cylinders are ~190 PSI ( a few were a little higher). Also pulled the PVC and I am getting smoke coming out (same as exhaust). After I pulled plugs (all were black, burnt and oily) I noticed AT LEAST 1 cylinder smoke was coming out of the spark plug hole. Also all holes had oily residue shooting and leaking out (normal ?). Stay tuned....next is leak down test.
 
#20 ·
SDLuck said:
I am thinking this is a small block chevy? This is a common problem that happens with some intakes and gasket not being matched properly.If the block has been decked or the wrong port gasket used ,there will be a vacuum leak in the valley and oil will be sucked into the intake and coat the spark plugs much like bad valve guides. Pull intake and see if the cylinder head ports are oily.
What SD said ^^

And... IF your valve covers are not baffled under the PCV, this will suck all kinds of oil in. Look down into the PCV grommet. You should NOT be able to see any part of the valve train.
 
#21 ·
What SD said ^^

And... IF your valve covers are not baffled under the PCV, this will suck all kinds of oil in. Look down into the PCV grommet. You should NOT be able to see any part of the valve train.
Thanks C-10 !! I am by no means an engine builder (I try and do everything myself: bodywork, drivetrain installs, etc) but when it comes to internal troubleshooting I have found that this forum is great; and I could not do it without you and all the others help !!! I did read about PVC problems....mine is NOT baffled. Pulled PVC off and looked in tube and PVC and their is no signs of oil. Contacted the engine builder (out of state) and advised me first to do a compression test (if that showed something than do leak down test); also insured me the cylinders were honed correctly for the moly rings. However he did believe it was a good possibility it is an intake gasket leaking and pulling oil out of the lifter valley; that the heads on the engine have a raised intake port, and sometimes you do have gasket sealing problem.

I did check withtthe intake manufacturer's instructions and it looks like the proper felpro 1205 was used (recipt). Just want to make sure it is the intake before I pull it....but as of now, that is what it looks like.
 
#23 ·
Although you didn't see oil in PCV when you checked, it would be a good idea to get baffles in those valvecovers anyways, so as to limit the possibility of it happening. Beyond that, it could be MANY different things that can cause blowby and/or consumption. With 190psi comp.readings, you've obviously got a decent compression ratio in that mill, (at least during cranking test), and that contributes to possibility of blowby during break-in. From what I saw you've now got AROUND 500 total miles on it? Perhaps it might be best, for now, to put fresh plugs (of proper heatrange, of course) in it, verify all ignition and carb. settings are correct, recheck for any "hidden" vacuum leaks, and run it a bit more mileage under varying loads, (so as to be certain that the rings have had every possibility to seat completely). If situation continues on beyond another 200-300 miles additional runtime, THEN dig in further. AT least you'll get to have some driver seat time in the interem. You might also check related posts/threads in the knowledge base and in this (engine section) of forum as well, for perspective on other rodders' similar experiences. :thumbup: Good luck with it all. -Jim
 
#24 ·
Although you didn't see oil in PCV when you checked, it would be a good idea to get baffles in those valvecovers anyways, so as to limit the possibility of it happening. Beyond that, it could be MANY different things that can cause blowby and/or consumption. With 190psi comp.readings, you've obviously got a decent compression ratio in that mill, (at least during cranking test), and that contributes to possibility of blowby during break-in. From what I saw you've now got AROUND 500 total miles on it? Perhaps it might be best, for now, to put fresh plugs (of proper heatrange, of course) in it, verify all ignition and carb. settings are correct, recheck for any "hidden" vacuum leaks, and run it a bit more mileage under varying loads, (so as to be certain that the rings have had every possibility to seat completely). If situation continues on beyond another 200-300 miles additional runtime, THEN dig in further. AT least you'll get to have some driver seat time in the interem. You might also check related posts/threads in the knowledge base and in this (engine section) of forum as well, for perspective on other rodders' similar experiences. Good luck with it all. -Jim
Thanks Jim....I will take your advice and reassemble, check tune and drive for a while; don't want to tear into the heads unless I know that it is the problem.
 
#25 ·
As mentioned on your other thread, change oil and filter again. Take a sniiff of the oil you drained and see if it has a "fuel smell" to it. If you've been running somewhat rich,(either from carb settings or characteristics of cam at lower rev's), oil may be getting thinned a bit with unburnt fuel, which will speedup the blowby process, if indeed that is what's occuring. When you are sure that everything is setup correctly and fresh plugs of correct heatrange are in place, take it out and try to spend some time putting it under load in the 2500-4500rpm range and keep a close eye on the oil consumption over the course of time. Also, if not already addressed, get some baffles on those valvecovers, because IF there is indeed some blowby occurring (due to rings not being fully seated in), this will help to slow it. I hope you get resolution to this issue through the processes and ideas everyone is offering, and fix turns out to be an easy one. :D -Jim.
 
#26 ·
y2k600f4 said:
compression test showed 190 PSI in each cylinder

Just pulled intake....no oil in intake ports

PVC not sucking oil

Anybody know the most likely culprit for oil burning ?

Thanks.
Good compression in and of itself does not mean oil isn't getting around the rings. But I'm getting ahead of myself.

The most frequent loss of oil into the combustion chamber is either down the valve guides (intake usually) or around the rings. Other choices run from damaged pistons or cylinder walls, an intake vacuum leak connecting the valley area to the intake ports. Blown head gasket. Most of these failures tend to be one or two cylinders not all. Breather issues especially where PVC or vacuum extraction is concerned will most often show up in all cylinders. Communication between the crankcase and the fuel pump could provide a source of oil getting into the fuel supply, this would show in all cylinders also, but the typical failure that communicates between the pump and crankcase put fuel into the crankcase rather than oil into the fuel. Still when we can't find the cause, you've got to consider the unlikely sources as well. Along that line is also the though that oil has been put into the fuel in the tank.

Back to guides, a very common source of oil into the combustion chamber, after all what you see as manifold vacuum is a force trying to fill the engine with what ever it can get to balance internal pressures with the atmosphere. It will take air from whereever it can get it. From the carb it comes with fuel, around the valve guides it comes with oil. This is why clearances between stem and guide are important, so is concentricity, and seal quality.

Rings get into orientation, a ring especially the second ring installed upside down will hold compression, but will pump oil into the combustion chamber with every stroke of the piston. Rings with too much or too little vertical clearance in their lands will do the same, as will rings riding in dirty or miss machined lands such that the ring cannot make a seal with the top or bottom of the land. While we worry end gap to death, how many guys checked land to ring clearance, flatness, and cleanliness. This gets into the correct wall finish for the type ring. A course finish of about 250 - 300 is used for chrome rings. This will seat a hard surface of a chrome ring, if this is used for a moly filled ring it will sand the finish off the ring. For a moly ring you want a 400 - 600 finish for a wide ring and 600 -1200 for a narrow ring. If you put a chrome ring against this surface it will skate forever, never making an oil tight seal. I'm talking compression rings here, in all cases a stainless steel or untreated cast oil ring works fine. It's the first and second ring that can be a problem when miss-matched against wall finish.

Leaping back to intake to valley sealing, when heads are milled and or the block is decked, the heads are lowered and brought closer together in relation to the intake manifold. A cut on either surface of about .020 inch is about all that can be tolerated without also trimming the bottom and sides of the manifold. Felpro also sells a range of gasket thicknesses that can be useful in adjusting these dimensions as well.

Bogie
 
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