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Massive Oil Consumption

77RHINO

Full Member
Joined
Feb 22, 2011
Messages
308
Engine Gurus, I'm running low on options. I have a 351w that has maybe 2500 miles on it that burns an incredible amount of oil - I just burned a quart in 40 miles on the interstate this morning on the way to work and back. I have been chasing this issue down for 2 years now, pulled the motor almost completely apart multiple times, swapping intake gaskets, rear main seals, head gaskets, new valve stems (on 2 year-old heads) lapped the valves, checked for warped head/intake surface with a square, swapped valve covers, PCVs, and I just put it back in this past Sunday with new 1262-S3 intake gaskets and I still haven't fixed the issue. I have fixed or looked at just about everything I know to do. I'm not sure if the rings haven't sealed yet, or are bad, or if there's enough vacuum sucking on both sides of the PCV to not allow oil to drain back down into the pan? Please take a look below at the build specs, and let me know your thoughts.

Links to past threads on same topic trying out additional tests:
http://www.classicbroncos.com/forums/showthread.php?t=271861

http://www.classicbroncos.com/forums/showthread.php?t=278529


1996 351w block bored .030 over
Ford Racing GT40X 64cc heads (bought brand new including beehive springs)
Comp 35-514-8 camshaft (.544/.555) (Also called XE266HR-12)
roller rockers
new hyd roller lifters
original pushrods
KB +6.50 Pistons w/ mahle rings (plasma-moly/ductile iron top ring, iron 2nd and 3rd)
factory connecting rods
Edelbrock carb (650) and intake (2181)
195* T stat
PCV routed from top of passenger valve cover into base of carb, oil cap w/line to base of air filter - Now running larger dia. PCV line to increase flow
factory '96 valve covers w/good baffles
WH longtube headers
Compression is probably in the upper 9s
factory ignition
factory coil
Holds about 15-18" of vacuum at idle running roughly 650 rpm
Compression test performed 11/2016 on cold motor after first discovering the massive oil consumption:
1 185 w/oil 215
2 185 w/oil 205
3 185 w/oil 205
4 180 w oil 213
5 177 w/oil 200
6 180 w/oil 205
7 177 w/oil 203
8 185 w/oil 195

*I wasnt able to get a completely equal amount of oil into each cylinder which may be why some readings were lower.


This engine rips, hard, but it just smokes alot. At idle I can barely see it, but if I stomp on it or am decelerating while in gear, its blowing smoke.


Thank you,
Ryan
 
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77RHINO

77RHINO

Full Member
Joined
Feb 22, 2011
Messages
308
I haven't done a leak down test, I don't have that tool yet. Can you rent those? The plugs have oil residue on them, as well as the intake valves.
 

pcf_mark

Bronco Guru
Joined
Jun 11, 2010
Messages
3,574
Wow you are going to get pummeled with ideas so better get ready!

Looking at your build it must run amazing - that cam / head / intake must pull like a beast.

Unless you have a real issue like the engine was not broken in right or the oil rings were installed incorrectly you are drawing oil from somewhere and sending it out the exhaust pipe. Can you pull the plugs and show us a picture?

Guesses:
1) PCV does not have a baffle in the valve cover
2) Intake is not machine at the same angle as the heads / intake gasket problem and you are drawing oil up from lifter valley
3) Intake or head is cracked sucking oil out of the valley
4) Big cam part I: Your cam has some beastly lift - if you do not have at least .060 between the bottom of the retainers and valve seals you smashed the seals to death and they are sucking oil.
5) Big cam part II - if you do not have at least .060 between the center coils of the springs you may have coild bind. This can have a really bad effect on valve guides and retainers. Beat up the guides they use oil.
6) Big cam part III - Are your rockers clearning the retainers with at least .060 at mid lift? If not the rocker can push the valve around taking out the seal and the guide.
7) With the rollers did you install oil restrictors? Not necessary but you do not need a ton of oil upstairs with rollers. Maybe you are pumping a ton of oil upstairs - take it for a blast then pull the oil fill and see if the valve covers are loaded.

Plug pics will tell a lot.
 
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77RHINO

77RHINO

Full Member
Joined
Feb 22, 2011
Messages
308
Thanks Mark!

I am concerned with the rings, just because it seems like I have tried just about everything else so far. to answer what I can below:

1) - Switched to factory '96 ford valve covers with 4-5" baffles under both PCV port and oil fill ports
2) - Just installed latest correctly-fitting gaskets on Sunday, don't know if that could be occurring or not. Intake runners do have oil residue on them but it could also be from PCV system.
3) - Heads/intake were bought new, have not closely inspected for cracks but will next time it is apart.
4) - The beehive springs came installed on these heads, and are supposed to be good for .600 lift.
5) - There is only one spring per valve, not a dual-spring setup
6) - The rocker seems to ride perfectly in the center of the valve stem, I haven't seen any evidence of pushing too far
7) - no oil restrictors, I haven't come across that term before

It looks like my contributor status expired, but there are pics of the plugs in the 2nd link. They look pretty similar, just a little blacker now but just as wet.

Thank you!
 

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
8,604
I agree with your concern about the rings BUT if in a couple hundred miles you can see fresh oil on the intake valves then that is/can be a big part of the problem...even tho you did some fresh valve work-like however said you must have a lot of oil going past the valves and you are burning it up!
 

pcf_mark

Bronco Guru
Joined
Jun 11, 2010
Messages
3,574
Check between the coils at max lift. By this I mean looking right at the stack can you fit a paper clip between coil 5 and 6 (for example)? Looking deeper can fit the paper clip between the bottom of the retainer and the valve seal?

This explains it well

http://www.lunatipower.com/Tech/Valvetrain/ValveSpringTech.aspx

Oil rings are really hard to foul up. Do you know if the shop used low tension drag racing rings? They don't last long and lose tension which can cause this but you have to ask for that stuff. No one would use that in a street build. If you had oil in the intake runners your problem is not rings - that can't get back up through the intake valve w/o a lot of work.

My money is on smashed seals.
 

Vintagetin

Jr. Member
Joined
May 19, 2017
Messages
58
If you are running 2 PCV's that is your problem. I installed 2 PCV's on a 302 ford 25 years ago because my thinking was if 1 is good 2 is better. I drove the vehicle on about a 200 mile trip and almost run it out of oil. I removed 1 PCV and put a vented cap and solved my problem. Just thought I'd mention it due to my issue.
 

pcf_mark

Bronco Guru
Joined
Jun 11, 2010
Messages
3,574
"PCV routed from top of passenger valve cover into base of carb, oil cap w/line to base of air filter - Now running larger dia. PCV line to increase flow
factory '96 valve covers w/good baffles"

Does this mean one PCV in one valve cover and the other is filtered air?
 
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77RHINO

77RHINO

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Joined
Feb 22, 2011
Messages
308
Yes Mark, passenger VC has the PCV going to the base of the carb, the drivers VC has a port right underneath the cap that I ran a line to the base of the air cleaner, getting filtered air.
I am going to try the paper clip test later tonight and I hope that has some merit to it, I guess that would just require shorter pushrods?

But If the air filter has vacuum, and the carb has vacuum, does that prevent a steady flow through the PCV system if it has vacuum on both sides?

Vintage, I am only running one PCV but that's good info to know.

Timmy, I tried the no-PCV test a month ago and the rear main leaked more. I believe the PCV is playing a factor, but with the consumption I'm having, I think there's another underlying issue.
 

Timmy390

Bronco Guru
Joined
Jan 1, 2011
Messages
5,609
Loc.
Conway, AR
Timmy, I tried the no-PCV test a month ago and the rear main leaked more. I believe the PCV is playing a factor, but with the consumption I'm having, I think there's another underlying issue.

Well that sucks.....

Man rear mains can really pump out the oil. I know your smoking badly but that rear main could be a gusher......

That 96 block is the same year as mine and being a one piece the crank either has a groove or it was installed dry and is now burned up or it's not seated properly.

Tim
 
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77RHINO

77RHINO

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Feb 22, 2011
Messages
308
I just installed a new one while I had it out and after driving it 3 days in a row, so far no leaks yet. That's why I'm hesitant to try the no PCV test again against new seals! I pulled the engine to install a new throwout bearing, rear main, and pilot bearing and swapped the intake gaskets while I had it out. I fixed the noises and leaking but not the smoking!
 

AZ73

Contributor
Bronco Guru
Joined
Mar 28, 2012
Messages
3,541
Has it been burning since the rebuild? Did it take you a while to get it started first time? I would pull the PVC and see how much blowby you're getting.

I worked on a new motor once that the guy couldn't start. His distributor was in 180 degrees off. After trying to start it for hours, he called me. I got it started almost immediately, but it burned oil like crazy. He had flooded the cylinders with fuel trying to start it, washing off the oil from the walls and the rings scored them. You might be able to look at them with one of those cameras that can fit through the spark plug hole. Look at the outside wall of the cylinders.
 
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77RHINO

77RHINO

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Feb 22, 2011
Messages
308
AZ, yes it has been since burning since the rebuild. I don't drive it a whole lot, longest trip in 2 years was about 560 miles round-trip and it burned roughly 8 quarts total. By the end of the trip I was using Lucas oil stabilizer, marvel mystery oil, and any oil I could find at local spots. I'm guessing it has 2500 miles on it total and that's probably a high estimate, just lots of small round-town trips where I add a quart before I leave. It runs great, I have tried deleting the PCV as well as swapping out different PCVs but I still cant get it to quit burning. Last time I had the heads off (July) the walls seemed to be in good shape. I did read somewhere recently that synthetic assembly lube can cause rings to have a hard time seating, which I used, but I still wouldn't think it'd burn this much oil or take this much time to seat the rings?
 

blubuckaroo

Grease Monkey
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Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
You said you replaced the valve stems. I'm sure you meant the seals. But how tight are the valve guides themselves? If you are using the standard umbrella type seals, and still have loose guides, it's burn oil and smoke on start-up and deceleration, just like you've described. All those umbrella type seals do is shed oil from the valve stems. Like an umbrella.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,833
OK, an adaption to the no PCV. Run a catch tank, a large one. Put it in the PCV line. Make it out of 3" home depot PVC if you have to. Stuff a few Brillo pads inside, or scrotch bright pads. What you are wanting to do is catch any oil mist and let it settle to the bottom. So that is why you want it a bit oversized, to slow the air speed down and let the oil drop out.

If you are catching the majority of the oil you are loosing this way, you have a PCV problem.

If it is fairly dry compared to what you are loosing, the problem is elsewhere. From what you have done already, I'm thinking rings. Maybe the dot was marked on the wrong side, maybe they are the odd rings that the dot is suppose to be on the other side? Oil scraper didn't go together right? There is a fair amount of stuff that can go wrong with the rings.
 

WheelHorse

Bronco Guru
Joined
Nov 22, 2004
Messages
2,491
How much, if any, oil is in the PCV line into the base of the carb? Is it dripping oil?

I'm with the others, leak down test is warranted at this point. A lot of blow by past the rings could cause the oil to be pushed past the pcv.
 

englewoodcowboy

Lick Creek Restorations
Joined
Jul 25, 2010
Messages
4,200
I had a similar issue, I ended up finding that it was injesting the oil through the pcv system and had to increase the length of the baffle quite a bit to better control it.
 

Timmy390

Bronco Guru
Joined
Jan 1, 2011
Messages
5,609
Loc.
Conway, AR
OK, an adaption to the no PCV. Run a catch tank, a large one. Put it in the PCV line. Make it out of 3" home depot PVC if you have to. Stuff a few Brillo pads inside, or scrotch bright pads. What you are wanting to do is catch any oil mist and let it settle to the bottom. So that is why you want it a bit oversized, to slow the air speed down and let the oil drop out.

If you are catching the majority of the oil you are loosing this way, you have a PCV problem.

If it is fairly dry compared to what you are loosing, the problem is elsewhere. From what you have done already, I'm thinking rings. Maybe the dot was marked on the wrong side, maybe they are the odd rings that the dot is suppose to be on the other side? Oil scraper didn't go together right? There is a fair amount of stuff that can go wrong with the rings.

My next suggestion was to run an oil separator. Lots of guys run them on "blown" applications such as Hellcats and Shelbys. I'm going to be adding one to my Shelby soon.

In this case you can see what's being trapped (if any) and then know for sure if it's PCV related or not.

Tim
 
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