Oil Pressure Frustration

[Arlene1965]

Don't see how blow-by can be an issue, my compression is excellent (165-170). I had a blow-by issue one time before the rebuild, had broken compression rings. It did result in fluctuating pressure and fouled plugs, so I can see how it would be something to consider. All kinds of weird internal pressures on that occasion. Actually had exhaust blowing out of the oil-fill tube. But that problem was obvious, compression in the affected cylinder was barely 50, and replacing the piston solved it immediately. With the recent rebuild I had the cylinders bored out with new pistons and rings. With the resultant good compression I am not inclined to think blow-by is the cause.

For now I am leaning toward the PCV / internal airflow possibilities. Will experiment a bit.

 

[drag-200stang]

Witch way is the rod oil spurt hole facing ,cam or major thrust side" passenger side"? I do not think this would cause this ,but it would not help.

So the oil spurt hole is it right, facing the away from the cam?

 

[CNC-Dude]

what would happen if all the rings were lined up @ assembly (rather than clocked away frm @ other)?
Unrelated?

Although this isn't an ideal situation, all the rings on each piston eventually align with each other periodically because they all rotate around in the ring grooves as the engine is running. Many people think that when you build an engine the rings stay in the orientation you place them in when you put them on the pistons, but they don't.

 

[chad]

Thanks, don't seem 2 B the prob in this case…
I'm wid da pcv system as the prob here…
let's C

 

[Arlene1965]

For a week now I have driven it without the PCV valve. I simply removed the valve and plugged the vacuum line to the intake. The valve cover has internal baffles where the PCV valve goes, so oil splatter is minimal.

It hasn't made much difference. Pressure fluctuates as before, plugs are just as fouled.

I have now spoken to a lot of different people about this. I have addressed everything conceivable and it's still happening.

 

[chad]

It's been awhile since I read the initial post (pretty long) have not really followed the thread, am not an expert (far from it). But -
there are quite a few components involved in this system and each might have to be gone over systematically to ID/diagnose this specific problem. Perhaps it is beyond this type of format (internet group) for following up? It might be time for some 1 who is knowledgable locally to start at the beginning and go down each aspect. If not following up on the 'open valve cover" idea, Y not plumb the pvc system properly rather than leave it open. That might B the last trial - tube from VC w/operating pcv valve installed to carb to VC . That wuz my crackpot thought for the prob...

 

[62Ranchero200]

For a week now I have driven it without the PCV valve. I simply removed the valve and plugged the vacuum line to the intake. The valve cover has internal baffles where the PCV valve goes, so oil splatter is minimal.

It hasn't made much difference. Pressure fluctuates as before, plugs are just as fouled.

I have now spoken to a lot of different people about this. I have addressed everything conceivable and it's still happening.

@Arlene1965,

Have you tried cutting the top off of an old value cover, then running the engine until warm and as close to your road RPM as you can? This will tell you if too much oil is accumulating in the head, or it you have some other issue such as a faulty oil pump pressure relief valve.

Thanks,
Bob

 

[Arlene1965]

Many people have mentioned the oil pump relief valve, suggestions about which I have some doubts.

This problem began with an older pump, a rebuild I first installed in 1998. Worked fine on the pre-rebuild engine, pressure was always rock-steady at 35-40, hot, when over 2000 RPM (a bit lower with lower RPM. Perfectly normal). The radical fluctuation started with this old pump, after the rebuild. Exactly the same thing happened when I replaced it with a brand-new pump. I have a hard time believing that the old pump suddenly developed this problem immediately after the rebuild, then the very same problem appeared in the brand-new pump.

But, just how would I check the relief valve?

 

[DannyG]

Might want to look for debris in one of the oil galleries ?
Remove the oil filter and try some suction ( vacuum cleaner hose ?)in the passageways to dislodge anything ?
Keep us posted...
DannyG

 

[Arlene1965]

Oil galleries are clear. Installed new lifters with the new camshaft, pistons etc.

Some time ago (June?) I was checking the oil pump mounting, pick-up tube, screen etc. and with the pump off I put my air hose in the oil port that the pump feeds. Got a strong stream of oil shooting out the side of the block, that port that connects to the oil pressure sensor / hose for my (mechanical) oil pressure gauge. Real messy. I am sure that the air pressure would have dislodged any obstructions. Did it a second time with the air pressure the opposite direction, starting with the port on the block. I also applied air pressure directly to the crankshaft oil ports when underneath examining the bearings. I saw no sign of any obstructions. And, from the beginning I have thought that if it were an obstruction, it would affect the pressure at all times, not just after the engine heats up.

Also had a look at the valve lifters when I had the head off, and found no problems. Did not disassemble them, but examined to make sure there was no binding or blockage.

On examination everything seems perfectly normal. The engine runs beautifully, until the plugs become oil-fouled and begin to fire poorly.

I am at a total complete loss on this. I have spoken to several professional mechanics, technical representatives at Summit Racing, home mechanics etc and no one has yet to come up with anything I haven't tried. I have never encountered an engine problem this baffling, and no one I ask has any idea what it is.

There is one question I have posed for which I have gotten no answer. . . could the camshaft bearings be installed improperly? I didn't to it myself, so I don't remember if they have oil ports like crankshaft bearings. My thought here is that if one of these bearings is mis-aligned, it would cause a blockage and oil would end up someplace where it wasn't intended. Haven't actually seen it yet but I suspect that oil is welling up in the lifter galleries, rising up those holes the push-rods go through, then flooding across the top of the cylinder head.

This winter I am likely to remove the engine and take a close look at everything. Infuriating. I had it bored out, with new pistons camshaft all new bearings etc with the intention that I wouldn't have to do it again for a long time.

If this turns out to be a mis-aligned cam bearing it will be hard keep any composure when I tell the machine shop about it.

 

[chad]

It's hard for me to tell if you've tried these suggestions:

1) plumb the pvc system properly;

2) take the top off an old value cover, then running the engine - observe if oil flows correctly;

Failing problem ID then it’s time for more drastic measures:
3) disassemble head, clean all oil passages, inc. entire rocker assembly, assure the oil passage near # 11 head bolt wuz enlargened after mill pass 2 true gasket surface (block & head),

4) then the block oil passages. (Note: no paper gasket @ oil pump).

My final offering beside what I've left above...

 

[cr_bobcat]

Oil pump drive shaft look good on both ends? The part of the distributor where the drivenshaft fits isn't rounded? If the shaft starts slipping that could do it i reckon. You wouldn't be miss firing because the cam gear is still fine. Maybe you checked that already....

 

[Arlene1965]

The one thing I haven't done is observe it closely while running. This is something I intend to do before embarking on anything more radical like a total disassembly. I have run it without the valve cover, but only for a few minutes to observe oil flow through the rocker assembly.

Here I did try something unorthodox, which I haven't mentioned. While I had the head off I tapped threads into the oil port underneath the rearward mounting pedestal for the rocker arms. That's supposed to be the only source of oil to the top of the cylinder head. My idea was to install a plug which would restrict oil flow. It can't possibly get loose. . . I tapped the threads only about 3/4" deep, and the plug can't back its way out very far once the pedestal is torqued down. I tried a succession of plugs (5/16" 24) with holes drilled in them to restrict oil flow. After installing a plug I always ran it for a few minutes with the valve cover off to see if there was enough oil flow through the rocker arm shaft. A surprising amount of oil flows out the rocker arms even with a fairly small hole in the plug. It made no difference, the fluctuation continued as before. This more than anything convinces me that oil is getting up there from some other source, and the only answer is that it's welling up from the lifter gallery.

In June I rebuilt the rocker assembly. Sealed Power makes new shafts, and I salvaged arms and pedestals from a '63 Falcon, which were in better shape than the original assembly I got with my car. I thought perhaps that worn surfaces might be letting too much oil squirt through. Rebuilt rocker assembly looks great, but it didn't make any difference.

I don't know what else I can do with the PCV system. It's simple enough, and it's plumbed exactly as in my Ford Shop Manual, with a new Valve. I have put it back to its original configuration after a few experiments.

And, don't think I mentioned this either. . . I replaced the hex-drive shaft for the oil pump some time ago. Summit Racing has them off the shelf.

So, a closer observation, probably followed by disassembly are the only things left to do.

Thank you all for your interest. It was refreshing NOT to re-explain the same things over and over and over (as I have done with a number of local mechanics). Not one local "expert" has taken me seriously when I posited my theory of the excessive oil on the cylinder head (of which I am convinced).

As a final note --- almost unrelated --- Summit Racing has lately been carrying more and more parts for this engine! One exciting find was a complete, new, clutch set (disc, bearings, pressure plate, alignment tool). For years I had wanted one, my cannibalized-mixed-and-matched clutch was on its last leg. Go to the Summit site, specify your application and you may be surprised.

 

[chad]

don't forget for what I've seen to be :
quality, price, availability - vintageinlines.com
cater exclusively to the falcon motor

 

[Arlene1965]

Evidence!

I have found proof that it really IS excessive oil to the top of the cylinder head!

Got the engine hot with a bit of highway run, went home, immediately removed valve cover and re-started the engine. Decided to ignore whatever oil spillage resulted.

Revved the engine to about 2000-2500 and watched. Very quickly saw oil spurting out of the push-rod holes, cylinders #5 and #6. These are also the plugs that have the worst oil fouling. The other cylinders showed no such oil welling up.

I posted a video on Youtube right here: https://www.youtube.com/watch?v=PLdwfIUjq9Y

At 25 seconds to the far left you'll see Cylinder #4 Exhaust push-rod, with very little oil. To the right are Cylinders #5 and #6.

This is only about 30 seconds, in the garage, at about 2000-2500 RPM. How much worse on the highway at 2500-3000 for extended periods?

Could someone please have a look and tell me what you think?

 

[RichCreations]

bad lifters, or out of spec lifter bores?

Evidence!

I have found proof that it really IS excessive oil to the top of the cylinder head!

Got the engine hot with a bit of highway run, went home, immediately removed valve cover and re-started the engine. Decided to ignore whatever oil spillage resulted.

Revved the engine to about 2000-2500 and watched. Very quickly saw oil spurting out of the push-rod holes, cylinders #5 and #6. These are also the plugs that have the worst oil fouling. The other cylinders showed no such oil welling up.

I posted a video on Youtube right here: https://www.youtube.com/watch?v=PLdwfIUjq9Y

At 25 seconds to the far left you'll see Cylinder #4 Exhaust push-rod, with very little oil. To the right are Cylinders #5 and #6.

This is only about 30 seconds, in the garage, at about 2000-2500 RPM. How much worse on the highway at 2500-3000 for extended periods?

Could someone please have a look and tell me what you think?

 

[bubba22349]

that looks like it's coming up from below :wow: i.e. the lifter side cover cavity! Now you might want to also pull that side cover and check inside for clogged up oil return holes. One other thing did you ever do a compression test yet? The head gasket may be blown or leaking between those two cyclinders. You could also try retorquing the head bolts again while the engine is warmed up too. Good luck

 

[drag-200stang]

It is not the cam bearings!

 

[drag-200stang]

that looks like it's coming up from below :wow: i.e. the lifter side cover cavity! Now you might want to also pull that side cover and check inside for clogged up oil return holes. One other thing did you ever do a compression test yet? The head gasket may be blown or leaking between those two cyclinders. You could also try retorquing the head bolts again while the engine is warmed up too. Good luck

I concur, but no side cover on sbi6 it will be harder to check the 3 drain back holes.

 

[Arlene1965]

I have no evidence that there is a head sealing problem. Broke a head bolt some time ago (it was about 50 yeas old!) and replaced them with a stud set from Classic Inlines, so I am confident that they are torqued down well. Compression has always been excellent, 165-175, very little variance between cylinders. I have none of the other indications of leaky head gasket. . . no coolant loss or coolant in the engine oil, etc.

I got the valve lifters new as part of a camshaft set that Mike at Classic Inlines recommended. I suppose it's possible that something is wrong with them, but at this point it's one thing that I haven't addressed. The feel as if the bore is correct, that is, they don't feel loose, but feel alone probably isn't a good way to judge them.

Just what could be causing this? I need to check the parts I have before replacing them, I hate getting new parts that later prove to be unnecessary. Is there a specification for the diameter of valve lifters? They would be easy enough to measure. And, how would I go about checking the oil pump relief valve? I really don't think this is it, but I don't want to go getting a new one, since I already have two that are probably all right to begin with.

And, someone said it's not the cam bearings. My thought on this is that if they had an oil port like crankshaft bearings, a mis-alignment might cause problems. But I don't remember if these bearing have such an oil port. It would be nice to know that it's not the bearings, I'd like to be able to resolve this without removing the engine.

It does feel so good to actually find something, however much I don't know (yet) how to fix it.