Pulled the motor..again... Latest update on page 4

77RHINO · Jun 25, 2017

I finally pulled the motor out this weekend to open it up and see what has been causing all my oil consumption. At first glance, the only thing I noticed was that one rocker was loose/off the valve a little bit but not enough to damage the valve or rocker arm. I went ahead and took the heads off, cleaned everything up, lapped the valves and put in new valve stem seals. The originals didn't seem to be in bad shape like I thought (2 years old). As the pics below show, there was alot more sludge/carbon buildup on the intake valves than I was expecting to see. It looks there was enough on there to not allow the valves to close properly, and you can see oil/fuel leaking out from under the intake valve in one of the pics. What do yall think is causing this? What else do I need to be looking for with the heads off?

blubuckaroo · Jun 25, 2017

What did the intake manifold gaskets look like?

77RHINO · Jun 25, 2017

They looked great, only had them in for about 3 months! I swapped them thinking that may have been the problem but knew as soon as I fired it up after install that the problem still existed. This time I pulled the whole motor out hoping it would be the valve stem seals. I just want to make sure I am not leaving something else unchecked before I start putting it all back together.

blubuckaroo · Jun 25, 2017

Yes, that much gunk on the intake valve stems indicates an upper end problem rather than rings.

Broncobowsher · Jun 25, 2017

I would be looking at rings. Bad rings will not only pump oil up into the combustion chamber but the added blowby will push into the PCV and breather to run in the top side.

77RHINO · Jun 25, 2017

Thats good to hear! This would take it back to a PCV/vacuum problem if it still does it after the new seals, correct? I just installed a vac gauge in the truck so I can see what it is doing as I drive. Now I just need to learn what levels of vacuum mean as far as carb tuning, timing advance, etc.

77RHINO · Jun 25, 2017

Whoops, posted before I saw bowshers comment..What all do I need to look at regarding the rings?

September 1972 · Jun 26, 2017

Bad ring sealing might be a problem but by the looks of the intake valve that's the oil burning problem after 2 years. Follow the ford factory manual engine rebuilding procedures and you can't go wrong.

dholder · Jun 26, 2017

Since you can't be sure of the cause, I would re-ring, lap all valves just to clean them up, and be very particular with installation of intake gasket.

pcf_mark · Jun 26, 2017

Looking at the valve I would say the valve stem seal(s) are probably failing. Oil from rings would have a hard time getting up behind and intake valve like that. I would have guesses intake gasket too because it is not widespread to all cylinders.

Those are nice heads I am sure they are good quality. But I would slip that intake valve back in the guide until the valve almost seats and see if it rocks side to side from top and bottom. If so the guides are worn. Some aftermarket heads (and guides) are made of cheap and easy to machine material. Silicone bronze is preferred.

You could be lucky and maybe your cam / spring / retainer package just beat up the valve stem seal. You have the valve in the photo but not the guide or other parts. If at higher rpm to retainer gets too close it can contact the valve seam and crack it then it leaks.

Next time before you pull the engine and head do a compression test dry and then add oil. That will tell you if your rings are good.

B RON CO · Jun 26, 2017

Hi, as mentioned, see if the valve is snug and smooth in the guide. Put the valve in the guide and put your finger over the guide where the seal goes to seal off the top. When you pull on the valve there should be suction and the valve should pop back a little unless the guides are worn. A machinist can measure the valve to guide clearance. Good luck

KyleQ · Jun 26, 2017

The heads are off - bring them to a machine shop and have the guides checked/replaced. That is coming from the valve seal and that is waaay excessive.

Rustytruck · Jun 26, 2017

What little I can see of the cylinders they look smooth and shiny. I would pull the piston from the cylinder with the most oil and check if the rings were installed correctly. Personally i would ball hone the cylinders and replace the rings while i was in there. Were these new heads when installed or used heads? What temperature thermostat were you running?

DirtDonk · Jun 26, 2017

And while we're on the subject of PCV, where/how is yours plumbed? Into the intake like a later 5.0, or in a valve cover like an earlier design?
Either way, what kind of baffling are you using near the pickup point and where is the main vacuum taken from?

Did we talk about that somewhere else? Even if it's not the problem, it's worth discussing.

Paul

DirtDonk · Jun 26, 2017

Looks like the exhaust was consistently getting past some parts of the gaskets too. With a full leak in at least one spot.
Running headers or stock type manifolds?

Paul

77RHINO · Jun 26, 2017

Thanks for all the responses guys, I will answer what I can now, and can get to the rest tonight with more pictures and info. This engine build is roughly 2 years old with new parts except block, pushrods, connecting rods and oil pan:
Engine info:
1996 351w block bored .030 over
Ford Racing GT40X 64cc heads (bought new including beehive springs)
Comp 35-514-8 camshaft (.544/.555)
roller rockers
new hyd roller lifters
original pushrods
KB +6.50 Pistons w/ mahle rings (moly top ring, iron 2nd and 3rd)
Edelbrock carb and intake
195* T stat
PCV routed from top of passenger valve cover into base of carb, oil cap w/line to base of air filter
WH longtube headers
Compression is probably in the upper 9s
Holds about 18-19" 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.

I can't run anything but premium fuel or else it will diesel/run or backfire when I turn the key off, base timing advance is about 12*

I will upload more engine pics tonight, thanks for all the help guys!

DirtDonk · Jun 26, 2017

Maybe the baffling in the valve cover is insufficient for the oil flow near the PCV valve?
Not that I'm leaning towards the PCV being the only problem, but if it's adding a little to another issue, then it's just going to contribute to more consumption.

Anyway, good luck on all the tracking down.
Did you measure for pushrods and determine that the originals were the right size? With all that new stuff on top of the engine, it's not unheard of, but still kind of a surprise.

Paul

73azbronco · Jun 26, 2017

Cylinder walls look rather smooth? Can't really tell.

I would bet wrong PCV, or just plane unbaffled valve cover? Exactly what PCV part number?

Rustytruck · Jun 26, 2017

do you have oil in the valve cover to air filter line?

pcf_mark · Jun 26, 2017

The cranking compression is pretty impressive it must have smallish chamber and / or a serious RV torque cam. With 18" vacuum it could be both. I have no worries about the short block with those numbers as long as you have good oil pressure.

Is there oil in all the cylinders it looks like some are worse or is that my imagination? I think Dirt Donk may be on to something if your PCV was not routed correctly you could be literally sucking oil out of the engine! It would look like loose guides but really be from PCV being distributed with the intake charge.

When I installed roller rockers I had to remove the baffle in the valve covers. This is OK with EFI if that is the air "in" but if that is where your PCV is connected then it goes to the back of a carb you could have found your problem.

Pulled the motor..again... Latest update on page 4

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