Pulling my hair out over this misfire

[runmikeyrun]

Ok. The truck was running great until one day a couple weeks ago it wasn’t. I had parked it for a week and went to head out for a car show that evening. It was running a little rough, but ran better when I gave it some gas. As I went down the street the missing got worse. No backfiring, just a miss that was getting progressively worse. Took it back after a 1/2 mile and the radiator was boiling over a touch (never happened before) and I had oil smoke wisping out of the oil fill tube breather.

History: It’s a Y block with Holley 4bbl and pertronix ignitor (first gen). Everything had been cleaned, rebuilt etc this winter and the truck had done about 30-40 solid miles with no issues and was running and idling Great. Pertronix is new this winter, as is all the wiring on the truck, the cap, rotor, plugs etc. The only thing I did in between the truck running fine and the start of the issue was install a 12v power port, which worked fine.

Back to the truck. Parked it and figured I lost a head gasket due to overheating. Oil and coolant ok.

Stuck thermostat contributing to overheating? Pulled housing, no thermostat in place. Changed the coolant because it was really rusty and flushed the system. Belts tight to spec. Checked the fan shaft and no play, spins freely.

The one distributor cap clip was only half on, prompting me to think the cap got loose and moved, changed the timing etc. Took off the cap- inside was chewed down (looks like the cap was a touch too short) and some fine brass shavings inside but ok otherwise. Cleaned the dizzy out, replaced the cap and rotor. Re-timed, still misfiring.

Since the cap was still loose, I figured I needed to tighten the clips. Replaced one assembly and got that side tight, but the other is pinned against the firewall and it’s still a little loose. The cap does have just the slightest amount of play but is 100 times better than it was.

Reset the timing to 10 btdc, where it was before when it ran perfectly.

Truck is still misfiring.

Cleaned all the spark plugs- many were sooty, a couple oily. Still misfiring.

Started pulling wires off the cap one at a time to isolate the bad cylinder(s) and it runs the same with pretty much any wire pulled off, the same rough idle. Didn’t seem to matter which wire I had off it still missed. Sometimes a with a certain wire off it would barely start, other times with that same wire off it still just missed. I could not isolate the problem to any single cylinder. After 8 hours I went home pissed off.


Fast forward a couple weeks. Today I came in and thinking I may have bumped a wire on that fuse block putting in that 12v power port, I checked the wire feeding the ballast resistor from the fuse box and it was loose. I plugged it back onto the terminal securely. That’ll do it! Nope. Still missing.

I figured maybe the Pertronix wasn’t getting enough voltage. Ground bad? I cleaned the dizzy base plate and ran a ground wire from the hold down screw of the pertronix to the plate. Still missing.

Checked my ballast resistor and coil resistance. Now, the resistor I ordered was 0.7 ohm and coil 0.8 ohm since the Pertronix wants to see a minimum of 1.5 ohms. I’m getting 1.6 across the resistor and 1.6 across the coil, for a total of 3.2 ohms. I’m getting 12.6v at the fuse side of the ballast resistor (which is where the Pertronix positive wire is connected) and getting 6.6v at the positive terminal of the coil. Theoretically, the coil should be ok with 6.6v since I assume the resistances of those two items are the same as before, right? I didn’t measure the coil or resistor when I bought them, so I’m assuming they were both like that.

Idle is rough. It does run smoother the higher I rev it. It’s just a dog until I get the revs up. This is very similar to how it ran before I re-timed it, cleaned the carb, did a tune up etc except I have done all of those things.

The kicker- the pass side exhaust pipe is showing evidence of burning a little oil and the driver’s is not. And every time I shut the truck off, little wisps of bluish oil smoke come out from that filler tube breather. I’m not convinced it’s related but also not convinced it’s a separate issue.


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[fordor41]

my instructions for the Pertronix igniter 1 said to supply 12V to the ignition, don't go thru the Ballast resistor.

[cousinjd]

Vacuum leak????

[40cpe]

compression check?

[Lanny]

Originally Posted by 40cpe

compression check?

============================================



And when you check compression, hold the throttle plate wide open
with something, so the cylinders can suck in air, so you get an
accurate compression reading.






.

[runmikeyrun]

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Originally Posted by fordor41

my instructions for the Pertronix igniter 1 said to supply 12V to the ignition, don't go thru the Ballast resistor.

Yup. Mine is connected before the resistor getting full 12v from ignition power


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[runmikeyrun]

Originally Posted by cousinjd

Vacuum leak????

A good thought. I’m gonna look around a little, there’s really no vacuum lines anywhere though (distributor has mechanical only, it’s a 1960 truck dizzy).

Will give the intake manifold, carb etc a good spray with wd-40 and see what happens.


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[KULTULZ]

A basic low cost vacuum gauge will most likely diagnose the problem(s), or lead you to the source.

[KULTULZ]

Originally Posted by fordor41

...my instructions for the Pertronix igniter 1 said to supply 12V to the ignition, don't go thru the Ballast resistor.

KEY WORDS SPOKEN HERE-

You also need to supply the correct VOLT to whatever coil design you have chosen to use.


The PERTRONIX I can fail if the IGN SW is left on with engine not running.

The DIST you have chosen (only mechanical advance) may have the incorrect advance curve for your application. Did you ever decide if the engine is PASS CAR or HD TRUCK?

[KULTULZ]

Originally Posted by runmikeyrun

Took it back after a 1/2 mile and the radiator was boiling over a touch (never happened before) and I had oil smoke wisping out of the oil fill tube breather.

... hmmpf ...

Just wondering, did you do the crankcase ventilation modification you posted earlier about?

Earlier Post Here - https://www.fordbarn.com/forum/showthread.php?t=245537

[runmikeyrun]

Originally Posted by KULTULZ

KEY WORDS SPOKEN HERE-

You also need to supply the correct VOLT to whatever coil design you have chosen to use.


The PERTRONIX I can fail if the IGN SW is left on with engine not running.

The DIST you have chosen (only mechanical advance) may have the incorrect advance curve for your application. Did you ever decide if the engine is PASS CAR or HD TRUCK?

I’m quite sure I have not left the key on at any time, I’m really diligent about that.

I’ll have to look into the coil, but the truck was running fine before so I think my coil setup is ok.

The block I have is 55-57, but distributor, intake manifold, and exhaust manifolds are all truck items. So not real sure LOL.

I have not performed the road draft tube modification yet that I discussed earlier, just haven’t had time.

I am going to pick up a vacuum gauge and go from there, thanks!!


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[scicala]

Use a timing light to double check that the base timing is correct. Specs say about 5 degrees BTDC, but 10 degrees works better on Y-Blocks. then with the timing light, make sure the timing is advancing when you rev the engine.
Retarded (or no) ignition advance causes very high exhaust temps and can cause overheating.


Sal

[runmikeyrun]

Originally Posted by scicala

Use a timing light to double check that the base timing is correct. Specs say about 5 degrees BTDC, but 10 degrees works better on Y-Blocks. then with the timing light, make sure the timing is advancing when you rev the engine.
Retarded (or no) ignition advance causes very high exhaust temps and can cause overheating.


Sal

Agreed, I think when the cap shifted it retarded the timing. It has since been set back to 10 btdc where it ran great.


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[KULTULZ]

Originally Posted by runmikeyrun

I’m quite sure I have not left the key on at any time, I’m really diligent about that

Just saying, the PERT I is delicate.

I’ll have to look into the coil, but the truck was running fine before so I think my coil setup is ok.

It all depends on what style coil you are using, internal or external resistor and if HP, you follow the manufacturer's instructions. It may take a while to damage a coil.

Think again about the distributor you are using. It is setup for a low RPM HT engine. It may not have correct timing curve if used on a higher RPM car or light truck engine. Improper/inadequate advance leads to over heating.

Be careful of the dist cap you decide to use. Aftermarket may be junk. You didn't have an earlier LOAD-O-MATIC cap on there did you?

[runmikeyrun]

Originally Posted by KULTULZ

Just saying, the PERT I is delicate.

It all depends on what style coil you are using, internal or external resistor and if HP, you follow the manufacturer's instructions. It may take a while to damage a coil.

Think again about the distributor you are using. It is setup for a low RPM HT engine. It may not have correct timing curve if used on a higher RPM car or light truck engine. Improper/inadequate advance leads to over heating.

Be careful of the dist cap you decide to use. Aftermarket may be junk. You didn't have an earlier LOAD-O-MATIC cap on there did you?

I see what you’re saying about the distributor and advance curve. I didn’t have an overheating problem until the day it ran really rough. I think so far the advance curve is ok, we don’t get the truck much over 35mph and I keep the revs low. It’s an old truck and we’re unsure of the previous maintenance so I baby it.

I put a Napa cap on it this time, for a 1960 truck. I had used a cap for a 1957 car before I knew what distributor I had. I think it was just a hair too short inside.


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[Daves55Sedan]

Wouldn't an easy way to determine which cylinder is mis-firing be to take an inductive timing light and clamp the sensor around each spark plug wire one-by-one while engine is running. If lamp does not flash on one cylinder, there's your misfire sure as heck. I'm not sure if you can detect misfiring due to low intake vacuum, but it will sure run lousy with low vacuum. Your intake vacuum on a Y-block should be about 20 inches of mercury.

[runmikeyrun]

Originally Posted by Daves55Sedan

Wouldn't an easy way to determine which cylinder is mis-firing be to take an inductive timing light and clamp the sensor around each spark plug wire one-by-one while engine is running. If lamp does not flash on one cylinder, there's your misfire sure as heck. I'm not sure if you can detect misfiring due to low intake vacuum, but it will sure run lousy with low vacuum. Your intake vacuum on a Y-block should be about 20 inches of mercury.

Thanks for the heads up on the timing light. I was planning on doing that. The problem is most of the time I don’t have a helper to start the truck and sit in the seat while I mess around under the hood. I will definitely do that if my vacuum findings are inconclusive. Thanks for giving me the spec, I was going to have to look that up lol.


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[Daves55Sedan]

Originally Posted by runmikeyrun

The problem is most of the time I don’t have a helper to start the truck and sit in the seat while I mess around under the hood.

You don't need a second person to do that as long as the engine will idle by itself. An inductive timing light has a spring loaded clamp that easily fits around the spark plug cable near the spark plug. You just squeeze the clamp to insert it around the cable, then push the trigger on the timing light to see if the lamp is flashing. Then, squeeze the clamp to release it from the cable and move to the next spark plug.
You can check all the cylinders on a Y-block in just a few minutes this way. I have done it before many times (by myself).

[Milt K from Pa]

Mike,
A friend recently went through the same situation on a '40 Ford Pertronix conversion. Same brass filings in the distributor, rough idle poor running. He thought it was an incorrect coil and replaced it. Nothing helped so he went back to the factory points, ran fine. So he converted it to use standard points feeding an MSD box and all is well. If you get tired of fiddling with the Pertronix, try the old points.

Milt K from Pa

[KULTULZ]

Originally Posted by Milt K from Pa

Mike,


A friend recently went through the same situation on a '40 Ford Pertronix conversion. Same brass filings in the distributor, rough idle poor running. He thought it was an incorrect coil and replaced it. Nothing helped so he went back to the factory points, ran fine. So he converted it to use standard points feeding an MSD box and all is well. If you get tired of fiddling with the Pertronix, try the old points.

Milt K from Pa

... hmmph ...

THANX! for that info. I have read where PERTRONIX has been having quality issues of late.

[KULTULZ]

I WONDER

Did FORD continue LOAD-O-MATIC on the HT engine(s) after the 1957 PASS CAR changeover? I used to have all of this info but got rid of most of it years ago. FORD did continue LOAD-O-MATIC on it's inline six cylinder engines up to 1968.

Unfortunately the "Load-O-Matic" distributors were designed for simplicity and economy, rather than performance. The primary reason for this, is that the "Load-O-Matic" distributors have no provisions for mechanical advance. Instead they rely solely on relatively weak vacuum signals to sense changes in load and speed (rpm). As a result the distributors are very slow to provide spark advance when the engine is accelerated under load, making them a poor choice for performance applications.

This is also why we don't like the Petronics Ignition for anything other than stock applications. While the Petronics Ignition may improve spark quality, your still stuck with the poor operation of the "Load-O-Matic" distributor, and your carburetor choices are limited to those that are equipped with a "Spark Control Valve", such as the Autolite 1100. Bottom line, if you want to improve throttle response and overall performance, you need to ditch the early "Load-O-Matic" distributor, swapping it for a late model or aftermarket distributor with mechanical (centrifugal) advance.

SOURCE- https://fordsix.com/ci/Loadomatic.html

runmikeyrun-

You mentioned in an earlier post you found DISTRIBUTOR TECH (shop manual) on a reference site. I could never source it. Do you have the URL by any chance?

If this dist is LOAD-O-MATIC and/or a variation, it could also explain the dist cap differences.


MAYBE- https://www.ford-trucks.com/forums/1...butor-cap.html

[big job]

Gettin old a terrible thing. I keep maint. records for every thing. My dump truck a 1953
F900 last time it got points or a tune up was 1997 and it works for its keep. shame on
me. lol sam

[runmikeyrun]

Originally Posted by KULTULZ

I WONDER

Did FORD continue LOAD-O-MATIC on the HT engine(s) after the 1957 PASS CAR changeover? I used to have all of this info but got rid of most of it years ago. FORD did continue LOAD-O-MATIC on it's inline six cylinder engines up to 1968.


SOURCE- https://fordsix.com/ci/Loadomatic.html

runmikeyrun-

You mentioned in an earlier post you found DISTRIBUTOR TECH (shop manual) on a reference site. I could never source it. Do you have the URL by any chance?

If this dist is LOAD-O-MATIC and/or a variation, it could also explain the dist cap differences.


MAYBE- https://www.ford-trucks.com/forums/1...butor-cap.html

I believe it is not a load-o-matic distributor. Based on the number stamped on it (12102 C0TF) it’s from a 1960 292 cu. in. HD truck engine. This is the link to the 1960 Ford Truck service manual (thumbnails of every page) starts here:

http://www.oldcarmanualproject.com/m...ks/index1.html

Group 2 has ignition/distributor info. A couple of the relative pages regarding the distributor are the following.

This is an exploded view. It is mechanical advance only.


This one shows/explains how the governor system for that distributor worked, however I do not have the factory carb so I plugged these vacuum lines. The vacuum doesn’t have an effect on ignition timing, only to regulate the governor operation.






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[KULTULZ]

THANX!

I could not find that anyway I tried ...

[runmikeyrun]

Originally Posted by KULTULZ

THANX!

I could not find that anyway I tried ...

You’re welcome. Even though it’s hosted on their website, it’s hard to find the link for it.


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[runmikeyrun]

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Ok, time for an update.

I checked intake and carb baseplate nuts, all are tight. Haven’t sprayed any wd-40 yet to see if there are leaks.

Vacuum gauge at idle is reading about 14 (manifold vacuum) and the needle is bouncing. From what I’ve read it’s not just a low reading but it also means there is a problem with one or two cylinders and not all of them.

Still blowing blue smoke out of the passenger exhaust pipe.

When I pulled plugs on the pass side today #2 was wet and plug #4 had oil pooled inside of it (pic).

Head gasket? Cracked block? I’m gonna have to do a compression test.


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[dmsfrr]

Originally Posted by runmikeyrun

. . Vacuum gauge at idle is reading about 14 (manifold vacuum) and the needle is bouncing. From what I’ve read it’s not just a low reading but it also means there is a problem with one or two cylinders and not all of them.
. . . I’m gonna have to do a compression test.

Bouncing can be from leaking intake valves.
Compression test, yes.
Remove all the spark plugs so the engine can turn over easier, and block the throttle butterfly open too.

Oil on plug #4 could easily explain the blue smoke on that side.

>edit<
Have the valves been adjusted recently? Some of them may be too tight.
.

[Daves55Sedan]

A vacuum reading of 14 is too low for a Y-block. Should be around 20. Could be a number of different issues responsible; leaky intake gaskets or carb base gasket, valves not seating all the way, could be internal to the carb.
Oil in the spark plug could be caused by bad piston rings.
Blue smoke....she's an oil burner.

[KULTULZ]

Did they include an illustrated diagnostic guide with the gauge?

[runmikeyrun]

Update:

Did a compression test on all the cylinders on the pass side since that’s the side blowing oil smoke. 120-125 on cyl 1-3 and 70 on #4. Then 0. Then 110. Then 0. Figured I had a valve sticking open since sometimes I had it and sometimes I didn’t.

Pulled the valve cover and I had a push rod sunk down into the head:


Slid the rocker arm to the side, pulled the pushrod out. Not bent and all there. Put it back in, loosened the rocker shaft to get the rocker arm back on, and tightened the rocker shaft hold down bolts.

Turning it over by hand (with all the plugs out) and it definitely gets hard to turn when that pushrod is moving. So I’m thinking the lifter and/or valve is sticking. I put a good dribble of seafoam on both and had it sit about an hour before reassembly.

Ran home to grab my torque wrench and goin go fire it up with the cover off to see what happens.


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[runmikeyrun]

Ok. Buttoned back up and cranked it over a few times to see what would happen. Either the intake valve is sticking open or lifter is sticking and holding the valve open.

When I had the pushrod loose, I could not push it down at all even when turning the motor over by hand. I knew the cam was turning underneath it. I had to loosen the rocker shaft to get the pushrod seated back into the rocker arm adjuster because the pushrod was up too high. Makes me think the lifter is sticking.

I also could not budge the valve by hand, but I know those springs are very strong.

If it’s the lifter am I looking at running some Marvel to see if it will free up? Or will I have to pull the intake and valley pan and yank it out?

Thanks guys for all your help so far!

https://youtu.be/wpu7ulExw0o




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[dmsfrr]

Originally Posted by runmikeyrun

. . .
Either the intake valve is sticking open or lifter is sticking and holding the valve open.

If it’s the lifter am I looking at running some Marvel to see if it will free up? Or will I have to pull the intake and valley pan and yank it out?

Thanks guys for all your help so far!

https://youtu.be/wpu7ulExw0o

Back in post #1, did you say the engine was rebuilt last winter?

After looking at your 6 sec video the lifter seems to be sticking in it's 'up' position, or I'd expect the pushrod to drop. It's possible that surface tension of the oil is holding the pushrod up, so it could be a stuck valve.
If it's a sticky lifter the MMO might loosen it up, but whatever is causing it to stick is not a good thing.

For a pushrod to have fallen out without it being bent the valve would be sticking open, unless the adjusting screw on that valve was very loose to start with.

Taking off the intake manifold and valley pan will let you see the top of the lifters.
To remove the lifters the cam has to come out.
.

[40cpe]

If you want to try to get the lifter down, take the distributor cap off and point the rotor to the cylinder's spark plug wire terminal on the cap. This will put the heel of the cam to both lifters on that cylinder. Use a wooden dowel on the push rod end of the rocker and tap it firmly with a hammer. If it moves down, turn the engine and see if it sticks again.

The only caveat I see is that if the lifter is fractured, pieces might line up and create enough force to break the cam or the block. Proceed at your own risk.

[runmikeyrun]

What about putting a little tranny fluid or marvel mystery oil down the pushrod journal? Let it sit for a day and then try cranking it over again?


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[CrownVic55]

Make sure you have the push rod in the lifter and not sitting on the block itself. Then when you turn the engine by hand you should feel it move. If for sure it is in the lifter then previous posters are probably correct and lifter is binding.

[runmikeyrun]

Originally Posted by CrownVic55

Make sure you have the push rod in the lifter and not sitting on the block itself. Then when you turn the engine by hand you should feel it move. If for sure it is in the lifter then previous posters are probably correct and lifter is binding.

Yup, it’s in there... we spent a little time figuring out which is wrong vs right lol. I will check again though. Kinda hard to see, but the pushrod is moving a little, just all the way at the end of its travel.


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[runmikeyrun]

Thought: can I snake a boroscope down the oil fill tube and visualize the lifters? You can get them pretty cheap on amazon that fit right into my phone. If the Marvel oil doesn’t unstick things I’d like to see if it’s broken before just tearing it down.


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[dmsfrr]

Originally Posted by runmikeyrun

Thought: can I snake a boroscope down the oil fill tube and visualize the lifters? . . .

Probably?
How about removing the rocker arm shafts & pushrods and looking at the lifters straight down thru each hole?

[runmikeyrun]

Originally Posted by dmsfrr

How about taking out the rocker arms & pushrods and looking at the lifters straight down thru each hole?

I could see the top, I’m thinking more if it’s broken in the middle. I might pick up one of those boroscopes regardless, I’ve got a bunch of old bikes that could an inspection haha


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[runmikeyrun]

I just dribbled some MMO down the pushrod journal. Going to let it soak 24 hours then dribble a little oil down there tomorrow and give it a few cranks.


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[dmsfrr]

Originally Posted by runmikeyrun

I could see the top, I’m thinking more if it’s broken in the middle. I might pick up one of those boroscopes regardless, I’ve got a bunch of old bikes that could an inspection haha

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The rest of the lifter is inside it's bore and can't be seen from the top.
Look at the first photo back in comment #32.

[runmikeyrun]

Originally Posted by dmsfrr

The rest of the lifter is inside it's bore and can't be seen from the top.
Look at the first photo back in comment #32.

Ah, nuts! Thanks for pointing that out. I was thinking of the picture from the service manual, which showed a cutaway, but only for visualization purposes.


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[KULTULZ]

OEM HARDENED TAPPETS

[runmikeyrun]

A couple days soaking with MMO didn’t unstick that lifter (I simply cranked the engine over a few times and watched). At this point I have two choices:

1. Put the valve cover back on and run the truck for a while, hoping the lifter frees up.

(Subquestion: can I run the truck with the valve cover off? Or will I get oil running all over?)

2. Put the #4 cylinder to TDC and pull that valve spring and check to make sure that valve isn’t bent/sticking.

Part of me wants to check the valve as long as I already have the valve cover off; the other part says the valve isn’t the problem, it’s the lifter so I shouldn’t waste the time taking it apart.

I have to run out of town for the night, I’ll be back working at it tomorrow evening (Tuesday).

Thanks!


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[Daves55Sedan]

Ummm...if the engine isn't totally gunked up inside, I would not run the engine with the valve cover off. It will look like a waterfall of oil sprayed all over everything, particularly exhaust manifold (smoke, smelly oil burning).
I would NOT attempt to remove a valve spring with the head installed on the engine. If the spring is removed and the valve is not stuck, the valve will slide down inside the cylinder and it will be impaled by the piston possibly causing damage.
Furthermore, I don't know of a way to make removal of the spring possible when the head is still mounted on the engine. To my knowledge, the head must be removed so that a valve spring compressor can be employed. It is not possible to use it when the head is mounted on the engine.

[Lanny]

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QUOTE----Put the #4 cylinder to TDC and pull that valve spring and check to make sure that valve isn’t bent/sticking.

================================================== ===



I removed the valve springs on a 289 Ford, so I could replace valve seals, and
that was with the heads in place on a runnable 289 engine.
I did it by putting the piston all the way up on each cylinder that I was working on.

I made a simple tool, many years ago, when I did that job. You should
be able to find a tool, or make one that will pry the spring down to
remove the keepers.









.

[runmikeyrun]

Originally Posted by Lanny

QUOTE----Put the #4 cylinder to TDC and pull that valve spring and check to make sure that valve isn’t bent/sticking.

================================================== ===



I removed the valve springs on a 289 Ford, so I could replace valve seals, and
that was with the heads in place on a runnable 289 engine.
I did it by putting the piston all the way up on each cylinder that I was working on.

I made a simple tool, many years ago, when I did that job. You should
be able to find a tool, or make one that will pry the spring down to
remove the keepers.









.

I was going to say- piston to TDC and/or stuff the cylinder with rope and it won’t fall in.

Thanks for the tip about not running with the cover off. I did see a video with one cut open and peeled back, but not off, that’s why I asked.

We’ll see how it goes...

Thanks again!



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[40cpe]

If the lifter was not stuck you could push the push-rod end of the rocker arm down when the #4 cylinder is at TDC compression stroke. Save yourself the effort. Tapping on the push rod end of the rocker arm with the piston at TDC compression stroke is your only hope short of a teardown.

[56sedandelivery]

I have used compressed air to keep the valve up while on the engine. You need a adapter to the spark plug hole and be sure both valves are closed.

[dmsfrr]

Originally Posted by runmikeyrun

A couple days soaking with MMO didn’t unstick that lifter . . . .

If the lifter can't move on its own it's got to come out to see if it's cracked or there's something wrong with that lifter bore. There's only one way I know to do that.....


.

[runmikeyrun]

Diagnosis made: it’s the valve sticking. Lifter is ok.

I turned the motor over by hand until the valve opened fully. I propped the rocker arm in place on the pushrod side so it stayed up, then turned the motor over to TDC and I was able to push the pushrod down with relative ease. So it’s not a stuck lifter.

In this video you can see when I turn the motor over the valve is slow to close (the other valves sprung right back) because the stem is dragging in the guide.

https://youtu.be/ScOWoeKBFCU

On top of that, you can (sort of) see in the photo that the valve seal is pushed up to the top of the stem, I’m assuming it’s being caught and moved up by the bent part of the stem. I pushed it back down where it belongs and turned the engine over some more. When the valve opened and closed again the seal rode right back up.



I buttoned up the motor and I’m exploring options. One is to have the local shop handle it. If it’s a straightforward repair it wouldnt be too expensive. If bolts start breaking (or if something else lets go in 6 months) it might be cheaper to do an engine swap. Since this originally had a flathead but has been modified to accept the Y block, I’m wondering if another motor would use the same mounting points?

Thanks a ton to everyone for all your help, you really made my diagnosis easier and faster.


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[runmikeyrun]

So on a whim I took her outside and dribbled a whole bottle of MMO down the carb while an assistant kept the revs up. It’s definitely running much better. Idles much better. Still burning oil but I’m going to replace that valve seal and see what happens.


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[40cpe]

I was told that those seals are designed to ride on the valve stem. When the valve is closed, it allows oil mist to lube the stem. When the valve opens the seal rides down on the guide to help prevent the intake valve sucking oil by the guide.

[runmikeyrun]

Originally Posted by 40cpe

I was told that those seals are designed to ride on the valve stem. When the valve is closed, it allows oil mist to lube the stem. When the valve opens the seal rides down on the guide to help prevent the intake valve sucking oil by the guide.

Interesting. That’s the only one of the valves that I saw the seals moving though.


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[KULTULZ]

Originally Posted by 40cpe

I was told that those seals are designed to ride on the valve stem. When the valve is closed, it allows oil mist to lube the stem. When the valve opens the seal rides down on the guide to help prevent the intake valve sucking oil by the guide.

That's correct, an umbrella seal.

[runmikeyrun]

Hmm. I wonder why I’m still burning so much oil on that side.


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[KULTULZ]

Originally Posted by runmikeyrun

Hmm. I wonder why I’m still burning so much oil on that side.

1) A cylinder can show good compression and stil have a defective oil ring.

2) Valve guide(s) and/or defective seal(s)

3) Poor crankcase ventilation

4) Blocked oil drainage

5) Did you ever read the spark plugs?

You said previously this engine had been rebuilt?

Something ain't right ...

[Daves55Sedan]

So I guess we have a valve sticking within the valve stem guide on a recently rebuilt engine, right?
I do not think this can be attributed to improper valve lash adjustment. A bent push rod, definitely would cause me to suspect having the adjustment screw down too far. All I can offer to that is....There is an excellent text is the shop manual that tells you how to do a proper valve lash adjustment.
We once had one engine builder in this town. The guy was absolutely a perfectionist. He would never have finished any engine without having checked the tolerances of the valve stem guides. The tinyest flaw, and he would have replaced the guides. But shoot, I don't know how they do 'em now. Maybe they don't even consider checking the valve guides now?

[runmikeyrun]

Originally Posted by Daves55Sedan

So I guess we have a valve sticking within the valve stem guide on a recently rebuilt engine, right?
I do not think this can be attributed to improper valve lash adjustment. A bent push rod, definitely would cause me to suspect having the adjustment screw down too far. All I can offer to that is....There is an excellent text is the shop manual that tells you how to do a proper valve lash adjustment.
We once had one engine builder in this town. The guy was absolutely a perfectionist. He would never have finished any engine without having checked the tolerances of the valve stem guides. The tinyest flaw, and he would have replaced the guides. But shoot, I don't know how they do 'em now. Maybe they don't even consider checking the valve guides now?

It was rebuilt in the early 80s, and not sure to what extent. It is surprisingly clean on the inside though.

I’m going to replace the seals on that cylinder with either positive or the seals with the spring. It didn’t start burning oil like that before the valve started sticking.

The plug for that cylinder has wet oil down inside the insulator. It’s possible a ring went bad when the valve was sticking but I see that as plausible since compression was actually lower. On motorcycles (where the majority of my experience lies) the compression actually helps expand the ring so if that’s the case it makes sense why a ring wouldn’t be sealing well.

We will see when I replace the seals, which will hopefully be Sunday.


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[KULTULZ]

Just read an old FORD SERVICE LETTER I came across notifying dealers about the Y throwing push-rods. It is (was) attributed to too loose valve-guide/valve stem clearance(s).

Now throw into this the different push-rod lengths used and their ability to be assembled into the wrong engine. Think VALVE-TRAIN GEOMETRY.

The FE and MEL had similar maladies.

[runmikeyrun]

Originally Posted by KULTULZ

Just read an old FORD SERVICE LETTER I came across notifying dealers about the Y throwing push-rods. It is (was) attributed to too loose valve-guide/valve stem clearance(s).

Now throw into this the different push-rod lengths used and their ability to be assembled into the wrong engine. Think VALVE-TRAIN GEOMETRY.

The FE and MEL had similar maladies.

Hey, thanks for the heads up! When I take the spring off for the new seals I will give it the “wiggle test”.




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[runmikeyrun]

Well, I’m done. I pulled the spring today and cant budge that valve. It had some black rubbery goo kind of like carbon but not hard. I was able to scrape it off with my fingernail. It was on the guide and the stem.

Whatever it is I suspect that’s what’s hanging it up. I put on a positive seal and buttoned things back up. No smoke at all for the first minute. Still running kind of rough at times. Once I took it on the road though it started smoking again. I think the head needs to come off and it needs to be cleaned. I’m tapping out at this time.

On a separate note I adjusted the valves on that side and it sounds real nice lol.

Thanks again for all your help. I’m sad I can’t fix it myself, but “A man’s got to know his limitations”


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[runmikeyrun]

Good news. I got the valve unstuck and she runs again!

The facility that was going to fix the truck had a month and a half before they could even get the truck in. Two days ago I said “screw it” and opened it up again. Sprayed some PB Blaster on the stem and let it sit for a half hour. Gave the valve a few whacks with a hammer and a wooden dowel and it started moving. More PB Blaster. A few more whacks and good to go! I couldn’t believe it. Put her together and she runs.

Thought you guys would want to know. Thanks for your help!


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[KULTULZ]

Originally Posted by runmikeyrun

Good news. I got the valve unstuck and she runs again!

The facility that was going to fix the truck had a month and a half before they could even get the truck in. Two days ago I said “screw it” and opened it up again. Sprayed some PB Blaster on the stem and let it sit for a half hour. Gave the valve a few whacks with a hammer and a wooden dowel and it started moving. More PB Blaster. A few more whacks and good to go! I couldn’t believe it. Put her together and she runs.

Thought you guys would want to know. Thanks for your help!

Guess you didn't know your limitations, you conquered it!

Actually, what you did is correct and leads to no need for head R&R.

I wonder if the black goop you described was what was left of a failed umbrella seal?

[runmikeyrun]

Originally Posted by KULTULZ

Guess you didn't know your limitations, you conquered it!


Actually, what you did is correct and leads to no need for head R&R.


I wonder if the black goop you described was what was left of a failed umbrella seal?

Most likely. It was a bit rubbery and not hard like carbon. I will plan on replacing them all this winter just to be safe.


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[funrunr]

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I just read this thread from beginning to end. That’s great news! Also thanks for following up with the final remedy post.
Good job!

[runmikeyrun]

Originally Posted by funrunr

I just read this thread from beginning to end. That’s great news! Also thanks for following up with the final remedy post.
Good job!

I just love a happy ending, haha.


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