[123pugsy]

Holy Cow Hawk!

Next time tell me to sit down before I read something this unbelievable!

You actually used the light.

When you hook it up again, you can rev the engine and the display on the light will give you the rpms.
Then dial the knob on the light until the mark lines up.
I hear 36* total at about 3000 rpm's mentioned for SBC's.

Hopefully Cobalt will chime in here.

[cobalt327]

123pugsy, you're spot on w/the 36 degrees at 3000 rpm. You want the total (w/o the vacuum advance) all in as early as the engine/vehicle combo will allow. This is usually around 3000 rpm (or less if it'll let you) w/o pinging when under a load.

If more info on the HEI is wanted, you can take a look here, especially the section on ignition advance.

[lt1silverhawk]

CORRECTION: That last cylinder listed for the compression should be #8, not #1.




Hey cobalt,

Originally Posted by cobalt327

Compression test is excellent. You propped the carb open?

Actually, the carb is off the truck. I never put it back on after installing the plastic cam in case I have to mess with the intake manifold gaskets again. Should the test have been done with the carb on?

Originally Posted by cobalt327

If the threads of the plugs are what's wet, that's usually from external oil getting down into the wells where the plugs live (often it comes from the v-cover gaskets). It's the color and condition of the electrodes and porcelain (wet [oil], dry/tannish [normal], fluffy/black [rich] or shiny/white [hot]) that's the main concern. If they are wet w/oil, you have a problem of some sort. Being as how the compression tested so good, I'd be looking at the PCV valve and the tranny vacuum modulator first.

Yes, the oil is actually limited to just the threads of the spark plugs. The electrodes and porcelain don't have anything on them and, from memory and the pictures posted, there was no dis-coloration.

I'm pretty sure the PCV valve is good because it does make a rattling noise. Not so sure on the hose, so I will check that. Yes, the transmission modulator is something I've been meaning to check, at least the small rubber hose that connects it to the metal line. Last I looked at it, it was bent into a bit of an "s" shape.

Originally Posted by cobalt327

What if anything were done w/the valve stem seals?

I never touched the valve stem seals.

Originally Posted by cobalt327

Do the plugs show more oily deposits on one side than the other?

According to one of the members, the images of the removed plugs from the first page of this thread shows that the passenger-side plugs appeared more fouled than the driver-side. This time around, it appears about even for both sides.

Originally Posted by cobalt327

If so, next time before removing the plugs (or now if they're still in order and you can put a few from each side back into the heads where they came from) you can mark the top of the plug w/a sharpie to see what the position of the plug's electrode is to the exhaust valve to see if the chambers are pulling oil past the seals. This is similar to "indexing" plugs if my explanation is unclear (which wouldn't surprise me! lol).

Yep, I didn't get it lol! I looked up indexing spark plugs and found a simple explanation in this article: "How to index spark plugs". So I am on board so far. Now, where I am needing more help is how to see the position of the electrode in relation to the exhaust valve. Will I need to removed the intake manifold and turn the engine manually to observe what's happening? The plugs are out right now, and in order.




----------



Hey Pugsy,

Originally Posted by 123pugsy

Holy Cow Hawk!

Next time tell me to sit down before I read something this unbelievable!

You actually used the light.

God, I hope you didn't break anything. Prayers do get answered, dreams do come true, miracles do happen, and Hawk does eventually realize that the only light at the end of the tunnel, is the timing light. Eventually.

Originally Posted by 123pugsy

When you hook it up again, you can rev the engine and the display on the light will give you the rpms.
Then dial the knob on the light until the mark lines up.
I hear 36* total at about 3000 rpm's mentioned for SBC's.

Hopefully Cobalt will chime in here.

Either I missed it, or my timing light doesn't have a knob. I will check when I get home and report back.

Originally Posted by cobalt327

123pugsy, you're spot on w/the 36 degrees at 3000 rpm. You want the total (w/o the vacuum advance) all in as early as the engine/vehicle combo will allow. This is usually around 3000 rpm (or less if it'll let you) w/o pinging when under a load.

When I set the base timing at 9*, I did it with the vacuum advance disconnected. I then revved the engine a few hundred rpm past 3,000, and there were no issues that I noticed. I then hooked up the advance and took the truck for a quick spin and it drove fine. This time I'll do the entire thing with the vacuum advance disconnected.

Since I have never heared it before, what exactly does pinging sound like?

Originally Posted by cobalt327

If more info on the HEI is wanted, you can take a look here, especially the section on ignition advance.

Thanks, that's actually quite informative.




Thank you for the continued help!

[cobalt327]

Originally Posted by lt1silverhawk

Should the test have been done with the carb on?

Carb off is fine.

Yes, the oil is actually limited to just the threads of the spark plugs. The electrodes and porcelain don't have anything on them and, from memory and the pictures posted, there was no dis-coloration

That's good, the oil leak is external and there's no need to fret any more about the rings, valve seals, PCV, or intake gaskets. Be sure to go back and retighten the intake a few times after it heat cycles until the bolts take a set.

You'll want to locate the oil leak that's getting into the plug recesses. It could be coming from the front of the engine and blowing back from the fan. It helps to have the engine clean. Another thing you can do that will sometimes help locate a leak is to put a piece of cardboard under the engine after running it. See where the drips are concentrated and look up- and possibly forward- from the heaviest spots.

Now, where I am needing more help is how to see the position of the electrode in relation to the exhaust valve. Will I need to removed the intake manifold and turn the engine manually to observe what's happening? The plugs are out right now, and in order.

No need to remove anything. What you want to see is if the plug electrode/porcelene are fouled or discolored more on one side of the electrode than the other. If they are, the next thing will be to determine what valve the fouled side is facing. The valve sequence on a SBC is:

E ¹ I I ³ E E ⁵ I I ⁷ E. A spark plug will sit where every numeral is. So looking at the sequence, you can see if the plug for cylinder #1 has more deposits on the left side when it's fully tightened into the head, that the deposits are coming from the exhaust guide.

If there is no "worse" side to the plugs and they look to be coloring equally, that's good and nothing need be done.

One thing about the vacuum advance- be sure to reattach the vacuum hose to it after setting the timing. When an engine pings, it'll sound like a faint metallic ticking. Some describe it as marbles in a can- but the detonation would need to be pretty severe for it to be that bad, IMHO. You'll notice it more when you load the engine in a higher gear, like going up an incline or hill.

[123pugsy]

My mistake.

Use the arrow buttons and it will advance the light until you see the mark on the balancer line up with the timing tab. Its real simple. Play around with it and you'll see. I can't set the VCR time but I can use that light.

[lt1silverhawk]

CORRECTION: Yes, the all of the spark plug electrodes did have oil on them both times when they were removed and cleaned. I had my terminology wrong, sorry.

Originally Posted by cobalt327

That's good, the oil leak is external and there's no need to fret any more about the rings, valve seals, PCV, or intake gaskets. Be sure to go back and retighten the intake a few times after it heat cycles until the bolts take a set.

Might be an issue now? Piston rings, perhaps?

Originally Posted by cobalt327

You'll want to locate the oil leak that's getting into the plug recesses. It could be coming from the front of the engine and blowing back from the fan. It helps to have the engine clean. Another thing you can do that will sometimes help locate a leak is to put a piece of cardboard under the engine after running it. See where the drips are concentrated and look up- and possibly forward- from the heaviest spots.

I did put a large aluminum drip tray with kitty litter under the truck for a couple of days to see where oil might be leaking from. It had dripped in three or four spots but I couldn't trace it back to anything. I paid special attention to valve covers since they had leaked before but those areas appeared to be oil free. The oil pan gasket also appeared to have no leaks.

Originally Posted by cobalt327

The leaks are concentrated more towards the rear of the engine bay. At this point, I am leaning towards rear main seal. But that obviously wouldn't explain the oil getting into the spark plug threads.




No need to remove anything. What you want to see is if the plug electrode/porcelene are fouled or discolored more on one side of the electrode than the other. If they are, the next thing will be to determine what valve the fouled side is facing. The valve sequence on a SBC is:

E ¹ I I ³ E E ⁵ I I ⁷ E. A spark plug will sit where every numeral is. So looking at the sequence, you can see if the plug for cylinder #1 has more deposits on the left side when it's fully tightened into the head, that the deposits are coming from the exhaust guide.

If there is no "worse" side to the plugs and they look to be coloring equally, that's good and nothing need be done.

Thanks for that break down, it helps tremendously. I'll take sharpie to the plugs before putting 'em back in.

Originally Posted by cobalt327

One thing about the vacuum advance- be sure to reattach the vacuum hose to it after setting the timing. When an engine pings, it'll sound like a faint metallic ticking. Some describe it as marbles in a can- but the detonation would need to be pretty severe for it to be that bad, IMHO. You'll notice it more when you load the engine in a higher gear, like going up an incline or hill.

Ok, that's the sound I'll keep an ear out for then.

Originally Posted by 123pugsy

My mistake.

Use the arrow buttons and it will advance the light until you see the mark on the balancer line up with the timing tab. Its real simple. Play around with it and you'll see. I can't set the VCR time but I can use that light.

Ah, that's what I suspected, but for some reason I thought that feature was for the distributor-less ignition systems.




Ok, got my list of what to do next: sharpie the plugs, torque down the intake manifold bolts, throw on the carb; check the PCV and trans modulator components, run it for a while, time it, and check the plugs again. Sounds good?

[lt1silverhawk]

Originally Posted by cobalt327

Be sure to go back and retighten the intake a few times after it heat cycles until the bolts take a set.

Ok, I went ahead and checked one intake manifold bolt right up front with a torque wrench, and it was showing at about 20 lb/ft. This page suggests 30 lbs/ft for a 350 with iron heads: Boxwrench: SB Chevy V8. Should I torque all the bolts to that?

Originally Posted by cobalt327

You'll want to locate the oil leak that's getting into the plug recesses.

I checked the and photographed the PCV, the hose as well as the general area for the spark plugs. Unfortunately, due to the camera I am using, I have to back off quite a bit in order for it to focus so I don't have pictures for all the spark plug holes. However, it does seem that there is oil right outside where the spark plugs go in on cylinders 6 and 8. I have not been able to verify it for 5 and 7 because there is too much in the way. However, 2,41 and 3 seem pretty dry on the outside.

[lt1silverhawk]

I was looking over the images of the spark plugs again and noticed that the spark plug electrode from cylinder #2 was caked with oil/sludge both times. The first instance can be seen in Post #9. The second instance can be seen (sort of) in Post #104.

[cobalt327]

Originally Posted by lt1silverhawk

I was looking over the images of the spark plugs again and noticed that the spark plug electrode from cylinder #2 was caked with oil/sludge both times. The first instance can be seen in Post #9. The second instance can be seen (sort of) in Post #104.

#2 seen in the first photo is horrible. 4,6, and 8 are nothing to write home about, but are better than #2.

The other side, at least what can be seen of the electrodes, look good and is what you'd like the color to be like on ALL of them.

There are cases where, because of how hard the plugs are to get to, that a guy will skip replacing those hard to reach plugs. In those cases the plugs that are not replaced can show a lot more wear- but they still should not be caked w/what is obviously oil reaching the combustion chamber. And if the plugs look like that, you can bet the tops pf the piston and the back of the valves will look as bad.

I might have to take back what I said about the oil on the threads being external. If there's enough, it could wick up the threads from the combustion chamber. But if that was happening, I would expect the engine to smoke badly.

The plugs, PCV and hose look old. If it was me, I'd bite the bullet and replace them. The PCV grommet is also old and starting to crack and it needs replacing. Be sure if you do that you don't knock it through into the valve cover. No huge deal if you do (the oil baffle will keep it from falling into the head), but if you're careful it can be avoided.

There's a chance that replacing the valve stem seals will help matters. The cost is low, but it's labor intensive. Plugs, hoses and vacuum lines are all consumables.

[lt1silverhawk]

Originally Posted by cobalt327

#2 seen in the first photo is horrible. 4,6, and 8 are nothing to write home about, but are better than #2.

The other side, at least what can be seen of the electrodes, look good and is what you'd like the color to be like on ALL of them.

Ok, that puts things in a helpful perspective. I will work on getting more detailed shots.

Originally Posted by cobalt327

There are cases where, because of how hard the plugs are to get to, that a guy will skip replacing those hard to reach plugs. In those cases the plugs that are not replaced can show a lot more wear- but they still should not be caked w/what is obviously oil reaching the combustion chamber. And if the plugs look like that, you can bet the tops pf the piston and the back of the valves will look as bad.

The plugs were replaced about two years ago, and have less than a thousand miles on them.

Originally Posted by cobalt327

I might have to take back what I said about the oil on the threads being external. If there's enough, it could wick up the threads from the combustion chamber. But if that was happening, I would expect the engine to smoke badly.

Yeah, sorry about the confusion on my part about electrodes not being covered in oil. I've seen some white steam/smoke from the back of the engine bay from time to time, but not in a while.

Originally Posted by cobalt327

The plugs, PCV and hose look old. If it was me, I'd bite the bullet and replace them. The PCV grommet is also old and starting to crack and it needs replacing. Be sure if you do that you don't knock it through into the valve cover. No huge deal if you do (the oil baffle will keep it from falling into the head), but if you're careful it can be avoided.

I don't mind replacing any of this stuff. I've been meaning to replace all of the vacuum hoses for a while anyway. And I'll take it easy on the grommet. Been thinking about upgrading to sturdier valve covers, and this might be the time to do it.

Originally Posted by cobalt327

There's a chance that replacing the valve stem seals will help matters. The cost is low, but it's labor intensive. Plugs, hoses and vacuum lines are all consumables.

I wonder if Vizard's rebuild book covers how to replace valve stem seals.

[cobalt327]

I there has to be YouTube videos of how to do them.

[123pugsy]

Check the vac hose coming up from the tranny to see if its wet inside. Take you a couple minutes, tops.

[lt1silverhawk]

Originally Posted by cobalt327

There's a chance that replacing the valve stem seals will help matters. The cost is low, but it's labor intensive.

It seems the most expensive parts are the tools: a good spring compressor and a valve holder.

Originally Posted by cobalt327

I there has to be YouTube videos of how to do them.

Yes, there are a few. This one seems to be the most detailed, covering everything from the beginning to the end.

Originally Posted by 123pugsy

Check the vac hose coming up from the tranny to see if its wet inside. Take you a couple minutes, tops.

Ok, will check that first thing when I get home tonight or tomorrow morning, and then report back. What does it mean if it turns out to be wet?

[cobalt327]

Sorry, I didn't consider having to buy tools. A good valve spring compressor will make the chore much easier. But if the budget is busted, a tool like shown below can be bought for under $10. I forget exactly where I found this one, it was a parts store though.

Cloths line can be used through the plug hole to wedge the valve closed for removal so a compressor isn't necessary. This has been covered here and elsewhere, I'm sure.




This tool (shown upside down) is used in place of the rocker arm. When the nut is tightened, the ears of the compressor bear down on the retainer. A different, non locking nut (and a washer) is used in place of the standard rocker adjusting nut.

[lt1silverhawk]

I think for the sake of safety and ease of work, I will look for a quality compressor. The one the the guy uses in the video, a Proform brand, seems pretty good so I'll look for that one. Although the valve holder tool isn't expensive ($10 on Amazon), I definitely appreciate the tip on the clothes line.



Btw, are the diameters for the seals pretty much the same, or will it vary by motor? I tried looking them up on Summit and they have several different diameters for an SBC. The reason I am concerned is that this engine is a crate engine, so I am not sure if it would be the same as the one for a stock motor in a '77 Chevy.