jpc647

I spent the afternoon after work today polishing up my car, to no real avail, because black still sucks and in the sun it still looks like a turd. Anyway, I took the car for a ride up the road and noticed it doesn't seem to have the same pull. Granted I've had the car for 3 years now and I haven't tuned it up, or done anything, and I don't know how long before I bought it it was done.

I pulled out the first three plugs on the passenger side and found this:

109_0140.jpg
Oil on the plug means?...
109_0151.jpg
What's all this crap? I picked it off and put it back in.
109_0164.jpg
More oil...

Am I looking at a complete rebuild because of the blowby?

CQR

They look like they have some time on them. I would install a new set, run it about 10K miles, and record how much oil you have to add between oil changes.If the plugs look like that after 10K miles, and you are adding more that a quart or 2 of oil (without leaks) then it's probably time to dive in.

Rickman48

Oil deposits would be black - the deposits I see are carbon.
Is all your driving city? That thing needs some highway miles to keep the crap off!
Did you re-gap the plugs before re-installing? That'd help, short of a new set.
Maybe go one step hotter to avoid carbon build-up. [46's instead of 45's]

Nilsson

Those plugs are trash time for a new set.

gregvm

I don't think that's carbon buildup....looks like some kind of fuel additive or such....
Do you use octane booster or other stuff in the gas?

Or maybe the gas supplier(you never know WHAT you get at the pump anymore)

Change them out and monitor in the future....

MDchanic

Guys, those pictures are a little blurry, but two of those plugs look like they're coated with lead to me.

Remember lead?

Plugs always used to look like that after a certain number of miles.

My question:
You've had the car for three years and haven't tuned it up - did you EVER change the plugs? If you didn't, they may have been in there a LONG time.

I agree - change 'em. And do the rest of the tune-up while you're at it.

- Eric

jaunty75

I agree with Eric. Unless you know how long these plugs have been in the car, you really can't rely too much on what they look like as an indicator of engine problems. Even a good engine will yield crappy looking plugs if left in long enough. Put some new ones in, run it for a few thousand miles, and then pull them out and look again.


If anything, I would say that the plug in the first photo doesn't look bad at all. Just normal use. No pitting, no corrosion, no deposits to speak of. But the rust around the outside suggests it has been in there a while.

109_0140.jpg



In fact, this plug looks so much better than the others that I would venture a guess that this plug might not have been in the engine as long as the others, as unusual as it might be to not replace all the plugs at the same time whenever it's done.

But this goes back to the original question. Do you know anything at all about the history of this engine?

jpc647

Well the breather element on the valve cover was never installed as the valve cover hole was never punched out, so it drips out of one of the lines up by the carb. There was a thread on here a while back about it from someone, I have to find it. I do add oil sometimes, usually about 1/2 quart at a time, but I think it's more so from the leaks than anything. There is always a little drip down by the pan, but nothing bad. But there looks to be oil in the threads of the plug, doesn't this suggest something bad?

I didn't regap them. I only took three out. Most of the driving is just around town, the car has 3.33 gears in the rear, and with the magnaflow exhaust, on the highway the car is sort of uncomfortable. I don't think 3.33's and a 350 are a good match. The problem I run into with buying new stuff is the car has a distributor from what looks like a newer 350. Like a 76 ish car with HEI. But I don't know what it's out of. Is there a way to tell? So I don't know what plugs and wires I need to go buy. I think it's been close to 9 years since it was tuned up, the plug wires are actaully degraded to the point that then slide forward and back in the boot(the black part that covers the plug).


A few thousand miles? That's like 3 seasons of use for me. What about the clearly oil coated threads, that was the first thing I saw. The ring, that's just like an insulator or sorts to keep the plug from touching the side of the block, right?

I do not know the history of the engine. I believe it to be original, but the ear on the side with the block stamped into it is completely illegible. I've gone back 3 owners which would be circa 1996 and it's been the same engine since.

jaunty75

It's about 5 seasons of use for me! I know the problem. But I still think that you can't read too much into these plugs without knowing the history of them. You need to put some fresh plugs in and drive the car for a while. As long as it runs ok and doesn't burn oil, you're not going to do it any harm accumulating 2000 or 3000 miles on it. Fix other things while the miles are piling up, and then pull the plugs and look at them.

The oil on the threads doesn't look that bad to me, either, because the oil isn't on the electrodes. It looks like whoever put the plugs in last put a little lubricant on the threads. Good for him, because that probably made it easier for you to remove them. In fact, how much work was it to loosen the plugs and get them out?

CQR

Just to help clear up some confusion.

http://www.ngkeurope.com/en/technolo...nosis/defects/

jaunty75

That's a good link, and the top photo there, which is of a plug showing normal wear, looks just like the top photo in the OP's original post. In fact, the "normal" plug looks worse!:


Photo of the "normal" plug:




The OP's first photo (cropped):





The OP is concerned about blowby. But my understanding of blowby is that it goes the OTHER way. In other words, unburned gasoline, water, and other combustion products are forced past the rings into the oil, not oil getting past the rings and into the combustion chamber. And if the oil IS going that way, why is the oil only on the threads and not on the electrodes?

He could check for ring problems by doing compression tests on all the cylinders.

When I've seen oil on spark plug threads, it's usually due to oil leaking out of the valve covers and seeping down the side of the engine into the spark plug slots.

jaunty75

Here's a photo of the 455 in my '73 Custom Cruiser taken when I first got the car. I've circled the oil seeping past the valve cover and down the side of the engine.

Exciting, isn't it?





It was doing this in a few locations on both sides. I've since cleaned things up and replaced both valve cover gaskets, and now you can eat off the side of the engine.

CQR

It 's like Elton John. Goes both ways. Under the high pressure of combustion, the gases are pushed past the rings into the crankcase, and under the vacuum of intake stroke it pulls oil into the cylinder.

oldcutlass

The oil on the threads is probably coming from a bad valve cover gasket!! I would put a new cap, rotor, wires, and plugs on it. I would also change my fuel filter, air filter, and pcv. I would set my gaps as per an HEI system and perform a tuneup.

Blowby is when oil and exhaust gases blowby the rings back into the crankcase. Usually a good indication of that is to pull your PCV and look at the smoke coming from the hole it came out of!! All older engines have it, just some more than others!

jaunty75

Yes, but during the intake stroke, the intake valve is open, so the vast majority of anything coming into the cylinder will come in that way and not past the rings. During the ignition stroke, all valves are closed, so if any gases are going to escape, the only place they can do so is past the rings and into the crankcase.

So I would assume that the vast majority of blowby goes from cylinder to crankcase and not the other way.

CQR

Blowby yes, Oil consumption no (Like the 2nd and 3rd plugs show). Valve seals can also show that type of buildup and will usually show a blue puff at start up.

MDchanic

Oil on the threads of the plugs is perfectly normal, and, as has been pointed out, is a good thing.

I think that the crux of the issue is that you haven't tuned it up in nine years.
NINE YEARS.
You'll find your answer there.

- Eric

jaunty75

Good point. It's why I wondered if he sees anything coming out of the tailpipe that shouldn't be there.

jpc647

It was actually pretty darn easy to remove the plugs. Used a 3/8 standard ratchet and a socket, came right out. You said you "know the problem".. Care to elaborate?

There isn't any indication of oil on the side of the motor though, no puddles o marks as in the picture of the 455. Clean and dry.

I do need a new air filter, and I changed my fuel filter (inline near the frame) in June. I do change that usually 2x a season.

Set the new plugs up for an HEI system for what? I don't know what to go buy, because I don't know what car the distributor came out of.(Sorry if that seems like a dumb question). I don't have a PCV valve? Isn't that the hole in the valve cover, that is covered with a plate, at the moment?


Nothing. No blue smoke. I've checked this time and time again. I've even revved the motor on a cold start right away, nothing.

jaunty75

All the more reason to put new plugs in, give it a proper tune-up, and drive it. Don't be looking to tear the engine apart now. Fix other things. Remove the plugs some time down the road and give them a look.

oldcutlass

You can use an R43S-R46SX plug or equivelent, gap them between 045-055 as the HEI puts out a bit more spark than standard ignitions. I would also run with 8mm wires! The timing remains the same anywhere between 10-20 BTDC. The cap and rotor is the same for all GM HEI systems.

jpc647

Thank you for the information. When I go to the parts store they are going to ask for a year, if they are the same, what is the starting year for the GM HEI ignition? Like 74, 75? I'm assuming those plugs are just copper plugs? And would I need a new coil? The coil would be the module in these cars, right? I bought one last year because mine died, I'm assuming you don't replace this all the time?

Between 10 and 20 BTDC? I was always told 10-12BTDC.

I think I'll do that. Either way, whether the engine needs to be rebuilt or not, it still needs a tune-up, so I might as well start there.

oldcutlass

The HEI units are the same, and so are all the parts. 1974 would be a good reference year! You can get away with more timing than the book says. I run 16BTDC in my olds and I know some of the guys get as hi as 20. No you don't need a coil! Just cap, rotor, 8mm wires and plugs! Just to be safe make sure you have 12v feeding your distributor!

jpc647

I will do that. Thank you very much. I know I checked last year there is a solid 12v to the distributor. The only thing I need is the clip that holds the power wire into the coil's clip is broken, and it's zip tied in place. It's a little plastic piece, can't find one anywhere.

Is there a way to tell at what timing my engine is best at? I don't want to set if 6 different times and flog it going up the street to see what feels fastest(I don't think the neighbors would like that very much).

gregvm

I'm a little confused... I your CURRENT setup a points type or HEI? If it a points type, you don't WANT a full 12 volts at the coil/points.....you need only like 8-9 (resistor/nichrome wire or ballast resistor) otherwise you'll burn the points out asap. If it were me, I'd convert the points to a pertronix type system. No more points replacements/adjustments, and it keeps the stock look.

Greg

MDchanic

"... the car has a distributor from what looks like a newer 350. Like a 76 ish car with HEI. "

Sounds like HEI to me.

And you need to check for those 12 volts with the engine running.

-Eric

jpc647

This R43S-R46SX, is that a range of plugs. I ended up getting R43S, but the car currently has R46SX. What is the different between the two plugs? Heat range? What denotes this? The standard replacement plugs are 8mm, so this shouldn't be a problem.

Maybe I should start a new thread about the tune-up part, being many peopl with the right knowledge might not look at this thread because of the title.

oldcutlass

The R43S will work fine! The differences are the heat range! Yes 8mm wires is what is called for! The heat range is based on what happens to your plugs during engine operation, there are a bunch of threads on here to explain what it is and how it works! Really not worth getting into great depth for this! Go ahead and scroll up and set everything to the the gaps and timing settings I told you earlier. Gap your plugs at .045 and set your timing to 12 deg BTDC and see how it runs from there! I bet you'll see a marked imrovement. Don't forget to replace your cap, rotor and wires also!

jpc647

I bought a new cap, rotor and wires. I found a thread about R46SX plugs, which are what came out. Those are HEI plugs for the emission cars.

Also, i've read a couple people use the original plugs and don't change the gap. Some change the cap.

Would there be a reason to put in the RS46SX plug? They are capped high, somewhere around .090. Which seems right. The car had *****, sort of, when I first bought it. Were these higher range plugs used to maybe cure a mal-running motor? Maybe to try and burn off excess oil?

Maybe I'm over thinking this, but is this motor maybe an emission motor? Should it have the 46sx plugs, etc in it?

oldcutlass

Here is a general link to all the motors and tuneup specs available from 1970-1975, as with any spec, they are just a guide. I listed the range of spark plugs and gaps for for an olds 350 that people have been successful with in the past!! I really don't know how you would think a gap of 90 is realistic on a plug that was in an engine for who knows how long. The second pic you listed shows a plug completely worn out and burnt with no tungston left. I'm sure at one time your car ran very well, and it probably will again.

There is alot of info to get off the internet with a few words describing what your looking for in the search window!

http://www.442.com/tech/tuneup.html

Heres another:

http://www.tpocr.com/olds2.html

And some from earlier:

http://www.tpocr.com/olds1.html

jpc647

Thank you! The reason I brought up the current gap, is because at the parts store today I was talking to an old timer with a 69 or 70 chevelle and he was explaining his HEI experiences. He said the 46 plugs were used in the later cars with emission and such. Those plugs ask for a gap of 0.080-0.090. On a thread here I read a similar statement. So I freaked out and though maybe this was a 350 motor from a later year, and maybe thats why those plugs were in my car.

You are right though, the plugs were old, possibly 10 years old. I understand it is hard to gauge anything off of them.

On a plus note, I did take a few minutes to sand the dog ear on the side of the motor and it is the original motor. All the numbers(except the last, which looks like a 3 to me, but could be an 8) match up to my VIN. So I'll end using the 45 series plugs. I have the 43's too atm but I'll use the 45's set the car up and see what happens.

Lastly, I do know there is a search tab, and I do use it. I search quite a bit, and usually don't find exactly what i'm looking for, usually close, but not exact. I found a thread of the exact questions for example, but for a 455.

Thanks for you're help. If the weather clears up tomorrow at all, I'll take the old girl for a ride and see what happens. Hopefully a "transformed" car.

Rickman48

The large cast letter or number on the head, above the center exhaust ports, should give you a real good idea which motor you have.

oldcutlass

I would just return the ones you don't use, the engine will run fine either way! Good luck!

64Rocket

I'm going to say that the plugs have been running lean for a long time.

Gene

jpc647

Sorry to sound like an idiot, but what can I check to see if the car is still running lean after a tune-up?

64Rocket

When you install an HEI dist and if you have installed dual exhaust or all was done before you, those upgrades tend to lean out the carb. You should install new plugs(with HEI gap them .040 to 045) new wires and cap and rotor, run it for a couple of thousand miles. The plugs should be a nice light brown to maybe a little darker brown. If they are still white or super light brown you are to lean. If they are black to dark, dark brown you are using oil or the carb is to rich. You said it does not use oil, so to me it is to lean. It looks to me like the timing is off and you are lean, for all the crud build up and white color. You should step up a jet size or two. The timing maybe on the retard side, that is why you do not hear the pinging. If you step up the timing to par, with the carb lean you will get pinging.

Gene

jpc647

Thanks for the info. I took the car out tonight and flogged the living crap out of it for almost an hour. On the highway up to 80-85 mph, around town, couple of hard accelerations, with the car downshifting into 2nd, and it seems a little eh.

I don't see a huge different in performance of the car. Not what I was expecting. I do notice it runs a little smoother, it's still got sort of a choppy idle, but I didn't notice it stumble like it used to. I'm guessing I should play with the idle screws on the carb, and check the timing. I was always told warm the car up, turn one screw to the left until the engine stumbles, then turn it 1/4 turn back. Do the same thing for the other side. This accurate?

I have a timing light, but nothing to measure RPM's so I'll check the timing tomorrow or the next day and report back.