Spark Plug Diagnosis help

[Anonymous]

Hey all,

I have a 66 Ford Falcon with a 200 I6 from that year in it. It has a Pertronix Ignitor II and an MSD blaster coil in it. The carb is the stock Autolite 1100 and the distributor is the stock Load-o-matic.

I have done a lot of rebuilding lately, adding headers, replacing the broken vacuum advance, rebuilding my C4 and a few other things. Before adding headers and replacing the vacuum advance on the distributor I had a lot of trouble with dieseling, sometimes ending in a horrible clatter. For a while I was turning my car off by putting my hand over the end of the air cleaner so it wouldn't diesel.

Today I pulled my plugs, Autolite Platinums, which have been on for the last about 6000 miles without having been looked at. Here is what I saw.

Cylinder 1,2 - some chalky white buildup

3 - LOTS of chalky white buildup, almost closing the gap

4,5 - one half of plug black and sooty, one half with lots of white, chalky buildup

6 - black all around, white chalky buildup only on far side of grounding arm

Also of note is that the piston in cylinder 2 happened to be up. It also looked chalky and white. I stuck a screwdriver in the hold and scraped the white and it came up. The piston looked about like the surface of the moon.

I should also add that on a few of the cylinders there was a little oil on the threads and the outside of the spark plugs. I figure it is just from a valve cover leak since I'm not sure where else it would come from.

I checked and they are all gapped around or a little over 0.050", which is about how they came from the store. What do I need to do to prevent this buildup? I looked at the NGK page,

http://www.ngksparkplugs.com/techinfo/s ... country=US

If you scroll down that page, my white plugs looked somewhere between the pictures labeled "Deposits" and "Normal Life". The dark parts of the plugs were definitely like the "dry and wet fouling" picture. The tips were also all somewhat eroded to a point.

Where do I go from here? Any advice is appreciated.

-Dan in Atlanta

 

[Anonymous]

I am guessing the white ash is due to oil. Have you replaced your valve stem seals. That might be a quick, somewhat short term fix.
Doug

 

[Anonymous]

I guess that I should add that the engine was rebuilt about 30k miles ago. The car is my daily driver. To school is only about 5 miles each way, so it sees a lot of short trips, but probably the bulk of the miles I put on this car are several hour road trips.

How do you replace valve stem seals? How much disassembly does it require?

-Dan in Atlanta

 

[Anonymous]

If the block and head were rebuilt, then the seals were likely replaced. To access the seals is just a matter of removing the valve cover. Many folks use a spark plug adapter connected to an air hose to pressurize the cylinder with shop air. When the cyl is at TDC, the air pressure will hold the valves up as you remove the rocker arms, and springs in order to replace the valve stem seals.

 

[Junk-Falcon]

id say that

 

[Anonymous]

I have been thinking about it and these spark plugs have been in for a while when my engine was running like complete crap. I had a leak in my exhaust manifold and carbon was being pulled up into the automatic choke so it wouldn't function properly. That may have been when the plugs got fouled cause I haven't checked em for a while. I looked in my shop manual last night at the spark plug diagnosis page and it said deposits can be formed if your choke isn't working right.

Since the car is running well now I think the best thing for me to do is to run these clean plugs for a while and check em. Soon I'm going to my aunt's house and that's 8 hours away so I'll check em after that drive and see if i see any noticable accumulation. Wish I had a way of cleaning all that moon dust out of my engine though. Maybe I'll try that Mobil super or else Chevron with Techron.

-Dan in Atlanta

 

[Anonymous]

You can pour small amounts of water down the carb while the engine is running to help clean the carbon on the valves and pistons. It used to be a common practice many years ago, when fuel quality was not as good and was more variable. I have done it one or twice on an old engine. Maybe one of the "gray beards" with more experience will chime in. My beard is just "salt & pepper" at this point.

 

[Anonymous]

Who knocked on my coffin?!... :!:
(Grey beards, indeed, that's me...)

Yep, water in the manifold is an excellent cleaner, but you gotta do it right. Done wrong, it can either do nothing or bend a rod.

Here's the right way:
1. Heat up the engine very well - like, drive it for an hour, hiway, if possible.
2. Connect a small vacuum hose (like 1/4" diameter or less) directly to one of the manifold vacuum ports, so you're going right into the manifold - not thru the carb's cooling venturi.
3. Have a friend hold the engine at high idle, like about 1500-1700 RPM.
4. Dip the open end of that vacuum hose into a small soup can of water and let it draw a little bit of the water, maybe 1/4" worth from the can. Pull it back out and let the engine clear.
5. Repeat step 4 above until the can is empty, about 8-10 ounces of water.
6. Take the car back out and hit a freeway on-ramp somewhere, with your foot in it to blow out the carbon that has been loosened.

Here's what happens:
The water enters the cylinders as drops (instead of vapor, as thru the carb) and cools tiny spots around the head and piston unevenly. This knocks the carbon's grip off of the surface. Water vapor won't do this as well, or at all. Then, when the engine is revved up pretty good, but still warmed up, the carbon comes loose and exits thru the exhaust valve. The trip down the on-ramp is specifically to make sure the carbon is cleaned off of the exhaust valves BEFORE they cool off again, or else it will stick and you'll have problems until it burns off again.

If you want the engine to run like silk afterward, go get a can of BG44 from NAPA and put it in the gas. You won't recognize your car after that tank of gas has gone thru!

 

[Anonymous]

Mark, that is a good description and a better method than I used where I just dribbled it in the carb while tying to keep the engine speed up. I like the vacuum hose connection idea. I figured I there was a better way than how I had done it.
I tried to be diplomatic calling out the "grey beards". "Grey Beard" sounds much more wise and experienced than had I just asked for the opinion of an old fart.
I always look forward to the excellent information provided in your posts.

 

[Anonymous]

I have to say that I am a little scared of putting water straight into my engine. As a mechanical engineer I know that water is an incompressible substance until it is very very hot or very very depressurized. I have heard several people mention that they have added water to their engine so I know you aren't making it up, but I am just a little nervous.

I do know that some older aircraft actually used water injection in their engines so it can't be terrible for the engine. Guess you just have to figure out how much water to add and get that right.

I am gonna have to think about this at least overnight. Anyone else have experience with adding water?

-Dan in Atlanta

 

[Anonymous]

FWIW, you had two engineers making the suggestion. You are right about being cautious. However, when done is small enough quantities, the water flashes to steam upon contact quicker than it would on your old skillet. When done, it doesn't sound any worse than when you squirt carb cleaner down the carburetor. I imagine, you could squirt too much carb cleaner in there too and hydraulic the cylinder. The alternative may be to pull the head and scrape off the carbon like as described as a routine maintenance procedure in my '58 Harley owner's manual.