60,000mi Spark Plug Change

[jjvincent]

Loved the 928s back in high school but now I am a 4 ringer.

This thread is reminding me I need to source plugs For the Audi and lots of fluids and plugs for the Wrangler this fall.

I worked on those 928's when they were new. The twin clutch ones got to the point, two of us could change those clutches in 30 minutes. It paid like 4 hours.

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[Old Jeeper]

Thing is, OEM's don't apply anti seize to spark plugs (if there is one they are an oddball). Plus, Porsche (which was strict about this on the air cooled ones) stopped. I do remember back in the days, we always did anti sieze. Problem was plugs went 15K. So by the time you had 60K on the clock, those threads were all gooped up and plus, the trick was, take a long screw driver down and clean off the sealing surface, then blow it out. If not, plugs would leak compression around them.

Yes, times have changed. Same for why unleaded gas does not cause burnt valves (lead was to cushion the valve seat) or all injection pumps on diesels would wear out because of low sulfer diesel or that you had to break in camshafts and the list goes on.

I beg to differ on the use of lead in gasoline. They began adding lead to gasoline in the 1920s. The reason was Lead is an 'antiknock agent' which improved the efficiency of vehicles and the performance of the engine. Not enough Lead to offer up much cushion to the valve seat.

Burnt valves have a plethora of causes: Ranging from and in order of occurrence: Incorrect sparkplug gap, incorrect fuel-air ratio, failing exhaust valves, and carbon build-up around the valve and the combustion chamber. It can be any or all of the above

I remember those days very well. There was elixirs and Motor Honey and even pills you put thru the spark plug hole to make your engine run better, more MPG and cure burnt valves...you Bible was the JC Whitney Catalog which offered gimmicks galore to get up to 100 mpg. Funny the only thing we did was pour plain old water thru the intake and clean out the engine carbon and it now ran better. We did that at every oil change...those were the days!

 

[Valpo Jeep]

Heard of many times that people would take the car out and run it hard and hot to clean out the carbon out of the engine.

 

[jjvincent]

I beg to differ on the use of lead in gasoline. They began adding lead to gasoline in the 1920s. The reason was Lead is an 'antiknock agent' which improved the efficiency of vehicles and the performance of the engine. Not enough Lead to offer up much cushion to the valve seat.

Burnt valves have a plethora of causes: Ranging from and in order of occurrence: Incorrect sparkplug gap, incorrect fuel-air ratio, failing exhaust valves, and carbon build-up around the valve and the combustion chamber. It can be any or all of the above

I remember those days very well. There was elixirs and Motor Honey and even pills you put thru the spark plug hole to make your engine run better, more MPG and cure burnt valves...you Bible was the JC Whitney Catalog which offered gimmicks galore to get up to 100 mpg. Funny the only thing we did was pour plain old water thru the intake and clean out the engine carbon and it now ran better. We did that at every oil change...those were the days!

Having done lots of valve jobs, the main issue was cars burnt valves because they were caked up on the backside. It was because oil and fuel technology was not what it is today. Lead was cheap and then we moved onto MTBE and after that, whatever they use today.

 

[jjvincent]

Heard of many times that people would take the car out and run it hard and hot to clean out the carbon out of the engine.

Yes, it was common. For example I have lots of experience with air cooled 911's. They run overly rich, thus you pretty much had to run those things like crazy to clean them out. Amazingly, with modern advances, not as much of a problem. Back in the day the spark plugs that were to be anti fouling, cost $12 each (Imagine paying that back in 1975). Today, about $40 each.

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[Old Jeeper]

Heard of many times that people would take the car out and run it hard and hot to clean out the carbon out of the engine.

YEP that another option, but you need a LONG stretch of Hwy and got to get the engine really hot. Helps if you have a Radar Detector or a BiL who is the Sheriff.

Having done lots of valve jobs, the main issue was cars burnt valves because they were caked up on the backside. It was because oil and fuel technology was not what it is today. Lead was cheap and then we moved onto MTBE and after that, whatever they use today.

Yes and its why I poured water down that intake at least once a year and makes the valves and heads look new, its that good, all the JC Whitney stuff did was take your money and clog your engine...

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