|
Just some advice, I have heard, about carbon on Pistons over my years about messing around with the pistons still in the engine. Not advisable!
You do not want to clean off the carbon around the outer edge of the piston.
This area on the top edge and down the inner side acts as an extra sealing ring.
The oil and gasoline deposits created at high temperatures form a flare towards the cylinder wall and helps overlay the clearance gap, that you see from the top because the engine is cold.
This space closes up under expansion of the Pistons head.
The super fine powder and super heated carbon particles makes a better seal than a man made mechanical seal can do.
The Carbon has has to be allowed, by a compromise of design, to be a natural hardened seal in this case.
If you disturbed particles from the piston and they fall into the that clearance, you are not ever going to get them back up out of there! Especially, after they hit any cylinder ridge at the top of the bore!
These particles will ride against the cylinder and act like a spacer, that either gets embedded into the aluminum piston or work at scratching a bore groove!
For this reason, despite what you see as dirty in there, JUST LEAVE IT ALONE!
It is allowed for!
Carbon will just return and go away again many times like before! As far as the white spots...was there a coolant seepage or loss?
Carbon black by itself, is one step below a diamond in hardness. Pressure and heat makes diamonds. There was not nearly enough pressure so you are left with the cheap stuff! (:-)
Carbon deposits, it could be said, "actually helps wear the engine "in" for a better fit" or later, "it helps it to wear out more to some extent.
Many more factors play in along this thinking of what wears out engines? I just say, look at so many drivers attitudes and I rest my case.
These engine deposits are very close to earths minerals used to hone a cylinder to final size. The hone is also used to put a crosshatch patterns on the surface of the bore. Usually at 30 to 45 degree angles.
Many a mechanic or the manufacturers themselves have studied the theory and use their own boring and finish techniques. From flat stone strips to wire suspended round balls, all developed over many years!
.
The theory or purpose of the crosshatch to allow the oil to channel and cling while flowing up to and between piston rings. Any remainder is suppose to provide a cushion film below where the really undersized and the out of round, when cold, piston-skirts lie.
This is where the thrust of the piston, that's perpendicular to the wrist pin, gets its needed support and cooling to the water jacket.
Any vertical scratch will negate a patch of the "cling" especially during off and start cycles. Gravity works "all" the time! When it's cold or running, the oiled can be pushed or drained away.
Here is another area of compromise engineering. How short can the skirt be for reduced weight for advantages of a quick rev speed over long life wear support. Racers or engineers play in this area a lot!
The race tracks lengths can play into the equations! Will it be a....Quarter mile or 500 miles or a "six year" payment car or a twenty year investment car?
Use to be a Volvo nameplate, don't know about their engines now with "blow apart "safety" bodies" that total out cars for more that a dent or scratch, on guess what.....carbon fiber!
It is the new age and the IOT today! (:-). Phil
|
