Question On Coated Pistons
#11
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Joined: Jun 2013
Posts: 145
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I never use oil in my builds except for wrist pin. Never had any problems. I put 2 heat cycles on an race engine and it's ready for the track! I'm not a believer in the whole break in process. I belive the motor starts wearing the first time it starts up. I have have good luck but I have blowed a few up too!!
#12
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Joined: Jan 2005
Posts: 3,570
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From: Pasadena, MD
Usually dip the whole piston in Rotella 20/50 (same oil I run in the motor) and move the rod around on the pin before pulling it out, draining out the bottom of the piston and a finger scrape off the top and then stuff it in the cylinders that were coated with the same oil if I plan on starting it soon or assembly lube if I plan on letting it sit.
#13
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Joined: Aug 2011
Posts: 2,733
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From: bel air, md
I guess it comes down to whatever makes you feel better. My motor was assembled dry except for a little oil on the bearings. I do prime the oil system and spin it over by hand a dew times b4 starting. After start up I try to get go WOT as soon as possible for optimum ring seal.
#16
I always wipe the cylinders down with oil and add some drops to the skirts, to ease sliding the piston and rings through the tapered ring compressor. That piston shown is probably going into a dirt bike or atv which has a nikasil plated cylinder. I would use, the recommended procedure from the manual or plating company, the rings are most likely chrome plated also, which the finish cross-hatch and RMA finish is going to be different from domestic applications.
Sealing the rings, isn't all about how much or how little oil you put in the cylinders. The oil is for lubrication of the skirts, the oil is below the 2nd ring, if using a napier 2nd it wipes the oil away allowing you to use a lower tension oil control. This is reducing friction and parasitic drag. The cross-hatch, and angle are which control the amount of oil left in the cylinder after the rings have wiped it away. If you have a rich condition, it will wash the cylinders, remove cross-hatching and add vertical grooves into your rings along with vertical scuffing from lack of lubrication on cylinders and pistons, which will decrease ring seal . Using a torque plate during honing, is the most important factor for ring seal, either a cast iron plate for cast heads and a alum plate for alum heads, the bolts or studs being used along with the length of spacers to simulate the boss length of heads, that creates the distortion of the block deck, when heads are torqued to specifications. I wouldn't consider; a dry start with excessive fuel a good start-up procedure.
Sealing the rings, isn't all about how much or how little oil you put in the cylinders. The oil is for lubrication of the skirts, the oil is below the 2nd ring, if using a napier 2nd it wipes the oil away allowing you to use a lower tension oil control. This is reducing friction and parasitic drag. The cross-hatch, and angle are which control the amount of oil left in the cylinder after the rings have wiped it away. If you have a rich condition, it will wash the cylinders, remove cross-hatching and add vertical grooves into your rings along with vertical scuffing from lack of lubrication on cylinders and pistons, which will decrease ring seal . Using a torque plate during honing, is the most important factor for ring seal, either a cast iron plate for cast heads and a alum plate for alum heads, the bolts or studs being used along with the length of spacers to simulate the boss length of heads, that creates the distortion of the block deck, when heads are torqued to specifications. I wouldn't consider; a dry start with excessive fuel a good start-up procedure.
#17
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Joined: Feb 2011
Posts: 2,640
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Mark, what is your opinion on plateau honing? It seems to be the hot trend in cylinder prep, and is supposed to greatly reduce the break-in period. I have even heard it said that a properly plateau honed cylinder will achieve ring break-in and seal almost immediately on startup.
#19
Mark, what is your opinion on plateau honing? It seems to be the hot trend in cylinder prep, and is supposed to greatly reduce the break-in period. I have even heard it said that a properly plateau honed cylinder will achieve ring break-in and seal almost immediately on startup.
#20



