clean engine,dirty pistons

Messages
747
Location
miami fl
I want to bring to light the fact that a clean looking engine on the inside does not mean the engine is in good condition. anyone actually taken down a good clean engine to find cooked baked piston ringlands? how about cylinder wall wear? I have taken down many engines that looked clean but consumed oil and smelled bad as they ran down the road. I find it funny that dino oil changed often cant stop the deposits from wiping out ring seal due to wear in the long run. I have a few examples if anyone would like to see?
 
Messages
22,188
Location
Colorado Springs
Then why have many many............hundreds of thousands of engines gone well past 200K with no issues - run on conventional oil? Your signature says it all... I've been maintaining my parents vehicles and my own with conventional oil. My Dad's truck now has 220K. Despite the rear main seal leak (common on the 4.3L and 5.7L GM engines) it still only consumes under a quart every 4,000 miles between changes and runs great. Passes emissions with flying colors, doesn't smell, yadda yadda yadda. Same with my mom's Olds with 160K, although it consumes even less oil. With 220K, my Pop's truck still get 16 mpg in town and about 23 all highway. My Mom's Olds gets 20 in town and about 32 highway (3.8L). I find it funny that you have your sig, and a few other posters under different screen names have the same sig. Why not just become a site sponser so you can sell Amsoil! Or, maybe you already are a site sponsor...under a different name. Twilight Zone maybe??? Do Do Do Do...
 
Messages
3,329
Location
Bolivia
One of the last engines I rebuilt ran mineral oil (first group I, then Group II. It was a Toyota 3.6 L diesel. It had 400,000 miles, and died because the air intake broke and it ate a lot of sand. 80% of its 400,000 miles was on dirt roads. My 4Runner engine was super clean when I pulled it apart at 65,000 miles or so when it hydrolocked and bent a rod and sleeve. Group I and then II oils for its 7 years. Synthetics are good, but not for everyone - I My BMW runs synthetic with once a year changes.
 
Messages
11,334
Location
Florida, Cape Coral
Ring pack varnish is more common now than in the past. In an effort to minimize unburnt fuel in the combustion chamber, manufactures have positioned the top ring closer to the piston crown. This minimizes the area between the piston and wall down to the top ring. So the rings runs hotter and you can get more varnish. In the past I have used Auto-RX and it has done a beautiful job at cleaning the ring pack.
 

lazaro

Thread starter
Messages
747
Location
miami fl
 Originally Posted By: LT4 Vette
Yes, please post the pictures.
the pictures I have will be from a 140,000 mile 1995 cobra 5.0 I will get them this weekend.
 
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