Re: engine bearings
Everyone seems to be giving opinion (which is fine if you have already answered the question that was asked...) So it's time for another opinion...
Facts in short form...
What you need to be looking for is;
If the bearings don't get the correct crush, (enough crush, no buckles, and crushes round) the bearing will fail.
If it doesn't crush enough, it won't transfer the heat and load to the block.
If it doesn't crush round, it may contact the crankshaft and scrape the oil wedge off.
The bearing has to carry the entire load of the crankshaft or piston and rod assembly on cold start up.
It has to be hard enough to support the load, yet soft enough not to damage the crank.
The inside surface material has to be soft enough to allow hardened material, like carbon or metal filings, to imbed in the bearing material.
If the inner surface of the bearing isn't soft enough to allow the imbedding of material, the hardened speck of whatever will stick in the bearing, and then start machining clearances in the crankshaft.
I really can't stress how important the ability to imbed (and capture) 'no see um's' is...
Directly related to how much bearing crush you get.
The heat created in the combustion chamber is somewhat passed to the cylinder walls by the piston rings.
Most of the heat is passed from the piston to the wrist pin, to the connecting rod, to the crankshaft, to the engine block.
The oil carries off a lot of the heat at the joints of the connecting rod to crankshaft, and the joint of the crankshaft to the engine block.
Much of the heat remains, and is supposed to be transferred to the block via the main bearings.
If the main bearings don't crush properly, the heat may not get transferred to the block, and remain in the crank, rods, and pistons with disastrous results.
Technically, the crankshaft is never supposed to touch the bearings.
There is supposed to be a non-compressable layer of oil between the bearing and the crankshaft.
In the real world, no oil pressure on start up is known in the business as a 'Dry Start'.
(That's why I preach and nag the pre-oiler before starting any fresh engine, or any engine that has set for any length of time longer than about a week)
Contaminants in the oil, such as water, acids, anti-freeze, and any combination of ten thousand assembly chemicals or fuel or coolant additives will aid in stripping the oil film from crankshafts and other parts.
Fine particles from normal combustion (soft and hard carbon), dirt and other contaminants from the atmosphere, normal wear of the steel and iron parts will find their free run in the oil no matter what kind or how many oil filters you use.
What brand of oil you run is not nearly as important as changing your oil in a timely manner, and getting ALL of the contaminants out of the engine by changing the filter at the same time.
These particles do mean and ugly things to engine bearings.
The hard truth is no additive, no synthetic oil, no supposed miracle filter will save you.
The only remedy is to change the oil and filter in a timely manner.
Now, For the opinion part...
I use A LOT of Clevite 77 bearings.
I like them.
They have regularly gone over 3,500 horse power in top fuel cars.
They have regularly gone over 200,000 miles in stock vehicles.
They have regularly gone over 13,000 RPM in racing engines.
I find no fault with Clevite 77 bearings...
Let the flames begin!
"I Have The Body Of A God... Buddha"