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Engine bearing double check

2K views 3 replies 2 participants last post by  eschaider 
#1 ·
Hello guys. I have built a short block that was going to be fed by a tvs blower. I selected to us king si series main and rod bearings per readings and advice of this forum.
I have since left the blower world and the car will be twin turbo, auto and trans brake, holley ecu car.
Will the si series still be the best bearing for my application? Car is setup to make peak power around 8000 to 8200 rpm.

Thanks for the help guys.
 
#2 ·
You still want the SI bearing Stuntstere. The reason for the SI choice was embedability and extended life during periods of less than optimum oil delivery. King bearings has an excellent tech section where they discuss the benefits of the various bearing materials they offer. Here is the article you want to read => Engine Bearing Materials. Download it, read it and pay special attention to page 7.

Since the paper was originally published King has come up with a polymer surface treatment that gives the P-Max style bearings similar embedability and long life in compromised lubrication environments. Don't misunderstand you do not want to run the engine in a compromised lubrication environment but it you accidentally do you want some level of insurance - that is what the SI class bearing materials do and also the new Polymer coated bearing offerings.

The SI bearings and the HP bearings are identical except for the oil groove treatment. The HP bearings come with King's improved U-Groove oil grooves. Other than the oil channel you are essentially looking at the King SI series bearing - except at 2x the price.

Your bearings are excellent for all types of supercharged applications especially the primary street application you are looking at. If it makes you feel better an 11,000 HP T/F engine uses a soft babbitt bearing for embedability and durability at those power levels. They absolutely do not use any of the hard bearings because they will not survive. The bearing's strength is significantly contributed to by the steel backing that carries delivers bearing load to the bearing bore in the rods and mains. The actual load on the bearing is carried by a hydrodynamic loading of the bearing surface. The crank actually rides on a film of oil never touching the actual bearing material! The SI material bearings allow for embedding of any foreign material in the softer SI material so as not to scratch the crank or seize the bearing on the crank.

Spend some time on the King website in Dr. Kopeliovich's technical papers. Be informed, learn about the bearing science used in your engine - it is time well spent.

You've got the right bearings!

Ed

p.s. Use Prolong oil treatment after break-in with every oil change.
 
#4 ·
They are excellent choices for sustained high load environments like high banked oval racing or boat engines where the engine is under a continuous high and sometimes variable loading.


Ed
 
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