Bearing Calculator

This program will help you determine if your crankshaft bearings are suitable. You can calculate the load on a main or rod bearing. This will tell you if a bearing size will provide acceptable performance in your engine. This program assumes that all bearings are made from 932 (SAE 660) bearing bronze.
Suggested loads are :
Main bearings : 500 - 700 PSI
Rod bearings : 1500 - 2500 PSI
These calculations are for pressure feed oiling, if pressure feed oiling is not used, you may want to consider keeping the bearing under a lesser load.
All fields are required, except the width of the oil groove, which is only required if you specify an oil groove.
Most of the information used to create this program is from Machinery's Handbook, except for the info on pressure/velocity.
The piston diameter and compression ratio is used to calculate the load on the bearing.
For a main bearing of .500 dia, a minimum oil groove of .030 wide, and .015 deep is suggested.

NOTE: When using this program, please keep in mind that this is not a final word on bearings. This will help you to size your bearings, but there are many things in bearing design that are not addressed here. I made this for my own use and will not be responsible for your use (or mis-use) of it.

Here are 2 PDF files that I found while searching for information on bearings. They have very little info pertaining to engine design. I don't remember where I got these files from, but I make them available here:
Bearing Design Guide (PDF) Free Download
Sleeve bearings (PDF)

Calculate Bearing Parameters for a Crank Shaft

The following values all assume the use
of 932 (SAE 660) bearing bronze.

Bearing parameter	Value	Status
Piston Bore Dia. :	in.
Compression Ratio :(Max = 15)	:1
Max operating speed :	RPM
This bearing has an oil hole This bearing has an oil groove
Oil Grove width :	in.
Select one for Main Bearings : (Max Load is 700 PSI) Rod Bearings : (Max Load is 2500 PSI)
Select one for main bearings only: This crank is supported by 1 bearing This crank is supported by 2 bearings
Enter the length of the bearing (inches):	in.
Enter the bore of the bearing (inches):	in.
Bearing L/D Ratio
Shaft Velocity	SFPM
Peak Piston Pressure	PSI
Bearing Load	PSI
Pressure Velocity (Max = 1500K)	K

This is a BETA version of this program.
Always make sure that the values are updated when you make any changes.
Sometimes, when CHANGING values, it doesn't update. You may have to reload (click the refresh button on your browser) and enter all values again.
Only the values in red can be changed.

This has been tested on IE 6.0, and konqueror 3.5.4, and Firefox (Linux).

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