Main Bearing Clearance

I cringed when I read about using plastigauge,,,,,,,, and a motor with a stroker crank and high rpm. Please take the time to find a way to get it measured with a dial bore gauge and a good mike. An ounce of prevention here is worth a hundred pounds of cure here. If you plan on doing more motor assembly, invest in these items. Then you can know exactly what you have for clearances. The reason for more than factory clearance is two fold. A little less turning resistance, but more importantly, allowing for more flex and distortion at higher stress levels, like more stroke and more rpm. If you aren't familier with how much metal deforms when pushed on, pulled, or squeezed, get a rod bolt stretch gauge and measure it un torqued. Then tighten with your FINGER tips only and remeasure. You will see at least .0002 stretch! I did this on an ARP2000 7/16 bolt. Now think of what is going on inside your motor at 6800 rpm with a 4 inch stroke. A quality set of mikes and a good dial bore gauge are not cheap, but niether is your mileage hauling stuff around to get it rechecked or redone. On top of that you will also be able to double check machine work done. That is essential in protecting your investment. I found the clearances varied by .0005 on my race motor from one side of the bearings to the other. It turned out to be a line hone I requested on a race block must never have been done!! Now that motor is .0035 on all main bearings, + or- .0001, rather than .0034 on one side of a bearing and .0040+ on the other side!