Tech request; proper plastigauge useage

im switching pistons out on a rebuilt 37 flathead. ive got the tork specs, im about ready to go. im removing the rods switching pistons and puting them back, do i need to check oil flow clearence w/ a plastigauge? ether way how is that used.

 

Zgears,
Plastigage is used to determine the clearence between a bearing and the shaft it fits. It comes in a range of sizes ie .000 to .005, .005 t0 .010 ect.
To use it wipe the crank journal comlpetely free of oil ( the rod bearings also). cut a length of the plastigage to the width of the bearing. Place it on the crank journal parallel to the crank axis at a point it will fall in the center of the rod cap. Tighten the bearing cap to specified tourck, thenremove cap and the plastigage will have been flatened. There is a gage printed on the little envelope it comes in. Place this gage over the flatened plastigage until it matches up with the width and viola you now know how much clearence you have. If the clearence is within specs, clean all plastigage from crank and bearing,put on a little ***embly lube, re torqe to specs and move on to the next piston.
Hope this helps,
Ted
PS: DON'T MOVE THE CRANK WHILE YOU ARE TORQING THE BEARING CAP.

 

Ps: ....or Loosening The Bearing Cap

 

Put some thin paper on one of the main bearings that you're not measuring and torque the cap down. This helps to hold the crank still while you measure the other main bearings. Obviously you need to make sure you remove the paper before you ****on the engine up!

 

thanks for the info. whatabout the gap size for a flathead full-floating brearing?

 

bttt, any one know gap size?

 

bttt one last time

 

Motors manual suggests .0015 to .003" for all Ford engines 1935-42.