Proper use of dial bore gauge

bugnut68 · Post by **bugnut68** » Sun Apr 02, 2006 3:52 pm

I recently purchased a dial bore gauge from Enco, as I've started delving into the wonderfully time-killing hobby of small engine rebuilding. The instructions that came with the kit are somewhat vague, so I was hoping some folks here might be able to steer me in the proper direction in terms of usage?

The range of the kit is from 2 to 6". Any help would be greatly appreciated.

The Noof · Post by **The Noof** » Sun Apr 02, 2006 3:58 pm

What is it you need to know specifically?For checking bore wear, look up the bore size for what you're measuring. Tranfer that reading to your dial indicator with an outside micrometer, with zero being your reference.Put the bore gauge in the cylinder. Measure top (under the ridge if this is an engine cylinder), middle, and bottom. This will tell you both wear and taper figures. Then, measure around the cylinders, top middle, and bottom. This is your out-of-round.Thats a start.

bugnut68 · Post by **bugnut68** » Sun Apr 02, 2006 4:12 pm

Thanks, it's much appreciated!

bugnut68 · Post by **bugnut68** » Thu Apr 20, 2006 6:42 pm

Actually, I do have one more question: how do you ensure you are getting an accurate reading? That is, determining the tool is "properly" centered when measuring, as the gauge is thrown off as the angle changes.

VGM · Post by **VGM** » Thu Apr 20, 2006 8:44 pm

It's all in the wrist.Rock the gauge back and forth to find the lowest reading.This will be the center of travel and the true reading.

nsracing · Post by **nsracing** » Mon Feb 05, 2007 7:16 am

VGM wrote:It's all in the wrist.Rock the gauge back and forth to find the lowest reading.This will be the center of travel and the true reading.

The lowest reading is true as VGM says. I'm a dummy.

Noof pretty much described how to set it up. But he left out how to read the dialbore gauge. BAD Noof!

AS you stick the dialbore gauge in the hole, it is true that you rock it back and forth or swing it up or down...following the plane of the measuring tip. You then watch the needle move and do its "bell curve". As you rock it, you will see the needle will move LOW--HIGH--LOW. The highest needle movement is CENTER. This will be the correct measurment. You will need a Micrometer to read what that dimension is. You will do the same thing once you transfer the dialbore gauge in the Mic...rock it back and forth until you see that highest point of the needle. Do it slow so you can appreciate it.

The dialbore gauge is in a tripod so you will always be centered in the hole.

If you "zero" the needle at zero (0), left side of "0" is loose and right side of "0" is tight.. It is like setting the "preload" on a dial indicator. You just move the dial face over to line up with whatever number you are looking for...in this case zero "0".

YOu can use the dialbore gauge as is... and measure the final dimension with a Mike, or use the Mike as a setting tool. YOur choice.

As for me, I just set up the dialbore gauge and stick it in the hole. Find highest reading of the needle and move the dial face ZERO over the needle. Move the bore gauge around and see out-of-round. Zero is the baseline...so any deviation is how much out of round. If I need to find out the exact dimension, then just grab a Micrometer and read what that ZERO position is on the thimble.

HOpe this helps.

VGM · Post by **VGM** » Mon Feb 05, 2007 9:22 pm

The dial bore gauge I'm familiar with is a T-style (no tripod). It requires finding the center of travel at each measuring location. The 0, or lowest reading indicates the gauge is centered in the bore, and not at an angle on the walls of the cylinder giving a higher false reading. This would be indicated by a HIGH-LOW-HIGH measurment with the LOW being the center or correct location. The gauge is rocked to find this center at each location to be measured.
Perhaps we are talking about different styles of gauges?

nsracing · Post by **nsracing** » Tue Feb 06, 2007 5:49 pm

I think we are talking about the same thing but describing it differently.

I hope we did not create even more confusion with it.

Right side of the dial indicator is the TIGHT SIDE and Left side is LOOSE SIDE...zero being middle ( if you zeroed the needle at "0").

The center essentially is the FARTHEST THE NEEDLE WILL GO TO THE RIGHT. The needle will swing like a rainbow. The middle of that rainbow is the farthest point the needle will go to the right.

I apologize for making this even worse. So sorry VGM. It is really easier done than said.

Peace.

VGM · Post by **VGM** » Tue Feb 06, 2007 11:30 pm

Fair enough.I hope we helped.