Cheaper Digital Bore Gage?

khamul02 · khamul02's Garage

I'm looking for something on the cheaper end. I found these two and have a T bore gauge set to double check.. Or is the T bore gauges good enough. I am working on an 80 911 and then at some point will use these on the 81. So it is really just for a couple uses.

https://www.amazon.com/Accusize-Tools-0-0005-Digital-EE20-5274/dp/B00IGELLRI/

https://www.amazon.com/Anytime-Tools-Electronic-Precision-Resolution/dp/B000XYND0M/

dtxscott · 07:03 AM

I have the Anytime Tools unit and it seems to work very well for the $$.

The last digit has an accuracy of +/- 5.

I looked at the telescoping bore gauge set but didn't like having two measurements that could induce error. One measurement is actually measuring the bore with the "T", then you have to measure the "T" with a micrometer. This is a good way to get stackup error.

As with any bore gauge, the cal/setup is tricky. I invested in a used ring gauge off ebay and double-checked the setting with a vernier micrometer.

stownsen914 · 03-25-2021, 07:36 AM

When it comes to high precision tools, my attitude is buy a good one or it may not be worth the $$ (or possible inaccurate/imprecise measurements you'll get from it). Maybe the one noted above is good, not sure. I bought a used Mitutoyo for like $150 and had it calibrated.

icarp · icarp's Garage

This type of bore mic usually offers .002" accuracy . repeatable measurements are key.
I spent $700 on a Sunnen dial type , used , to the .ooo1"
Always repeatable .
Pay now or pay later , off by .002" can seize a piston . Resolution is not the same as accuracy.
Ian

cgarr · cgarr's Garage

the key is all in the setup, get a good set of gauge blocks or setup ring or you will just be guessing

911 tweaks · 03-26-2021, 11:36 AM

hey ian... r u still playing out in the sw desert...? hope all is good...
ps add to your team mark burkit...))

stownsen914 · 03-27-2021, 04:09 PM

The ad says it's accurate to .0005". Not bad, but .0001" would be better depending on what you're doing.

Speedy Squirrel · Speedy Squirrel's Garage

I’m answering the more expensive bore gauge question:

https://youtu.be/DgqE_ab3t_s

Dpmulvan · 04-06-2021, 06:53 AM

You can simply remove the cheap dial gauge and swap it out for one that reads down to .001.

Jeff Alton · 07:46 PM

T bore gauge not accurate.

The first one you showed reads to half a thou (if I read it correctly) or based on the picture, the second one to another decimal point.... The second one would be my choice between the two.

Cheers