Can you measure bore with telescoping gauges & calipers

Posted By: cudabitten

Can you measure bore with telescoping gauges & calipers - 07/31/12 09:25 PM

I picked up some telescoping gauges and a digital caliper that measures to .001.
I spent only about 20 minutes and got consistent readings with these tools. I understand there is a process to measure for taper and out of round. I didn't want to waste a whole bunch of time if this method is not reliable.
For example, I'm checking the bore on a 318, the spec says 3.910 to 3.912 is the standard bore. I got 3.9060 consistently in three of the cylinders. That gives me .004, the maximum tolerance is over .005 before requiring reconditioning.
Anyone use these tools for this?

Posted By: MoparforLife

Re: Can you measure bore with telescoping gauges & calipers - 07/31/12 11:36 PM

If you are measuring at 3.906 you are measuring smaller than the standard 3.91-3.92 not .004 wear.
3.91 is bigger than 3.906 unless new math changed things

Posted By: Bill MeLater

Re: Can you measure bore with telescoping gauges & calipers - 08/01/12 02:57 AM

Not gonna give you what you really need to know, find someone with a bore guage. And don't get to hung up on the .005 thing, looser still works, just makes a little more noise....

Posted By: Cab_Burge

Re: Can you measure bore with telescoping gauges & calipers - 08/01/12 03:41 AM

If you had a standard to calibrate the digital calipers it might be halfway accurate to use them and the snap gauges, without it your guessing how far the calipers are out from being accurate at any size

See if you can borrow or buy a 2,3 and 4 inch outside micrometer checking tool, standard, to work with now

And use both the snap gauges and the calipers to measure both the bores and pistons

Posted By: fishy68

Re: Can you measure bore with telescoping gauges & calipers - 08/01/12 05:19 AM

Moparforlife nailed it. You said you measured 3.906". That's .004" smaller than the minimum. That right there should tell you it's not accurate. The biggest problem is probably the caliper. I have 3 and none read the same. Their all within 2-3 thousandths which is ok for most things but not all.

Posted By: 383man

Re: Can you measure bore with telescoping gauges & calipers - 08/01/12 08:16 AM

I have a full set of telescoping gauges I use. I have digital calipers and outside mikes up to 5 inches. The mikes are dead accurate as I check them and calibrate them all the time. The digital caliper is very accurate as I can also calibrate it. The thing is you need a good touch with telescoping gauges to be very accurate. I like to use them for general readings but use my bore gauge for very accurate readings. Ron

Posted By: mopfried

Re: Can you measure bore with telescoping gauges & calipers - 08/01/12 12:41 PM

Quote:

I have a full set of telescoping gauges I use. I have digital calipers and outside mikes up to 5 inches. The mikes are dead accurate as I check them and calibrate them all the time. The digital caliper is very accurate as I can also calibrate it. The thing is you need a good touch with telescoping gauges to be very accurate. I like to use them for general readings but use my bore gauge for very accurate readings. Ron

I agree 100%.. Mikes and a good feel for the telescope gauge. Dial bore gauges are dead on.

Posted By: 451Mopar

Re: Can you measure bore with telescoping gauges & calipers - 08/01/12 05:03 PM

The snap gauge and calipers could be OK for a rough measurement, but don't have the accuracy required for most inside measurements on an engine where you would want at least 0.0005" resolution or better for measuring main, rod and piston bore clearances.
A dial bore gauge is a comparison tool. It is setup using a known standard, usually a calibrated micrometer.

Posted By: dogdays

Re: Can you measure bore with telescoping gauges & calipers - 08/01/12 11:51 PM

Unless your snap gauges have rounded ends you will be measuring slightly under the bore size. Like this: (!---!)

I really don't like snap gauges and after using a good bore gauge I am spoiled.

R.

Posted By: 383man

Re: Can you measure bore with telescoping gauges & calipers - 08/02/12 04:31 AM

Quote:

Unless your snap gauges have rounded ends you will be measuring slightly under the bore size. Like this: (!---!)

I really don't like snap gauges and after using a good bore gauge I am spoiled.

R.

Mine do have rounded ends on all of them. Ron

Posted By: runinonmt

Re: Can you measure bore with telescoping gauges & calipers - 08/02/12 01:01 PM

go to your local parts store that rents tools,get the right size Mic,for the standard if nothing else.
Ron

Posted By: Supercuda

Re: Can you measure bore with telescoping gauges & calipers - 08/02/12 01:33 PM

Snap gauges work fine, but it's one of those things that work fine if you have a lots of practice using them. A bore gauge is more user friendly, especially for someone who doesn't do it often enough.