I just got a dial bore gauge and tried to use it last night, with mixed success. To measure the bore of my used SL6 block. I set the dial calipers to 3.4" and tried to measure. Well, it only would measure things smaller than 3.4". So I tried to split the difference and zero. That was better. It occured to me that if I measured the bottom of the bores it might be easier to use as the reference diameter than use the dial caliper(this is a pain).

Someone walk me through this setup. I am sure I am doing it the wrong way.

bwhitejr

_________________
'72 Duster (Performance 360)
'83 Ramcharger (Performance 318)
'80 TrailDuster (360)
'80 D-150 Truck (See Below)
CompCams 252S, Holley 390cfm, Offy manifold
Ported, Polished and Gasket Matched
P4286813 Springs,0.040 Overbore,
0.090 Shaved Head

I always thought it was a 2-step process.

You have the part that's a rod with rounded ends that you stick down the bore, then you lock it, take it out then measure the length of the rod.

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

you'll need a 3-4" micrometer to zero the dial bore gauge. set it to the standard spec in the service manual. set up you dial bore gauge with a rod that will slightly depress the plunger when it is fitted to the bore. place it in the jaws of the micrometer then zero the gauge and note the position of the smaller needle in the center of the face. then you are ready to take some readings. you're supposed to measure at three points along the thrust sides of the bore and three more parallel to the crankshaft in order to find the bore taper and see if it is out of round. one measurement about 1/4-1/2" from the bottom, one in the center and one more @ 1/4-1/2" from the top of each bore on both axis'. rock the gauge back and forth slightly at each point and use the highest reading. keep a pencil and paper handy to take down each measurement. add each measurement to the standard and you will know what kind of shape you are in.

-james

_________________

The set I have has a pin for 3.4". I tested it with the dial calipers and it is longer than the 3.4", but that puts it so it reads + or - numbers on either side of 3.4". So, if I am doing this right the 3.4" pin is the exact one needed for a stock Slant Six bore.

bwhitejr

_________________
'72 Duster (Performance 360)
'83 Ramcharger (Performance 318)
'80 TrailDuster (360)
'80 D-150 Truck (See Below)
CompCams 252S, Holley 390cfm, Offy manifold
Ported, Polished and Gasket Matched
P4286813 Springs,0.040 Overbore,
0.090 Shaved Head

i'm not sure what you are asking. set your micrometer to read 3.40" and lock it. use the rod on your dial bore gauge kit that will depress the plunger so the small needle reads about halfway when it is placed in the jaws of the mic. then twist the dial so the large needle points to zero. when you place the gauge in the bore, the new reading is the difference between standard and the actual bore diameter.

-james

_________________

The Dial indicator says it is accurate to 0.0005". The dial reads plus or minus 0.025" or 0.25", I can't tell. It makes sense if it reads plus or minus 0.025", because that is what it looks like, to me.
The problem with that is the cylinders are within original specification of 3.4000 - 3.4020. And the odometer reads 71,000 miles (171,000) miles.

bwhitejr

_________________
'72 Duster (Performance 360)
'83 Ramcharger (Performance 318)
'80 TrailDuster (360)
'80 D-150 Truck (See Below)
CompCams 252S, Holley 390cfm, Offy manifold
Ported, Polished and Gasket Matched
P4286813 Springs,0.040 Overbore,
0.090 Shaved Head