My Kingdom for a Freaking Dial Bore Gauge
#17
[QUOTE=Mike Simard;5083452]
Good point Mike, I never thought of it that way but that's very true.
Hammer
what is your opinion on digital compared to analog?
I don't have any digital measuring gages except for a high precision one in inspection.
In general dial gages are superior to digital. Not just in the shop. A dial gives you an immediate sense of change whereas your brain has to translate digital readings. I also like full sweep gages in the dash. In the driver's seat you can instantly tell a reading by the dial orientation without taking time to read a number and compare it inside your head to an ideal.
When measuring a bore in the shop you want to be able to move the gage about to sense variations. you just cant do that with a digital gage.
I don't have any digital measuring gages except for a high precision one in inspection.
In general dial gages are superior to digital. Not just in the shop. A dial gives you an immediate sense of change whereas your brain has to translate digital readings. I also like full sweep gages in the dash. In the driver's seat you can instantly tell a reading by the dial orientation without taking time to read a number and compare it inside your head to an ideal.
When measuring a bore in the shop you want to be able to move the gage about to sense variations. you just cant do that with a digital gage.
Hammer
#18
More importantly you don't have to look at a guage, you can see it in your peripheral vision, whereas reading a digital display means you have to take your eyes off the road (or at least I do).
#19
Just a heads up BC. When I used a dial bore gauge to measure the internal diameter of the mainline with bearings installed and then mic'd the crank, the difference was closer than the factory minimum tolerance. I think it was Garrity that told me to just follow the WSM procedure and use the plastigauge, which I did and it was right in the middle of spec. That was a relief, but afterword I went back and did everything possible in my measuring technique to find that extra half a thou of clearance (that registered with the plastigauge) and couldn't do it. So, there is definitely a crush factor that needs to be taken into account when measuring crank clearance.
I'll be curious if you have the same experience.
I'll be curious if you have the same experience.
Last edited by atb; 02-08-2008 at 09:44 PM.
#20
Just a heads up BC. When I used a dial bore gauge to measure the internal diameter of the mainline with bearings installed and then mic'd the crank, the difference was closer than the factory minimum tolerance. I think it was Garrity that told me to just follow the WSM procedure and use the plastigauge, which I did and it was right in the middle of spec. That was a relief, but afterword I went back and did everything possible in my measuring technique to find that extra half a thou of clearance (that registered with the plastigauge) and couldn't do it. So, there is definitely a crush factor that needs to be taken into account when measuring crank clearance.
I'll be curious if you have the same experience.
I'll be curious if you have the same experience.
BTW - ALL the rod bearings I am being set are yellow. There are no blue or red ones in all 16 packages.
#21
Chronic Tool Dropper
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Brendan--
I've used the telescoping bore gauges with the corresponding micormeter for more than a few projects, no complaints. Not as much fun as the dial type doing ovalled bores with cam'd pistons but what the heck. Using the same mic for inside and outside means the clearance will be obvious regardless of cal on the micrometer. Verify with plastigage of course, but plenty good for the pre-assembly checks.
I've used the telescoping bore gauges with the corresponding micormeter for more than a few projects, no complaints. Not as much fun as the dial type doing ovalled bores with cam'd pistons but what the heck. Using the same mic for inside and outside means the clearance will be obvious regardless of cal on the micrometer. Verify with plastigage of course, but plenty good for the pre-assembly checks.
#23
Well, it came, and its pretty.
It also was followed by an inch thick novel, I mean, uh, catalog from Enco.
So, its not as easy to use as I originally thought. The Dial bore gauge I mean. So you set the anvil and spacer to best suit being a bit larger than the bore you are measuring right?
Then you set the zero line at a prescribed distance - maybe like 3.9", and then when I stick in the bore of a 5.0L, which should be right around 3.937, I can then see what its true diameter is by adding the number I see above 3.9 to it?
It also was followed by an inch thick novel, I mean, uh, catalog from Enco.
So, its not as easy to use as I originally thought. The Dial bore gauge I mean. So you set the anvil and spacer to best suit being a bit larger than the bore you are measuring right?
Then you set the zero line at a prescribed distance - maybe like 3.9", and then when I stick in the bore of a 5.0L, which should be right around 3.937, I can then see what its true diameter is by adding the number I see above 3.9 to it?
#24
Brendan, it's not quite as easy as that. The bore is probably not perfectly round, and it probably has a taper. The $60,000 question is, are the out-of-round and taper within spec. You will have to take a number of measurements in each bore to see where you're at.
You may not be able to detect any such irregularities with the gauge you have. If that's the case, then the machinist did an excellent job. It does NOT mean there are no such irregularities, though. At this stage of the game you can make it or break it by overlooking a detail or taking something for granted.
You may not be able to detect any such irregularities with the gauge you have. If that's the case, then the machinist did an excellent job. It does NOT mean there are no such irregularities, though. At this stage of the game you can make it or break it by overlooking a detail or taking something for granted.