Was wondering if wither or both of you fellas would give your opinion on basic engine clearance tools for the home engine assembler?

What kind of quality tool is required for very limited usage...like tools being used once every couple years?

For example, was looking at Powerhouse Products and many times they have two or three quality/price ranges of micrometers, dial bore gauges, etc. Is the cheaper tool just not worth having due to inaccuracy? The dial bore gauges come in .0005" or .0001" choices with the one being $99 and the other $299...would the .0005" model be OK for limited use?

Also, I'm sure user feel plays into the accuracy of the measurements as well.

What might you guys recommend? Would likely be lookng at a mic for crank journals, dial bore gauge, and proabably a rod bolt stretch gauge.

Just wondering if the less expensive tools are OK for limited use, or there just not worth the $$$ due to inaccuracy?

mainly looking to measure rod & main bearing clearance and set proper rod bolt stretch. I guess if the size works out on the crank mic, it could be used to measure & record new/static rod bolt length before stretch and that measurement could be used in the future to determine if the fastener had stretched beyond it's yield.

Any thoughts or suggestions would be appreciated.

Todd,

I'm not Bill or Mike but I can tell you what I did prior to recently assembling my shortblock. I went on to EBay and bought a set of quality used inside/outside MICs. I looked at Starett (sp?) as well as a few other brands. I ended up buying all Mitutoyo mics. All mics were recently calibrated and one was even brand new. When buying used outside mics make sure that they come with the standards so that the accuracy of the tool can be verified. You can then use the outside mics to verify the accuracy of the inside mic. Mine were all spot on. I bought a 2"-3" inside mic that I used to mic the crank journals. I also bought a 4"-5" mic that I used to mic the pistons. Lastly I bought a 2"-12" inside mic set to check the rods, mains and cylinder bores. I checked the price of the same tools in my Harbor Freight catalog and on average I paid 45% of what the tools would have cost new and all mics were in new or like new shape. You're right about using these tools; there is definately a "feel" aspect to learning how to use them properly. Like you I will be building 1-2 engines a year or every two years max, but I feel like it was a good investment as with purchasing any quality tools. I think a dial bore gauge would be nice to have buy a good inside mic set may be more versatile. I also purchased a quality rod bolt stretch gauge and valve height mic. I already had a good 3 in 1 machinist tool set with a 1" outside mic, 6" dial caliper and 6" machinist rule. The only thing I ended up not having was a valve spring compressor tool stout enough to compress the new springs enough to get the keepers in (pulled a few springs to make sure that the place that did my heads set the springs up to my specification). Luckily my local machinist loaned me a pneumatic compressor; piece of cake with that.

my $0.02

Good idea Ken. I've begun a search although I must admit I hate Ebay. I have found a source where mics aren't priced terribly (new), especially if I only need one or two, not a complete set. The 2-3" Mututoyo .001" mic (#103-217) is $89. The same brand series 141 inside mic set for 2" to 8' are $115 new.

Todd,
I own and operate a machine shop also so here's
my two cents. I can get you a 0-6" micrometer
set for less than $60. These are imported from
China and are a pretty decent tool. We use these for some of our production jobs in the shop as
"throw around tools". You could spend $2000. on
Tesa or Etalon, or something between. My experience is that the cheap tools will not stand
up to abuse as well as the higher quality tools.
But for someone who will only see occasional use,
they'd be fine. They come with standards and a
wood case too. I use both, and either will accomplish the occasional crank inspection.

Contact any local machine shops (not necessarily engine shops but general machine shops especially the small owner/machinist type). These shops typically always buy out machine shop tooling in lots. Good quality micrometers are avaialble in abundance at these shops. Make a few calls or visit in person, ask them if they have any surplus mics they would be willing to sell.

I probably have 20 micrometers of various size floating in my shop and yard - we use them daily to check metal thickness. Have not bought one new mic in 20 years. Everyone I have has come from some tool buyout. Unless they are really abused, they just don't wear out. The older ones are extremely high quality.

I've had pretty good luck with moderately priced mics for the little I do. I would definately go with .0001 resolution. As said get some with a standard. For bores, what I use is not as accurate a sunnen piece, etc, but it does the job. I use a bore gauge that I have to initially measure with a mic. If my mains come in at .0029 then I feel pretty good. If I got a .0040, I would borrow some tools. There is feel for sure involved.

I triple check measurements, if they are all withing .0001-.0002 I feel good about what I did assuming the tool is accurate.

Hi Todd,
I pretty much agree for what you are doing except for the 0-6" mikes with interchangeable anvils,,, I hate those things as you are constantly having to change the anvil & recalibrate the damn things.
Get a decent set of mikes,
0-1, 1-2, 2-3, 3-4 & 4-5,, all tenth reading with setting standards for each.
I would suggest used good quality ones in lieu of cheap ones.
You don't need brand new "top of the line" stuff simply because you do not need to be as concerned with the actual exact size of the crank or piston, you are more concerned with the difference in sizes.
It is very nice to have top quality & if you decide on that direction you will not regret it but you don't really need it with one exception.
Get a really good .0001 reading bore gauge as this is what you will be using for the "difference" readings.
If you set the mikes on the crank journal at 2.xxxx & adjust the bore gauge with these mikes to zero, what ever it says when you put it into the rod or main is your clearance.
Same deal with bores.
Try to stay with a brand name bore gauge like Mitutoyo or Sunnen.
For info, I rarely use inside mikes for anything anymore.
It is EXTREMELY DIFFICULT to get a good reading in a bore with a "single point" measurement instrument & the bigger the bore the worse it gets.
A quality bore gauge is in my opinion a must have tool for consistent bore measurement

Mike,
From your experience, assuming reasonable circumstances, what kind of error does a single point bore gauge induce? I know there are a lot of variable, just say in a case where it is done fairly well to the ability of the tool.

.0002, .0005, or more possibly, on both a 4" bore or a 2" rod?

Originally posted by Doug F.:
Mike,
From your experience, assuming reasonable circumstances, what kind of error does a single point bore gauge induce? I know there are a lot of variable, just say in a case where it is done fairly well to the ability of the tool.

.0002, .0005, or more possibly, on both a 4" bore or a 2" rod? Hi Doug,
A bore gauge although reading from a single point has centering shoes & is very accurate.
What I was referring to is inside mikes, telescoping gauges etc.
These can be pretty difficult to get accurate repeatable measurements with especially for someone who doesn't do it all the time as it is so hard to be sure you are in the exact center of the circle.
I would say .0005 is pretty good on bigger bores although with practice you can get pretty good at it.
I just prefer a good bore gauge as it is difficult to screw up with one,,, not impossible,, just difficult :D

Hi Wolfy, I had a friend who has done all kinds of machine work for all kinds of people tell me a long time ago that the Mitutoyo tools are very good quality for foreign manufactured tools and are quite reasonably priced. My son now does CNC lathe work and says that even cheap micrometers are very accurate. Probably being inexperienced creates the most problems and the cheaper tools might not handle abuse to well. I even have a Mitutoyo dial bore guage set that i've never used, yet.

Originally posted by Harold Sutton:
Hi Wolfy, I had a friend who has done all kinds of machine work for all kinds of people tell me a long time ago that the Mitutoyo tools are very good quality for foreign manufactured tools and are quite reasonably priced. My son now does CNC lathe work and says that even cheap micrometers are very accurate. Probably being inexperienced creates the most problems and the cheaper tools might not handle abuse to well. I even have a Mitutoyo dial bore guage set that i've never used, yet. =
HI Harold,
I really like Mitutoyo stuff. I have 3 of the regular tenth reading bore gauges plus another special one with larger radius fingers for measuring bearings that doesn't gouge them like the pointed ones do.
It is a real nice piece but kinda pricey,,
Also have five of their digital electronic mikes from 0 to 5" that read to 5 digits & love em except they are a little hard on batteries.
You can reset them at will, set zero anywhere you want for comparative measurements etc,,, nice stuff but you gotta be using it all the time to justify having them as they ain't real cheap :(

I got more damn money in measuring stuff than I care to think about sometimes,, all the mikes, bore gauges,, along with Audies cam measurement stuff, computerized spring tester,,,, the list goes on graemlins/sad.gif

Hey,, we all gotta have our "toys" though :D

Those sound like some nice toys, Wolfy. My son has picked up the CNC Lathe, machine work, pretty fast and likes it too. He is real good at math and that helps a lot. Maybe one of these days i can come out and visit you'all. Now if i just get him to try a few new things on the Chevelle.