Micrometer
 

Working on an engine build and need advice on a good micrometer. Looking at Starrett and Mitutuyo. Any suggestions?

Either will work well, the machinists at work say the new starrett stuff isnt as good as Mitutuyo but I doubt it will matter for that application.

I agree, the newer Starretts aren't as good as they used to be. When I was working at a mavhine shop they switched to the Mitutuyo.

Would this be a good set or do you recommend up to 4"? Crank journals for the connecting rods is only about 2.720 IIRC so I think 3" would be good.

Get at least a 4" size so you can measure cylinder bores and main bearings too. I'd look at getting individual mics like you are doing. I've got a 0-6" mic, which I hate changing anvils on when you're not finished measuring that size, and you always have the chance of it being off a little bit when you put them back in.

I'd always go for a Mitutoyo unless the Starrett is super cheap. I hate the feel of Starretts, always stiff and heavy.

starrett or Mitutuyo

I buy all used stuff as its simple to re calibrate and the same as the new stuff. Might want to buy a digital one if your dont know how to read em hahaha

Most people selling a set of expensive mics took care of them.

Only gauges we are allowed to have at work are Starret, Mit or Brown/Sharp. I'm not actually sure if B&S makes a mic, but I like their gauges, seem to be smoother compared to the Mitutoyo gauges (.0001 readings)

What setup would work best for measuring piston protrusion? First engine build here, bear with me.

Depth mic or a dial. You can use a mag base and dial, zero it on the deck and then, by moving the base, swing it over the piston. Dial is much faster than using a depth mic, and you'll have the piston rock to account for as well.

Thanks for the help everyone. Ended up going with Mitutoyo for everything. Got a set of outside micrometers 0-3", dial calipers, 2 dial indicators (trying to find a dual dial indicator base to account for piston rock), and a magnetic base in case I can't find a dual base.

You can mount two dials to a single base, but I don't see the point. If you position the dial on the axis of the wrist pin, the rocking effect will be virtually nothing. Remember to zero the dial on the deck, swing it over the piston and take your measurement, and then check for zero on the deck again. Moving the base may affect the settings of the dial, so its good practice to make sure nothing moved after the measure.

I was referring to piston rock when using a depth mic, since you'll be pressing the base down fairly hard to keep it flat, and probably off center due to stampings in the top of the piston.


http://www.jegs.com/p/B-B/B-B-Perfor...46426/10002/-1
That is another tool thats handy for doing piston protrusion or TDC location.

Ok, that makes sense.

I went ahead and bought some feeler gauges and am now looking for a straight edge to make sure the block deck is perfectly straight. Even though the machine shop checked it, I want to make sure. Here is the one I'm looking at:

They are good straight edges. I guess it depends on how often you'd use it to deem if its worth buying. It appears this one doesn't come with a case, so its a good idea to build one, or hang it to keep it from bending.