Inside Micrometer - Is this harbor freight unit worth a a darn?

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DoubleDingo

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I need to mic the cylinders in my 292 and have been looking for a micrometer to do the job. On Grainger they range from $800 to $4,000+. For something I won't use very often I am not going to pay a huge amount, but I want it to be accurate.

Do any of you have experience with these harbor freight micrometers? https://www.harborfreight.com/6-piece-telescoping-gauge-set-5649.html?_br_psugg_q=micrometer

Or can you lead me to something else that is good and won't break the bank?

I saw a video of a guy miking a cylinder, and he had the outside mic, which he set to the factory bore of the cylinders, and then had a dial indicator type setup that he zeroed on the outside mic, and then inserted in the cylinder to mic it for size and out of round.
 

DoubleDingo

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From what I read in the reviews, you lock these down once you get the bore, then use an inside micrometer to take the measurement. Wondering if a caliper would suffice to taking the measurements?
 

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Sounds like you're looking for what's known as a "dial bore set". We use those telescope gauges at work for quick reference and just measure them with calipers, but anything that has a tolerance tighter than +/- .005" we use dial bores instead. They're not as precise because it's more based on feel than an actual measurement, it is very hard to get them into the exact correct position and there is absolutely no way to know because there is no gauge to watch as you fish them around, it is also extremely common for them to tighten up a few thou when turning the lock screw just by nature of how they work

I would stay away from anything harbor freight when it comes to precision measuring instruments. Some of their tools are decent, but cannot possibly be accurate enough for this type of work. Even some "well known" brands are inaccurate junk (Spi) which I guess would be good enough for DIY stuff at home, but definitely don't get some el cheapo chinese ****.

Try looking for a used set on ebay or the like, you may even have good luck at pawn shops if you're in an area that has a lot of manufacturing. You're gonna want something in the neighborhood of a 2-6" set for measuring cylinders. They have tiny sets that will do you no good
 
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75gmck25

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I used to buy Harbor Freight tools under the assumption that for backyard mechanic use they were fine. However, I just returned an automotive tune-up multimeter because the first and second ones I brought home were off by at least 400 rpm at idle speeds (for example, 1250 rpm idle showed 1600 rpm on the meter). They charged me an $8 restocking fee on a $40 meter (part #95670) I returned, even though I told them it was too inaccurate to use. I now have a new Innova timing light with tach that is much better made, and dead accurate.

Bruce
 

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Keep an eye on Ebay. I found reasonable prices on both inside and outside Mitutoyo sets to 6”.
 

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And Fowler is actually really good bang for the buck. That's what I use at work. Good quality and it won't break the bank

edit: hah after watching the little video in the ad I'm fairly certain that is the excact one I have, and for a better price than I paid
 

DoubleDingo

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Thank you.

I'll check ebay and other sites for Fowler.

Would rather check it here instead of hauling the engine to Mom and Pops. If need be, hauling it is, and spending time with the folks.
 

DoubleDingo

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Hmmm, my post I wrote out didn't post...lol...

@RecklessWOT , it looks like I'll haul the engine up to Mom and Pop's. He has the measuring equipment. Thank you for saving me from disaster. That video I mentioned, he was moving the instruments until he was able to get a reading that matched. And those were a thou here or there until he saw what matched. Using something with no dial indicator just seems very inaccurate to me, which is why I asked. Thanks again.
 

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I need to mic the cylinders in my 292 and have been looking for a micrometer to do the job. On Grainger they range from $800 to $4,000+. For something I won't use very often I am not going to pay a huge amount, but I want it to be accurate.

Do any of you have experience with these harbor freight micrometers? https://www.harborfreight.com/6-piece-telescoping-gauge-set-5649.html?_br_psugg_q=micrometer

Or can you lead me to something else that is good and won't break the bank?

I saw a video of a guy miking a cylinder, and he had the outside mic, which he set to the factory bore of the cylinders, and then had a dial indicator type setup that he zeroed on the outside mic, and then inserted in the cylinder to mic it for size and out of round.
Those just give you a replication of the measurement of the bore. The micrometer give you the actual number. It depends on what you’re planning to do or decipher with the measurement ( wear ) ? You absolutely can detect bore taper with these guages. The more critical tool is the extra large micrometer (4”) or larger you need to measure it.


Sent from my iPhone using Tapatalk
 

DoubleDingo

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81-C20 Silverado Camper Special-TH400-4.10s; 65-C20 with 4:57 gears and Borg Warner Overdrive
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Carb'ed Vortec 350; 1972 L48 350
Those just give you a replication of the measurement of the bore. The micrometer give you the actual number. It depends on what you’re planning to do or decipher with the measurement ( wear ) ? You absolutely can detect bore taper with these guages. The more critical tool is the extra large micrometer (4”) or larger you need to measure it.


Sent from my iPhone using Tapatalk

Accuracy is always key with me, so I will be taking the engine up to Mom and Pop's so we can mic the bores accurately to see if they are true, and if we can just do a simple re-ring and hone or not. Was just trying to avoid hauling it when I want to work on it in my backyard and maximize my time. But, it's always a good visit with the folks and learning stuff from Pop.
 

DoubleDingo

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Just looked up Fowler, and the video I mentioned, he was using a dial bore gauge, after zeroing out the bore gauge on a micrometer.
 

DoubleDingo

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Carb'ed Vortec 350; 1972 L48 350
Figured what the heck. Even if Pop has a dial bore gauge, I bought one just now, a Fowler 72-646-300. I know he has an outside micrometer, so we can zero out my new tool on the micrometer and go from there.
 

82sbshortbed

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You could use the HF ID mic. Then take it back when your done. ;)
 

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I need to mic the cylinders in my 292 and have been looking for a micrometer to do the job. On Grainger they range from $800 to $4,000+. For something I won't use very often I am not going to pay a huge amount, but I want it to be accurate.

Do any of you have experience with these harbor freight micrometers? https://www.harborfreight.com/6-piece-telescoping-gauge-set-5649.html?_br_psugg_q=micrometer

Or can you lead me to something else that is good and won't break the bank?

I saw a video of a guy miking a cylinder, and he had the outside mic, which he set to the factory bore of the cylinders, and then had a dial indicator type setup that he zeroed on the outside mic, and then inserted in the cylinder to mic it for size and out of round.


I have plenty of snap guages, what your looking at, as well as an micrometer I would be happy to let you use. If your looking to buy ebay is your best bet, Fowler is fine, as is SPI, Lufkin (my favorite) Mititoyo. Starrett and Brown and sharp are fine but usually over priced.
 

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