Cylinder Bore Gauge and Caliper recommendations

DogBunny

DogBunny

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I am considering buying the tools needed to measure my cylinders.
http://www.eastwood.com/dial-type-c...om&utm_medium=Merchant-Centre&SRCCODE=1SE1531
It looks like I can get a bore gauge such as the one above,
http://www.harborfreight.com/catalogsearch/result?q=caliper
and a HF caliper (to calibrate the bore gauge) such as those above, and spend less than $100 total.
What are you using? What are your recommendations?

http://www.mikesxs.net/product/35-1770.html
I just noticed that MikesXS also offers a caliper, shown above.
 
I just picked up one of these from eBay several weeks ago .....

http://www.ebay.com/itm/CYLINDER-BO..._Automotive_Tools&hash=item5af14b5913&vxp=mtr

I've measured several cylinders with it and think it works quite well. I calibrate (zero) it with a 2"-3" micrometer as per the included instructions. This is about a $200 to $250 gauge. I paid about $60 for mine and feel it was well worth that. There's lots of different ones listed on eBay, including that Eastwood one you're considering. What I like about the one I got is the "sled" on one side. This squares the gauge in the bore for you. It's very simple to slide the gauge up and down in the bore, getting accurate measurements at the top, bottom, and middle.
 
Nice tools. If they don't come with certification, recommend a set of standards. Also recommend 12" feeler guages .0015", .002", .0025", .003".
 
I like the fact that now I will be able to check the cylinders both before and after honing to see what, if any, effect that has on the size.
 
I have the correctly sized flex hone, the BC3" I think, from here .....

http://www.ruffstuff.com/pages/flex.html

I'm not sure of the grit, I'd have to check the package. I also have a bottle of the special oil although I don't think that is absolutely necessary, but hey, I'm a tool junky, lol.
 
DogBunny, the bore gauge you are looking at isn't used to measure the bore per se. It's used to tell if the bore is out of round, tapered, belled or choked, etc.

I think what you may be looking for is something like [This Snap Gauge]. You put these in the bore, unlock it and it snaps out to the walls. You then lock it, remove it and measure it with something [Like This].

I have all three of these gauges and even the cheapo HF ones have never let me down.
 
5twins said:
I like the fact that now I will be able to check the cylinders both before and after honing to see what, if any, effect that has on the size.
Click to expand...
The local XS650 expert, who has done scores of re-builds, recommends that when you get cylinders bored, to specify 2 thousandths under. The idea is that the hone will remove that final 2 thousandths, and you will end up with a cylinder exactly on spec.

Thanks for the input so far. Any other advice and recommendations will be appreciated. Any opinions on those HF calipers? Thoughts on digital verses dial calipers?
 
I have a dial type, digital, and plain old ruler style caliper. The digital seems to be easiest to use but does tend to go through batteries. They're just those little watch batteries so don't last long. Calibrating (zeroing) a bore gauge with one of them will be more difficult than using a micrometer. You'll be trying to position the bore gauge between 2 knife edges on the caliper, like I said, difficult at best. Even setting the bore gauge using a micrometer takes some fussing, and you're working against two 1/4" round flat surfaces.

That's how bores are supposed to be done. Bored to just under size, then honed to final size. When you get one done, it should come back like that. Bored 1st, then honed with a stone hone to size, then a quick bottle brush hone to give a better finish more conducive to ring seating.
 
Uncle Bryan, my understanding is that you use the caliper to calibrate (zero) the bore gauge, then you can use the bore gauge to measure the cylinder.
I considered telescoping gauges, but then I saw this video:
He compares readings from the telescoping gauges to those from a bore gauge, and determines that the bore gauge is more accurate. I don't know, I'm just trying to figure this whole thing out.
 
I've had those telescoping gauges for years and, frankly, gave up trying to use them. Too much room for error. You must be perfectly square in the bore with them, then hope you don't disturb the setting as you remove and measure it. You will encounter similar problems with the gauge you linked to. If it's not perfectly square in the bore, the reading will be larger than it should be. Yes, you can (and should) rock the gauge back and forth to find the lowest reading but you will have to go through all this at every spot you try to measure, top, bottom, and middle.

That gauge I linked to, the Central 6460, eliminates all that dicking around. You simply slide it up and down in the bore, holding the "sled" side firmly against the cylinder wall. It works really slick and I highly recommend it, especially if you can score one cheap off eBay.
 
Hey, DogBunny. That was a fun video. He does hit on the main drawback, and that is technique. It takes a deft hand and a lot of practice to do these measurements correctly. Somewhere out there is a post that describes a technique/procedure to ensure repeatability. Looking for precise values is one thing, I prefer using the feeler guage as final sayso. But just looking for aberrations, 5Twins tool may be best. It's measurement method is repeatable, less skill intensive, very easy to use and read. If cost is the objective, the simple telescoping guages will work, just need to learn that deft technique. Also, be advised that some of those cheaper telescoping guages have a rough slot, and won't feel right or hold properly.
 
Man, I can’t say it any better then TwoManyXS1Bs just did.
The video was good and the dude is right on. Looks like you’re all set to go, DogBunny.
Let us know how it goes. :thumbsup:
Bryan
 
Uncle Bryan, your avitar makes me cackle every time! I still don't know how long I blacked-out after trying that, just that I regained consciousness 8' away from the wall...
 
I welcome all views, but so far, I am sold on 5twins 6420 bore gauge, and TwoManyXS1Bs long feeler gauges seem like a good idea for a double-check.
I'm now beginning to wonder about calibrating the calipers. Until someone says otherwise, I'm thinking of buying an HF digital caliper, but I don't have a micrometer to calibrate the caliper. Is it necessary to do so?
http://www.ebay.com/itm/SHARS-1-PAI...365?pt=LH_DefaultDomain_0&hash=item46067dd835
What about using gauge blocks like those above? I'd use the 3" sides to make sure the caliper is accurate and adjust if necessary. Is this going too far, and am I worrying too much?
 
The digital caliper has a "Zero" button on it. You close it up fully, making sure the jaws are clean, and hit the button. You don't have to calibrate it on any sort of fixture. But like I said, setting the bore gauge between those knife jaws is going to be difficult. The instructions tell you to use an outside micrometer. I use the 2" to 3" one from this set .....

http://buy1.snapon.com/catalog/item...roup_ID=675344&store=snapon-store&dir=catalog

Believe it or not, a guy gave me these for tuning his 650, lol. I was more than happy to accept them. He used to work for Snap-On so I doubt he even paid for them. He gave me the 3" - 4" one as well along with a Snap-On 4 piece hook and pick set. Very cool, and well worth the drive into the city and an afternoon spent servicing this guy's bike.
 
5Twins micrometers are Snapon's Bluepoint quality/certified version of Enco's cheap chinese 3-piece micrometer set, I'd do tune-ups in trade for those...

Measuring instruments go thru a strict test/inspection to ensure accuracy, repeatability, within specific tolerances, at various measurement values that test various positions of thread engagement or gear tooth positions or capacitive circuit position. They are then graded, certified if top-notch, and the best go to the original contractor or top-bidder. The lower grades are scooped-up by the discount houses, and end up in your mailbox.

Knowing this, choose based on your intentions. Looking for bores that are maybe .001" over, and have some taper/egg/out-of-round, deciding whether to rebore, the 6420 guage and a good micrometer will be fine. Add the long feeler guages to do the final check. If you're in the business of boring cylinders, your clients will appreciate the hi-dollar stuff.
 
Thanks for the caliper calibration info.
Here's a related question:
So I did a light de-glaze of the cylinders, followed by washing with soap and water, then I dried with compressed air and immediately got flash rust on the cylinders. What should I have done? Coated with grease while the cylinders were still wet? Should I worry about the flash rust, should I remove it, and how?
 
You might try a wipe down with kerosene then oil afterwards. Flash rust usually wipes off pretty easy. After honing and washing, I wipe the bores dry with clean paper towels, then immediately oil them. Then I blow dry the rest of the jug. Wiping with the clean paper towels shows me if I've gotten the bore clean. I want to see a perfectly clean paper towel coming out of that bore after wiping.
 
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