Starrett Dial Bore Gauge - Anyone Used One?

Discussion in 'Wrenchin' Secrets' started by patwhac, Mar 15, 2018.

  1. patwhac

    patwhac Well-Known Member

    Hey all, I'm thinking about buying a dial bore gauge to check out a used 455 core that I bought to see if I need to have it bored or if I can get away with just honing it myself with an electric drill. I'm guessing a shop around here (northern CA) would probably charge at least $100 to $200 to check it for me, plus the expense of moving the engine to them. So for not that much more I feel like buying my own tool would be a smart move and plus I can use it next time! Anyone have any experience with this one?

    I've used Starrett tools a lot in the shop before and love 'em, but if anyone has any experience with this tool or a similar one for about the same price or cheaper please let me know!

    Found it for $250 on Amazon:

    I'll probably be trying to buy a sonic tester in the same vein but I'll save that for a separate thread . . .
  2. flynbuick

    flynbuick Guest

    Do you think a used 455 core block exists that should not be bored? There is a good discussion about this in an old thread.
  3. Mart

    Mart Gold level member

    You may want one that reads out in one tenth (.0001) increments.
    Maybe even one that reads from 1.4" to 6" for added small dia. checking like rod bearing dia's.
    8ad-f85 likes this.
  4. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    I've got all fowler stuff and I'm happy with it. I'm assuming you already have the calipers?
  5. patwhac

    patwhac Well-Known Member

    Of that I have no idea, I guess I've always heard that 455s should be bored as little as possible, which would hopefully be zero haha, but wouldn't a shop check the out-of-round and taper before boring anyways? Keep in mind this would be my first ever engine build, so forgive my ignorance!

    Good idea. I'm not attached o the Starrett unit, I just recognize their name.

    I actually don't have anything yet as far as engine building specific tools, only basic hand tools and the core engine! I know calipers are super useful for lots of things, but for my purpose what would I need them for most? Does one use them to measure deck height?

    Things I *think* I need to buy (or rent) for rebuilding an engine. Please correct me if I'm wrong:

    -Dial bore gauge
    -Sonic Tester
    -Flex Hone (if I can get away with just honing)
    -Piston ring squaring tool for checking ring gaps
    -Specialty feeler gauges for checking ring gaps and piston to ring side clearance
    -Plasti-Gauge for checking bearings
    -Dial Indicator for checking piston height and degreeing cam
    -Cam degree wheel
    -Cam bearing installation tool?

    This is going to be a street build, low budget engine going into my 70 Skylark. I will post another thread in the Street/Strip 455 section asking advice about my build, but I just want to be able to factor the cost of tools in to my plan. I'm the type of guy who'd rather invest in reusable tools than machine shop labor . . .

    Ahhhhh the planning seems to never end . . .
    300sbb_overkill likes this.
  6. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    for starters you need the calipers to use the dial bore gauge. you need the caliper to set your size.
  7. Jim Weise

    Jim Weise EFI/DIS 482

    I am sure you mean micrometer Joe..

    The dial bore gauge is one half of the equation.. you need a full set of micrometers to go with it, if your going to check anything accurately.

    I will use a vernier caliper on something when I am looking for just a ballparkish, within a couple thousanths figure. Setting a dial bore gauge with a veneer caliper is just slightly more accurate than a tape measure.

    For the OP, I realize your maybe not super familiar with the terms for these tools, so here are some pics.

    Vernier Caliper

    veneer caliper.jpg


    Starret Mircometer.jpg

    For what your wanting to do, you need the original pistons that came out of the engine, a 4-5" micrometer, and that dial bore gauge.

    You measure the piston skirt at the prescribed area, and then lock the Mic.. then install the proper probes/spacers on the dial bore gauge, and zero the gauge with the mic,

    Then you go back to the hole that the measured piston came out of, and in one measurement, you can identify piston to wall clearance, taper and out of round.

    If you want to be more accurate, then bolt the head on with a head gasket, torque it up, and flip the motor over and check it from the bottom, the head distorts the bores more than you might think.

    If you saying by now that it seems a lot easier and cheaper to simply take the block to my machinist, have them hot tank it and then bore it enough to clean it up, then your on the same page with most of the guys that replied here.

    While technically not impossible, finding a block that is still round and straight, after thousands of heating and cooling cycles, is not likely.

    Last edited: Mar 16, 2018
  8. Mart

    Mart Gold level member

    What Jim says above, and the mics(on the barrel) should also readout in tenths, like the bore gage. Calipers are all you need to see if a bore is stock size or has been bored some already, in about 3 seconds.
    You can measure the crank main & rod journals with calipers, to see if they've been ground before.
    Last edited: Mar 16, 2018
  9. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!


    I would also suggest buying the fixture to set the dial bore gauge up if one is available for that model. It's a cumbersome process without it.
  10. patwhac

    patwhac Well-Known Member

    Thanks for all the info guys! As I expected it does seem a lot more complex than I envisioned. If finding a block that doesn't need to be bored is that unlikely, then maybe I should just skip checking it and move right to sonic testing.

    Now I have read a lot of mixed experiences with the cheaper sonic testers you can find online right now. Most say they work great, but for engine specific applications they say it's hard to find one with a curved probe to match the radius of a cylinder bore. The model that most pros seem to use is the Dakota Ultrasonics PR-82 which goes for like $1200. Most of the cheaper ones go for like $200.

    I expect it may be easier to let the machine shop do this too, just like the bore checking? Has anyone here who is not a pro ever sonic tested their own blocks?

    In response to Mart, I think at least investing in a good set of vernier calipers is a good idea so I can see if the block has been bored before, crank ground etc.
  11. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

  12. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    i wouldn't buy a sonic tester. maybe a used one if the price was right but otherwise it's not worth it
  13. 8ad-f85

    8ad-f85 Well-Known Member

    While on the topic...the sonic testers are worth it the first time you use them.
    If you search the topic on Speedtalk you'll find the general consensus to be that they are as good as any.
    The technology isn't any different.
    You can see visually and by attachments welded to pliers, crude calipers and extensions...about as much as you need to, there are a few tricky places in every brand casting that justify their use.
    There's a need to be wary of overly pocked and rusty blocks regardless of sonic testing.
    DBS likes this.
  14. DBS

    DBS Well-Known Member

    This may be a dumb question (I'm not a machinist) and I've set my bore gauge with mics, but what's the advantage of the bore gauge setting fixture you linked to vs. a using height gauge on a surface plate?
  15. Mart

    Mart Gold level member

    Doesn't even need to be top of the line caliper. Your mics & dial bore gage will be the most accurate for close tolerance measuring. Fowler stuff is ok. They used to be made in Japan, now in china, but adaquite.
    DBS likes this.
  16. 8ad-f85

    8ad-f85 Well-Known Member

    You won't be able to hone a block more than a couple thou with a flex or 3 stone hone without messing them up worse.
    They follow what's there and lack rigidity to do much else.
    If you use a hone that can crank in some pressure you'll be able to true up the bore and keep from tapering, like what would result from a flex hone or glazebreaker.
    There's a Lisle AN style 2 stone (+2 wipers) that will give acceptable results for about $250? and a better one for $600+ from Woodward supply(?) that both can be driven by drill or electric motor at about 400 rpm.
    Truthfully, unless you already experienced in honing or are willing to to a ton of research, the cost of the shop's hone is quite reasonable compared to potential outcome.
    In addition to size and taper issues, there are serious concerns of proper lubrication and heat transfer to the point of ruining pistons, detonation, engine seizure, etc.
    It's a cheap price to pay compared to an all day arm flexing session. (Don't skip leg day too)

    If you are REALLY into DIY machinery...automatic hones of the highest quality have been made where overseas shipping is not feasible.

  17. DBS

    DBS Well-Known Member

    Exactly. Even a cheap caliper will be pretty close for this purpose. Also usually good deals on Mitutoyo on eBay. IMHO equal to Starrett in quality, but the Starrett name on eBay commands higher $.
  18. 8ad-f85

    8ad-f85 Well-Known Member

    Mitutoyo or Fowler is as good as anything else regarding calipers.
    That type of tool is given an accuracy range in a shop much wider than what it can measure. (.005, even though it will repeat to .001" normally)
    The dial type is probably better to start with than digital, as long as you keep dust out of the gear rack.
    That way you can develop a better feel for how to use it.
    The digital ones are nice next to machines being set up where there can be a mess, and some still have issues with slipping even though they say 'coolant proof'.

    Instead of paying for a shop to measure it to determine where it will clean up at (which they may not even do), you can get a good idea by judging the ridge and seeing any massive out of round/taper with your bore gauge.
    The most profitable way for them to "check" is to clamp it into the machine and bore it :) .

    It isn't necessary to have the ultimate in calibrated gauging when you are mostly using the bore/piston or crank itself for comparative measurements.
    Plenty of prototype machining guys get the inexpensive mics and have their company's inspection dept. calibrate and qualify the gauges.
    They usually get a dated sticker for periodic calib. as well as mandate that any dropped or roughly handled or otherwise suspect gauge is you see that it isn't imperative to start off with the best for hobby/learning purposes.

    To the question about using a height gauge on a surface plate...what exactly set up are you referring to? :) :)
    For folks wanting to use the mic to set a bore gauge, they can be lightly and protectively clamped by a 3rd hand type fixture or (cringe) vise. It isn't that hard to deal with if you aren't retarded or completely ham-handed.
    For that matter, a quick and dirty way is to use your caliper set after calibrating it to something first. It should lock into position just fine.
    Setting gauging in general can be quite time consuming, that's why shops might have a dept. that does only this.
  19. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    The setup fixture uses gauge blocks that are accurate to the millionths of an inch(.00001") tolerance. While a veneer or crank dial indicator height gauge is only accurate in the thousands of an inch(.001") only slightly more accurate than a caliper, better off using mics.

    When using a bore gauge that reads in the one tenth of an inch increments(.0001") you want to set it up with something that is as accurate or more accurate.(mics{as accurate} or the bore gauge setting master{more accurate})
    DBS and 8ad-f85 like this.
  20. patwhac

    patwhac Well-Known Member

    Well truth be told, the first thing I was going to invest in was a engine run stand. I have both this 455 (‘76) and a 350 (unknown year) sitting in the garage and if I can get them both running on the stand I can compression/leak down test em and maybe I’ll just drop one in while I save $ to actually rebuild the other one, that is if one of them isn’t totally boned.

    Either way I’ll probably be trying to rebuild something at some point and I’m just trying to figure out what I can do myself and what is best left to the pros. Sounds like I can at least check to see if my block has been bored, crank ground, and get a general idea cylinder wear by measuring ring ridge. And for can use a set of decent (but not super $$$) vernier calipers and a dial bore gauge, and some sore of calibration stand (or a vise), correct?

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