Inexpensive Sonic Testers

Discussion in 'Street/strip 400/430/455' started by BennyK81, Jun 22, 2019.

  1. BennyK81

    BennyK81 Well-Known Member

    Has anyone tried on of those cheaper Sonic Testers available on the bay?

    https://www.ebay.com/p/Lotfancy-Dig...r-Range-1-2-220mm/9026515991?iid=202691642475

    my Machine shop does not own one but knows someone that has one. But bringing them my block and have them measure it will be more expensive..

    My numbers matching block is already .030 over and you can literally wiggle all the pistons around. And my spare 73 block looks like it has some core shift but it is otherwise untouched...

    Benny
     
    Donuts & Peelouts likes this.
  2. 69a-body

    69a-body Well-Known Member

    We just bought a $1000 unit where I work. The main thing is being able to calibrate the frequency on the exact material you are testing. Find a place on the block you can measure and make it match that reading. Also radius readings are sensitive to probe orientation. Ours is a "economy" one but repeatability is really good. I'd probably gamble on that one for $75 .
     
  3. Thumper (aka greatscat)

    Thumper (aka greatscat) Well-Known Member

    The ad says less than 20mm the accuracy is plus or minus 5%, 20mm is 3/4", will 5% accuracy satisfy you on wall thickness? I'd haul it to a machine shop if your contemplating .038"or more over bore.
     
  4. Stevem

    Stevem Well-Known Member

    I would get it.
    Once you map out your Bores at many locations 99% of the time you then know how the shop can offset Bore your block if need be to keep the most meat on the thrust side of the Bore or avoid too thin a wall area if it was just bored the normal way.
    You did not post up how much of a rebuild your going for here, but lighter Pistons and longer C toC Rods go a long way towards keeping a somewhat thin thrust side wall of a Bore from being a issue.
    If you find one or 2 that will still be a issue with its meat in the thrust area even when a offset Bore deal gets used then you can sleeve those holes then Bore .

    Also if you can pay the shop to Hone out the last .008" to get to the final size.

    After that if the shop does not have one get a Plateau Ball Hone to use on your Bores and if the shop Honed the Bores with the needed 320 grit Hone your ring break in period will be near nil and you have the added plus of cleaner less grit loaded breakin oil!
     
  5. Julian

    Julian Well-Known Member

    I'd pass on that one
     
  6. BennyK81

    BennyK81 Well-Known Member

    I have ordered a slighty better one.

    The block is untouched but has corrosion from water in cylinder 1. so it will need 0.030 at least.

    450hp plus is the goal
     
  7. Bluzilla

    Bluzilla a.k.a. "THE DOCTOR"

    I use a Dakota Ultra Sonics PR-82. I calibrate first and check the calibration about halfway through just to be sure. This one will pick up the slightest core discrepancy so you have to get used to moving it around. I attached the worksheet from my current engine build. It’s totally not necessary to test in 192 places as I did, .... though if you have the time it will give you a interesting perspective of what the walls are like.

    C2490BC8-D1AF-4A2C-9EA0-BBF9D1B15516.jpeg

    Larry
     
    Last edited: Jun 24, 2019
    Donuts & Peelouts likes this.
  8. BennyK81

    BennyK81 Well-Known Member

    Larry,

    I got my tester and played around with it. Actually it's quite accurate. I did check with a special sliding gauge on several places.

    where do you measure from top to bottom? where the rings travel or the whole bore lenght?

    I played around with my numbers matching block that had 0.030 pistons in it. on the back pin side of cylinder 3 I had .096
     
  9. telriv

    telriv Founders Club Member

    Basically when offset boring a block you should ONLY bore East to West. Front & Rear. IF boring North or South, Top or Bottom it will upset the 90*.
     
  10. BennyK81

    BennyK81 Well-Known Member

    seems logical. but what when it's off the 90* from the factory?

    My questian was, when taking sonic measurements. where should I measure? top of bore, middle and very end of it or only where the rings travel?
     
  11. telriv

    telriv Founders Club Member

    1/2" down from the deck. 1/2" up from the bottom by using a screwdriver that goes to the bottom. Then in the middle. Can be marked with a magic marker.
     
  12. BennyK81

    BennyK81 Well-Known Member

    thanks. going to do this tomorrow on my untouched 73 block to see if it's useable
     

Share This Page