G Posted October 19, 2014 Share Posted October 19, 2014 Assuming I can get my hands on a sonic tester, does anyone know how to measure an L28 block so I can determine maximum possible bore? Looking to try to get to 89 or 90mm if I can. Quote Link to comment Share on other sites More sharing options...
dat2kman Posted October 19, 2014 Share Posted October 19, 2014 You use an inside mcrometer, and measure at three points down the bore, on fore and aft, then same again sideways. You are looking for ovality, or the lack of. If it is within tolerance for wear, top to bottom, and there is no, or very little edge at top of ring travel, run a Flexhone through them. Only way to do it is with head off. Quote Link to comment Share on other sites More sharing options...
G Posted October 19, 2014 Author Share Posted October 19, 2014 Hi Jason Perhaps I should've been clearer (or I misunderstood your reply). I'm trying to find a block I can bore to 90mm, but I know I need to ascertain cylinder wall thickness when I'm looking at potential blocks. I was wondering how I figure out which block to use. Quote Link to comment Share on other sites More sharing options...
pauly_adams Posted October 19, 2014 Share Posted October 19, 2014 luck of the draw my friend, some can be bored out that far others cant, I know people who have purchased 5 or 6 blocks just to find one that can take 89mm comfortably Quote Link to comment Share on other sites More sharing options...
G Posted October 19, 2014 Author Share Posted October 19, 2014 I know its a luck thing, I'd like to know how to test each block. Quote Link to comment Share on other sites More sharing options...
dat2kman Posted October 19, 2014 Share Posted October 19, 2014 Aha, yes a lucky dip. On sonic testing, ask themm to measure both sides, front, and back, of each bore, at three positions. This will give you existing wall thicknesses. You may get a surprise at the big differences in figures from bore to bore. This is due to "core shift" in manufacturing. ( these blcks were punched out in thousands,, the tolerance for allowable core shift of the sand cores for the water passeges was quite excessive) I see up to between 4mm to 7mm thickness in the one bore. One particular four cylinder block I have, came with 93 mm bores, and walls from 3.3 to 7.8mm Once you have a few blcks done, make sure to code the test with each block, go talk to a maching shop, with photocopies of your test tesults, ask them about possibility of offset boring. One other method, if block walls, top face and at bottom, will take it, consider CDC Thick Wall sleeving, to a bottom step. The Specific Graphite content of the CDC sleeves is higher than a block, and gives less friction, which means more horsepower! Chose the most appropriate, then order pistons. Quote Link to comment Share on other sites More sharing options...
Administrators gav240z Posted October 19, 2014 Administrators Share Posted October 19, 2014 I had a block sonic tested, which is the only really reliable way to know I think. Unfortunately the block I had tested is only good for a 1mm overbore. I may still do that because I'm only going for a standard rebuild at this point. Quote Link to comment Share on other sites More sharing options...
G Posted October 19, 2014 Author Share Posted October 19, 2014 Are you going 2.4 Gav? Quote Link to comment Share on other sites More sharing options...
Administrators gav240z Posted October 19, 2014 Administrators Share Posted October 19, 2014 No think I'm going to go standard L28 at this point. Quote Link to comment Share on other sites More sharing options...
ZED83 Posted October 20, 2014 Share Posted October 20, 2014 I got lucky with my F54 block from my 83zx. Its bored out to 90mm but can go to 91mm if I had to. I first went out to 89.5 but the machine shop that done the job screwed up the bores. Long story but just make sure you go an accredited shop that has a clue!. Quote Link to comment Share on other sites More sharing options...
Administrators gav240z Posted October 20, 2014 Administrators Share Posted October 20, 2014 I got lucky with my F54 block from my 83zx. Don't take it as the gospel but I've heard the last of the L28 blocks had more consistent blocks and often can be bored further out. After what engine number I couldn't tell you, but if yours was an 83 model it was probably 1 of the later blocks. Quote Link to comment Share on other sites More sharing options...
C.A.R. Posted October 20, 2014 Share Posted October 20, 2014 I've got a very late '83 block here: 900,000+. It's still only good to 88.5mm... It's just luck of the draw as to how thick they are. Quote Link to comment Share on other sites More sharing options...
Administrators gav240z Posted October 20, 2014 Administrators Share Posted October 20, 2014 Fair enough, that settles that then! . Quote Link to comment Share on other sites More sharing options...
1600dave Posted March 26, 2018 Share Posted March 26, 2018 (edited) Assuming I can get my hands on a sonic tester Thread revived from the past. Anyone had any experience with cheap chinese ultrasonic thickness testers ? Accurate enough to do basic measurement of cylinder wall thickness / cylinder head port wall thickness ? Anything else I need to know about these gadgets (I've never used or seen one used) ? https://www.aliexpress.com/item/FREE-shipping-GM100-Digital-LCD-Ultrasonic-Thickness-Meter-Tester-Gauge-Metal-Testering-Width-Measuring-Instruments/32625596093.html?src=google&albslr=221216182&isdl=y&aff_short_key=UneMJZVf&source=%7Bifdyn:dyn%7D%7Bifpla:pla%7D%7Bifdbm:DBM&albch=DID%7D&src=google&albch=shopping&acnt=494-037-6276&isdl=y&albcp=1001731409&albag=50593269078&slnk=&trgt=296303633664&plac=&crea=en32625596093&netw=g&device=c&mtctp=&gclid=CjwKCAjw-bLVBRBMEiwAmKSB84JYVpKayqI-iGLcS3PJT-6B_EQhAvf6196O7mA8VUQ5SBsz55iJLhoCziUQAvD_BwE Edited March 26, 2018 by 1600dave Quote Link to comment Share on other sites More sharing options...
Roady Posted March 27, 2018 Share Posted March 27, 2018 Hey Dave, I used one ages ago - seemed to be accurate as best I could tell. The booklet has figures for each material that you are working with, they seemed to be pretty close. Before measuring the bore I used a digital vernier caliper (from memory where there was space in the water jacket at either cylinder 1 or 6) to get an accurate reading. Then dialled in the ultra sonic tester (you can adjust it) to get it exact. I haven't had anyone confirm my results though but when I came back a week later to run the test again it gave me the same results throughout all the bores, so at least it's consistent. Good luck Quote Link to comment Share on other sites More sharing options...
1600dave Posted March 27, 2018 Share Posted March 27, 2018 Cheers, I'll give it a go and see what happens. Quote Link to comment Share on other sites More sharing options...
1600dave Posted April 17, 2018 Share Posted April 17, 2018 Thickness tester arrived today, gives results within 0.1mm of micrometer measurements on some test pieces so good enough for me. Now to get down the shed with some KY gel and measure a few bores........ Quote Link to comment Share on other sites More sharing options...
C.A.R. Posted April 17, 2018 Share Posted April 17, 2018 (edited) Now to get down the shed with some KY gel and measure a few whores........ Edited April 17, 2018 by Lurch ™ OdinZ 1 Quote Link to comment Share on other sites More sharing options...
Cozza Posted April 17, 2018 Share Posted April 17, 2018 ^^^^ Forever bringing down the level of our community Lurch. Quote Link to comment Share on other sites More sharing options...
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