How to measure max bore

[G]

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.

[dat2kman]

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.

[G]

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.

[pauly_adams]

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

[G]

I know its a luck thing, I'd like to know how to test each block.

[dat2kman]

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.

 

[gav240z]

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.

[G]

Are you going 2.4 Gav?

[gav240z]

No think I'm going to go standard L28 at this point.

[ZED83]

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!.

[gav240z]

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.

[C.A.R.]

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.

 

[gav240z]

Fair enough, that settles that then! .

[1600dave]

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

[Roady]

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

[1600dave]

Cheers, I'll give it a go and see what happens.

[1600dave]

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........

[C.A.R.]

Now to get down the shed with some KY gel and measure a few whores........

Edited April 17, 2018 by Lurch ™

[Cozza]

^^^^

Forever bringing down the level of our community Lurch.