How much overbore on D4TE block?

[6667fan]

Taking apart one now and it has .030 pistons in it. Can these blocks usually go .040?
Thanks

[fekbmax]

Should go .040 ok, always a good idea to check. I have taken several D3te and D4te blocks to .040 over without issues.  Wouldn't go past that without a thorough check.

[manofmerc]

I had a really nice one that had been bored .080 I had it sonic tested the thinnest cylinder was .167 .I sold it to a racer and he ran it several years in a low six second mustang with no issues .Sonic test is your friend.Doug

[Gaugster]

I had a really nice one that had been bored .080 I had it sonic tested the thinnest cylinder was .167 .I sold it to a racer and he ran it several years in a low six second mustang with no issues .Sonic test is your friend.Doug

Some shops around my area got away from doing sonic checks. "No money in it." Had to really search out an old school machinist from Aurora, IL. My .030” over D3TE is around .195” on the thrust sides. Thinnest was .145 low down on the non thrust area. Block is going 0.040" over so will thin accordingly. Using a girdle fitted by Jay Brown himself. Should be plenty strong for a stout street car.

[bulletpruf]

We should be able to sonic test our own stuff for not much $, but I've been beating my head against a wall for years trying to get set up to do it.  The problem is finding a decent quality but affordable unit that comes with a curved transducer that's capable of reading cylinder walls.  The flat transducers won't work, and I tried filing a flat transducer to fit the inner contour of a bore and it quit working altogether.

Dakota Ultrasonics is the only company that I know that manufactured one made for this purpose - the original model was the PR-82.  It's been replaced by the PR-9, and these sell for $1,325.  If anyone knows of a less expensive option, please let me know.

As for the original question, you should be good at .040" but I don't have any specific experience with the D4TE.  I had a 390 bored .080" and thinnest reading afterwards was .086" and that was only because of core shift on #1.  My block is dated 1971.  Need to drag the Fairlane out of the storage unit and get it going again when I retire from the Army this summer. 

[jayb]

Mine is just a cheap unit sourced from ebay.  I was able to put the curve into the transducer with some very careful work on a small belt sander, with fine grit paper.  You want to stay away from the center line of the transducer, just try to taper the edges up to that.  Been working fine for years now, and still gives accurate results based on the measurement of the block china wall.

[thatdarncat]

Mine is just a cheap unit sourced from ebay.  I was able to put the curve into the transducer with some very careful work on a small belt sander, with fine grit paper.  You want to stay away from the center line of the transducer, just try to taper the edges up to that.  Been working fine for years now, and still gives accurate results based on the measurement of the block china wall.

I bought mine after I saw Jay’s. Following Jay’s advice I put the curve in my transducer with a sanding block by hand, and it also is still working fine. I’ve recommended them quite a few times, and I’ve posted in the past that not only is it accurate based on readings at places on the block you can verify, but also in double checking some blocks I had sonic tested previously by a professional shop. They really are handy device.

Here’s a link to an old discussion about the testers:

https://fepower.net/simplemachinesforum/index.php?topic=5449.msg58346#msg58346

[66FAIRLANE]

Plus one. Curved mine as per pic in other post and it works fine.

[frnkeore]

I bought the same model as Jay has but, when got mine, it was to port a set of C6 289 heads so, it needed a little smaller radius. I rounded mine on my disk sander, being careful to stay away from that middle bar but, a smooth radius, up to it.

I later sonic tested my two FE blocks, using the china wall to certify the readings and had no problems with it's repeat ability, going back and forth between the china wall with each cylinder.

[fairlaniac]

I had a really nice one that had been bored .080 I had it sonic tested the thinnest cylinder was .167 .I sold it to a racer and he ran it several years in a low six second mustang with no issues .Sonic test is your friend.Doug

That's crazy to think at a maximum there was only about .200 coolant passage between cylinders.

[machoneman]

Maybe Darton sleeves as a very pricey solution: https://dartonsleeves.com/darton-factory-video/

[wsu0702]

This subject comes up a lot on the FE forums and groups.  After reading all of the posts (including some from guys who worked in Flat Rock) over the past 25 years here is my take on the MCC FE blocks.  The nominal cylinder wall thickness is the same as the earlier DIF and CF blocks.  The difference is that the new MCC plant used robotic casting core placement processes versus the manual core setting used at the DIF.  Therefore the relative positions of the bore and water jacket cores were more precise than at the DIF.  So this means that MCC blocks (D3TE and D4TE) can "usually" be safely overbored more than a DIF block.  I understand why people assume that they must have thicker cylinder walls than DIF blocks but I am pretty sure this is not the case. I could be wrong but that is my humble opinion on this subject.

[6667fan]

I wonder if anyone ever did a side by side weight difference? Even if the MCC blocks scaled heavier it would be difficult to learn where the beef was.