I am the owner of 3 cracked 6.5 turbo diesel blocks.

One of these blocks had been checked by a machine shop and certified "crack free". At that time, I was doing a motor project and was ecstatic about having a "599" block to work with... so off it went for boring, align honing, decking, etc...

I spent $1000 on machining the block and then threw several thousand more dollars into parts for my build. ARP head studs and a bottom end girdle were purchased to suck everything into the block.

I had the heads machined, including all the crack fixes done. This included the installation of intersecting Mac hardened valve seats.

Everything was ready for assembly so I took out my camera before we got started, and noticed a fatal crack on the 2nd main web.



OK... that was 6 months ago. Many of you know I went out and purchased the P400 and ended that nightmare.

I am back on this build after finding a reputable shop who repairs cracked 6.5 TD blocks. Guaranteed!

Here is the same bolt crack after it was repaired.



The shop machines in steel inserts which draws/pulls in the surrounding metal with spiral hooked threads. The inserts can withstand 3000 psi hydraulic pressure. Enough of the sales pitch.. which I'm not that good at anyway.

This shop (its a machine shop) has been repairing diesel blocks for the last 4 years and guarantees their work. They had to opportunity to tear down 2 blocks last year due to "Chinese heads" with porosity issues... This gave them a chance to review previously repaired cracks/inserts for stability. NO ISSUES. Ya... no issues.

I had all 3 of the 3 cracks repaired... here are the other 2.




The shop usually does all 6 outer bolt holes on the inner 3 main webs. They do this even if they are not cracked as a preventative measure. This is not cheap... at $100 per hole.

They finish off with align honing to ensure everything rotates straight.

I will be building the engine and selling it to recoup some of my $,$$$. I am happy to provide any info to those who are in need of this type of repair... I am a believer !

The product is a LOCK-N-STITCH product and the inserts are called Full-Torque... apparently well known in the cast iron repair field.

Caution: you can possess the right product to fix a crack, but you still require a skilled shop to ensure you end up with a stable repair.