I think the gasoline v8 of the 99 or 100 defender

 

Hmm, interesting information on this topic. Yeah the O-ring thing is an interesting option but yeah I too question how long it would work, there's some really amazing materials that O-rings can be made out of these days but they have their limitations...

Maybe one day my engine could run again in some combination of a fix, I would really think welding it would be the first option, maybe even at that point install a tophat liner and o-ring as a backup in case the weld somehow failed. I suppose time will tell us more on how these fixes work.

 

If you're going to give away the electronic function of the Disco 2, I wouldn't do it for an even older engine..... Hell, might as well just swap in a Gen IV GM motor with far better mileage, hp and a transmission that's matched.

 

Yeah, but I wonder how well a tig weld would work on a super thin casting, that failed because it was thin and weak.
Would it leak around or near the weld, or simply fail again at the next weakest point?
And, if the crack is directly behind the liner, then any weld would have to be ground completely smooth and flush before the sleeve could be put back in.
Which then brings the question; given the rate of expansion/contraction of different metals, how well is the weld going to hold on the cast block, during heating of the block to reinstall the sleeve, and normal engine operation(I'm really asking, as I am not a welder)??

 

Valid questions. I suppose it would depend on the details, certainly a job for a welder who knows his ****. I would think he'd be able to put enough material in the right places to sort of interlock his weld but it's hard to say I suppose. Judging from the cut-away photos of blocks chopped up demonstrating the casting issues, it seems some blocks have one weak point, some have two but rarely more than one. I would think if it ran 75k miles finally failing that one point, that fixing that one point would solve the issue for good but it's a guess. The metal area where it's thin is usually quite small in surface area so I wouldn't imagine it to start failing around the weld itself. I'm not a welder by trade, I can weld however though my aluminum welds aren't anything to brag about lol. I suppose we'd have to show the details to someone who really knows their **** and get their opinion. In my limited experience, so long as the proper penetrations occur in welding. I don't think it'd ever fail. The welded material and the block will indeed be dissimilar technically but they'd be pretty close in creativeness to thermal expansion properties from what I've always been told.

I can tell you I've welded the heads of aluminum Rotax karting engines and Honda Motocross engines and they've held for years of abuse. Whatever that's worth in comparison idk.

 

I wonder, my tune will be for a 01 silverado with a 5,3L LM7 but in reality though I've a 2003 (or was it 04?) Tahoe EXC with a LM4 as a donor motor. Everyone seems to say that these are the same minus the fact that the LM4 is an aluminum block but I wonder if there's any further differences in tuning worth giving any time to. Of course there's always very small gains in a specific tuning an engine but if it's very minimal, who cares.

 

You can download EFILive software for free, download stock tunes and compare the various settings. You won't be able to change anything without a license but at least you could look over the settings.

 

Yes, I have set up a hot pressure test fixture. I will likely heat the block to a temperature where I can easily remove the sleeves, then hot pressure test the block to examine the cracks. Although cracked blocks could probably be repaired I just don't think it would be worth the time and energy given the plentiful supply of good early 4.0 blocks. We know LR was getting sloppy with the tooling, my guess is they let the boring machine wear out that bored the blocks and the bores are just a bit thin on the late model 4.6's, resulting in cracked cylinder walls. They were probably sourcing the lines from a supplier but the block castings were done internal. That is why I am going to remove the sleeves from your block and measure the tolerance range. My working theory is the block is bored .001-.002 too large.

 

Well that's at least useful. Ok, I'll download that for the hell of it anyway then.

 

I hope everyone has been doing well. I wanted to say that we are very excited that over 35 kits have been sold. Parts have travelled as far as France, where one bellhousing setup is being used in a 5.7L LS1, 4HP24, Defender-based RallyX truck! We also have several installers throughout the country that have experience with the kit now. I have been working on a few new projects that y’all will be excited about and I’ll follow up on soon.

As always, if you have any questions, feel free to send me an email.