LBZ cracked piston - What long block to with ?

[ski1]

Been a while since I have been on. Converted from LB7 to an LBZ in 2016 with an unknown engine, and now have a cracked piston in cylinder 3. I am looking for suggestions for a long block to start from a known good position going forward.

Mods are minimal, tune from ATP, Transgo JR, EGR delete and 3 " down pipe from Pro Fab. and am currently around 460ish with my largest tune

I am looking for a reliable way ahead to maintain 500-550 rwhp, with mixed use as a DD and towing. Only other mods I have thought of are bigger injectors to reduce pulse width and timing, and a remote possibility of a Danville turbo.

I have looked at DFC Engines, but their street series is all stock, and $10K. After some research, I found Xcaliber Diesel Performance, where Jeremy recommends mahle LB7 delipped Pistons, keyed crank/cam, wagler oil pump and ARP heads studs. I was also going to add a Callie AF cam to help reduce crankshaft pressures, and am around $8k

Sorry for the long winded post, does anyone have experience with or can anyone suggest who to go to for my budget build of around 10K ? Goal is a final config that will be safe to around 550 hp....

-Marc

 

[Mike L.]

You'll need a trans build to go with that. Transgo jr won't save you.

 

[Chevy1925]

you aint going to get a rebuilt/semi built engine for less than 8k from a shop that has them readily available and if you do find it for less, i sure as hell wouldnt trust it if they claim "100% rebuilt from heads down" with any kind of upgrades. Only way you will get it for less is acquiring the parts yourself, assembling your self and having a good machine shop do the work. Long blocks are not cheap. rebuilt heads them selves are 1000+.

as mike said, you better build that trans too.

 

[Bdsankey]

As Mike and James said. For a stock injector truck I believe you could get away with doing a budget build yourself. Some LB7 or Mahle motorsport pistons, LBZ rods, and some good fasteners will get you there but it'll take time to assemble and you have to find a good machine shop that can actually be trusted and is familiar with machining a duramax.

 

[TheBac]

You could build that for about $4000 doing it yourself if you had to.

 

[ski1]

appreciate the replies so far. my issue is a good local machine shop, don't really have one. the long block i am looking at from Xcaliber (i have no experience with them at all) seems reasonable as they address some of the LBZ weak points (LB7 delipped piston, keyed cam/crank shafts, pinned wagler oil pump), but does use LBZ rods, re-uses valves (new guides) and maple grade c head gaskets and arp studs. I would post the eBay link here for review, but don't want to appear as advertising or break any vendor rules....

A concern is the lack of reviews of the shop, and conditions of the LBZ rods re-utilized. I am not looking for a lot more power than what i have now, i was thinking the Danville 3794 as a replacement to reduce EGTs and larger injectors to reduce strain on the lower end with less timing/pulse width, if that is possible. That allows me to get the tranny built and tune for it. Bad plan ?

Any suggest with a known shop for a quality long block in the $10K range ?

 

[Chevy1925]

Location?

 

[ski1]

Sorry, was filling out my profile. I am in Las Cruces, NM. About 40 miles west of El Paso..

 

[Chevy1925]

Oh hell, shoot a PM to Blake at UDT. He is a vendor here and not far from you. Hes had a couple engines done iirc.

 

[ski1]

Well, I went through a bunch of different options, companies, local vs distant machine shops, and decided a long block was still the way to go for me. I narrowed it down to Wagler and Xcalibur Diesel, and in the end, it came down to time, similarities and of course, what I could get done by a reputable shop for the money. In the end I went with Jereme at Xcalibur. I really had to think hard as I wanted to go with Wagler, but it was going to be a couple months after I got them the motor, that I could get it back, but thanks to Austin and company for taking the time to try to help me out. If the truck had not been down for a couple months already at a local diesel shop (whole other story), I might have been more ok with another few months to get back up.

With that, does any one have suggestions for cleaning up valve covers intake manifold, hard fuel lines, etc ? All filthy.......will never buy another East Coast motor again either, lol, dayum do things rust out that way. I like my desert climate......

Also, suggestions for who to clean and test injectors ? Right now, it is exergy or bitterroot. Suggestions for who to test the CP3 ?

Any one in a similar situation take advantage of the motor being out and do additional work because you can and its accessible? I am going to paint most of the covers and manifolds after being cleaned up or sandblasted, but other suggestions and methods are welcomed....

 

[gmduramax]

Mahle LB7 pistons are complete trash and will crack.

 

[ski1]

Mahle LB7 pistons are complete trash and will crack.

in general, or at higher power levels ? what do you suggest instead ?

 

[gmduramax]

in general, or at higher power levels ? what do you suggest instead ?

In general. Mahle Motorsports pistons are much better

 

[OleBlackyLBZ]

I just seen this post, I am running a $5,900 long block from Jeremy at XCalibur as well. 650+hp for around 10K miles now. So far so good!

 

[OleBlackyLBZ]

Mahle LB7 pistons are complete trash and will crack.

Mahle lb7 pistons are not "complete trash". Back in the day if you wanted 8-900 hp they were the go to piston, most will agree they are fairly safe at around 700 hp but have been ran for short periods around 1,000 hp although they won't last long at that. They are plenty tough for what they are.

 

[gmduramax]

Mahle lb7 pistons are not "complete trash". Back in the day if you wanted 8-900 hp they were the go to piston, most will agree they are fairly safe at around 700 hp but have been ran for short periods around 1,000 hp although they won't last long at that. They are plenty tough for what they are.

LB7/LLY pistons are what you’re talking about. Pistons you buy from Mahle are not the same.

 

[OleBlackyLBZ]

The newer mahle cast race pistons are a good bit stronger even than the lb7/lly pistons that were made by mahle. I guess I'm not understanding you..

 

[Bdsankey]

The newer mahle cast pistons are a good bit stronger even than the lb7/lly pistons that were made by mahle. I guess I'm not understanding you..

He's talking about the Mahle OE repalcement piston, not the GM piston. I cannot confirm as I haven't had them side by side but have also been told the same thing, that the Mahle OE replacement piston is not the same as the GM piston.


IMO for the cost difference between a OEM replacement piston and the Mahle Motorsport piston, I would rather spend the extra cash on the Mahle Motorsport cast piston as they are overall stronger/better.

 

[OleBlackyLBZ]

Mahle LB7 pistons are complete trash and will crack.

This is the post I was referring too, mahle lb7/lly pistons are definitely not as good as mahle race cast or the mahle/fingers but they do the job just fine for mild builds and are not complete trash.

 

[gmduramax]

This is the post I was referring too, mahle lb7/lly pistons are definitely not as good as mahle race cast or the mahle/fingers but they do the job just fine for mild builds and are not complete trash.

If you get pistons out of a truck from a LLY/LB7 (I guess if you even get them from gm they come in an isuzu box and are standard bore or .050 over last I checked) they are decent and will handle some power

Pistons you get directly from Mahle the LB7/LLY OE replacement are trash

The mahle motorsports Pistons are a decent option.