Duramax block

[Seventy468]

Was just wondering, I have never had my hands on any blocks.. is there a difference between the lb7,lly,lbz,lmm blocks? I know those engines have other changes, but didnt know if the blocks really changed much.

 

[malibu795]

main difference is the main journal webing between LB7/LLY and LBZ and newer

some of the blocks have ear lobes inthe front for the MD application (mounts were ont he front of the engine not 6" back.. and a couple other extrenal bosses....

the reluctor tone ring is diff between lb7/lly and lbz and newer tooth count lbz has one more iirc

LBZ cranks have a smaller spin/swing circle then the LB7/lly.. this also mean the the balancer and flexplate are diff as well. they can be miss match... down side need to add a **** load of mallory to balance it out.(experinece on that one)

thats about it.. when talking about the short block related stuff ... heads are a different story though

i am runing a 06 blck crank cam everything else is 02lb7

 

[Seventy468]

So as of right now the best duramax engine combo is LBZ short block with Lb7 pistons.. that seem right? How about heads? I am just curious.. I am not trying anything secret. lol I couldnt afford it anyway! I just like knowing that stuff and hopefully will be able to get my hands on it one day. For now.. all I can afford are my BBC's!

 

[malibu795]

So as of right now the best duramax engine combo is LBZ short block with Lb7 pistons.. that seem right? How about heads? I am just curious.. I am not trying anything secret. lol I couldnt afford it anyway! I just like knowing that stuff and hopefully will be able to get my hands on it one day. For now.. all I can afford are my BBC's!

yes the LB7 mahle style piston are the best option for under 750-800hp reliably..

usually the way most are going is cutting hte lip of the bowl of the piston to allow a straight shot to the bowl.

alot upgrade to "C" gaskets as well.. afaik factory gaskets are currently the best option for less the 800hp crowd.

crower billet rods are the cheapest and proven rods out there. i know couple people have lost pistons checked the rod found that they were still in spec and re-used them

if you dont have to bore the block building a short block is pretty easy and not too expensive.. can be done for alot less then a merlin crate 540 BBC. even with boreing the motor out and .0X over piston and rings.

as for head flow.. LB7 were the only motor the came with egr and non egr heads. and also the only one wiht internal nozzles. every one else is external.

operating systems change from delphi to bosh between the LLY/LBZ change