LBZ vs LML

[DmaxKnightmare]

I have a LLY that cracked a piston and i am tearing into it now. I was gunna just replace pistons, doing all the stuff needed for that. But when i removed one of the rods from the piston, the wrist pin bushing turned in the rod. So basically i dont think its worth using these rods. I have narrowed my choices down to 2 options. Buy used LBZ or LML rods from Wagler, or buy SoCal street rods. Now i know what the best option is as far as strength. Thats obvious. But my question is if i go with a stock rod, is there any strength difference between LBZ and LML rods? I am not looking to put any more power down than what my stock fuel system will take. So im not gunna be running 800hp. Will lml rods hold a consistent and reliable 600hp?

 

[08lmm72mm]

Reliable 600hp? Go with SoCal street. I wouldn't even for second consider putting stock pistons or rods back in if I was going to run at that power level and needed to build but that's just IMO.

 

[Chevy1925]

How will you be achieving 600hp? That is a big factor in rod choice

What pistons do you plan to run?

 

[Jezzum450]

As far as what rod is best I cant comment. However I've been running my LML for the last 3.5-4 years with at least 730WHP. So yes will it hold 600, YES for how long I have no clue. But I'm not nice to her ether.

 

[DmaxKnightmare]

I emailed wagler on the matter too. They said they wouldnt put a lml rod in. They would stick with a lbz/lmm rod. I would assume its because of the smaller rod end or whatever on the lml rods and pistons. Ive finally found a set of pistons that will get here before October, and they are delipped LB7s from DHD. I was looking at Mahle motorsports cast piston but with these cheaper ones i can budget for a set of street rods. So, thats my plan for now unless im not thinking of something. In the future i would like a set of 45 overs and a 65-68mm turbo, but we'll have to see. Right now i need to get the bottom end together.

 

[08lmm72mm]

If sticking with a stock piston might aswell run a lmm rod. Maybe I overthink things no point in having an over built rod for a mediocre piston

 

[N2BRK]

with the time and cost of the job overall, I'd look for better than stock options on the pistons and rods if my goal is 600hp. Just my unprofessional opinion

 

[Chevy1925]

a delipped lb7/lly piston will be PLENTY at 600hp. i put those through their paces with all the towing i did at 500-600hp and grossing 23-26k. they saw 750-800hp quote a few times at the track, dyno and mexico. the only donwfall i had with them was when the heads cracked and the coolant buring in the cylinders caused pitting in the pistons.

a LBZ/LMM rod will work for what you want but keep good tuning on it based on what you are saying for to reach your goal. if you are staying on stock injectors and turbo for a while, stay off the max effort tunes till you can drop in bigger injectors, that will help rods and pistons live a long life. going those 45% overs sooner than later are a big plus.

 

[DmaxKnightmare]

I appreciate the help! I sent my injectors off to get tested and received my results today. All injectors failed by just a little bit. Like 1 # on the full load test. So i am probably gunna need to replace them. Thats definitely the right thing to do. Im using a very well known and good rated tuner on efilive so i should be good there. If i grab some LBZ rods and 45 overs yet, i hope we'll be good to go.

 

[Chevy1925]

I appreciate the help! I sent my injectors off to get tested and received my results today. All injectors failed by just a little bit. Like 1 # on the full load test. So i am probably gunna need to replace them. Thats definitely the right thing to do. Im using a very well known and good rated tuner on efilive so i should be good there. If i grab some LBZ rods and 45 overs yet, i hope we'll be good to go.

yup, you will be. Keep tolerances tight on the machine work (match factory) and slightly looser ring gap than stock, it will be a good engine.

 

[DmaxKnightmare]

Wheres the recommended place for injectors?

 

[Chevy1925]

S&S would be my suggestion. @JoshH on here or @Bdsankey can help you out

 

[gmduramax]

Go 60% overs at minimum 100% overs would be better.

 

[OleBlackyLBZ]

I have the delipped lb7 piston/lbz rod combo with 45% injectors and am between 650-700 for 20,000ish miles of beating on it. I also ran lbz rods on my old setup for around 30,000 miles making the same power until I broke a crank. Rods were fine, and I beat on that motor hard too. From my experience you perfectly fine at 600 with good tuning. I agree go 60's on the injectors, I wish I would have..

 

[Yngdmax92]

in my opinion, doing a full set of rods an pistons to make 800hp is a bad call, a truck at 600-700hp can live a long happy life and be fun. once you go above that where you truly need a built engine. Dang things just require to much maintenance and your taking the joy out of it being a truck.
Like others have stated, lb7 cut pistons and lbz/lmm rods.... done and done.

wish they could figure out a way to make the l5p rods work in the older blocks..... they appear to be holding up really well, even up to 1000 hp territory.

 

[turbospoolindmax]

600 hp is nothing on stock rods. guys including myself have been pushing them over 1000hp for years. Tq bends rods not hp keep it under 1300ish lb ft of torque and stock 06+ rods will last pretty much forever for 600 hp. I would do lbz rods and lb7/lly pistons and call it a day. If you plan to make more than that down the road mabe consider mahle race cast pistons just for peace of mind but it's not really necessary. I would also recommend 100%over injectors or bigger depending on future power goals. running a big injector will help it make 600hp+ much more efficiently than a smaller injector that will require more timing and US to make the same power

 

[Chevy1925]

in my opinion, doing a full set of rods an pistons to make 800hp is a bad call, a truck at 600-700hp can live a long happy life and be fun. once you go above that where you truly need a built engine. Dang things just require to much maintenance and your taking the joy out of it being a truck.
Like others have stated, lb7 cut pistons and lbz/lmm rods.... done and done.

wish they could figure out a way to make the l5p rods work in the older blocks..... they appear to be holding up really well, even up to 1000 hp territory.

you cant put a L5P rod in any older truck due to crank rod journal size. at min, you have to change the crank out to make it work. by that point, you are now dumping 1300-1500 (what ever a stock L5P crank costs), plus what ever custom work needs done to make it fit OR dropping 3-5k on a custom crank from someone.

cheaper to just put older style rods in it. if you are pushing to the 1000+ hp and want reliablitly, then thats where those costs can become warranted.

 

[2004LB7]

you cant put a L5P rod in any older truck due to crank rod journal size. at min, you have to change the crank out to make it work. by that point, you are now dumping 1300-1500 (what ever a stock L5P crank costs), plus what ever custom work needs done to make it fit OR dropping 3-5k on a custom crank from someone.

cheaper to just put older style rods in it. if you are pushing to the 1000+ hp and want reliablitly, then thats where those costs can become warranted.

I thought the L5P crank was slightly longer too so it's not just machining the block to make it fit. you'd have to get an L5P block. if you are going that far just get the L5P engine and roll with that

 

[Chevy1925]

I thought the L5P crank was slightly longer too so it's not just machining the block to make it fit. you'd have to get an L5P block. if you are going that far just get the L5P engine and roll with that

no sure on that. i think its just off set different on the mains due to the crank trigger wheel being on the back of the crank now but very possible they made it longer. Depending on how much longer, it still may be able to be machined down to older specs without loosing integrity. I need a bigger lathe

 

[JoshH]

Cranks are interchangeable.