LBZ: Rods needed?

[x MadMAX DIESEL]

Just wondering here.. I've heard its a good idea to get some stronger rods once you plan on getting dual or a modifed cp3, other than that not really needed. My question is if I were to use say 50% over injectors with a modded pump, would I really need rods?

Yes I know it is a good idea

But Cylinder pressures are what bends rods, corect?
With bigger injecters the pressure will be lower with the same fuel volume?

Where does the need for rods and pistons come into play then, once I plan on getting an after market turbo?

 

[dmaxfireman]

imho torque is what bends rods.

 

[Redbowties88]

Bigger injectors should lead to a greater cylinder pressure but over a shorter span of time if my train of thought is correct

 

[Redbowties88]

That's with the same fuel load of course. Now if you can dial back the fuel to achieve the same clyinder pressure as previously but for a shorter period you should be ok. Of course adding injectors and pumps isn't what kills these it's taking advantage of those items that stresses parts. You can tune it to be equally taxing as your running now with stock pump and sticks

 

[x MadMAX DIESEL]

Yeah I know that, but I really would like to get these after the trans build. Once I have them I'm scared I won't be able to control myself and want to turn it up more

 

[TrentNell]

Just wondering here.. I've heard its a good idea to get some stronger rods once you plan on getting dual or a modifed cp3, other than that not really needed. My question is if I were to use say 50% over injectors with a modded pump, would I really need rods?

Yes I know it is a good idea

But Cylinder pressures are what bends rods, corect?
With bigger injecters the pressure will be lower with the same fuel volume?

Where does the need for rods and pistons come into play then, once I plan on getting an after market turbo?

I think with a stock cp3 you wold be OK on LBZ rods , even with a modded pump maybe but they will fail eventually at anything above 600-650 of regularly used hp , the less used the more power you may be able to get away with for longer . A lot of people get a kick out of how much I got out of my stock motor and use it for reference , but they rarely mentioned is that i never , ever used the power unless in competition . IMOP the truck is only going to get X amount of WOT passes at certain power levels , stock maybe 10,000 , 500 hp maybe 1000-3000 , 700 50-100 , 800+ 0-5 ( just guessing out loud ) . I almost used LBZ rods once apon a time , and if you havce a LBZ then this doesnt aply , but after doing a motor myself I would never consider them again as a performance option other than putting them in a 550 hp truck( stock turbo tune only) and never going higher , which lb7 rods are almost up to that task anyway so ? it is alot of time and money to spend for something 15% stronger , and if you have a LBZ then you will loose a piston well before a rod unless you keep EGT's well in check . Bottom line i guess is its your money do what you want with it but rods are the one and only thing i wouldnt , nor did I skimp on .

 

[x MadMAX DIESEL]

I've just been trying to figure out a way to make good power, without having my truck down for weeks ya know. I think the option that looks best for me is to get my trans built, and buy a LBZ engine that I can work on in the mean time in the garage. Swap it out in a year or so when I've got everything I want. That way I can still drive my truck and what not. Thats not a for sure thought but it looks like the best way to save time and not skip out on the important stuff I guess

But This is a good discussion and I'm still interested in hearing from you guys about it.

I would be more than happy to run mid low 12s in my truck without pulling the engine

 

[Redbowties88]

How much does your truck weigh?

 

[x MadMAX DIESEL]

IDK I'll go weight it full tank this weekend at Link-Belt. Its an extended cab short bed. Basioc interior benchseat, with nerf bars

 

[SmokeShow]

my 02 ec sb weighed 6900ish with me in it at the landfill scales (aka certified). Can't remember the fuel level and all that but it's relatively light compared to some cc sb numbers I've seen kicked around. Be interesting to see what yours weighs being and LBZ. I'm gonna guess 7000.


And you will likely crack or blow a hole in a piston before you bend your rods. I'd do as you said and start build a spare on the side as you can afford parts. EVEN THEN, you have to exhibit control as to not blow your heap up before you have the spare built and ready to go in.


Thats my $0.02. Take it for what it's worth.

 

[hondarider552]

weighed mine yesterday and with me out of the truck with 1/8 tank(transferflow) fuel, truck was 6610 lbs.

 

[SmokeShow]

wow, a friends cc sb 4wd lbz is 7400. no idea how much fuel that was or with or without him in it but wow, what a difference.

Mine does have a small toolbox in the bed and I'm sure there was plenty in the back seat floorboards.


C-ya

 

[WolfLMM]

Cylinder pressure is what makes tq. The only way to make big hp with low tq is to move the power up in the rpm band. Tune your motor for no more than 1200 ftlbs below 2000 rpms and it should last a while.

 

[TrentNell]

Cylinder pressure is what makes tq. The only way to make big hp with low tq is to move the power up in the rpm band. Tune your motor for no more than 1200 ftlbs below 2000 rpms and it should last a while.

100% true , the only problem is IMOP to keep a stock motor alive you need to limit torque higher than that , like 3k which in turn will slow the truck down a bit because most trucks cant be reved high enough to not get into peak torque right after the 4-5 shift so fuel and timing has to be limited for some of the run down the strip and a bit out of the whole depending on how high/hard you can launch , granted this alply's to decent power trucks on a stock motor ,not milder ones , same is still true but alot more leeway.

 

[durallymax]

^^exactly torque down low is what bends them.

I would build a motor on the side if you want but thats another wad of cash to blow when you could be spending it on parts for your motor.

Your truck would more than likely be down for about a week to remove the motor, build it and replace it. The only thing that will hold you up is your determination and the machine shop

 

[rebel7777]

Just wondering here.. I've heard its a good idea to get some stronger rods once you plan on getting dual or a modifed cp3, other than that not really needed. My question is if I were to use say 50% over injectors with a modded pump, would I really need rods?

Yes I know it is a good idea

But Cylinder pressures are what bends rods, corect?
With bigger injecters the pressure will be lower with the same fuel volume?

Where does the need for rods and pistons come into play then, once I plan on getting an after market turbo?

I have the smae questions as well, I'm building another engine for about 600hp. I would like to utilize what is mostly stock, I have been told when you get near this hp your should consider the rods and pistons. "Bottom End" is always what fails, what I've been told.

 

[durallymax]

I have the smae questions as well, I'm building another engine for about 600hp. I would like to utilize what is mostly stock, I have been told when you get near this hp your should consider the rods and pistons. "Bottom End" is always what fails, what I've been told.

600hp has been hit on stock stuff but its tricky.

JIMDMAX was running a little over 590hp with an Aurora 5000 on his LB7 and it help up fine, havent heard from him if his rods were shortend or not.

Trent was running a lot through his stock stuff as well.

In my case I bent the rods the second i drove it out the shop door, but I failed to reduce the timing in the tune and the large amounts of boost and timing took care of the rods the first time I put the pedal down.

If you do want to build the bottom end, buy some good rods, there are many rods out there such as the Carillos, Crowers and DPR X Beams (also known as Howards X Beams) with the latter being my personal choice.

The stock LB7 pistons can be delipped and coated if in good condition and have been holding up fairly well.

Keying the cam and crank is a must.

 

[TrentNell]

600hp has been hit on stock stuff but its tricky.

JIMDMAX was running a little over 590hp with an Aurora 5000 on his LB7 and it help up fine, havent heard from him if his rods were shortend or not.

Trent was running a lot through his stock stuff as well.

In my case I bent the rods the second i drove it out the shop door, but I failed to reduce the timing in the tune and the large amounts of boost and timing took care of the rods the first time I put the pedal down.
If you do want to build the bottom end, buy some good rods, there are many rods out there such as the Carillos, Crowers and DPR X Beams (also known as Howards X Beams) with the latter being my personal choice.

The stock LB7 pistons can be delipped and coated if in good condition and have been holding up fairly well.

Keying the cam and crank is a must.

Thats the exact reason i would never build a LB7 using stock LBZ rods unless for a close to stock tune only truck ( 500-550 hp ) , poor tuning or alot of other things could still take out you 4-$5000.00 15% stronger than stock motor , when the same motor plus 2500 bucks for decent rods can hold a thousand HP .

 

[jdlover1]

IMHO if your gonna take the time and effort to pull the motor to change the stock rods put some high quality rods back in it. Do it right the first time, plus you will have a piece of mind knowing your rods will hold up to what ever you throw at it.

 

[LBZ]

Thats the exact reason i would never build a LB7 using stock LBZ rods unless for a close to stock tune only truck ( 500-550 hp ) , poor tuning or alot of other things could still take out you 4-$5000.00 15% stronger than stock motor , when the same motor plus 2500 bucks for decent rods can hold a thousand HP .

Exactly. Plus a de-lip of the pistons if using stockers.

Unless your just planning to sell the truck. Then by all means throw the LBZ/LMM ones in.