LB7: Rod limits

[plowboy_lbz]

Well there ya go.

I don't care how many years, I want to know how many miles you've been over 600 hp. My truck has been at 500 for 15,000, 570ish for 15,000, and over 600 for 10,000. I know I have an lbz so I'm in a different catagory but this how it should be explained. Also I drive like a normal white man.

 

[dmax711]

If you can't afford a motor build rite now to me the risk isn't worth it. Save up and when you can build a spare motor. Then give your current one hell. And report back.

 

[Muff]

Ill ask something, been wondering for awhile.... Has there actually been any factual strength testing on the difference in lb7 to lbz rods? If so, where's the test results?

What he said. Where's the scientific proof.

 

[x MadMAX DIESEL]

What if there the same rods lol. Just think there stronger cause the pistons are weaker and hurt first

 

[Xternal]

They are indeed different. The if you compare to the side by side you can see the difference. I think it was Henry who reported first of the difference but I could be wrong.

 

[hondarider552]

I made 649/1140 in my stock bottom end GMC, daily drove at 585/1010. yes it can be done but guys Tom is right. When I bent #1 rod in the single cab it had 200psi compression and overall the rest of the engine was 50-60psi low, highest was 320. I still think for safety and reliability you shouldn't go over 500-550rwhp on a lb7/lly

 

[SickLL7Crenshaw]

I like how I keep showing up in this thread. Tom don't be so damn grouchy lol

 

[skintback]

It all depends on your right foot and how often you use that max effort tune :thumb:

If it was me i would put some 60 overs in retune and start saving

 

[red1977]

Mikes 600 hp is also custom auto numbers if I remember. His track times don't show 600, high 500s I run a 473 on stock bottom end with 375k, im sure I have bent some but dont want to check, I will just run it tell it blows I put my big single on knowing I'm playing with fire.

 

[paul06d-max]

Last week I saw a topic on the limits of stock rods. Anyone have the link to it? I can't find it now.

Someone suggested I run a s475, and was wondering if anyone had any feedback on these turbos. The plans for my truck are 800hp street truck but I want to break 600 this year. Is the 475 too much for stock rods. I also still want to be able to pull my boat. Been thinking about the 366 because of all the good things I have been hearing about them. Is the 366 capable of 800hp? Any input would be nice.



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I would never suggest running a 475 on a stock engine, I would look into a smaller inducer S400, Like a 463 would drive really nice and still have the ability to make good power and sling rods.. I would also look into a Fleece Tapshifter, it will give you the ODLO and the ability to tapshift your Allison like the 06+ trucks have from the factory. Another thing to think about even if you get a smaller frame S4 your just a small wheel upgrade away once you build your engine. Also a 475 would not be needed for even 800hp on a built engine, Fleece has a 468 that has made 918rwhp on a few different trucks.. food for thought bigger is not always better, especially if your wanting to still tow!

 

[jacobdewey]

It's funny, I dyno'd over 600hp multiple times, but my track #'s only ever added up to 540hp. Ran it like that for 3 years. I sold the truck, and the kid that bought it threw a bigger tune on and lifted the heads. Bottom end was still fine.

 

[Chevy1925]

People like you are the reason I come to this forum. You don't just tell everyone to throw whatever on and go. If my truck were to go down I wouldn't have a weekend ride. So I am going to take your advice and just wait til I have enough saved to do it all.

What besides rods, main studs and head studs would I need to get to 800 HP? Cam? Heads? Pistons? I'm not to sure what all I would need to get there. I'm trying to get a grasp on how much I need saved. I have built many gas engines in my time but when it comes to diesel I don't know what needs to be done/changed and not.

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this is what i told you at the beginning of the thread. you can make 800hp many different ways now a days. How you want to do it will come down to what you feel is best for you and your driving habbits. No one will be able to tell you the perfect setup cause everyone has their own favorite flavor so to speak.

the question then becomes:

do you want via more air than fuel? or more fuel than air? or a maxed out mixture of both? or 800 to be the small side of the tuning with more to go with just a tuning change?

then, do you want the turbo to light fast for low rpm daily driving? will you ever tow more than that 1500lbs? are you always going to DD on that 800hp tune or run less? How big is your budget going to be? are you wanting bare minimum reliablitly or do you want to spend some extra coin in other areas to make your "choosen setup" shine its best?

and it goes on and on and on and on.

i can say this much. ive been DDing a true 600rwhp tune that is not detorqued for the last 2 years and have 20k on the clock without one issue. i tow 12k with it regularly, i floor it at least a few times a week when im DDing it for the week and generally just enjoy it. When my samurai runs, the truck gets parked and sits for the weekends, when the samurai goes down, this becomes my reliable transportation and has done so without an issue. EGTs never go over 1300egts now unloaded, hardly smoke (leave a just a faint haze), gets 17mpg with a bit more room to go, and i really couldnt ask for more. i built it to suit ME and what i do and it came out spot now.

 

[coker6303]

If you don't have the coin to do a build, don't play with fire. But ultimately it's your truck and you can do what you want. Advice is generally spot on here, these guys have pushed the limits.

I know my motor is hurt, no question about it. Ran a 11.8 (dual cp3) on tune 4 and 12.3 (stock cp3) on tune 3. I daily drive tune 3 and thrash on it everyday just to do it. I'm a wot guy, I don't baby anything I own. I drive everyday for work to see customers, so it gets lots of road time too.

I know what the consequences are, I've just been VERY, VERY lucky to this point. I have a spare motor and build parts on stand by. I'm ready! Lol

Good luck, I'll keep my fingers crossed for you! Lol

 

[SSchmi5519]

I know what the consequences are, I've just been VERY, VERY lucky to this point. I have a spare motor and build parts on stand by. I'm ready! Lol

I'm in the same boat except for the spare motor and build parts LOL :angel:

 

[mike diesel]

So what exactly is considered low compression? What is a new engine make for compression?

I'm about to go buy a compression tester and I will post the results. If I'm low on any cylinder, I will put my foot in my mouth and eat all my words.

My motor has grade c gaskets and 161,000 miles.

 

[SSchmi5519]

So what exactly is considered low compression? What is a new engine make for compression?

I'm about to go buy a compression tester and I will post the results. If I'm low on any cylinder, I will put my foot in my mouth and eat all my words.

My motor has grade c gaskets and 161,000 miles.

What is your weight and timeslip info for your 600+hp? 600 plus how much?

If you know the above info you know your rwhp.

 

[SickLL7Crenshaw]

What's my calculated rwhp Steve? Et and trap is in sig. Weight was 7020 the day I ran that time. I'm assuming I'm over 600?

 

[SSchmi5519]

What's my calculated rwhp Steve? Et and trap is in sig. Weight was 7020 the day I ran that time. I'm assuming I'm over 600?

What was your 60 on the 12.41@110 run?

 

[SickLL7Crenshaw]

What was your 60 on the 12.41@110 run?

1.79 and 7.96 in the 1/8

 

[DAVe3283]

600 HP is probably pushing your luck on LB7 rods, as everyone has said.

I ran a dynoed 425 hp / 800 tq for a couple years, then got bigger sticks (60%) and turbo (S371) and pushed north of 560 HP (by MPH and weight) for another year. Finally a glow plug ran through the #1 cylinder, but when I pulled the head, the rods all seemed good. Once I get them out I will see if anything bent for sure.

So, yes, you can get right near 600 HP on a stock bottom end. Big injectors and a good turbo help, as does sane tuning. However... you are on borrowed time. Just a matter of when.

If you can afford the risk of blowing a motor, then crank it up! Who knows, you may not. I put 25k miles on at 560+ HP, and I am not easy on the throttle. And in the end, it wasn't even the rods that killed the motor, but a bad glow plug (long story). Many people have bent rods at or below 500 HP, so bear that in mind too. Good luck!