LBZ/LMM rods?

[Dazedandconfused]

Ok if you shotpeened a set of stock rods do you think it would help out a bit? What is the limits on them? I'm trying to plan a near stock rebuild on my LLY and figured I'd throw in a set of these rods. Plans for this engine are simple it will stay low on the power scale. Its going to be a family/DD/tow pig. I'm just gathering ideas right now to plan out. Most it will have on it is a hot juice or 425-450RWHP EFI live tune on it. The other truck I'm planing on repowering will have a built motor for playing so this one will be fine like this.

Thanks
Andy

 

[Bako_Dmax]

People say 650rwhp is the limit for LBZ/LMM rods, at the power level you said the rods will be just fine.

 

[McRat]

I'd be stunned if shot-peening had any effect at all on Dmax rods. The beam bends, they don't crack. Shot-peening only affects about .010" deep, and helps stop cracks from forming.

One experiment I always wanted to try was to run a stock engine up to 900rwhp with de-torquing. I believe it will work. Basically, restrict engine output below 3000rpm to 500hp max, then extend the powerband to 4500rpm. The truck would drive normal on the street, but when you let the RPM climb, it would do a Jekyll & Hyde thingy. Already, Casper's 900+ rwhp build makes no more torque than a "tune-only" Duramax. I just can't afford the risk to be wrong about it and lose a race.

 

[Dazedandconfused]

Thats what I was wondering about the shot-peening them. I just want to keep my dd reasonable and close to stock. It will loose the EGR setup and that but want to do a budget build. I was going to run my stock rods but I just dont feel comfortable pushing the LLY rod limit especially with 300,000 or more miles on them.

 

[Mike]

I just can't afford the risk to be wrong about it and lose a race.

Is this race during the 1/4 mile or salt flats Pat? I remember sometime back you desired this. I just don't remember what kind of torque you wanted limited.

Don't we already run past 3000 rpm down the quarter? I mean once past the 60ft I never see below 3000 rpm again till.....

 

[The Neens]

Is this race during the 1/4 mile or salt flats Pat? I remember sometime back you desired this. I just don't remember what kind of torque you wanted limited.

Don't we already run past 3000 rpm down the quarter? I mean once past the 60ft I never see below 3000 rpm again till.....

I think it's a race in which you actually race...Not one in which you give up and sell parts...

 

[McRat]

Is this race during the 1/4 mile or salt flats Pat? I remember sometime back you desired this. I just don't remember what kind of torque you wanted limited.

Don't we already run past 3000 rpm down the quarter? I mean once past the 60ft I never see below 3000 rpm again till.....

Any racing or pulling. I think we are good to about 1200ftlb max on stock LBZ rods, and know that 1500ftlb can bend rods.

You have to shift at 4300+ and keep the converter unlocked in the beginning of second to stay 3000+ rpm. That requires a minimum of a 3.0" turbocharger, a 3.2 preferably with a single, to get solid HP up there. Tach lag is a bitch, so you need to do the math to see where your RPM falls.

 

[Mike]

I think it's a race in which you actually race...Not one in which you give up and sell parts...

I haven't sold any, I don't have anything to sell. Or maybe I don't have anything someone would buy.

Any racing or pulling. I think we are good to about 1200ftlb max on stock LBZ rods, and know that 1500ftlb can bend rods.

You have to shift at 4300+ and keep the converter unlocked in the beginning of second to stay 3000+ rpm. That requires a minimum of a 3.0" turbocharger, a 3.2 preferably with a single, to get solid HP up there. Tach lag is a bitch, so you need to do the math to see where your RPM falls.

At 4300 and 1200lbs limit, just under 1000hp would be possible. For 3000rpm and that torque limit, under 750hp would be required. I see what your getting at. I broke an input shaft with the converter locked, I don't run in tow haul or the ats controller any longer. I'm scared . Seems what you are saying here makes since as to why. Converter slippage or fin damage may be helping me keep higher rpm's. Your idea makes since to me.

 

[Stingpuller]

Rods

Pat I agree with you on the limited power down low and keeping a motor together. That's what we done on Matt's truck and it seem to work good. He runs a stock turbo but when you add NOS it's just like going to a big turbo. Now the motor want's to rpm like it has a 3" charger on it.Matt's rods checked out fine when I took his motor apart. The pistons were burn't and I think thats a matter of being out of fuel. With his stock injectors the pw was up in the 3300's and just not enough fuel to cool the charge any. I agree totaly with you that tq kills and rpm is your friend. I'm not sure what power his was making but it run 123 mph at i'm guessing 6500 to 6600 lbs. Thanks for the tip years ago I think it paid off for Matt and I well. Jeff

 

[bullfrogjohnson]

Any racing or pulling. I think we are good to about 1200ftlb max on stock LBZ rods, and know that 1500ftlb can bend rods.

You have to shift at 4300+ and keep the converter unlocked in the beginning of second to stay 3000+ rpm. That requires a minimum of a 3.0" turbocharger, a 3.2 preferably with a single, to get solid HP up there. Tach lag is a bitch, so you need to do the math to see where your RPM falls.

Pat,

Do you think a cam is a must in making power up there with a large single? My truck made 741hp and 1268ftlb at 3200rpms but bent the lb7 rods. I plan on trying a set of lbz rods for one season. I am gonna try a 3.2 single and some low gears to push everything up in the rpms. We will see if it works

 

[McRat]

Pat,

Do you think a cam is a must in making power up there with a large single? My truck made 741hp and 1268ftlb at 3200rpms but bent the lb7 rods. I plan on trying a set of lbz rods for one season. I am gonna try a 3.2 single and some low gears to push everything up in the rpms. We will see if it works

No, I've made peak HP at 4400 with a 3.2 on a factory cam. A bigger cam might help HP though.

 

[othrgrl]

Pat I agree with you on the limited power down low and keeping a motor together. That's what we done on Matt's truck and it seem to work good. He runs a stock turbo but when you add NOS it's just like going to a big turbo. Now the motor want's to rpm like it has a 3" charger on it.Matt's rods checked out fine when I took his motor apart. The pistons were burn't and I think thats a matter of being out of fuel. With his stock injectors the pw was up in the 3300's and just not enough fuel to cool the charge any. I agree totaly with you that tq kills and rpm is your friend. I'm not sure what power his was making but it run 123 mph at i'm guessing 6500 to 6600 lbs. Thanks for the tip years ago I think it paid off for Matt and I well. Jeff

At his weight and times he had to have been around 800hp.

 

[bullfrogjohnson]

No, I've made peak HP at 4400 with a 3.2 on a factory cam. A bigger cam might help HP though.

How big of an exhaust wheel on the 3.2? I'm assuming this is with a 1.10 AR?

 

[McRat]

You'd have to call PPE, I was running the early version of the GT42mag.