I just got me a LBZ that I'm swapping into my H1. I want to make maximum power without injector upgrades. Is there anything that I should change such as head studs, head gaskets ect. to make it reliable. What's the max power and tq I can expect on a stock Duramax?

Stock baseline dyno #'s on that motor should be around 310 rwhp. You won't need to make any real motor work (studs, rods, etc.) until you get over about 550 rwhp. Some still run stock internals at higher than that.

But get yourself a good downpipe-back exhaust, a PPE tuner, and a filtration lift pump (such as a FASS or Airdog 150) and you'll be good to go. Should be layin down somewhere around 450 rwhp, reliable as hell, with stock turbo and injectors.

BTW, why not just buy a Hummer H1 Alpha (already has a Duramax) rather than mess with the hassle of a swap?

If you stick to a single CP3 then you should be fine on being reliable. Tune it properly and it will just run out of fuel.

if you want the most power you can get on stock turbo, injectors, and CP3 pump, then do yourself a favor and replace your pistons before you put the motor in. The LBZ pistons are hit or miss when it comes to putting holes in them or cracking them... Just some bad pistons in random motors from what I can tell. But to be reliable and to depend on it to run I would replace them.

The Alpha is over $100K and I don't have that kind of money for a toy. I got the LBZ at a great deal and I'll be doing all the work myself except for the LBZ wire harness modifications. I've done a lot of work on my H1 and is not worth it to sell it, I'll never get what I invested in it. Most importantly it's paid off. How can I give her up? Look at her she's beautiful.

BTW Drholliday what exactly did you do to get 531 RWHP / 940 RWTQ 10/11/08 on Wayne's Dyno in Jville NC? I see you do have some minor mods? Does not look major.

Hard to argue with that. Damn good lookin' rig. I wouldn't give her up either. Good luck with the swap, and keep us posted. I'd like to see how it turns out.

BTW Drholliday what exactly did you do to get 531 RWHP / 940 RWTQ 10/11/08 on Wayne's Dyno in Jville NC? I see you do have some minor mods? Does not look major.

I'm pretty sure it was just the mods in his sig. With tranny, fuel, exhaust, good tuning, and a few other little mods you can get to around where he is

But get yourself a good downpipe-back exhaust, a PPE tuner, and a filtration lift pump (such as a FASS or Airdog 150) and you'll be good to go. Should be layin down somewhere around 450 rwhp, reliable as hell, with stock turbo and injectors.

I'll agree with this but you can buy a Predator for $300 new and put down around 430 to the wheels on the 120 tune. Thats it, no FASS or anything else. For the money, you cant beat it and besides, PPE's are pretty figgen pricey.

Someone correct me if I'm wrong. The limitation on the H1 as far as the LBZ is going to be concerned is the limited area for the intercooler. If you do keep the LBZ stock/mild tune you shouldn't have an issue.

Nice lookin Hummer. H1s were the only way to go with a Hummer unless you got a Military one from a DRMO sale.

BTW Drholliday what exactly did you do to get 531 RWHP / 940 RWTQ 10/11/08 on Wayne's Dyno in Jville NC? I see you do have some minor mods? Does not look major.

Just the trans to handle it, FPRV shim and a lift pump to keep rail pressure, the rest is all tuning.

I'm starting to get a little nervous about my engine though after seeing all the LBZ's that have put holes in pistons, some mines getting built this fall after I get back from Iraq.

Are the stock pistons they only Limitations on the LBZ that are making it unsafe past 550hp? Im not looking to make a ton of power.. Hopefully around 600-620rwhp.. Is the stock pistons only thing that needs to go? What do you guys swap them with?

As far as I've read and heard pistons and rods are pretty high on the list of internals to swap. Lots of people either go with LB7 pistons or/and get theirs de-lipped and cut to lower compression a bit. Crower sounds like good rods... I couldn't really say though...

the rods on the lbz's are strong. they are stronger than the lly or lb7's. lbz problems are the pistons

short of catastrophic failure...what do I need to watch for re-pistons.?? I do mostly hiway driving/cruising. keep banks on 2-3 depending...rest of my info in my sig.

Nice HumV..! goona be sweet with an lbz powering it.!

cheers,

stk

So the pistons being the only problem with the LBZ's, what is the issue they have? Cracking? Are the LB7 pistons alot stronger?

So the pistons being the only problem with the LBZ's, what is the issue they have? Cracking? Are the LB7 pistons alot stronger?

As of fight now the best answer is its hit or miss on the casting of the LBZ pistons, some live at high power, others die in the 400-500 range.

For daily drivers most go with LB7 pistons and have them de-lipped and coated to help prevent heat soak.

As of fight now the best answer is its hit or miss on the casting of the LBZ pistons, some live at high power, others die in the 400-500 range.

For daily drivers most go with LB7 pistons and have them de-lipped and coated to help prevent heat soak.
Doc, I see your times before and after lift pump/shimming. Before you shimmed with just the lift pumps were you getting any codes or low fuel issues? Ive been debating shimming as my truck never gives Fuel codes and runs good on my 350 horse tune. thanks!

........But get yourself a good downpipe-back exhaust, a PPE tuner, and a filtration lift pump (such as a FASS or Airdog 150) and you'll be good to go. Should be layin down somewhere around 450 rwhp, reliable as hell, with stock turbo and injectors......


Any required trans upgrades for these exact mods listed?

As of fight now the best answer is its hit or miss on the casting of the LBZ pistons, some live at high power, others die in the 400-500 range.

For daily drivers most go with LB7 pistons and have them de-lipped and coated to help prevent heat soak.

How much does it run to have them delipped and coated? Say if decided to install the LB7 pistons, if the motor is low mileage then you shouldn't need to bore the motor. Just New rings and bearings and gaskets and be good to go right?

Any required trans upgrades for these exact mods listed?

You might get a Transgo, Jr. kit (around 60 bucks), but MANY run this setup/power level without ever touching the tranny.

Doc, I see your times before and after lift pump/shimming. Before you shimmed with just the lift pumps were you getting any codes or low fuel issues? Ive been debating shimming as my truck never gives Fuel codes and runs good on my 350 horse tune. thanks!

Yes I was throwing low fuel rail pressure codes every run down the strip, it would turn on the CEL just before the 1/8 mile marker.

How much does it run to have them delipped and coated? Say if decided to install the LB7 pistons, if the motor is low mileage then you shouldn't need to bore the motor. Just New rings and bearings and gaskets and be good to go right?

I'm not sure on the pricing, If you call Guy at SoCal Diesel he sells the pistons and is very knowledgeable on what would be a good set up to run for your end goals.

Thanks Doc.

You might get a Transgo, Jr. kit (around 60 bucks), but MANY run this setup/power level without ever touching the tranny.

Wow, awesome!:D That is wonderful to hear!!:clap:


That is really what I am after next, at least for a first step. And that will be plenty, as it will be double to what my old truck was!!