I've got an '07 H3 with a 3.7L. The rig is pretty off road capable but just pathetic keeping up with street traffic. I looked up H3 LS swap and you're video was right on top. I guess the magic question everyone wants to know is cost.
This is awesome, please post more videos detailing the modifications. I have a 2006 H3 with a 3.5L, so this would turn it into a different car. Thanks a million for sharing
Omar Helmy I plan on posting another video that kind of sums it all up. I finished the torque converter, exhaust and final tune so I'll do a video of a 0-80 run.One thing, this conversion was an Alpha that already had a V8 in it. For the inline 5 conversion there will be a bunch of custom cutting and welding for the new mounts. I imagine unless you own a custom shop your going to spend a lot more than I did on the swap, it would definitely be a new truck though!
I got my '08 hummer H3 Alpha last December and I saw your video that made me drooling at your badass LS3 engine! I will definitely upgrade that LS3 after my engine gets blown up. 👍
Something to think about, if you wait until your current 5.3 is worn out, broke, etc. then you won't get much for it. If it is in resonably good shape you can sell it to the Jeep guys for good money. The 5.3 is an aluminum block V8 that they love to beef up a bit and swap out the V6 that came with the Jeep. You can just about cover the cost of installation of the LS with what you get for your 5.3. Just saying....
+Sean Adams you have a good point about that... Lol. I read some comments of yours about mpg that you drove around 11 city and 14 hwy after LS3. Aren't your big massively tires effect to your mpg gets low? I would be appreciated that if you have a patient to read and answer my question. thanks! your hummer is beastly one. Hummer H3 from SoCali!
+Javier Espinoza Jr. Yup the 35's do make a difference but the motor just doesn't work hard so good milage. Now if I get on it and drive fast the milage goes WAY down, 7 or 8 mpg.
Javier Espinoza Jr. Hey if your looking to hotrod a 7000 pound truck fuel economy should be your last concern. When I drive like a sane person I get 300 miles out of 24 gallons no problem. It's just nice to have the power when you want it! Good luck!
Hey guys, getting a lot of questions that have already been answered adnauseum in the thread. Read down a bit and all will be revealed! Also driving video coming soon!
Sean Adams definitely waiting on the video! how are you liking the 2500 converter? ls3 is going in my brothers in March. also doing the rancho lift w/coilovers!
Thanks! I keep threatening to post another video of me driving around fast like a crazy person, just got new meats, (BFGOODRICH All Terrain KO2's), so I will do that soon.
+Sean Adams I've got a 06 h3 and it's got the odd ball motor 3.5 and when it starts to die I was thinking of the diesel swap but that's way to much LS3 much better but will that match up to the stock tranny? & being all wheel drive , does that stay the same also?
JASON JACKSON It's a huge job to swap the 3.5 out for anything other than a 3.7. You are looking at at least $11,000 up to $20,000. Trust me, I know, because I owned an '06 3.5 and upgraded to a 5.3 Alpha because of this.
+Caddy Strophic so do they not use the same motor mounts and harness and or tranny? Cause idk what GM was thinking when they made this 3.5 motor for this giant truck / suv. but my 97 blazer motor is way better and yet a lighter smaller truck /suv
Great work here. Very nice build. I see you're bombarded with comments/questions. We have plenty of our own. What can we do to help get an update video???
Did you cut and weld for motor mounts or other clearance issues and did you use a 4l60e trans ? I realize this is an old video but 6.0 liter engines are cheap on facebook & I can get a similar green H3 for $3000 with a bad motor. Will look online for more info regardless but mine will be supercharged cuz I can!!!
As mine was a V8 to begin with the new LS3 just dropped right in, no mods at all. Yes used the stock 4L60 trans but ate it in about 6 months. Problem with these is you cant just replace the trans, its got the 4 wheel drive hookups that are just for this vehicle in a proprietary case. You will need at least a 2800 stall converter and have the trans race rebuilt to hold up to the horsepower. All the rest of the 4 wheel drive system handled the extra HP fine.
The 5.3 is still very powerful with a Silverado and so in a hummer it would be very fast and powerful and way off road capable. I guess I’m just wondering why a 6.2 is needed when you have a much powerful engine, that is way more powerful then a 3.5 or 3.7. Sure the 6.2 is more powerful but why add it if the 5.3 is already there. I would understand if you just direct from the 3.5 or 3.7. But still very cool vehicle.
In the 4X4 Hummer the 5.3 proved to be pretty anemic, especially when you lift and put 33's on it. So my choices were to beef up the 5.3 with supercharger, (total cost with labor $8000), or buy a brand new 500HP LS3 crate engine from GM and just drop it in. 5.3 dyno numbers were 200HP/180FPT at wheels, LS3 pulled 430HP/380FPT at wheels. Total cost with labor $6500. It really was a no brainer.
It really depends on how I drive. on Highway it's pretty consistent at 14-16 MPG. In town is another story, I tend to have a heavy foot, love listening to it. I get about 10MPG in town. Driving video is coming, I swear!!
+Kevin Kildal Just plugged right in. The 5.3 and the LS3 are the same motors, just bigger. Same computer, same harness, no mods at all to swap. Even kept the same gas pedal, (electronic). I had the program remapped for the bigger motor and drove away. No dash lights and all the same alerts work great.
I've got my swap all finished but my intake. My question is being that the ls3 Intake sits lower how did you route your pullys.also is that the stock fan and where did you get air intake setup from
That's awesome, your gonna really dig how it drives now. So the only issue I had was the alternator, if you notice it is not stock mount but just slightly modified to clear the tighter area. all other pulleys are stock. Got a thinner fan from somewhere, sorry forgot where from. Only needed to trim about an inch off the thickness for it to work.The air intake was from a box of air intakes my installer had lying around, sorry I cant be more specific but this was a while ago. I routed back to the stock air box but I always kind of wanted to remove the stock box and just go to a round filter like you see on Mustangs, Chevy's etc. If you do that you can use almost any kit from wherever but you lose the dirt/dust protection if you plan on doing a lot of off roading.
The drop in crate motor was just a bolt in basically and it more than doubled the torque and horsepower without any mods, keeping the full factory warranty.
It's been a bit since I spent the money, things are more expensive now. The crate LS3 was $5000 delivered when I did it, I opted for the 480HP version. They are probably way more now. My installer charged me $1500 plus the old 5.3L motor for the swap including new tune. You'll need a 3000rpm stall converter put in while the motor is out and plan on a transmission rebuild withing 5k miles. The rest of the drive train seemed to hold up pretty well with double the wheel HP but that 4L60 just fell apart. You cant swap it for another transmission because the case they use is propriatary to the Hummer. It connects the Hummer 4 wheel drive system and no other transmission will work. You are stuck with the 4L60 that came with it. After the second rebuild I finally sent it off for a race rebuild by someone who knows what they are doing and it's been fine ever since. I was all in when I sold her at about 10k. Now if you are starting with a inline 6 all bets are off. From the folks I've talked to it's cheaper to sell your I6, buy a V8 and start there. The 5.3L V8 and the 6.2L V8 are the exact same size block, just bolts right in. Also the computer, throttle and accessories are all a bolt on fit too. To change from I6 to V8, unless you own a machine shop, is probably 30k in fitment, computer, throttle, and tune cost. Hope this helps! Good luck!
Sean, I have a 2009 H3 CE. It has the 5.3 w/ 79K on it. You mentioned the install cost was basically covered in exchange for your original engine. Do you mind sharing a rough dollar amount on what those install costs where? I am considering doing something with my H3 and I am bouncing from supercharger, to bolt ons, to engine swap. Struggling to pick a direction and looking for every shred of info I can gather.
I went through the same struggles, supercharger gets you about 100 + HP but cost 6k plus install. Bolt on ' s can give you up to 200HP but it's still a 5.3 with 79k on it. After doing the research the only logical answer was a swap. I got the LS378/480 package direct from GM Performance shop delivered to my builders door for 6.2k Dyno says 420HP and 400lb torque to the wheels. Basically doubling what you have now. Builder gave me 1500 for my 5.3, (they are aluminum block), and charged me 500 for the swap. you will need a 3300rpm torque converter, do that while the motors out, that was extra. there were a couple hundred bucks of odds and ends but that's it. You will need to find a builder with experience tuning these motors, your current computer works great if tuned right. Good luck and have fun!
+Sean Adams Awesome info. Thanks. I am leaning toward swap. Engine is fine and well taken care of so who knows what I can get for it. This info helps as a benchmark.
I have a 2008 h3 lux with the 3.7. I swear i read somewhere that the 2008 and up models all had their engine compartment and firewall modified to the alpha specs, is this true or am i going to have to do some more research?
I'll have to ask again what transmission is going in. I'm not sure what they choose, it's not the stock transmission it's a completely different transmission, any suggestions there or will I still need the converter regardless? And if so did you go with the 278mm circle d or the 300mm I saw a few different types
300. Problem with putting in another tranny is nothing fits except the stock 4L60. the case is a specific to the transfer case and anything else you will have to modify a bunch to wedge in. In a perfect world a 4L80 would be the choice but it won't fit. I ended up just building the stock 4L60 to a monster.
hey there ,its great to see ur work on your car , do you think the transmission will be okay with this kind of engine ?? and how did you make it fit bcoz i wanna do the same to my h3 ?? . thanx
Hi, I am thinking about getting this motor LS3/480. Does it have any surging issues under 2500 rpm? How's the street driveability especially at low speeds? Would you buy this motor again?
This is THE motor for the truck. It is very well mannered at low speed and extremely drive-able. You can putt around town at 1200RPM or scream around at 6500RPM, its just smooth. The street drivability will be dependent on what you do to your tranny but stock tranny with a 2500-2800 stall converter is the best solution.
Thanks. I am going to get a Tremec T56 Manual. Not sure how it would work with this engine for street driveability. You got this motor for $6,200 shipped? From www.gmperformancemotor.com?
Changed my name, Thanks for your help. I pulled the trigger on a LS3 430 /Tremec T56 manual, clutch kit, engine controller - connect and cruise package. Got it from the same place which is Gandrud Chevrolet, Green Bay, WI. Got an awesome deal. Thanks
In my opinion I would have used a truck motor ex... escalade Denali or Tahoe they get better torque numbers doable cam a lil head work and boom u gotten torque u need to get that tank to speed
Hello, One of the greatest conversions I've ever seen, I was just wondering, is the 4WD system still functioning? and did you replace the the transmission as well? Thanks in advance, Cheers...
i have a 2006 h3 (not a alpha) and want to do thos conversion. what would be the price i am looking at to do all this and did you do it alone or have a professional put in the engine for you
Rohith Sajja It was pretty significant and immediate. Horsepower was more than doubled to the wheels so the truck became instantly quicker not just faster. It now drives like a much lighter truck and interestingly enough gas mileage is the same or better than before as the motor does not have to work as hard as the old one. Now if I get on it the mileage will drop a bit but man it sure is fun!!
This is insane man, Think you're gonna turbo charge it in the near future? because that right there would be insane.. though i don't think theres any room for a turbo, i drive a 2006 hummer H3, and even with the inline 5 i can't find any room...
So I'm putting a new transmission in with the new engine, will I still need to put in a torque converter or does the transmission just need to be a good match to produce that low end power?
The stock TC will not work. you have to go with a higher RPM TC or you'll wear out your brakes. The truck will idle at 30mph... Go with a CircleD if you're sticking with the 4L60.
A. Ovation Technically yes you can swap the I5 with a V8 but it's a lot more money and effort. I followed a guy who did it and he ended up spending 30 or 40 grand.
Nicola Miles smith the short answer is yes but it's much more expensive than converting an Alpha. There is a group on FB called H3 engine swap, a guy on it did a I5. He has a couple videos posted explaining everything he went through.
Funny thing is. The 3.7 will wheel just as good as a v8 swap. I imagine this guy never goes off road and doesn't understand the basics of 4wheelin. 80% of off roadimg is best ratio and tires. Not hp
Sean Adams it seems like it Boggs down after initially starting and going out the driveway, I went from an i5 to an ls3 I assume the fuel pumps are the same for alpha. The shop was saying something about return and returnless systems. It has not been properly tuned yet, still waiting for the break in. Did you experience any power loss with your fuel pump?
So I had an 8 cylinder Alpha and upgraded to the LS3. The fuel system was fine for the new motor. Going from the 5 cylinder I would think you would definitely want more volume from the pump than stock. My new motor ran fine with the computer tune and we just adjusted for added power. Did you replace the computer also?
Sean Adams yes brand new computer, almost everything is new. At high rpm it has no lack of power I was just wondering if you had to change it from returnless to a return style pump. Once I get it tuned I'll see how it performs. The psi is 60 for both the alpha and the i5 fuel pump. I also have no rear o2 sensors and that is throwing an engine code so that may be messing with my air fuel ratio. Once I tune it those will be shut off and shouldn't be an issue
It was a Rancho 4" lift with Rancho shocks but they don't produce it anymore. Nobody to my knowledge makes lift kits for Hummers anymore, you will have to dig around for NOS from somebody.
I wanted to know who did the swap on your hummer I have a 07 H3 with the i5 and also want to do a ls3 swap wanted to know how much it would cost and if it is able to do
+Sean Adams sweet that is awesome to hear! this video is the exact reason I love my truck again. you have done a great service to all hummer h3 owners. can't thank you enough.
The stock 4L60 got me about 5000 miles before it gave up the ghost. I put a top of the line 3200 RPM torque converter in it but had to take it out and beef the tranny up. Cant just drop in a better transmission because the case is proprietary to the Hummer 4 wheel drive system. In the end the trany was the weakest link, had to send it off to get race built to handle all the HP and torque.
Nope, the stock computer ran the new engine just fine, no check engine lights and no issues with anything. The stock engine is just a smaller V8 so the mappings were pretty close, just had my tuner dial in the bigger motor and all gauges were fine.
It was a V8, GM 4L60 trans. I put in a 3000rpm torque converter but did have to rebuild the 4L60. In stock form its not beefy enough to handle all the HP.
Thank you im starting this build im a ford guy and dont know much about GM stuff i have a H3 adventure with that sad i5 is there anything you would do differently or anything i need to know that i might run into or anything that i need to tell the speed shop thats going to put this together for me im throwing big money at this project to make it the best family vehicle mostly for me wife dont really care until she sees the bill but thanks for the response and anything else you can give me would greatly appreciate
@@bernardpo2749 Sooo... I worked with a couple guys who tried to convert the I5 to V8, didnt end well. Lots of fitment issues, tranny is way wrong, you cant put in a decent tranny because the case is specific to the Hummer 4 wheel drive transfer case, I wanted to drop a beefed up 6L90 but wont fit. Then when you spend 10's of thousands redesigning everything you start to break 4 wheel drive running parts because none of it was designed to hold up to that kind of HP. What they ended up doing was sell the I5, buy a whole different V8 truck and save 30 grand and everything works good. If you're just trying to get 100 HP more out of the I5 I think there are kits that will do that now. Pull it out, build it up and hang a great big turbo off it, done.
Interestingly enough better than with the small V8 in it. With the 5.3 it was so underpowered you had your foot to the floor all the time just to get it to move. Now with the big 6.2 you just feather the gas, actually gets about 15-18mpg which was better than the 13 I was getting before.
The short answer is yes but there is a LOT more modding needed to make it work. Unless you own a build shop the cost would be too high. It would actually be cheaper to sell your I5, buy an Alpha and do the swap than to start with an I5.
Jerry Luna Yes, I used the stock 4L60 and had it rebuilt and beefed up to handle the extra horsepower. Need to use same tranny to mate up to transfer case, another 4L60 would not work.
HUCKLE BERRY I absolutely hate that answer. There’s always one in any hummer video comments section. It’s a very legitimate question, even for a hummer owner. It’s fucking engine was swapped. It’s a major change, and sometimes people are just genuinely curious.
As the 5.3 block is basically the same size as the LS3 block I run about 1 needle width hotter than before but still less than half way on the gauge. I don't know the actual temp number but the Alpha cooling system cools this motor just fine. If you are trying to convert an I5 than all bets are off, not sure if that's the same size radiator, etc.
+Amr El-Ghawi Yup, used the one off the old motor. There was a little bit of drama getting it to fit right as the new motor pushes forward an inch or two more but I just moved the air intake a bit higher and it was fine. I figured if I needed to I would get an electric but no need.
Nope, the LS3 used the same computer and control system from the 5.3 I pulled out. Same size block actually so that made it a no brainer. 4x4, throttle, all sensors were perfect and no warning lights at all. We just modified a tune on the old computer for the bigger motor and off we went.
