engine swap for h3
 

just out of curiosity has anyone swapped out a motor into an h3, rebuilt v8 or maybe aftermarket gm crate motor?

It has been done a couple of times, but it gets pricey because of the electrical workings of the PCM... you need to reprogram it and that adds to the price...

Yep, the factory made them with the 5.3L LH8 V8, it's called an Alpha.

There is absolutely no reason to mess with a swap, when you can buy the truck that way. Even if you are capable of the wrenching the swap yourself, buying an Alpha would put you way ahead in price, and even further ahead in resale.

The price of a crate motor alone is more than the difference in price from acomparably equipped I5 to and Alpha. No brainer.

more power!!!

I have the 5.3 Alpha and have been asking the same question. I am also wondering if it's been done and with what ?

X2 buy an Alpha or an Alpha OffRoad (Rear locker in 08, Front and Rear locker in 09-10). Then if your are still not satisfied, you can build on that platform. In the long run it will cost you less $.

Remember it's not a Lambo or Vette it's a HUMMER.

This is not that hard to do and alot cheaper than buying a V8 hummer. You should be-able to do this for about 5 grand if you shop around a bit.

Check this out it is a colorado but, very similar, and based off the same platform as the H3. At the end of the thread you will see a list of possible parts needed.

https://www.hummerforums.com/forum/o...ou-guys-23952/

The trans won't directly bolt up, automatics just have to swap input shafts, bell-housings, torque convertors.

Ma5 manual needs new fly-wheel clutch, advanced adapters bell-housing, trans spacer, and a few mods here and there.

06-07 hummer should use E40 PCM and 24x ignition motor.
08-12 hummer could use E67 and a 58x ignition motor.

You can go either way, but sticking with the above rule is the easiest.
in 08 hummer changed the fire wall, and frame rails for the V8 making room for a truck style intake. The older models will work still, just use the car style intake manifold.

Current performance, makes engine mounts (called colorado LSX mounts) should also work on the H3 hummer.

I offer wiring harness, etc

First, welcome!:D So you know how to modify the oil pan to get a V8 into an I5 h3??? Oh, and you know about the clearance issuse with the front driveshaft too???:rolleyes: Oh and you can buy an Alpha for less than the $5000 engine swap difference.

You are WRONG! H3/H3T Platform is GMT 345s. The Colorado and Canyon are GMT 355s. I have nothing bad to say about the 355s, personally I have owned 3 of them in the past.

H3s only share 10% of any off the shelf GM parts. You may want to do some research before throwing out blanket statements.
-Engine, Trans and a few other parts are "similar" then the difference begins.
-Our frames aree boxed with different crossmembers and assed crossmembers
-We use mostly 1/2 ton running gear
-Etc, Etc, Etc

Oh, and the H3 rear diffs are open, unless they are Adventure/OffRoad package vehicles which have an Eton Electronic locker. I5s have 4:56s and Alphas (V8s) have 4:10 gears

So it looks like you are trying to "sell" us some engine swap wiring harnesses. Hmmm, you don't know the differences between the GMT 345s and the GMT 355s but you know all about what will fit and work properly????????:rolleyes:

Please tell me how to edit a posting?? I would like to remove anywhere were it says I can build you a harness.

If a Mod does this than, I would depreciate leaving up the other info, as it is useful to people, and does not benefit, me in anyway!

Also I removed the words in my sig, until someone let's me know if that is ok or not! Again sorry, and no need to nail be to the wall I honestly didn't mean to upset the apple cart, and offend you Tainter! My name is Jamie, and maybe you will forgive me, and teach me all I want to know about 345, some day!!


The 345s as I have so graciously learned from.. you!!! And you have certainly rubbed it in!! Are similar enough wiring wise..at least engine wise, that yes I can build a wiring harness! You obviously can't just take a harness meant for a COLORADO SWAP and install it on a 345 hummer!!

Sorry I don't know every exact mechanical difference, from a Colorado to a H3!!!

"So you know how to modify the oil pan to get a V8 into an I5 h3??? Oh, and you know about the clearance issuse with the front driveshaft too???" never said I did (I will wispier that the LH8 pan will most likely work, on hopes that you don't crucify me!)

"Oh and you can buy an Alpha for less than the $5000 engine swap difference." Maybe true I was just laying the options out there, perhaps "JOE" has spent 25,000 in wheels stereo upgrade, and 10,000 in custom paint. Now it is a little bit more worth it to swap in a V8

Maybe someone wants to build a custom high performance, motor..like a 6.0 or 7.0L then there is no point getting a factory V8 to, do that to!

You know plenty of techinal terms "LH8" and stuff. Do you know how many different LH8 oil pans there are out there?

If "JOE" is looking for a custom high performance V8 (of any litre) he would have to also consider the strength of the transmission, transfercase (which you do not have), front diff and all of its components as well as the drive shafts. So a stright forward swap/install would be/is much more complicated.

I wasn't saying cut and dry just through motor in there and be done with it! Apparently I was miss informed about your axles and transmissions! Most of the people on the colorado/canyon board, look to your trucks for heaver duty axels transmissions etc.. I figured yours were heavy enough to support I mild V8 swap. I was told the H3 use 8.6" ring gears, same as the colorado 09-10 V8, and some 1/2 ton pickups. Most of the colorado/canyons use the 8" ring gear rear axle, and the G80 locker is known to break even with the I5!

Also being the first person other than mallet to adapt a LSX motor to the Aisin MA5/Ar5 series transmission. I did alot of research on it and the H3 Ma5 has carbon sychros on some of the gears, and hardened gears as well. So it might be up to the task of a mild V8, that doesn't Hot rod, and go hardcore off roading!

I am by no means a auto trans "guy" I have mostly owned and rebuilt manual transmission vehicles. I thought you guys had the 4L65E, and was under the impression this is loosely based of the 4L60E. I was under the impression they shared the same case, and in-order to make it bolt up to a V8 you would just change the input shaft, bell-housing front plate, and torque converter. Maybe install a corvette servo, and a performance rebuild. This would save the aggravation of mating a V8 tranny to your "T" case!

Again somebody miss informed me about the LH8 pan. Here is what I know/heard.. perhaps completely wrong! I thought the LH8 refereed to the 5.3 aluminum block Gen IV motor used in the 2008 Hummer H3 Alpha, and the 2009 Colorado.. the Colorado might have been referred to as the LH9.

I thought LH8 pan has a integral mount for the oil filter and has a major "kick" in for 4 wheel drive colorado V8s. I thought this also cleared the Hummer H3 diff. Apparently not!

No idea what "T" case you guys have, other than the fact hat I heard guys wanting to swap them into colorado/canyons because they are supposedly stronger.

Again was just trying to help, didn't mean to push any of my "wares" or knowledge, on anyone.. even though it sure looks that way!

Hey I have stumbled across this post and have some questions regarding the installation of a 5.3 v8 from an Alpha into my 06 H3. My ex-wife recently blew the motor and trans in her H3 that I bought for her 2 years ago and decided I could have it back (Yes I know so generous of her). So I'm stuck with a complete mess and I would like to consider putting a 5.3 from an Alpha into it. I can order the motor, trans, computer, intake, wiring harness and some other crap I was told I needed from my local dealership. I was wondering if it would be possible to order everything for a H3 Alpha and just swap into my 06 H3? Or would I have to do some serious modifications? Just curious to if this might be possible since I have to go the route of a complete replace of the internals anyways. Let me know what you guys think and possible scenarios of going about this.

Sounds like the perfect candidate for a Mash Motors 6.0 conversion! mmm, torque! :)

Torque that is equal to the cost of buying another Hummer:rolleyes:

As much money, time, and effort it would take to do a Alpha conversion...It would be easier to just fix the 06 and trade-in for another Hummer

Before you order a complete engine and crap from the stealership.... PM thebroken and ask him if he currently has anything. The savings might be HUGE....

If I were going to do an engine swap, it wouldn't be a V8. I'd be more interested in a diesel swap.

So he spends $6k or more, fixes the 06 and sells it for around 16-17k and buys an alpha for 30-34k. The difference in what it costs to fix the motor/tranny and spend buying the Alpha could be put to use on a professionally installed 6.0 Vortech/4L60 and fulltime or selectable transfer case that starts with 325 HP and easilly hotrodded for more. Plus (and this is a biggie! ) NO CODES! With a blown motor and transmission this is the perfect time for a trip to Witchita, especially if he was thinking of making a swap for a stock V8 anyway.

Of course price figures into it and I don't know if he's got bills falling out of his pockets or if the 06 is paid for but if you have to spend the $$ for a new V8, tranny, computer, etc. then you already know it's not going to be cheap going in.

Don't get me wrong, Mash Motors would be an awesome way to go. I have been there and talked to them personally. BUT, who has $18,500 laying around for the conversion? And that's the starting price. For that amount of money, there are plenty of cheaper options. Hell, for that amount you could throw in another I5 and add all kinds of accessories.

Yeah, that's my problem- I could keep my 07 and buy another for that price, but if I ever grenade my driveline I think I'm gonna have to sell a kidney or two for one of these!

Yea I paid cash when I bought her the H3 so I don't have any payments. I make decent cash so I am really thinking about investing in the 6.0. As a lot of good points were made as the pro installation, no codes, and the starting HP there are a lot of good benefits to that. The only draw back is the 18,500 start price, it is a little steep but as far as going the route of a new motor, trans and T-Case plus the cost of a pro install it equals out to around the same price give or take a few grand.

Like Songman said the thought of a diesel swap made me go make love to my wife for a few hours but I haven't really seen a lot on them. I know someone mentioned somewhere about a 6.6 Duramax install but when I read on the article it was way out of my price range with all the custom wiring and fab to make it fit and work. Yes good HP numbers and all the torque you could shake a stick at but a lot headache trying to find someone who knows what their doing and could attempt it again.

$18,500 isn't such a bad price because she is paid for, my interior is still in extremely good shape and the body in really good condition.

Has anyone on here had a 6.0 install and would like to comment on how it runs now after the install? Just curious I would like to hear some good things before I spend that kind of money.

will the 3.7 auto trans fit the 5.3? cause you can get a vette engine and ecu with wiring for around 3K. h3 with a vette engine?? hell yeahhhhhhh

Not sue I understand your question exactly? You want to know weather the 3.& L trans will bolt to a 5.3 , but then you want to get a vette engine, the vette motor could be a 5.7L, 6.0L, 7.0L or a 6.2L supercharged motor.


Anyway the bolt pattern should be the same on all these motors, just that the 6.2L, and possible the 7.0L will need a different flex-plate, GM changed the bolt pattern on these... added few more wholes, to handle all the power!

The 3.7L trans definitely will not bolt up to the 5.3, 6.0L, etc.. (LS series or vortec truck based LS motors) . The 3.7L is part of the atlas family of engines and shares a completely different bolt pattern. Atlas series motors are; 2.8L, 2.9L, 3.5L, 3.7L, 4.2L, 4.3L Inline 4, 5, 6 motors.

You can however change the bell-housings, input shaft and torque converter to the V8 style, and maybe change-out the servo to a corvette one.