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.