H3 engine swap to Vortec 4.2
 

Hi Hummer riders,


I'm still thinking of purchasing H3 with manual 5 speed (AR-5 or named as MA5 too).


* My idea; To convert from the engine from 3.5 L (5 cyl - 220 hp) to Vortec 4200 (6 cyl - 291 hp)!!! Will be taken from 2006-up GMC Envoy, or even 2006-up Chevy Trailblazer.. I will swap only to get (higher torque + higher horsepower). Swapping from Vortec 3.5 (5cyl- 220 hp) to Vortec 4.2 (6 cyl- 291 hp) will make me feel a big difference !!

Guys, do you agree with me ??
Do you see that my idea would be successful & excellent ??

PLEASE post your comments..

From my idea, I feel that I'll get bigger torque, hp and fuel economy (Better mpg).

- Before engine swapping: Jeep Wranglers & Toyota FJs can beat the H3 ''sometimes''..

- After engine swapping: Jeep Wranglers & Toyota FJs WON'T beat my 4.2 L H3 !!


- With few modifications like;

1. Magnaflow exhaust (Part# 16630).
http://www.jegs.com/images/photos/600/642/642-16630.jpg

2. Safari air snorkel kit (Part# SS1200HF).
http://www.safarisnorkel.com/snorkel...h3_detail1.jpg

3. Granatelli performance spark plug wires "NOTE: For both GMC Envoy & Chevy Trailblazer" (Part# 36-1798MPG).
http://www.granatellimotorsports.com...s/mpgwires.jpg

4. Jet Performance chip "NOTE: For both GMC Envoy & Chevy Trailblazer" (Part# 20709).
http://www.kmjent.com/images/JET/ima...Module%202.jpg


Hope you comment...

I think the engine bay is way too short for a straight six. If you intend to go through the trouble of a swap, putting in a V8 would be better.

2006-up Vortec 4200 stock horsepower (291 hp) !

As I suggested that modifications above, I can get more than 40 horsepower from them.


* Continued:

5. E3 performance spark plugs "NOTE: For GMC Envoy & Chevy Trailblazer". (Part# E3.66).
http://i.ebayimg.com/t/E3-Spark-Plugs-E3-66-E3-SPARK-PLUG-/00/s/MjY1WDQwMA==/z/dVUAAOxyY9VRQzRq/$T2eC16RHJG8E9nyfnUUhBRQzRqS,gQ~~60_12.JPG

-
 

I know that dear NJTEX,

But the shape & the size of both VORTECs either 3.5 or 4.2 looks the same size!
Straight 5 & straight 6 approximately look the same size..
- Look them up here:

here is 6 cylinder straight for both Envoy & Trailblazer:

http://o.aolcdn.com/commerce/images/...gine_Large.jpg

http://photos.ecarlist.com/NA/FK/f4/.../S7/ag_800.jpg

http://server42.texasdirectauto.com/...6/043_0043.jpg



Now here is 5 cylinder straight for Hummer H3:

http://server29.texasdirectauto.com/...9/040_0040.jpg

http://photos.ecarlist.com/cg/un/9o/.../IC/SQ_640.jpg



Compare both straight 5 & 6 engine sizes.. waiting for comments ! :eek: :confused:

If I remember correctly from our old Envoy, unlike the H3, the back of the engine tucks into and under the firewall. Those pictures are a bit misleading regarding the true length of the 4.2 engine.

Simple, a 6 will NOT fit in the H3.

The AR-5 is rated to 260# of TQ, so that is not going to work either.

It is not about what pictures look like, it is about what it is.

The factory already swapped in the 5.3 LH8, it is called an Alpha, much easier to buy one of those.



I do not know what you are thinking regarding E3 plugs, but they work for crap in the Coil on Plug UHEI used in the GM Atlas line.... and spark plugs do not make power.

Improve the 3.5:

Colorado: Header Shorty Style for Chevrolet Colorado 5-cylinder, Colorado Conversion, Stealth Conversions

or

I5 Colorado/Canyon Stock Replacement Header

Tune the PCM and Trans from Home

first of all if you do any research, you would totally understand that the only difference in the engines is the number of cylinders, and that both of them being inline motors that means the six is longer. I have no idea if you have even looked into the engine bay of an H3, but doesn't sound like it

mechanics the ez part!
 

even if it fit,the wiring,AND a new pcm module to go from 5 o 6 cylinders is not probable with all the other differences involved.
no, the mechanics would be the small problem.

years ago,toss the 4 banger,bolt in a v8,hook up a starter wire,gas line,a couple wires for ignition and a throttle lashup and headers and you were shreding asphalt.
no more