Need to replace motor... Whats the best for off-road torque

[LagunaH1]

My two cents would be to diagnose what's causing the loss of power and then go from there.

 

[USMC_TOP]

I think I remember finding a website that sold used but fully checked out complete engines. I wann say $2,200 will get you a 3.7 out of a 07 that will bolt right up to your 06. You said you already did the PCM tune so I would think it would run fine. Guys say the 3.7 runs all over the 3.5 all the way through the RPM range. Might be a an option for very little money. Get a cherry picker and have at it! It will prob cost you close to that price for head work. Just remember rebuilding an engine isn't just boring and honing of cylinders, you have a crank shaft rods cams valves and springs, might want some porting done etc...... I have to believe a good engine builder can make a 3.5 a 3.7 plus some extra hp and tourqe with head work and cam lift and duration. When mine needs it I plan on getting an 07 3.7 and beef it up enternaly. I'm not very familiar with these new 5 cylinder engines but I know with in line 6 cylinders the crank shaft has lot more main caps that hold it to the block by design than a v8. Giving you more longevity. If you could see your crankshaft spinning at high rpm's it actually is bouncing in the journals so more holding it in place the better. That's why all your big dog off roaders running small block v8 and big blocks want 4 bolt main caps to hold that crankshaft.......... I am surprised to hear that these inline 5 cylinder engines are only getting about 200k before rebuild time. And I have read tons of post hear with them failing long before. I remember reading about that inline 6 4.2 liter I think it was anyway, when it first came out GM claimed they test ran one over 400k, tire it down and it was still within specs, ie bearing tolerance cylinder bore etc. I had one in a 04 Buick Renieer and loved it. Plenty of power and smooth as silk.

 

[CaseyS]

I had a head replaced under warranty at about 50k, paid for a new head at 180k due to burnt cam journals and managed about 260k on the lower end.

All I can say is do your homework and figure out what your budget is and what you want to get out of the truck. I went through the same choices of options that you are reviewing.

Didn't want a 3.5 back in it.
Could have rebuilt the 3.5 to a 3.7
Could have had a V8
Could have sold the truck for salvage (260k with blown motor)
Really wanted a diesel.

Settled on the Cummins 4bt for form factor, and available tech and aftermarket support, plus availablity of transmission adapters.

My truck was paid for at the time of my swap. I even evaluated selling it and buying something else to drive. End the end the 11k I have in the swap works out to about a year and a half of notes on something else so by the end of the year I'll be money ahead on a truck that should last as long as I do.

 

[USMC_TOP]

CaseyS......do u have a build thread on your cummins conversion?

 

[SuperBuickGuy]

I got a 10.2:1 462 big block sitting in my shop. I bet that would wake things up!

too bad it's not a 427, then we'd talk about a new motor for my Corvette

I agree with the trend of recommending the 3.7l to replace what's there. The little bit extra hp and torque makes a huge difference. Or get an alpha.

 

[hodges81]

Thanks everybody.... I'm still trying to weigh out my options. I'm in the middle of installing a Whipple Supercharger in my '13 ALC Silverado...I have exspensive hobbies

 

[Kyle]

CaseyS......do u have a build thread on your cummins conversion?

heres the build thread for Casey's cummins swap. http://www.4btswaps.com/forum/showthread.php?27760-2006-Hummer-H3-Build-Thread/page11

 

[USMC_TOP]

Thank you Kyle!

 

[hodges81]

I'm going to have to check that out!!!
:horns:

 

[chaos254]

I would say a 5.3(these are super cheap in junkyards and can make tons of power) or turbo i5. 4bt is awesone but lets be honest. Most of us dont have the fab skills for that.

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[06 H3]

I vote 5.3 too. It seems the easiest. 4bt's issue I see is wiring not the fab. Wiring seems intense...

I gave up the supercharger idea on the I5 when I got quoted 5k JUST for the supercharger, no injectors, no inter cooler, nothing else. **** that! I would be in 7k when I'm done or buy a 5.3 from the yard for 2k or less. it can fit just not sure what wiring will go on

 

[chaos254]

I vote 5.3 too. It seems the easiest. 4bt's issue I see is wiring not the fab. Wiring seems intense...

I gave up the supercharger idea on the I5 when I got quoted 5k JUST for the supercharger, no injectors, no inter cooler, nothing else. **** that! I would be in 7k when I'm done or buy a 5.3 from the yard for 2k or less. it can fit just not sure what wiring will go on

Yeh thats crazy. turbo actually wouldnt be so expensive and relatively easy as long as you can weld your own manifold/downpipe. 60lb injectors and replace the the pump in the tank with a 255 walbro. Find someone to tune it and your good to go.

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[Airborne]

GM bored out the 3.5 to 3.7 for the 07. And I've been told the computer software didn't change.
There are others here better than me at this. They can help you determine if you just need a new head out a complete rebuild.
From vehicle history. My vote Is you most likely need just a new head.

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The 07 has it's own PCM different from the 06 and the 08 on up, which came with a TCM as well as the PCM. The 07 actually has the most free memory of all the PCM's.

 

[06 H3]

Yeh thats crazy. turbo actually wouldnt be so expensive and relatively easy as long as you can weld your own manifold/downpipe. 60lb injectors and replace the the pump in the tank with a 255 walbro. Find someone to tune it and your good to go.

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Hmmm....Any good threads? A turbo wouldnt help much offroad but I dont need any more power for wheeling, thats what low range is for. Its the street that kills me, I live in a hilly area and any road trip I am constantly climbing up and down hills and 65-70 mph with a heavy fully loaded H3.

Supercharger is out for me. too pricey
4bt is out for me, its badass but its too over the top for me.
5.3 I dont mind fabbing crap up for the swap its just electronics worry me
Turbo, I like that idea seeing its cheaper then a swap and supercharger, my only concern is engine longevity. Smog I can deal with...not worried about that. I know nugget HATED his turbo because turbonetics ****ed some things up but I would avoid them.

 

[06 H3]

The 07 has it's own PCM different from the 06 and the 08 on up, which came with a TCM as well as the PCM. The 07 actually has the most free memory of all the PCM's.

so swapping in a 5.3 from an electrical standpoint would be easier into an 06 08 09 or 10 then swapping a 5.3 into a 07?

 

[CaseyS]

Electrical is not bad on the 4bt. Its mostly deleting stuff. Transmission controller is standalone. It can stay in its own prefab harness. I chose to graft it into mine for cleanliness.

** That said **

I have not evaluated how the traction control behaves yet without the engine present.

There will be 4bt swap parts available in the future when I can get time dedicated to making that happen.

 

[06 H3]

Traction control should stay the same as it's monitored by the axles but then again who knows with this crazy computer. Any engine lights or things in the DIC. Does cruise control work? Etc

 

[3Hummers]

I would think the 5.3 would be the easiest swap. The 4bt is an interesting choice but damn those things are loud.

 

[chaos254]

Hmmm....Any good threads? A turbo wouldnt help much offroad but I dont need any more power for wheeling, thats what low range is for. Its the street that kills me, I live in a hilly area and any road trip I am constantly climbing up and down hills and 65-70 mph with a heavy fully loaded H3.

Supercharger is out for me. too pricey
4bt is out for me, its badass but its too over the top for me.
5.3 I dont mind fabbing crap up for the swap its just electronics worry me
Turbo, I like that idea seeing its cheaper then a swap and supercharger, my only concern is engine longevity. Smog I can deal with...not worried about that. I know nugget HATED his turbo because turbonetics ****ed some things up but I would avoid them.

there are few turbo builds over on 355nation but i dont think anyone has attempted it on our h3s

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[06 H3]

I would think the 5.3 would be the easiest swap. The 4bt is an interesting choice but damn those things are loud.

I agree, the mileage is a perk. I dont have diesels but have ridden in them. I see pros and cons to both

there are few turbo builds over on 355nation but i dont think anyone has attempted it on our h3s

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If I can do that reliably I would be game for one.

 

[3Hummers]

The 4bt is about the loudest diesel motor I have been around. Bulletproof, great power and torque and louder than I want to be around.

 

[Hunner]

Remember to shoe horn the 5.3 in the H3 they flared the front frame and moved the firewall back some, or so I heard from a reliable source. lol
Might want to do some serious measuring on that.

 

[06 H3]

Remember to shoe horn the 5.3 in the H3 they flared the front frame and moved the firewall back some, or so I heard from a reliable source. lol
Might want to do some serious measuring on that.

I remember hearing that but I'm not too worried since people have put 6.0s in 06s

 

[Hans3T]

Not to thread hijack too much...but Casey, can you blow black smoke out of the 3?? :giggle:

 

[CaseyS]

The 4bt is an interesting choice but damn those things are loud.

The 4bt is about the loudest diesel motor I have been around.

Right on both accounts. I'm definitely not going to sneak up on anyone.

Not to thread hijack too much...but Casey, can you blow black smoke out of the 3??

No. Nor do I want to. I have not had the chance to tune anything yet, but smoke is not acceptable to me once I reach a final tune. It does make a little puff right on startup though.