View Full Version : Silverbullet75's V8 Swap - 6.0L LQ4!

02/18/2013, 11:30 AM
Hi All!

I've been doing tons of research for the last year+ on GM LS V8 engines for a swap into my VX. I've only seen people use the 5.3L so far. Well, I've taken the next step in my quest and just purchased a 2005 GM LQ4 6.0L engine with 4L80E automatic transmission. It has 60k miles on it, and is from a 2500HD truck. As of right now, my decision is to go 2WD (as is the current configuration of the transmission). But, in time I may change my mind. Note: The LQ4 was also used in the Hummer H2, and Yukon Denali.

I chose the LQ4 due to cost, reliability, durability, and mod potential. The 2005 LQ4 is rated at 325 hp (+/-) stock. With a cam swap and/or heads it will generate much more (add variables here). But, my goal is to run it stock for a while, then slowly increase the fun-factor.

My timeline and project plan is as follows:

Now thru end of year:
- Purchase engine/trans (Complete)
- Pay off the engine
- Clean-up, re-seal, replace external parts like water pump, main/rear seals
- Find a 1998-2001 Isuzu Trooper/Rodeo (or VX if price is right) with a bad engine
- Swap the VX's engine and/or drivetrain into the Trooper
- Use the Trooper as my daily driver.
- Sell Trooper's old engine or part it out cheaply
- Clean up the VX's engine/trans cavity
- Remove front wheel drivetrain of 4x4 (TBD)
- Insert LQ4 and transmission for mockup of mounts, etc.
- To be continued

I'll keep this thread going as I progress, and keep a running tally of pricing for those interested. Oh, and pics too!

I'm hoping to prove that this swap can be "affordable."
Autopros did the 5.3 build and projected a way high estimate for completion (IIRC: ~$40k).
I think this can be done way under $8k. Crossing fingers.

I'm doing the labor, BTW,This isn't my first rodeo.
The challenge for me will be the wiring.

So, with all that, here is the engine as it sits on my little Harbor Freight trailer in my garage.

http://www.vehicross.info/gallery/data/500/thumbs/Copy_of_My_LQ4_-_Clean.JPG (http://www.vehicross.info/gallery/showphoto.php?photo=23312)

List of Parts and Pricing

Engine/Trans/Harnesses/ECU/etc...: $2250.00

02/18/2013, 11:47 AM
Well, I've taken the next step in my quest and just purchased a 2005 GM LQ4 6.0L engine with 4L80E automatic transmission.


I'll keep this thread going as I progress, and keep a running tally of pricing for those interested...

So how much did the engine and trans run you?

02/18/2013, 11:51 AM
He was asking $3000... I got him down to $2250. :yesgray:
BTW... It came complete with all harnesses, electronics, throttle pedal (Throttle by wire), etc... even a block heater LOL.

02/18/2013, 11:54 AM
Nice, i'll be following... :thumbup:

02/18/2013, 03:29 PM
Very ambitious build, cant wait to see the progress. You might also be one of the first people to put a VX engine in a Trooper. Most people do it the other way around. :)

02/21/2013, 09:19 AM
Photos, photos, photos!

Leon R
02/21/2013, 10:17 AM
Damn! I wish you would have gone with the "bolt on", LS4 instead.... But purely for selfish reasons (I want someone else do the research ;)).

Good luck with the project!

02/21/2013, 07:50 PM
I almost had total failure with this project right after it started.
I went to the DMV Emissions Lab yesterday to talk to them about the rules for re-certification of the vehicle when swapping engines.
The first thing the guy brought up when I told him I bought an engine was: "Did you verify if the engine came from a HEAVY DUTY vehicle or LIGHT DUTY vehicle?"
I was under the impression that Heavy Duty meant Big Block V8 vs. Small Block... wrong.
He explained that if the engine was manufactured for a vehicle rated 8500+ Gross Vehicle Weight, then it's considered HD. If less than 8500, then it's LD.
So, unless I can prove that at least one vehicle produced with this engine had a rating of less than 8500 GVW, then I'd have to sell and recoup...

So on my way home, I told my wife what happened and she jumped on her iPad to search GVWs for the vehicles I knew of that had the LQ4 in 2005. (Hummer H2, Suburban, 1500HD, 2500HD, Express Van, Yukon Denali, etc..)
The ONLY one that is rated under 8500 was the Denali! It's rated at 7000. I pulled up multiple sites that showed 7000 and printed them out for backup.
The guy told me that I will need to provide documentation/proof for everything I do.
For example... one question I had for him was about the fuel pump. Can I use an aftermarket, in-line fuel pump. Answer: Yes, as long as it feeds the system properly, giving factory-like emissions.
Also, exhaust: Can I use aftermarket Catalytic Converters? Yes, as long as I provide a screen shot/print out from the web site showing that it is designed for my engine.
So, I'm pretty happy today. I get to continue!
The info I got from the guy eased my fears too. I've heard horror stories from projects in CA that were denied certification due to random things. It seems Nevada is a little more relaxed.

Update on engine progress:
I tested compression last night and today.
Last night (dry):
165 max psi, most at 150, and 95 least psi on one cyl.
I took some oil and poured it into the cylinder and tried again. I got it up to 152.
Then, I went to the store and bought an oil squirt can, then squirted oil into all cylinders (3 pumps). I let it sit until after work today.

Today (wet):
The one with issues last night had the highest number... 195 psi. The rest were all approx. 160-175.

So, I'm a little concerned about that 195 psi cylinder. I tested it multiple times too.

Overall I'm happy with the compression results. Per the shop manual, as long as they are over 100 psi, all is good. But, if there is a 10% separation between the numbers or more, then a rebuild is possibly needed.

I think I'm going to try to get the engine running on my trailer. I'll warm it up thoroughly through a few cycles, then retest. (at a much later date).

Leon R
02/22/2013, 07:59 AM
Mass is supposed to have CA emissions, but they are much less strict. As long as you do not make it louder and keep the cat, they do not care about most performance mods.

However, plugging into OBD2 port can be a liability! In the last year, they started tagging "tuner cars" with reflashed ECUs and sending them to a higher level inspection (these are ran by state, as opposed to local repair shops)! I wonder what it would do if your VX gives them mid 00's GM readiness codes?

In Mass, they stop checking OBD2 after 15 years, so I have 3 more years of worrying about it ;)

02/24/2013, 08:15 PM
So, I'm a little concerned about that 195 psi cylinder. I tested it multiple times too.

I think I had a "Duh" moment...
Hydrodynamics 101... I added twice the amount of oil to this cylinder. If it hadn't drained out (which it probably couldn't have...) of course it's going to increase the compression. Lucky I didn't put TOO much oil in. Would have been bye bye valves, etc...


Leon R
02/25/2013, 09:52 AM
Actually, hydrolocking the piston usually results in bending of the connecting rod ;). Valves just naturally keep the pressure in.

But you are correct, adding too much oil can affect the compression reading, simply by taking up the value in the combustion chamber.

I usually just spray some oil (2-3 "quick shots") through a straw and hope that it makes its way to the piston rings...

03/24/2013, 09:40 PM

Well... Unfortunately THIS project has reached it's end.

Here are a few updates:

- Bought a 2001 Isuzu Trooper Limited in really good shape, other than a rod-knock'n motor for $2250, with ALL the cool options like tan leather, wood inlays, 4x4, TOD, HUGE moon roof, inclinometer, roof racks, etc...
It even came with a few bonuses: Clifford remote start, snow board mounts, and a full brush guard!

- While talking to DMV again about the EVAP system requirements and the ECU, it was determined that THIS particular engine, FROM the 2500HD truck will NOT work according to their rules. I have to have the exact same configuration and readings from the EVAP system of the vehicle I'm trying to get my vehicle to imitate (Yukon Denali, since it's the only one that had the LQ4 and is under 8k GVWR). To do this I would have to transplant the Denali's fuel tank and EVAP equipment. Red flag... all GM "trucks" have fuel tanks mounted along the frame... and they are huge.

- Also, since I'm trying to clone the Denali, I would have to replace the ECU since it is programmed as a 2500HD, and would show up as such on a computer.

So, I've decided to cut bait on THIS engine/project.
I just sold the LQ4 and transmission package to a guy in Iowa.
(got my money back!)

I'll try again later.
After doing some further research on the issues I ran into, the next most interesting engine is the 2002 LS1 5.7 from the Corvette. The gas tank of the Vette is similar in shape/size to the VX's.
Next time I'll buy/borrow a gas tank and get it to fit FIRST, then the EVAP controls, THEN buy the engine/transmission.

For right now, I have a more pressing adventure to attend to!
My second child, my son, will be born on 3/31 (Easter Sunday) or earlier.
So, the recoup of the engine funds came at a perfect time.

For a project, the Trooper I bought will be a fun exercise.
Cylinder #1 is at 160 psi while all the others are at 185.
That's consistent with rod bearing failure.
I'm going to remove the engine and see if it's salvageable. If not, there are always Troopers on Craigslist for sale with bad transmissions and good engines... heck, maybe I'll just hold out for a good, driving manual Trooper and steal the engine for the Trooper project and the AR-5 for the VX! LOL
Fun fun fun...
My wife actually wants me to give up the V8 idea and go with a supercharger... anyone selling one?? :)

01/12/2016, 11:58 PM
I know this thread is a bit old now, but according to post #45 (Feb 2015) of this LINK (http://forum.ih8mud.com/threads/engine-swap-and-regs-in-reno.680810/page-3) the NV DMV is maybe taking a new approach to swaps. By emissions equipment you could readily argue that they are only talking about sensors and systems. Hopefully this is the case in Vegas too. Might be worth it to take another look.