LS4 V8 Engine Swap

[Leon R]

I keep going to back to this being the best engine for VX V8 swap... Why is it better than others?

1. It has "GM Metric" bell housing bolt pattern, so it is a direct bolt up to the VX transmission.
2. It is CHEAP! The cheapest LS family engine you can get ($900-$1200)! Since it does not bolt up to the usual RWD GM transmissions, it isn't sought after by the "engine swap enthusiasts" who can't get enough LS(x) engines for swaps into just about EVERYTHING!
3. It has lower profile accessory drive/belt, which should be better suited for VX's engine bay (originally designed for a shorter V6).

Problems:
1. No one (to the best of my knowledge), had done this swap into VX
2. The block has no provisions for the starter (it is meant to be mounted on the transmission), so stock VX transmission will have to be modified to accept a starter (not a HUGE deal, assuming that we have clearance in the firewall/tranny tunnel area).
3. "Weakness" of VX transmission. I specifically want to STAY AWAY from this issue in this thread! I would like to get myself a 400hp VX and THEN I will deal with the transmission inadequacies. There are many methods of straightening automatic transmission, including replacing it with a 5sp .

I also found that Fiero guys also seem to like this engine:
http://www.fiero.nl/forum/Archives/A...-2-113207.html

Using his method, we can adapt a starter to a VX tranny:



But my first question, do we have enough clearance for the starter mounted above the tranny? If not, what resides on the inside? Can we intrude into the passenger compartment, without interfering with something critical?

[ND92]

I don't have any advice but I'd like to see how this works out. I'm thinking of a 5.7 hemi swap but of course that's a whole drive train mod.

[SilverBullet75]

One thing to seriously consider is the emissions laws for your area. My LQ4 project was scrapped because I wouldn't be able to meet all the rules set by DMV for vehicle recertification... No matter WHAT engine I used.
You can get the physical engine/engineering setup completed and end up having to scrap the project because you can't get it registered.

I hate how painful of a process it is here!

[Leon R]

Come on... There ways round rules like that . What SPECIFIC rule did your project violate? Usually, you can take advantage of inspector's general engine swap ignorance and slip thing through.

In Mass, vehicles older than 15 years old are exempt from emission testing. At best, they check for a CAT, but even that is rarely done. So I only have to worry about for couple of more years.

[SilverBullet75]

NV sucks for rules!
The issue was that the EVAP system has to be as it was from factory, on the vehicle that the engine came FROM.
It can't throw a CEL, and the EVAP can't be deleted by a tuner.
So, in order to get that to work, the gas tank from the donor vehicle would need to be transplanted into the VX with all EVAP systems attached and functional... BUT, the 2500HD (or any other vehicle that the LQ4 came in for that matter) has front to back gas tank along the frame rail... yeah... that's not gonna work.

So, my next idea was to try an FBody (Camaro, Firebird..) with LS1. Gas tank is "similar" in shape/size. In theory it could have worked... BUT, the killer of that one was finding out that the EVAP is tied electrically to the actual FUEL GAUGE in the dash of the FBody! (not just the sender).

I just need to move to a different state (or county) that doesn't have as tough of rules as Vegas (Clark Co.).

[Leon R]

The issue was that the EVAP system has to be as it was from factory, on the vehicle that the engine came FROM.
It can't throw a CEL, and the EVAP can't be deleted by a tuner.

Agreed! Pretty sure that this is a federal requirement for ALL states! What differs from state to state is the enforcement of such laws!

So, in order to get that to work, the gas tank from the donor vehicle would need to be transplanted into the VX with all EVAP systems attached and functional...

But this is where were we disagree Rules and regulations can be interpreted in many different ways (I am pretty sure that they made a profession out of this ). While your interpretation is correct, it is probably THE most difficult way of achieving desired effect!

Instead of transplanting an ENTIRE fuel system from the donor vehicle you need to understand how EVAP system works in the donor vehicle, compare it to VX's EVAP system and then figure out a way of making they play together! Most of these systems work in a very similar manner, so a simple purge solenoid valve swap might do the trick! Considering that Isuzu used many GM parts, you might even find that the two are compatible.

The bottom line, you want to make GM computer happy and CE light free! There are MANY different ways of achieving this without transplanting 100% of emission controls from the donor vehicle (which is impossible!). Are they 100% legal in a full sense? Probably not, as they weren't designed by GM to work together. But no one is going to apply THAT level of scrutiny to your project!

Have you tried talking to others in your state, who have performed an engine swap?

[evillecutter]

would you have to drop the transmission to change a bad starter?

[Leon R]

Probably, but how often to you expect to change starters?

Something people do not realize about engine swaps, is that they are NOT up to the same quality as OEM designed parts! Things like:

- engine wiring
- motor mounts
- maintenance access
- under hood temperatures

Are typically less than ideal. That is why engine swaps should be done only if the rewards are enough to offset the negatives! And that will vary for each individual.

[SilverBullet75]

Yes, I talked to a couple tuning/mod shops actually. But the difference is that ALL of their customers that did a swap did it in an OLD vehicle that doesn't have the requirements applicable. None had done it in a '96+ vehicle where the rules are completely different.

I had thought about trying to fit the donor equipment to the VX as you said.
This might work. But, I don't have the knowledge required to do this.

Now, if you want to take point, PLEASE DO
I would love to start this project up again, but this time with an LS1/2/4!
(BTW... I too looked into the LS4. VERY interesting option.)

[bartmanS4]

Will it be possible to maintain the TOD or would this require a manual transfer case? I know the TOD has it's own computer but I have no idea how this interacts with the ECU. I think this would be a really cool swap and if not too complicated provide a good alternative to our standard power plants as they get older and older.

I my opinion the emissions standard should simply be: does the vehicle pass the individual output tests period. My guess based on, well nothing, would be that this would achieve a more efficient power plant solution resulting in lower emissions.

[SilverBullet75]

GREAT point! TOD would be disabled if I understand correctly. The VX or Trooper 5Speed computer is required to run it. In that case, wouldn't you be forced to go 5 speed anyway? Does the 4L30e receive input from the engine's computer?

[SilverBullet75]

Wait... I don't know WHAT I was thinking...
Scratch that last post.
The engine's computer doesn't control the TOD...

But, it does control the transmission, does it not? That's why there's two versions... Manual and Auto.

[Leon R]

I do not know how TOD works, but at the very minimum, I suspect that it receives a TPS signal. That can happen directly from the TPS sensor or from factory ECU.

Honestly, I think that TOD is neat, but I do not buy into a hype.

Is there a transfer case with conventional AWD option?

[clipper 03 rodeo]

Sounds awesome, keep us posted on what you end up doing and be sure to take tons of pics.

I'm really considering a swap like this on my 03 Rodeo if everything including the A/C can still be used. My Rodeo has the stronger Aisin automatic transmission, so it should hold up to the extra power pretty well since it's the same one used in the 250hp Direct Injector Rodeos/Axioms.

[Leon R]

I spent a couple of hours under my VX last couple of days, changing tranny oil/filter and I am pretty sure that there isn't enough clearance between the tranny and the tunnel. I believe that we would have to make clearance by going into the underdash area.