LV1 and LV3 Questions - for a unique swap.

[Tony S.]

When the LV3 first came out I knew I wanted to install one into one of our coaches.

It's my understanding the LV1 is basically the same - but it doesn't have the Fuel Management System, like the LV3 does.

Which one, LV1 or LV3; will provide the best life, least headaches and good gas milage? (I'm after best torque / milage and most important - reliability vs going for HP.)

Would I be better off without the FMS and the LV1 or should I stick with the LV3?

Anyone out there able to crack them and change most if not all the settings? Are there any restrictions in what can be changed?

EXAMPLE: The vehicles these engines come in run 30" to 31" tall tires. That size tire will NEVER fit on the coach I want to install this power-plant in.
I'll also need to change the final drive ratio and thus the settings in the computer to match what ratio I go with.
(So far, using a RMP calculator; I believe the factory used 4.11 final drive with this power-plant and I'll need to go with 3.42 to make it run in the same range with the limited size tire I can use.)

I'll need someone who can change the setting and take care of the wiring harness for me.

Thank you,

[Tony S.]

Can someone please help. I worked as a line mechanic for GM for 10 years (back in the day) and the next one of these coaches I get running, I want to be all custom and have the GM Gen 5 - 4.3 LV1 or LV3 in the back. I need a tuner and someone who can clean up the engine harness for me.

BTW - Here are the 2 of the coaches I got running in less than a year of becoming the new caretaker of.

This was the first one that got us hook on these. It has a Corvair flat 6 air cooled engine. (The engine that came in it was locked up.)
2009 Car Show-Tag Covered.jpg

Front Table.jpg

Kitchen.jpg

Here is the second one. It has an Olds Toronado 455 in the back. (It had not run in over 20 years before we got it.)
UV520 at its First Car Show in 2014-2.jpg

455 in UV520.jpg

Engine.jpg

[Tony S.]

Concerns:

I need to make sure the wrecked vehicle I buy can be tuned - before I buy it. (I once purchased a vehicle 1 year to young and it could not be tuned. The following years could.) I learned that one the hard way.
I need to know I have someone who can tune it for me and take care of the engine harness.
I would like to have an idea of the turnaround time, where I need to ship the stuff and how much it is going to cost.

Can someone Please recommend someone or a place that will do the LV1 / LV3, 4.3 V6?

Thank you,

[Shrek]

I believe the following to be true ... however, I do not hold myself out to be any sort of an expert with respect to this V6 platform.

The LV3 engine was used in the Silverado / Sierra truck platform - from 2014 to 2021.

The LV1 engine was used in the Express / Savana van platform - from 2018 to 2021.

From a control module perspective - the 2014 and 2015 E92 ECMs are the easiest and least costly with respect to configuring and tuning in a conversion platform - these control the LV3 engine.

Regarding where to source standalone control systems (wiring harness and ECM), there are many options out there. Howell Engine Development manufactures a very nice wiring harness for this engine.

You could rework a used GM wiring harness for standalone use - however, if you actually track the amount of time and materials that this requires for a quality outcome (cleaning, eliminating, repairing, adding new circuits, etc.) the cost of a new custom made wiring harness is often a reasonable expenditure.

[Tony S.]

Thank you.

I guess I need to find out more about the 2 different engines, their systems and the PROS and CONS for each. I got to thinking less bell and whistle might be better. But then again I don't know much about all they have to offer and what breaks down. Grin

[SiriusC1024]

LV3 has Displacement on Demand. LV1 does not. You're going to be working the engine pushing that brick down the road. I'd go with LV1 since you will probably never be operating where DoD is active. It's more reliable due to lack the DoD system.

I definitely recommend an oil cooler.

But really, why not a gen 3 or gen 4 V8? For this application you'd get more reliability, power, and fuel mileage at a cheaper price.

[Tony S.]

Thank you.

I had thought about a V8. But I thought the V6 would get better milage and take up less interior space. Plus, I'm one who likes to do something different.

My guess is that it will weigh in around 6,000 to no more than 7,000lbs and my design for the engine compartment is to make room for a V8 from the start - should it need to be swapped out after the fact.

But my hope is that the newer LS style V6 will work just fine.

FYI - These coaches weigh a lot less than the GMC ones. Example: The first one in post #2 with the Corvair engine weighed in at 3,620lbs.
The second coach with the BIG 455 Olds Toronado power-plant, frame and suspension came in at just over 5,000lbs.
YES - they are a brick being pushed through the wind. But at least they are not a heavy brick. Grin