LV3 Engine Swap (Page 1/2)
Reborn756 DEC 29, 04:23 PM
Howdy folks! Reborn back again with another engine swap question. This time looking at something I've found little information on: the 4.3L LV3 Ecotec3 engine.

From everything I'm seeing, this seems like it could be the perfect Fiero engine paired with a 440-T4: double the power of the 2.8L (stock for stock) while possibly being lighter than the 2.8L.

Has anyone done (or know someone who has) done or at least attempted this swap?

I know, I know: "There are easier and cheaper swaps!" "3800sc swap it!"

I'm interested in the ecotec3 due to the space and weight savings over the other options, not potential cost factor. The 3800SC is over 60 pounds heavier than the 2.8L.

My goals are:

To keep the weight balance as close to factory as possible.

keep the car sub 3,000 LBs (without me in it).

Increase engine power by at least double without boost.

Modify the car as little as possible (no removing the passenger seat and spare tire for "weight reduction").

Keep a reasonable sized engine in it so it's not more difficult to work on.

The LV3 seems to give the ability to meet all of these goals, whereas every other option seems to cause a compromise somewhere. 3800SC screws up weight balance. Northstar is a tight fit. 4.9L Caddy doesn't meet my power expectations, unless I boost it (throwing out the weight savings).

Any information and input would be greatly appreciated!

------------------
- Darryl

Gall757 DEC 29, 04:56 PM
For those unfamiliar with the code LV3.............from Wikipedia

4.3L (262 CID)
Commencing with the 2014 model year, a new LV3 EcoTec3 4300, based on GM's GEN V (LT1) Small Block V8, became the new base motor for the next generation Chevrolet Silverado/GMC Sierra light duty trucks, and was phased in throughout the rest of the truck/van line after the 2015 model year. This aluminum block and head design was significantly different from the cast iron block and head engine it replaced, signalling an end to a design dating back to 1955. Like its small block V8 counterparts, GM Powertrain also sells the motor for marine and industrial applications.

[This message has been edited by Gall757 (edited 12-29-2020).]

Reborn756 DEC 29, 05:15 PM
Thanks for that, Gall! Should have clarified that. I do appreciate you adding the information
Will DEC 30, 08:00 AM
The reason relatively few people swapped the previous 4.3 is that such a swap requires most of the same effort as a V8 swap, but only gives 3/4 the results.
If you want to be the first to try the new 4.3, go for it!
The power output is much higher, the bang/buck is better. V8's are long enough that squeezing everything into the engine bay tends not to be much fun and people end up resorting to remote electric waterpumps and other fun plumbing shenanigans.
The V6 should fit better and skip some/most of that effort.

You'll still need an adapter plate and a big chunk of the parts required for an LS swap, so you'll spend a lot of the same money and end up with 270 HP.

Do you have a medical condition that prevents you from driving a stick? You focus on weight in the engine, but the 440-T4 is hardly a light transmission. The 6T70E would be more appropriate to the engine.
sourmash DEC 30, 09:46 AM
I see a write up about redesigned oil delivery, but we'll see if it still produces oil starvation to the crank in somewhat less than extreme driving conditions.

"Oiling System: the oiling system is revised and features a new, dual-pressure-control and variable-displacement vane pump with increased flow capacity. As with the Gen-III/Gen IV engines, the oil pump is driven by the crankshaft. Variable displacement enables the pump to efficiently deliver oil pump flow as demanded. Dual pressure-control enables operation at a very efficient oil pressure at lower rpm coordinated with the Active Fuel Management and operation at a higher pressure at higher engine speeds providing a more robust lube system with aggressive engine operation. All Gen V engines are designed to be used with GM’s Dexos semi-synthetic motor oil. “Thinner” oil is used, too, which helps reduce friction to enhance efficiency. The 4.3L V6 uses 5W30 oil, held in a six-quart aluminum oil pan."


It doesn't really discuss the issue that sometimes grenades the LS engines, which is extended high speed corning where the oil pickup starves of oil. "Aggressive engine operation" isn't the issue. It's high speed cornering.
Will DEC 30, 12:51 PM
If the oil drains back over the cam as it does in all the LS engines, there's no way it can be significantly better than those engines. GM fixes this problem by going to a dry sump oil system.

There are baffle kits for LS engines that are supposedly very helpful, but only the dry sump truly fixes the problem (and even then only below 1.4 g's)

https://www.improvedracing....ank-scraper-kit.html
Reborn756 DEC 30, 04:48 PM
Hey folks, sorry for the late response here. I do appreciate the information!

Will: No medical condition that keeps me from driving stick, I just prefer an automatic. Much more consistent shifts. In my experience, the transverse autos seem to be stronger than the manuals as well, and durability is a must. This is my daily driver in the spring and summer months, need it as reliable as a Fiero can be. Now before I get a "why worry about power if it needs to be reliable?" comment from anyone: It's a daily by choice, but I enjoy the heck out of the car. Don't want it to sit due to a poor mechanical choice on my part. That's also why I was looking at the 440-T4, I've had bad experiences with GM's Longitudinal E transmissions, I find it hard to believe they somehow managed to build a transverse unit correctly. If you have more information on this unit, I'd love to know more though. Being newer, it may naturally pair better with this engine. I forget if I mentioned, but I'm trying to wring 400HP out of the engine naturally aspirated, so the transmission needs to be able to hold up to that, max.

Sourmash: I did not know this about LS engines, and I appreciate that information. Fortunately this isn't a track car: It'll see some spirited driving, but nothing like the stresses of a race track. I like to drive fast and have fun, but I also don't like to beat on my vehicles. The engine should last, though I will look into the information that Will added to this part of the discussion. I'm going to build the engine up (as much as is possible for the LV3, given the tiny aftermarket), so some durability upgrades are definitely on the menu.

For anyone that has some background on the LV3: Are there any factors that will make this an obscenely difficult swap, such as:

Starter location needing swapped without a good way of doing it?

Transmission options not being viable?

Extensive modification required to the cradle (modification beyond the usual items, such as mounting brackets and reinforcement)?

Thanks a ton for all of the information so far guys, I do appreciate it. Over this summer I'm hoping to begin the Restomod project on the car, and need to get my swap sorted. I was originally considering the 4.9L Cadillac due to the weight balancing and sound, but the severe lack of aftermarket (making it very hard to hit my power goals) turned me off from that idea. Driving the car for a while now with the 2.8L in it has actually caused the V6 to grow on me, and I'm finding that this LV3 may be my Golden Ticket, if I can figure everything out.

[This message has been edited by Reborn756 (edited 12-30-2020).]

Gall757 DEC 30, 05:19 PM
The usual problem with newer engines is the computer. It probably wants to know all sorts of things the Fiero cannot provide, so you need a re-program. Perhaps you are an ace with computers or you know one.....but most of us don't.
Reborn756 DEC 30, 05:26 PM
Thanks for the reply Gall!

I've done my homework, and I think I have found a company that makes a 100% standalone controller for the LV3. From what I gathered, they are getting popular in the dune buggy scene or something like that. So there's some standalones that aren't too horribly priced. That is of course providing my homework was correct!
fieroguru DEC 30, 07:57 PM
If I was going to do a V6, it would be the LV3.

I swapped a 1992 4.3 CPI engine with the 4T60 in an 88 back in 2007ish and drove it daily until about 2011. I really liked the engine, hated the auto. It had plenty of power and torque to be fun, but not so far over the top where I couldn't drive it in the snow. As for why I didn't just do a SBC... I already had a SBC fiero and really didn't need two of them. The shorter length really made the swap easier than doing a SBC.

I have had a LS4/F40 with 382 whp since 2013 and 55K miles and really love the LS platform, but GM never made a 3/4 LS and stuck with the SBC variant until the LT/Ecotec3 series engines were developed. If I ever get to having a 2nd FIero, I would love to swap in the LV3 with the F40. Back in 2015, there was a link to GM offering the LV3 as a crate engine for marine application and it also had the controller package, so I doubt there will be any unsurmountable issues, but it will definately be some uncharted territory.

You will have to:
Cut the starter mount pad off the engine to clear the 4T60/440-T4
Use an adapter plate to bolt the engine to the transmission (Street Dreams SBC one would be good to start with, but will need modified).
Use 142 tooth flex plate to fit inside the bellhousing (Lt engines only come with 168 tooth flex plates, and I think they all run the 8 bolt pattern on the crankshaft so you can't use the LS4 flex plate).
Create some spacers and crank support for the torque converter to take up the extra space from the adapter plate.
Figure out a starter solution - my LS4 starter solution could likely be adapted to work.
The rear exhaust manifold probably won't clear the auto, but you might be able to use two front (or driver side) manifolds (that is what I did for my 4.3 CPI swap).
The oil pan will likely need to be trimmed down to let the engine sit nice and low in the engine bay.
A/C compressor is right where the passenger axle needs to be, so it will have to be removed or relocated - so some accessory rework will be needed.
The 4T60/440-T4 can use stock GM mounts (probably wouldn't want to based on your power goals) and stock GM axles.

From there it is just a matter of plumbing, wiring, and ecm. The water pump is nice for the FIero layout