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Discussion Starter #1
So I currently have the 2.4 Sky and want to upgrade the engine with a turbo. But I am questioning the upgrade.

For the same price I could just buy a Redline and have a turbo. And later upgrade the turbo to gain more power.

If you started with each engine straight from factory. And added all the upgrades as possible, which one would be more reliable and have more power?
 

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Settle in, this should be a long one....

 
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So I currently have the 2.4 Sky and want to upgrade the engine with a turbo. But I am questioning the upgrade.

For the same price I could just buy a Redline and have a turbo. And later upgrade the turbo to gain more power.

If you started with each engine straight from factory. And added all the upgrades as possible, which one would be more reliable and have more power?
You will get more power for a lot less effort with the RL. You will also get traction and stability control, in case those interest you.

Out of the box, the 2.4's LE5 engine is more reliable than the RL's LNF, as the water pumps seem to last longer and there is no High Pressure Fuel Pump to fail. There isn't enough data to indicate how relatively reliable they are at maximum power, but my thought is that the RL will generally be more reliable at the same output as the turbocharged 2.4.

How much power do you want, and how much are you willing to invest to get it?
 

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Discussion Starter #4
I plan for this to be a full project. So higher stage turbo, upgrade in fuel delivery, pretty much any upgrade available. Including suspension, brakes, etc
These would all be done for a “project” time line so not all at once.
I thought of just doing an LS swap but I like the idea of pushing the smaller engine to its limit.
I also wanted to note that the base model was given to me so I have no money currently invested into the car.
 

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Has anyone considered installing a C5 Corvette N/A 5.7L 350hp/350tq engine? Those engines are not only exceptionally strong, they are not that heavy and are also very reliable power plants. The power band is consistent from 0 to 100. It will keep you deep in your seat up to that speed in a Corvette. I can't imagine what it would do in a Sky. If doing such a project, I would surely start out with a Red Line to gain all the peripheral benefits.
 

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Many SBC swaps have been done, but many also prefer to work with the original engines. There is no problem getting up into the 400-500 bhp range with the LNF, and they have a torque curve that equals the V8s - in fact even the stock version is artificially limited in first gear so that it doesn't just sit there and spin the tires when you apply too much gas.

There is no loger any middle ground (formerly held by the V6) given that a turbo 4 is in the same output level class as an NA V8.
 

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Well if you ever plan to move to California, just forget about the V8 or V6. Be careful of what you do to a RL or NA. They will get you eventually. I got my Mallett thru somehow. But others have tried since and all have failed. Eventually all states will come along on this quest.

The engine must appear stock, meaning no CAI unless it has the GMPP #, no modified or even painted charge tubes. I know that is crazy, but if they are you will end up at the Ref, he will pass the car for paint, but you will always have to go to the Ref for smog and who ever buys the car from you will have the same problem.

California is having a lot of problems with kids blocking the freeways and major intersections with this donut frenzy. If you are stopped and the police officer thinks your car is not stock he can refer you the smog ref. There for every infraction it is a 1000.00 fine. Meaning CAI, Charge tubes, high flow car, you are looking at a 3000.00 fine and all must be removed. If you are caught again the fine triples and a third time, I am told they take the car and destroy it. This comes from a friend that manages a large Ford dealership in Hemet, California. He drives, or drove a very modified fusion. It is now stock.

I would sell the NA and buy a Redline and do the basic Trifecta tune. You will never get more bang for the buck out of the car and it will keep its relatively dependable level. I have both, and I honestly enjoy the NA's ride over the Redline. The wife drives the NA and has absolutely no problem keeping up with modified Redlines. But she is nuts as @Robotech can testify. lol
 

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Went looking for past posts, but couldn’t find any-

Anyone ever take the turbo components/equipment off a 2.0 and install them on a 2.4?
 

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It is far from plug and play.

Yes Robotech did, and I think there were some problems, but now has moved to a larger turbo, and is still having some problems making it work. He has done a lot with his engine and I think he is getting closer. You might want to talk with him before you begin on the project.
 

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Discussion Starter #12
Well if you ever plan to move to California, just forget about the V8 or V6. Be careful of what you do to a RL or NA. They will get you eventually. I got my Mallett thru somehow. But others have tried since and all have failed. Eventually all states will come along on this quest.

The engine must appear stock, meaning no CAI unless it has the GMPP #, no modified or even painted charge tubes. I know that is crazy, but if they are you will end up at the Ref, he will pass the car for paint, but you will always have to go to the Ref for smog and who ever buys the car from you will have the same problem.

California is having a lot of problems with kids blocking the freeways and major intersections with this donut frenzy. If you are stopped and the police officer thinks your car is not stock he can refer you the smog ref. There for every infraction it is a 1000.00 fine. Meaning CAI, Charge tubes, high flow car, you are looking at a 3000.00 fine and all must be removed. If you are caught again the fine triples and a third time, I am told they take the car and destroy it. This comes from a friend that manages a large Ford dealership in Hemet, California. He drives, or drove a very modified fusion. It is now stock.

I would sell the NA and buy a Redline and do the basic Trifecta tune. You will never get more bang for the buck out of the car and it will keep its relatively dependable level. I have both, and I honestly enjoy the NA's ride over the Redline. The wife drives the NA and has absolutely no problem keeping up with modified Redlines. But she is nuts as @Robotech can testify. lol
I live in the LA area and have a guy that can get me pass a smog test no questions asked.
 

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It is easily said, but not normally easily done when the car is setting there. I was told the same exact thing and it took jumping thru several hoops. I was about to register it in Arizona. @Robotech got busted at a car show I believe and had to take everything off to get past smog. This may have been on his Velociter, not sure. There hasn't been a lot of shows lately due to the virus, but I would guess with all the crap on the freeways and city streets going on, they will become a favorite for the local gestapo. They were starting to hit them last fall and winter. Excessive noise I think is what Troy said was the cause for most of the tickets being issued, I think he said 40 cars were cited. Once they opened the hood all bets were off I guess.

I have never been bothered by the local law enforcement. Mine would not pass currently, due to the fact that mine is a 2007 and I have a GMPP CAI on it. Not legal on a 2007, and I have polished DDM charge tubes. Again not legal in California. It is ridiculous for sure. But they are going to be looking for anything to bring in money when this thing is over is my guess.

Good luck with what ever you decide to do, and keep in touch. We have a fairly active club out of San Diego. We actually have a run this weekend up to Palomar Mountain from Fallbrook.
 

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The California smog Nazis are apparently a pain. We had similar smog tests up here in BC, and as long as your car passed you were good. I told the manager of the system that as the intention of the legislation was to have less emissions, it was ludicrous to fail a car that had a later cleaner running engine in an older car - basically running too clean?

I managed to get my turbo Fiero through for years, but only because it had a good high performace CAT and none of the testing people had a clue what it should look like under the lid anyway.
 

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Just get a redline. You will get stiffer suspension, LSD, etc beyond just the engine.

As far as the engine itself, the LNF is extremely strong. With just a tune youre looking at over 300rwhp while maintaining reliability. To get much more than that from the LE5 you are going to have to start replacing internals. The LNF has other goodies like more oil cooling passages, sodium filled valves, etc.

To me, seems a pretty simple decision. The only reason I could see to try and work with the LE5 would be a fun project.
 

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If you are building it out completely, I don't know why you wouldn't start with the 2.4.

Start with an LEA block. The LNF and LE5 are Gen II Ecotec engines. The LEA and LDK blocks (LEA is 2.4l, LDK is 2.0l) is a stronger block. We have seen LNF blocks fail due to the thinner cylinder walls as a result of them having larger water jackets. Of course building an LNF with an LDK block would address this too. These Gen III blocks are superior to the older blocks. In addition, the LEA has oil squirters too like the LNF.

The only thing you are giving up in the 2.4 build is a forged crank. There isn't one available for it. The 2.0 has a forged crank from factory. The 2.0 and 2006-7 2.4s have factory forged rods stock but if you're going all out, aftermarket forged rods are far superior anyway. Both will need forged pistons but if you're going turbo you'll want to drop the 2.4's 10.4:1 compression. I went with 8.8 Wisecos for my 2.4.

Yes the 2.0 has nicer valve material but again, if you are going all out you can go bigger valves with better profiles and do some port and polishing. Most companies offer 0.5mm oversized valves. I have a shop in Ridgecrest that got 1.0mm Ferrea valves and did a port and polish on the LE5 head. Intake flow was improved 5-8% but exhaust flow was improved over 30%. There isn't a large power gain BUT turbo spool time is improved a lot. I'm running the PAW WR-4 turbo for the 2.0 and everyone I talked to said it was a great turbo but a lot of lag on the 2.0. I have none. This thing spools up fast.

...and that may be because of another factor people never mention when talking about these two engines. The 2.4 is flat out bigger. 20% bigger as a matter of fact. It's almost like throwing a 5th cylinder on the 2.0. The extra displacement will result in shorter spool times on the same size turbo. Couple that with my headwork and I have a lot of power without the lag.

Fueling is another thing. The 2.4 uses port injection while the 2.0 uses direct injection. Both systems can be built to support big power but the LE5 does it in ways you may be more familiar with. I find it easier to upgrade the LE5 fueling system (bigger injectors, bigger in tank pump and maybe a boost referenced fuel pressure regulator modification) than the LNF (slightly bigger injectors, new high pressure and in tank fuel pumps, possibly fuel pump cam and the addition of a single port injector). What I understand though is that with the new high pressure fuel pump on the LNF the fuel cam and additional injector may not be necessary.

So if you're going for easy power now without doing engine internals, there are a number of benefits to starting with an LNF. If you are doing a big build and want to stick with one of the two engines that came with the car, I like the additional displacement and more traditional fueling of the LE5.

BUT...the fastest 4 cylinder in the world is an Ecotec...and it uses the older Gen I engines as its base with the non-VVT heads. So really depends on where your project is headed.
 

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I want to address the issues I've had with my builds. My original LNF K04 turbo system on my LE5 was a solid build. I put it on with 70K miles already on the car. I went 75K more while upping the boost and had no issues with it reliability wise. It wasn't until I was pushing 15 psi (with spikes up to 15.9 on occasion) that the head gasket gave out. Had I known I could conceivably replace the OEM head bolts with ARP head studs without tearing apart the whole top of the engine, it probably would have never failed.

The only issue I tried to address was the power curve. The little K04 turbo starts falling off at 5,000 rpm...on the 2.0. On the 2.4 it started falling at 4200. Boost would drop off from 12-13 psi at 4300 rpm to 8-9 psi at redline. I got an eBoost2 controller to compensate for the boost drop but the turbo was being driven off its map and peak whp was still around 4200 rpm and dropped off to just under 200 by redline. Power came in fast though and there was zero lag.

The new build has a problem in the clutch bell area...may be a bad main seal. Just haven't had the time to get into it but have the parts. We'll see but god the new setup...at only 15 psi mind you...still is making a ton more power than the old setup. Things happen so this is nothing against PAW. Just have to figure it out.
 

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  • The LNF has thicker cylinder walls 86mm bore to support the higher cylinder pressures. The LE5's walls 88mm bore are thinner to accommodate the larger pistons. I had an SC2 with the LLO engine which was a predecessor to the LNF. You could easily determine that it was cast with the lost foam process because the block had the imprints of styrofoam. There were porosity issues with the lost foam process. It is possible that early LNF's in Cobalt's were cast that way but it appears to be sand cast in my 07 Sky. Photo is of lost foam casting marks.
    112719
 

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It has thicker cylinder walls because its a smaller bore and smaller displacement with a universal block acorss the production...has nothing to do with needing to hold higher cylinder pressures. It WILL hold more pressure but that is not the reason why its thicker or why the 2.0 got the turbo. The pressure a 2.4 LEA will hold is more than the engine should ever see unless the OP is doing a tube frame drag build...at which point the LNF or LE5 are not the ideal choice either way. A 2.2 Ecotec has thicker walls than the 2.4 too but they are not boosted.

2.0 liter engines were chosen because in certain parts of the world (looking at you Europe) you pay an additional tax on cars with engines larger than 2.0. This is why the Opel GT was only offered in the turbo version. GM looked at worldwide sales for this platform when building it and a 2.0 turbo engine made sense for that criteria.

The issues with water jacket failures and porosity issues is why I recommend...if you are doing a big build...starting off with the LEA Gen III 2.4 blocks. They are a better and stronger foundation than the LE5 Gen II blocks.
 

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Discussion Starter #20
It has thicker cylinder walls because its a smaller bore and smaller displacement with a universal block acorss the production...has nothing to do with needing to hold higher cylinder pressures. It WILL hold more pressure but that is not the reason why its thicker or why the 2.0 got the turbo. The pressure a 2.4 LEA will hold is more than the engine should ever see unless the OP is doing a tube frame drag build...at which point the LNF or LE5 are not the ideal choice either way. A 2.2 Ecotec has thicker walls than the 2.4 too but they are not boosted.

2.0 liter engines were chosen because in certain parts of the world (looking at you Europe) you pay an additional tax on cars with engines larger than 2.0. This is why the Opel GT was only offered in the turbo version. GM looked at worldwide sales for this platform when building it and a 2.0 turbo engine made sense for that criteria.

The issues with water jacket failures and porosity issues is why I recommend...if you are doing a big build...starting off with the LEA Gen III 2.4 blocks. They are a better and stronger foundation than the LE5 Gen II blocks.
you have been super helpful. This is exactly what I was looking for. I assumed I would get a stronger block with LEA but want sure. I will need to get that shop name that did your port and polish. Something I will need to get done once the turbo is on.
 
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