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Thread: LNF-LDK-LHU Compare

  1. #1
    Senior Tuner cobaltssoverbooster's Avatar
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    LNF-LDK-LHU Compare

    So here it is, the answers to one of the newest big unknowns.
    I personally own a A20NHT Ecotec Motor and have found a bunch of new information about it. Most of it through a minor tear down to verify parts for performing a swap that would allow me to run the current Bosch LNF ECU.

    Engine Block Series Numbers will be found on the Oil Filter pod. There is a flat machined spot where the manufacture stamps all the engine data into the casting. If having a hard time reading spray the pad with parts cleaner and scrub with brass wire brush until clean, then use a brush and some paint in a dark or medium bright color and paint the entire machined pad. the paint i used is the same paint that can be found at a hobby store for painting hobby model parts. you may also be able to use touch-up car paint or a paint pen if you have those. two best colors to use would be red or black, dark green does show well too. after you apply said paint use a paper or shop towel (dry) and wipe the pad clean leaving the paint to dry in the depths of the stamped numbers/nomenclature. Take a picture and keep it for reference or spray parts clean and wipe off remaining paint to return to a completely factory state.


    LNF:
    86x86mm bore x stroke
    9.2:1 compression
    3 lobe hpfp takeoff on the intake cam
    white fuel injector seals (non ethanol compatible)
    sleeved cylinders
    retarding intake adjuster and advancing exhaust adjuster
    forged crank and rods
    sodium-filled stainless steel Inconel exhaust valves
    low-friction cast aluminum pistons with oil squirter's (gen 1 non adjustable)
    5qrt oil system

    A2NFT/A20NHT LDK (nickname Franken Blocks)
    86x86mm bore x stroke
    Upgraded girdle (material added here and there to prevent flex)
    3 lobe hpfp takeoff on the intake cam (*still doing comparison testing to verify changes)
    internal spring modification (measure higher pressure on the A20NHT spring until more are inspected not considered upgrade)
    black fuel injector seals (ethanol compatible)
    Non-Sleeved cylinders
    retarding intake adjuster and advancing exhaust adjuster
    Exhaust cam driven Vacuum Pump for Brake Booster System (may be removed and blocked off in some engine swap situations)
    forged crank and rods
    sodium-filled stainless steel Inconel exhaust valves
    low-friction cast aluminum pistons with oil squirter's (gen 2 adjustable and from tear down measurements looks like a slight amount of material dimension changes on the underside but could be machine %error so not chalking it up to an upgrade yet)
    6 qrt oil system with level sensor

    LHU
    Same as the LDK with the exception to new part number fuel injectors with black ethanol compatible seals. Slight pump flow modification on hpfp and ECU from Sidi with Ethanol Compatibility. (more tables for controlling blending of ethanol via use of a factory ethanol % sensor.)


    As i was going through the engine replacement stages many questions arose:

    1) With the new exhaust camshaft design for vacuum pump drive did they change the profiles?
    A) Yes, although minute in change the cams have a slight duration timing change. at this point from only inspecting one set of camshafts i wish to not disclose the information until it can be further verified.

    2) The cylinder head has been modified visually in a minor ways, did they change the oil passages to the cam phaser's?
    A) No, to save money the oil passages are left in the same operation so they could utilize the same cam phaser design. The cam phaser's have gone through revisions over the years so make sure yours are up to date if you replace them on any DI Ecotec Motor.

    3) Can i use the new vacuum pump assembly that is offered as an upgrade and found standard issue on the Buick Regal's?
    A) Yes, if you purchase the Buick Regal brake booster vacuum line assembly you can use that with minor modification. In my case i used 1/4" ID tubing and flared the ends with a double fold to connect tubes to the t connector so i can connect the vacuum pump into the system and i utilized an crimp that puts a bulge in a short distance after the end of the tubing so when i connect the vacuum hoses it does not allow the hose clamp to just slide off the end if movement occurs.

    4) Will i be able to utilize the LNF Bosch ECU? The money question of the whole post...
    A) YES!!!! the crank reference wheel and the cam phaser's work the same in the LDK/LHU as the LNF. This allows a simple motor swap to take place. All the connectors for the engines sensor array and output drivers are exactly the same on the LDK/LHU as the LNF making the swap as easy as it could possibly be. On the LDK/LHU you may be the lucky owner of a deepened oil pan which takes the 5qrt LNF system capacity and raises it to a 6qrt system. If you have this oil pan you will notice a new sensors which is located on the right side of the motor on the side of the oil pan. (in easy terms it will be on the intake manifold side of the motor, located on the side of the oil pan about even to where the drain plug's location is on the opposite side)

    5) Well with the new upgrades what will need calibrating and should i pre-tune any tables before i start the engine?
    A) With the new upgrades and update changes in the motor you don't need to pre-tune any tables. Later down the road you may find the camshafts prefer to be located in a different position which could be a result of the profile change that hasn't been officially verified. Injector changes may be required but wont be verified until you start logging the car around town and find out the total percentage of trim skew which is simple and quick to adjust.

    6) Do i need to break in the motor i just purchased and whats the recommended way?
    A) Each motor is engine dyno tested at the factory to meet quality control standards but it is up to the owner if they decide that was enough break in or not. I personally recommend flashing a tune that is non-gm stage kit where you have re-calibrated for 3bar sensors and updated the turbocharger tables to match those out of the stage kit. Keep the tune as factory as possible with the exception to tuning the maf curve and base tables so your fuel trims will be on point for the new motor. Run NON-Synthetic oil in the motor for the first 500 miles or tank and a half of gas keeping an eye on oil pressure and engine temperature. afterwords perform a complete oil and filter change switching back to synthetic oil as recommended by factory. during this time you will prevent the motor from idling for long periods of time and vary the load on the engine in a range of 2200-3500 rpm. stay out of boost in pressure ranges over 8-10 psi. (in the DI Ecotec motors 10 psi is common amount of boost for climbing hills so if you live in a steep hilly area just try to limit the max boost by changing gears even if it means going over the 3500 rpm range.) unless you took the plunge and already have the GM Stage kit flash then i recommend for you to just revert to the most factory base and while driving sort out fuel trims to satisfy the new engines airflow requirements and follow the same beak-in procedure from before.
    This technique helps the parts break in more efficiently by increasing the drag coefficients. With Synthetic oil the molecules are small enough to filter through the gaps and lubricate the tightest of clearances between rotating assemblies. This reduces the drag Coefficient and floats the parts over each other unlocking hp, extending parts life, and lessening the effects during the break-in process. We switch to regular Non-Synthetic oil because its molecules are bigger and don't fill into the smallest of places as well as the synthetic does. This allows the parts to have a higher friction coefficient and during the break in procedure causes a minor sanding/polishing of parts. This is most effective in properly seating the rings after assembly of a brand new engine. Reverting to regular oil for a short period of time will not hurt your motor and will allow parts to be properly seated and make for a better seal when they are pushed to the limits of our calibrating techniques.

    *With that said the sanding action that takes place is not on a level you can measure via grades of sandpaper. This contact is more like a polishing effect that allows the parts to reach their final dimension and provide the best seal possible for the maximum time possible for the engines life. More info can be researched using the internet as this technique is not new to the engine building industry.

    Hope this helps anyone trying to figure out what motor to purchase and what will be the benefits of each motor. As new information becomes available regarding comparisons and upgrades they will be added so feel free to share your findings with us.
    Last edited by cobaltssoverbooster; 07-29-2013 at 12:45 AM.
    2000 Ford Mustang - Top Sportsman

  2. #2
    You have been busy CBSSOB huh? LOL awesome info!!!

  3. #3
    Senior Tuner cobaltssoverbooster's Avatar
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    i found a little free time last week but unfortunately i have once again hit the speed bumps.
    2000 Ford Mustang - Top Sportsman

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    Great info. Thanks the sharing buddy
    09 RY Cobalt SS Coupe - 19K miles - Bolt ons + 7163 ZFR, HP tuned on ethanol

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    Sold - 09 RY Cobalt SS Sedan

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    in my car i have a lhu engine. the most problem will be the can bus (gmlan) wenn you change to bosch.

  6. #6
    Senior Tuner cobaltssoverbooster's Avatar
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    i have a lnf harness and computer so what we do is plug the whole thing in and no problems with can because its already set up for the computers in use. thanks for the information though, someone will need it!
    2000 Ford Mustang - Top Sportsman

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    Great info here. Good job. I have a few questions in mind.

    As for the vacuum pump stated as a "upgrade" on the Buick. How will this benefit us LNF Cobalt's? Is this something similar to what Powell designed to prevent valve coking/gunk? Or am i overthinking this?

    Waiting on camshaft specs. Would be nice as a alternative to ZZP's expensive cam set.

    Does the slight pump flow modification on on the hpfp provide any hp increase? Think ZZP's larger cam fuel lobe for hpfp.

  8. #8
    Senior Tuner cobaltssoverbooster's Avatar
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    the powell part you speak of is a catch can. it catches the oil and separates it into a can so it doesnt get sucked into the intake manifold and coat the valves. this coating collects carbon during reversion on the overlap cam event.
    2000 Ford Mustang - Top Sportsman

  9. #9
    Advanced Tuner |V3nom|'s Avatar
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    i thought the ecms in the ldk/lhu were supposed to be better/easier to tune? why use the difficult lnf ecm?
    2008 Sky RL

  10. #10
    Senior Tuner cobaltssoverbooster's Avatar
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    why.. because i dont have to finger fuck my oem wiring harness to make it work. plus, it may not be perfect but i can still put the same power down.
    2000 Ford Mustang - Top Sportsman

  11. #11
    Advanced Tuner |V3nom|'s Avatar
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    if you put the same power down why swap to begin with?
    2008 Sky RL

  12. #12
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    Quote Originally Posted by cobaltssoverbooster View Post
    the powell part you speak of is a catch can. it catches the oil and separates it into a can so it doesnt get sucked into the intake manifold and coat the valves. this coating collects carbon during reversion on the overlap cam event.
    Please explain more on this. Not the powell part but the Buick part.

  13. #13
    Senior Tuner cobaltssoverbooster's Avatar
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    Iirc the vacuum pump only helps supply vacuum to the brake booster not the valve cover purge

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    I see, so its to benefit braking?

  15. #15
    Senior Tuner cobaltssoverbooster's Avatar
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    when i go back to the dealership i will get a printout of the parts diagram so you can see where it goes.
    2000 Ford Mustang - Top Sportsman

  16. #16
    Senior Tuner cobaltssoverbooster's Avatar
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    got new information from my recently swapped personal dd cobalt ss.

    the clutch on a manual lhu is the one the sky has, it is a floating flywheel with clutch housing. if you have an aftermarket clutch with good condition you can swap the entire clutch assembly to the lhu. bolt patterns for the flywheel are the same as a cobalt/hhr lnf.

    the real name for the vacuum pump driven by the cam according to the dealer is called a booster pump. it has a special line going from the manifold to the pump then the brake booster. if you buy the original manifold to booster line for a lnf cobalt then the price according to the california dealer was 130$ for the preformed hose. the preformed plastic tubing for the new booster pump assembly is abo 50$ according to the same dealer. both parts will most likely be special order back to the factory.

    the crank pulley is a 5 rib belt drive and the alternator and ac pump on the cobalt ss 2008 si a 4 rib so make sure you use put the belt in the right spot on the crankshaft. for my motor this was all the way to the back (right up against the timing cover).

    i have a bosch lnf ecu and harness running my new lhu and it is sound and rocking. no numbers or power tunes for it yet since i just started the break in process but so far its very smooth with just a standard stock tune with minor changes.

    for the cooling system there is a banjo on the top of the motor-by the timing chain side of motor- this is where a coolant hose to the radiator is and there will be a banjo routing a tube to the turbocharger. on the lhu this tube will be secured with a standard banjo bolt. on the cobalt and hhr the banjo has a modified bolt with a coolant hose takeoff on the top that routes back to the coolant reservoir. this must be swapped over to retain the factory coolant system standards.

    the fuel lines are standard use the special tool to separate the hose from the damper line at the hpfp. if you don't use the special connector tool make sure you pull the 4 tabs inside to connector out just a tad so it can lock onto the new assembly correctly.

    the lhu charge pipes bolt directly to the turbo using a 2 bolt flange. if you want to use your original charge pipes which i highly recommend due to restrictions and fitment, you will have to transfer either your entire turbocharger (only if the crate engine was not supplied with one) or you will remove the outlet adapter from the original and bolt it to the new one since it utilizes the same 2 bolt flange pattern.

    the oil pan will have a sensor in the side if you utilize the factory wiring system you will not have a connector for this sensor. leave it in place for obvious reasons. the sensor is supposed to be an oil level and quality sensor so if you find a gauge that can read that type of signal then let us know.

    i have powell racing solid motor mounts and i will say this... when you talk to someone and they say oh it will rattle a bit....just expect everything on the car to vibrate enough for your eyes to see a visual shift in part position. these are both awesome parts but if vibrations and a motor hum through the chassis are something you wish to not have then these parts are not for you.



    alright with that said i have two final notes:
    1) during your break in period do not tune the car for more than 18 psi, your motor needs about 1000-1500 miles with varying loads that do not meet an extreme stress level. if you keep the timing around 15* max you will find a good street use power level that will not push the load limits during break in. this time at break in will also allow you a few logs of valuable camshaft shifting information. use this time to shift your cruising and lower load camshaft positions and dals.

    2) if anyone wishes to have a stat up tune for this particular setup then i am sorry but i will not supply one to you. a basic lnf tune works fine and if you don't understand how to make one then you haven't study enough information to get going yet. the lnf information has been around since late 2008 early 2009 when support was released and the information from that time is still around and followed by everyone so please take the time to read it a few times first.
    Last edited by cobaltssoverbooster; 08-21-2013 at 06:48 PM.
    2000 Ford Mustang - Top Sportsman

  17. #17
    Senior Tuner cobaltssoverbooster's Avatar
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    Lhu injectors spray 10% more fuel for the same pulse values an LNF runs.

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    cobaltssoverbooster,

    I am helping a friend make this engine swap as well. We are currently transferring parts between old(LNF) and new motors(LHU) and hoping to have this new motor in today. The only problem we have been unable to solve is what to do with the new Vacuum pump. In trying to understand your post above I can special order a plastic hose to connect the vacuum pump to my brake reservoir? Would you happen to have a part #?

    Lastly what is your opinion on the LHU's unsleeved piston walls strength and durability? vs LNF?

    Thanks again.

  19. #19
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    Quote Originally Posted by cobaltssoverbooster View Post
    Lhu injectors spray 10% more fuel for the same pulse values an LNF runs.
    I wonder if that's the fuel injector that ZZP was broadcasting about on their FB page recently.

  20. #20
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    ^probably