Supercharged Engine Rebuild

jcdman

jcdman

Active Member
As the title implies I plan on rebuilding my 05 supercharged motor. Currently has 160k miles so it seems like an appropriate thing to do while I wait for my kit. I don't plan on increasing power way beyond stock, maybe a small tune later down the line but I wanna keep it solidly reliable. Unfortunately I'm not considering forged rods/pistons, budget doesn't allow that right now. I've built a few motors before but I'm not too familiar with the Ecotec platform, so any recommendations on things to swap out would be appreciated!
 
Ross

Ross

Goblin Guru
Ecotec LSJ maintenance items:
- check if your electric water pump is working for the intercooler. Common for these to wear out their brushes.
Replace the timing chain guide bolt with a Dorman bolt.
If the stock bolt is broken off:
- your cam chain is stretched, and needs replacing. Sprockets too.
- you should probably drop the pan, fish the broken parts out of the bottom of the pan. I had the broken bolt, and plastic from the broken cam chain guides.
If your timing chain tensioner has a flat top, replace it with a tensioner with the new design, bump top.

Performance items:
I bought HP Tuners, and have been learning my engine.
HP Tuners showed me that I was getting bad data from a $25 MAP sensor. Replacing that gave me a noticeable performance gain. 30% to 50% gain?
HP Tuners showed me the stock injectors (32lb green injectors) are at 100% duty cycle at the stock redline.
So if I do any performance upgrades, I need bigger injectors. With bigger injectors, I can raise the stock 6500 RPM redline to 7200, as I have heard the stock valvetrain is good for that. Also can tune the engine for E85 fuel, and gain some performance, so double win with injectors.

I have bought
- 82lb Bosch EV14 injectors (These might be too big for idle... but I am hoping the split spray and Bosch technology allows it to idle)
- 2.9" pulley (for 93 octane) and a 2.7" pulley (for E85), a bigger idler pulley to help use up some of the extra slack in the 6 rib belt.
- balance shaft delete parts.
 
Last edited:
jcdman

jcdman

Active Member
Ross said:
Ecotec LSJ maintenance items:
- check if your electric water pump is working for the intercooler. Common for these to wear out their brushes.
Replace the timing chain guide bolt with a Dorman bolt.
If the stock bolt is broken off:
- your cam chain is stretched, and needs replacing. Sprockets too.
- you should probably drop the pan, fish the broken parts out of the bottom of the pan. I had the broken bolt, and plastic from the broken cam chain guides.
If your timing chain tensioner has a flat top, replace it with a tensioner with the new design, bump top.

Performance items:
I bought HP Tuners, and have been learning my engine.
HP Tuners showed me that I was getting bad data from a $25 MAP sensor. Replacing that gave me a noticeable performance gain. 30% to 50% gain?
HP Tuners showed me the stock injectors (32lb green injectors) are at 100% duty cycle at the stock redline.
So if I do any performance upgrades, I need bigger injectors. With bigger injectors, I can raise the stock 6500 RPM redline to 7200, as I have heard the stock valvetrain is good for that. Also can tune the engine for E85 fuel, and gain some performance, so double win with injectors.

I have bought
- 82lb Bosch EV14 injectors (These might be too big for idle... but I am hoping the split spray and Bosch technology allows it to idle)
- 2.9" pulley (for 93 octane) and a 2.7" pulley (for E85), a bigger idler pulley to help use up some of the extra slack in the 6 rib belt.
- balance shaft delete parts.
Click to expand...
That's pretty thorough. Sounds like the whole timing system needs a good look through. What do the different pulley sizes affect? Based on your choices for fuel I'm assuming a smaller pulley equals more boost so a higher octane fuel is needed?
 
R

r3drckt

Goblin Guru
jcdman said:
That's pretty thorough. Sounds like the whole timing system needs a good look through. What do the different pulley sizes affect? Based on your choices for fuel I'm assuming a smaller pulley equals more boost so a higher octane fuel is needed?
Click to expand...
That is correct. Smaller pulley means more boost. That means higher octane fuel like you mentioned. The timing chain is probably the only issue with the Ecotec engines. Everything else on the lsj is stout enough that it’ll last if it’s kept at factory tune and maintained regularly.
 
comegetjoe

comegetjoe

Goblin Guru
Ross said:
Ecotec LSJ maintenance items:
- check if your electric water pump is working for the intercooler. Common for these to wear out their brushes.
Replace the timing chain guide bolt with a Dorman bolt.
If the stock bolt is broken off:
- your cam chain is stretched, and needs replacing. Sprockets too.
- you should probably drop the pan, fish the broken parts out of the bottom of the pan. I had the broken bolt, and plastic from the broken cam chain guides.
If your timing chain tensioner has a flat top, replace it with a tensioner with the new design, bump top.

Performance items:
I bought HP Tuners, and have been learning my engine.
HP Tuners showed me that I was getting bad data from a $25 MAP sensor. Replacing that gave me a noticeable performance gain. 30% to 50% gain?
HP Tuners showed me the stock injectors (32lb green injectors) are at 100% duty cycle at the stock redline.
So if I do any performance upgrades, I need bigger injectors. With bigger injectors, I can raise the stock 6500 RPM redline to 7200, as I have heard the stock valvetrain is good for that. Also can tune the engine for E85 fuel, and gain some performance, so double win with injectors.

I have bought
- 82lb Bosch EV14 injectors (These might be too big for idle... but I am hoping the split spray and Bosch technology allows it to idle)
- 2.9" pulley (for 93 octane) and a 2.7" pulley (for E85), a bigger idler pulley to help use up some of the extra slack in the 6 rib belt.
- balance shaft delete parts.
Click to expand...
Your level of knowledge is astonishing sometimes :)
 
C

CajunJeff

Active Member
Replace your laminova O-rings... they tend to wear out over time. Cheap and easy to replace if you already have the engine out. My car (also 160K miles) blows smoke under boost because the O-rings are going bad.
 
jcdman

jcdman

Active Member
CajunJeff said:
Replace your laminova O-rings... they tend to wear out over time. Cheap and easy to replace if you already have the engine out. My car (also 160K miles) blows smoke under boost because the O-rings are going bad.
Click to expand...
Laminova o-rings? I'm not familiar with those, where are they located?
 
Corgithulhu

Corgithulhu

Well-Known Member
The "Laminova" would be the heat exchanger that the compressed air passes through. It looks like a clamshell on the front of the engine. There are four tubes that have O-rings on either end when you pull the end cap off.

If you search something like "cobalt SS laminova tubes" on google images, you'll see a ton of pictures.
 
Waterdriver

Waterdriver

Goblin Guru
Laminova tubes are a part of the heatexchanger system and located inside the manifold.
Cool coolant passes through the laminova tubes to extract the heat out of the compressed air from the supercharger, lowering the intake charge going into the cylinders. Heat = bad. Cool=good, more hp, etc.
If the laminova tube orings start failing, you could start losing coolant into your manifold and cylinders. Lose boost pressure by it leaking into the heatexchanger coolant system. Or both.
Note: This heatexchanger coolant system is a completely separate from the engine coolant system. They do not share the same coolant.
 
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