Ecotec burning oil
 

Hey all,

I've been reading up on combustion efficiency, mixture motion, mixture preparation, et.al. I want to modify my LE5 Ecotec for improved FE, and I noticed that every picture of the heads is coated in heavy carbon. I hope that the Ecotec is reasonably efficient, and that it's not soot buildup. Instead, I believe it's oil from the PCV system. The intake manifold is coated with oil, as well as the ports (up until the fuel spray), but the air intake and throttle body plate are clean :/

http://i.imgur.com/aQDfo.jpg

First order is to fix the oil burning. I've seen some catch cans that are supposed to eliminate this almost entirely. Oil doesn't burn too well, and it masks other symptoms of poor combustion.

RX Catch Can w/ Single Check Valve

I would like to port and polish the head, as the stock ports are pretty rough. Reducing pumping loss is a 1:1 FE improvement. I work with a very talented porter, and I just have to pay for parts, and R&R.

I want to install flat faced valves, to minimize shadowing, and improve the burn. I'm looking to increase compression well beyond 11.0 (from 10.4:1). It should be fine with 87 octane at idle/cruise, when the intake closing is retarded, and dynamic compression is low. It will improve efficiency, as well as throttle response.

I have HP Tuners, and enough credits to edit my ECM. I've considered lean burn (16.1:1) to improve FE by ~10%. fwiw, stable combustion, and a stronger ignition will enable even leaner operation.

Is your ecotec direct injection or port fuel injection?

It's the LE5 2.4L port fuel injected.

The DI heads have a better chamber, but won't work on the LE5. The 2.0L supercharged LSJ has port injectors, but no VVT.

There may be some welding involved...

I finished installing a compressor air filter on the PCV hose (no valve on the stock engine). It's not plumbed to the intake atm.

I chopped off the helmholtz chambers from the engine cover. Now I have more room, and l can see the engine. I used pieces of the original cover to close in the "short ram" intake. I now know the joys of JB Weld :)

Next, l will paint the valve cover. Painting the valve cover is for more than just looks. I'm getting used to quickly R&R parts on my daily driver. I'm not confident to degree the cams myself yet. I can get the heads ported for free, but I have to put it together myself, or pay someone else. I have to get it all done in a day...maybe two.

It turns out my valve guides have an obscene amount of play. I'll replace them and the valve seals. Loads of issues with the head. I'm detailing the process on the malibuforums.

Ported heads - Chevy Malibu Forum: Chevrolet Malibu Forums

My goal is lower fuel consumption. I will post results when l can.