LG4 Tune up / performace enhancement
 

All,

Following a posting on the electrical board about "tuning" an LG4 one of our members asked how I did mine. I thought I'd share this since many third gens came with this motor. I'm no expert but I tinker. An LG4 will never beat an LSx mod for mod (I don't compare modded to stock) without the phrase "drive off a cliff", but there are things you can do to make it quicker and more responsive without an engine rebuild. You can find a lot of this information on thirdgen.org. Search "LG4 tuneup" or "LG4 buildup".

You are not going to be able to just plug in a lap top or scanner like you see on SpikeTV's powerblock since our engines do not have that advanced conputer control. There may chips for the carb but I dont know too much about them.

The first thing you need to do is properly tune up your car. Without the equipment you have properly working there is no need to add additional equipment. I have not done the exhaust and cam but may in the future

Step 1: LG4 Tune up

1. Plugs / wires.
2. Cap / rotor / ignition module.
3. Air filter.
4. Fuel Filter.
5. Carb cleaner (put this down the carb with someone else revving the engine at 2500 RPM).
6. Check / change all of your fluids.
7. Get your alignment checked and tires properly inflated, all 4 tires.
8. Use a bottle of "dry gas" for your gas tank.
9. Check / change the belts and hoses.
10. Check / replace the battery and alternator. Most auto parts stores will do a free charging system check.
11. Fix and fluid / oil leaks.
12. Get your brakes checked and replace any worn components. You might have to replace the rubber hoses with steel braided ones.
13. Perform a cooling system check.
14. Replace the O2 Sensor.
15. Adust timing to spec or whatever advancement suits you.

Step 2: Breathing

The most restrictive pieces of the LG4 is the single-snorkel air cleaner and tiny exhaust. Get the dual-snorkel or make a homemade version. Get a header-back sysem for either an L69 or TPI setup. The dual snorkel and L69 will give you the breathing room and still be emissions legal.

Step 3: Cam

Replace that stock peanut cam. Thirdgen has many threads on cam selection.

Step 4: Carb / Intake

The folks on third gen seemed to have mixed opinions on this. Some felt it ws a waste of money, especially considering emissions issues, others felt you could make changes. On this one I'll leave it to you. Once I complete step three I'll see how much power I have.

Good luck.

don't worry about spending money on a dual snorkel set up. just get an open element and be done with it. you can fit a 14x3 flat base below the stock hood pretty easy with the stock intake.
for cam i would sugest taking a look at comp cams extreme enegy line. for a mild to moderate 305 an XE268 or maybe an XE274 if you want a bit more would work great.
carb and intake i would jsut suggest keeping it simple. something along the lines of a performer would be just fine. add a holley 650 or use the stock CCC with some tuning and you will be throwing down nice numbers emissions legal and extremely driveable.

I want to use my stock carb. where do i get that tuned?

8 ) Dry Gas- great way to pour 5$ of nothing into ur tank, that stuff desont work. and if u really wanna clean out a motor, get some GM Top End Engine cleaner, that will get all the carbon out

Does seaform work as good as that?

seafoam worked great on my old cavalier. car got way better mileage and ran tons smoother.

I heard seafoam can free up some particles in the engine that are potentialy dangerous to the motor

There are 2 or 3 guys over on Thirdgen.org that kept their original ccc q-jets with some minor tweaks when they swapped in mild 350's and are running low-mid 13's and still getting 23-24 MPG. There is now way to achieve that combination of performance and mileage by dumping the computer carb for a Holley. If the car is going to be a daily driver or weekend cruiser I think money would be much better spent in areas other than a carb and dizzy swap.

Steve's carb shop in lyndhurst did mine

he knew all the free mods from thirdgen.org and opened the av to make the carb flow 750 cfm

he also has an assload of rods and hangers to help tune the secondaries.

we also put a quicker secondary pull off on it

im selling my carb soon lemme know if your interested

How much?

use PM's for that, no need to muck up a thread. :)

Ignition module - why? I didn't see any mention of a performace module. They work or they don't. I would think a quality coil upgrade is more useful.

The dual snorkel is nice if you have it. Engine air is hot. Firebirds can use the turbo hood & get the operating vent setup - even better. When you are trying to squeeze blood from a stone, might as well squeeze everything you can out of it.

I'm not sure the carb cleaner will do much for a daily driver. One that I have seen work is old school: the old hand over the carb (in a choking manner) & give it throttle to pull the **** out of all the passages. I've seen that work for older Qjets.

A good old Performer EGR manifold should help. I wouldn't do a cam w/o a manifold too. And some roller rockers. New cam should bring new valve springs to the game too, and stem seals. Better heads would be nice too. I see those 305 world heads for sale a lot. There used to be a great carb guy in Trenton, I forget his name. Airflow Carbs, maybe.

Electric fans are a good bet for cars with clutch fan setups. Use a lower temp switch, tstat & get a hypertech to correct for it. (edit: I am out of the loop on chips-sounds like guys around here can burn them now too)

Some of that stuff sounds like a dealer hit list - check battery & alternator? Plus other non-engine stuff on the list. Stay focused. That sounds more like a winterization check.

I was so happy my LU5 305 blew up 3 weeks after I bought it! :D

i heard seafoam is the cure to erectile dysfunction

I heard that too!

and yes, the list might sound like a dealer hit list (partly because it is) but all that stuff is important. I think what he is trying to do is give a check list to make a daily driver run better and also help performance.

seafoam or GM top end engine cleaner works the best 2