What were the biggest probs with the LG4? I did some mods (in sig.) but i know there have to be bigger things? lik e exhaust or anything? I'm gonna be running into some money soon so what should i do to it?

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87Camaro RS
305 carb.
K&N air filter
HyperTech Stage II chip
160 Thermostat
Autolite wires and NGK plugs

 

Exhaust, cam, air cleaner, heads - probably in that order. Although picking between the first three is just about moot - they're all bad, change them all.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam and intake, World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. 0.030 over 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlock header mufflers, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, LT MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Best 15.1/95.5 @ 5800' Bandimere.

[This message has been edited by five7kid (edited June 20, 2001).]

 

The Lg4 is not a performance oriented engine.
The other 305 "number evades me at the moment" is more performance oriented.
Differences are.
LG4- Dished pistons and crappy cam.
The HO 305- flat top pistons and some have provisions for roller cams.
If you changed the pistons from an lg4 to flat tops and swaped a cam in it would run alot better but them it would be easyer to go for a 350.
SSC

 

57 said it, although i'd get rid of the stock air cleaner first just cuz it's cheap and easy. It's a shame to waste the KN, but the stock housing holds no performance value, not only is the snorkel restrictive, but the top plate is too close to the carb to allow real airflow.
Exhaust and cam will prolly yield similar gains. Also, if you have 2.73s, gears should be at the top of the list too, you will never get it to run respectably w/ 2.73s. 3.08s aren't nearly as bad. Not sure what 87s got.
...ed

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Ed Maher - Moderator @ The Carb Board
92 Z28 Convertible - Quasar blue / Tan top
LB9 4L60 GU2 G80 - stock, soon to be sleeper
-=ICON Motorsports=-

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die

 

L69's were the 305 HO motors and they were good for around 160hp. The LG4 started at 145(?) and went up to 160(?) If you are doing work the head, cam and exhuast are all good. If you want to make power though, scrap the quarda jet and get a holly/edelbrock carb and a good intake. It will be a lot easier to tune and you will not have to deal with the computer which is a plus when you modify that type of car.


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--Spyder--

1992 Camaro RS
LO3, T-56,centerforce clutch, ported and polished 305 TPI heads, Edelbrock Performer Intake, 14X3 Open Element w/ K&N, hiflow cats with two pipes going back, AC delete, SMOG delete, alu drive shaft, 3.73 posi, 160 stat w/ fan switch, Ed Wright Fast Chip, MSD Igniton Coil, STB, Subframe connectors, KYB AGX, Eagle GSC, and poly bushings.

1982 Z-28
This July 350 4 bolt, ZZ4 cam and heads and the rest to still be purchased. If you have anything e-mail me.

 

If you're looking to go fast, pretty much the whole engine is a restriction. It doesn't flow!!! For Mods, anything having to do with induction, exhaust will help. I would do, Intake manifold, Headers, camshaft, and take the heads off and get a valve job done. A LG4 can be worked up to about 325 hp max.

The last thing I would do would be mess with the heads, and you're probably better off getting aftermarket heads, and by that time you should get some that will work on a 350 and use it for that.

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--Steve S--
1984 Trans Am 305 LG4, 5 speed Daily Driver, Flowmaster 80 Series
Holley 600 cfm & vacuum advance
Soon: Edlebrock Intake & TES

 

Cam Intake, exhuast.


Lookit the sig.

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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver 14.82 @ 91.1
Reader's ride -> My Ride

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

Dual snorkel from an HO car, K/N filter, swap the secondary metering rods for some a bit leaner, mess with the air/valve tension, set the timing to four to six, cam, intake, high-flow cat and cat back system. The LG4 is much maligned, but given what it is, with a few mod and not a whole lot of expense, you can smile like a cat.

JamesC

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