Can some of you smart guys tell me what changes were made to the carburated LG4 from '82 to '8X. I noticed that it started at 145hp '82, 150hp in 83, 155hp '84, .....

I think one difference from '82 to '83 was the cat. converter is better in 83. Not as good as the L69 though.

thanks,
phil

 

For the most part it was pure "specmanship", as the competition (F*rd) improved from laughable to respectable over the same period. Absolutely nothing whatsoever changed about the parts that motor was built out of from 82 to 85; then IIRC in 86 they went to flat-top pistons instead of dished; and in 87, they went to the roller version of the same lame "peanut" cam, and self-aligning rockers. About the only thing that really changed its actual power output significantly was the compression change from the piston improvement.

 

The cat converter did go through some upgrades from an early (very restrictive) "bed style" cat to a more modern (less restrictive) "brick style" cat. That was the other thing that changed aside from the bump in compression in 85 (from 8.5:1 to 9.5:1).

 

My 86 LG4 had these pistons in there,

 

Oh, SWEET! Just a little detonation on #5, eh?

 

I don't think it was detonation since the car was running pig rich.
I think one of the rings went bad and was getting pounded around in there. But I could be wrong.

 

82 and 83-86 had different cams.

85 got the aluminum intake and 4 bolt cat.

86 got 1 point more compression.

Most 87's got a roller cam and centerbolt heads.



I know everyone here states the 85 was the first year for the bump, but my 85 owner's manual says otherwise. It clearly shows the "H" engine being only 8.5:1. I also have an 86 manual that states the "H" engine had 9.5:1

That would explain the 10HP rated difference between 85 and 86...

 

My cars running pig rich but I'm still hearing detonation at part throttle once it warms up, even on 91 octane. I hope mine doesn't end up like that one. How many miles were on it and did u beat on it? I've got about 140k and I beat on mine.

 

I had 143K miles on mine and beat the living **** out of it.
I had a prom problem and the car was running in limp home mode for the 6 weeks after I finished the TPI swap till the motor died. Found out the day before the motor died that I had burned a bunch of bad chips for my car.
It still was fast as ****, 14.1 @ 99mph in limp home mode.

 

What happened when it died and how was it running before that? What exactly does limp home mode do? I hope I don't wreck my engine. It seems like its in good shape, no valvetrain noise or anything, oil stays gold for 6000km between oil changes with mobil 1. Only problem is tuning. Maybe I need a carb rebuild or just a new float. I get a bad smell when I drive it hard and black smoke sometimes comes out. When I stop hard the car feels like its flooding out for a second.