LT1 - High Mileage - Old School

How To Create A Reliable and Powerful High-Mile LT1

Rick Jensen Jun 1, 2005 0 Comment(s)

Step By Step

Comp Cams 1.6 Rocker 1418-16 $186

Comp Cams Timing Chain, Pushrods, Valve Springs/Retainers/Locks 3206, 7940, 983-KIT $469, $124, $120

MSD Blaster Coil, Super Conductor Wires 8226, 32143 $44, $76

LT1 F-bodies have good looks, great performance, and huge potential. And lately, they're getting damn cheap, too. Look on some of the big trader Web sites and you can find a running example for under three-grand! So if you're in the market for a high-mileage Z or 'Bird, or have one already sitting at home, lucky you.

Of course, most of the low-ducat rides out there have between 80,000 and 170,000 miles on them. That means some of the car's original components will, by this time, be in sorry shape. Along with those low prices comes a catch: the LT1 engine was the bridge between the archaic GM small-block and the futuristic Gen III/IV. This torquey work-in-progress produced good power, but was more complex than it had to be, and suffered because of it. Oftentimes, newbies find themselves way over their heads when something goes wrong.

GMHTP wanted to update and enhance an LT1, and 83-year-old speed demon King Rhiley offered up a 119,000-mile Z28 that was so near factory it was sick. It's go-time.

We approached Chatsworth, California-based Los Angeles Performance Division to do the work. This crew, which works out of an enormous Canoga Avenue shop with several lifts and a Dynojet, specializes in Gen III Corvette performance. However, they were still willing to tear into the LT1 motor in the name of science.

The plan was to baseline the car on LAPD's dyno, replace the worn-out OEM stuff, then bolt up some high-quality speed parts. Wearing only an airfoil and air intake, 236 horses and 280 lb-ft of torque showed at the rear wheels. The baseline dyno was without incident, but due to the LT1's age and complexity, we hit a few bumps later on. Read on to see what happened--and learn how to make aging LT1 upgrades hassle-free.

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