
Express Mouse
Rebuilding a ZZ3 to Make 485 HP
By Sky Wallace
photographer: Sky Wallace
Regular CHP readers may recognize Larry Richards as that guy who has been top-speed racing in Nevada at the Pony Express 100 in his immaculate '87 Monte Carlo for the past couple of years. But neither of his outings there, unfortunately, was exactly flawless.
In the '97 race, Larry had the tire pressure set too low, resulting in a high-speed blowout that also took out some of the bodywork on the right rear. In 1998, the tire pressure was carefully checked before the race, only to have the ZZ3 crate motor shatter the valvetrain after an extended period of wide-open throttle.
According to Michael "Ron" Slover, Richards' navigator, his immediate post-race investigation consisted of slightly lifting up one valve cover and peeking under it, then saying only, "Ooh, it's ugly!" before putting the valve cover right back down. The postmortem concluded that the hydraulic lifters had pumped up during the extended high-rpm exercise and provoked the inevitable carnage, which was luckily confined to shattered valvesprings and lifters.
At this point, the need for a better Pony Express engine was painfully obvious. Scrapping the hydraulic lifters was the first decision, so the step up to a mechanical roller cam was an easy one. Since there was no damage to the block, Bow Tie heads, or crank, retaining them also seemed to be the logical choice. And since this car is no trailer queen, maintaining a reliable pump-gas motor was an essential part of the equation.
When it came time to pick an engine builder to put everything back together, it didn't take long to find a volunteer. Besides being the Monte Carlo's navigator, Slover is also the in-house porting wizard at Reggie Jackson's High Performance (RJHP) in San Bruno, California. RJHP's manager and engine builder John Gianoli readily agreed to take on the Mouse motor's resurrection.
Once the wounded motor arrived at Gianoli's shop, it was dismantled and all the broken and useless pieces hit the trash can. Gianoli then decked and align-honed the block while the cylinder bores were cleaned up by 0.020 inch, just to conform to Gianoli's preferred clearances and set-up.
Gianoli consulted with Glenn Steyers of Crane Cams, who designed the roller-cam profile specifically for this application. Steyers plotted the camshaft on Crane's computer software and chose Crane's H11 tool-steel "endurance" valvesprings to avoid further problems. The cam is ground out of an 8620-steel billet with a cast-iron distributor gear pressed onto the back of the cam. This avoids the problems associated with the use of a bronze distributor gear that, according to Gianoli, would be junk within 1,500 miles.
While the machine work progressed, Slover began massaging the heads with a standard RJHP street/strip porting job. The spring seats were also machined larger to accept the endurance valvesprings (230 pounds on the seat; 610 pounds open), which have a larger diameter and different installed height than the stock springs. The heads were then stuffed with Manley severe-duty valves (2.02-inch intake; 1.60-inch exhaust) that are 0.100 inch longer than stock, with the rest of the valvetrain components (roller timing-chain set, lifters, pushrods, rocker arms, titanium retainers) also coming from Crane's catalog. The valvetrain action is hidden from view under a set of aluminum Billet Fabrication valve covers that are fitted with internal spring-oiling tubes.
Other hardware finding its way into this now-353-inch small-block came from a variety of sources. ARP provided all the fasteners used throughout, and an Aviaid oil pan covers up the bottom; an Edelbrock timing cover and Super Victor intake manifold reside out front and up top, respectively. Inside, Sportsman Racing Products (SRP) pistons and rings ride up and down on SCAT 6-inch, H-beam connecting rods.
Aside from building a reliable motor suitable for both the extended rigors of the Pony Express 100 and the daily grind of street driving, one of the theoretical goals with this project was to see if the small-block could hit 500 hp. After a fairly extensive test session on the RJHP dyno, the best numbers were 486 hp at 6,800 rpm and 409 lb-ft of torque at 5,200 rpm, utilizing Richards' original, decades-old four-barrel and a 2-inch spacer.
Naturally, we were anxious to find out how everything went in the '99 Pony Express race. We quizzed Slover when he returned to the RJHP shop after the event, but his ear-to-ear grin told the story. The motor ran cool and never missed a beat. They came in second in the 160-mph class, behind only a $200,000 twin-turbo, 190-mph-plus, European/gray-market Porsche. The only problem they encountered was that the car's handling was a bit scary on the long straight and a handful in the corners.
Richards subsequently discovered that the front end was incorrectly aligned, which accounted for the high-speed disorder. With that now literally straightened out, he confessed that he has indeed been taking it out on the streets around his town (just for testing purposes, of course), leaving plenty of slack jaws in the wake of this sleeper of a street-sweeper. And he's counting the days until the first Pony Express 100 of the new millennium.