V6 Chevette: A Bolt-In That Cuts 15-Second ETs and 27 MPG

By Marlan Davis, Photography: Marlan Davis, Jeff Tann & Jeff Smith

It's 1965, and a plain, box-like Chevy II pulls up beside you. Aha, you think, Junior has Grandma's "Supermarket Special" out for a spin. And then this "S-box" blows you into the weeds. What you missed were the little "327" emblems on the fenders.

Now it's 1982, and Junior has his brand-new Z28 out for a spin. Up beside him pulls a square-cut Chevette (nice wheels and paint, mind you, but still a Chevette). Aha, Junior thinks, the kid has some fancy paint, and he thinks he's "Grumpy" Jenkins. And then this "S-box" blows Junior into the weeds. (After all, like father like son.) What Junior missed was the little V6 emblem on the right rear taillight bezel.

Neither of these tales are tall; they are down-to-earth reality. The '65 327/325 horse Chevy II was perhaps the all-time sleeper musclecar of the '60s. It even fooled the insurance companies, and just about everyone could afford one. In short, performance for the masses.

The '82 Chevette could be the sleeper musclecar of the '80s. Right now, only one exists: a prototype built by Chevrolet's Product Promotion Engineering (aka the Bow Tie Brigade or the Chevy non-Racing Division). This latest plaything from the people who brought you the aluminum small-block Z28 and various turbocharged Corvettes has a compact, stock longitudinally-mounted 60-degree V6 from a new S-pickup or Camaro/Firebird (F-car). Two different Corvette transmissions have backed it up—a Warner Super T10 manual 4-speed and the current 700R4 4-speed automatic overdrive beefed by GM's Hydramatic division. A reworked Chevette 3-speed automatic trans shifter handles the gear selection for the present trans, feeding the power back to a stock non-posi 3.36-geared Chevette rearend that seems to be holding up okay so far.

The automatic-transmissioned combo has powered the 2260-pound car to consistent 15.99-second clockings in the quarter-mile, letting the trans shift for itself, all this while averaging about 23 mpg in combined lead-footed city/highway driving. Truly, this is performance that's right in tune with the times; faster than a new Z28, Trans Am, or Turbo Regal, yet also more economical. Plus, there's also loads of carrying capacity: 27 cubic feet, to be exact, with even more space on tap once the super-comfortable Corvette bucket seats are folded flat.

But what's really neat is how well the V6 fits in, no hacking required! While the swap does add 140 pounds, there is no steering shimmy or unwelcome vibration as there is in V8 Vegas or home-built Chevettes equipped with larger 90-degree V6s. It handles well for a car in its class, and stops quickly in a straight line (with stock power brakes, no less).

There's also one other good thing going for it: the projected price. Unlike other (so-called) fast cars, the V6 Chevette would be affordable. One estimate is that Chevy could produce stripped down "Scooter" V6 Chevettes minus the back seats like ours (but without the fancy wheels and tires) for around $6500! Once again, performance for the masses would appear to be obtainable.

Of course, the $6500 question is whether or not such a package will actually be produced. Unfortunately, lots of factors mitigate against a production line run: GM would like to sell plenty of more expensive (and higher profit margin) XI Is, Z28s, and Corvettes; there is a cash flow problem, and GM is loath to spend the money on tooling costs in such uncertain times, especially when the 7-year-old Chevette will soon be due for retirement. And then there's the problem of the government-mandated Corporate Average Fuel Economy standards (CAFE). While the V6 Chevette is plenty economical by performance car standards, it's not nearly as thrifty as the standard 98-inch 4-cylinder engine or the miserly optional 111-cubic-inch diesel, millions of which are needed to offset the relatively poor (by today's standards) Corvettes, Camaros, and Impalas. So, at this point, things just don't look good. Maybe if there was enough public demand (hint)

A. If some people in Chevrolet Product Promotion Engineering have their way, foreign car owners could be in real trouble In fact, even some Z28 and Trans Am owners could be in for a nasty surprise from the V6 hidden under the fresh-air scoop, made by grafting a Citation XI1 hood blister onto the stock hood. The exterior was dressed up using Pittsburgh Plate Glass "corporate blue" paint, along with blacked-out grilles and moldings.

B. Inside, a Camaro/Monza-style steering wheel and Corvette buckets were added, although the dash remains stock. A stock Chevette 3-speed automatic shifter was reworked to handle the Vette 4-speed overdrive automatic trans There are 27 cubic feet of luggage space in back, even more when the Corvette seats are folded flat. Our Chevette started life as a stripped-down "Scooter" version sans back seat. (Every little pound counts.)

C. Those expensive imported Gotti wheels probably never would make it into production, but they sure look good. And Goodyear NCT rubber sticks good, too.

1. To start, you'll need a block out of an S-10/15 pickup or F-car (Camaro/Firebird), since unlike the transverse-engined Citation (X-car) block these new vehicles mount the V6 longitudinally, with the "conventional" blocks having their mounting lugs in a more favorable location. Also, the transverse blocks have the starter on the "wrong" (driver) side for conventional mounting with regular transmissions.

2. Made from flat sheet stock, your fabricated engine mounts should look like these (A). To clear the fuel pump, the driver's side mount had to be trimmed and rewelded (A, left and B). There's plenty of clearance on the passenger's side (C). Below the mounts are standard Chevette diesel rubber biscuits. Stiffer-than-regular Chevette gasoline engine biscuits, they better help to minimize the engine's torque reaction. The biscuits in turn are attached to fabricated frame adapters that bolt to the stock Chevette frame's mounting holes (D and E). Note that the right angle oil filter adapter used on the S-truck is not needed, and the oil filter screws directly into the block.

3. Two different transmissions were used—a late Z28/Corvette Warner Super T-10 4-speed (a Muncie or Saginaw 4-speed would work, too) and a 700R4 4-speed automatic overdrive. With the manual trans, the biggest problem encountered was the clutch fork pivot ball stud in the S-10 bellhousing that was used. S-10s have conventional mechanical clutch linkage, while Chevettes use a cable that pulls instead of pushes the clutch fork. To accommodate it, the pivot inside the bellhousing had to be relocated (A, arrow) before the clutch fork could be positioned correctly (B). The tunnel was also modified because of shift linkage interference. The automatic went in a lot easier. Corvette mounts were used with both transmissions, with the hookup to a reworked stock crossmember slightly to the rear of the original mounting locations (C, automatic trans shown). With these longer-than-stock transmissions, the stock driveshaft was shortened to make up the difference (D).

4. The right intake to use is from an S-truck or F-car with the front-mounted water outlet (bottom). Citations and their kin have the outlet at the rear.

5. Likewise, only S or F-body exhaust manifolds will work, but they are a tight fit. Clearance on many late catalytic converter cars makes fabricating dual exhaust systems a real problem, and the Chevette is no exception. Chevy went with a single large-diameter pipe, two mufflers, and no converter on this engineering prototype.

6. Firewall and heater case clearance is tight, but satisfactory. The steering did not have to be modified, either.

7. However, underneath there was a tight squeeze between the aluminum boss on the steering pinion and rack housing assembly and the S/F-body oil pan. The top of the boss (arrow) was filed for clearance, which was lots easier than denting the pan. The pan's sump was also sectioned and raised approximately 1 inch for ground clearance. Naturally, the pickup and dipstick had to be reworked accordingly.

Whether or not Chevy ever gets around to building any V6 Chevettes, with a little "blood, toil, sweat, and tears" you can have one of your very own. There are literally millions of Chevettes and sister Pontiac T 1000s around, and soon longitudinally-mounted 60-degree V6s should start filling the wrecking yards.

E. It's tight … but everything fits, even under the stock hood. The fresh air setup is there not because of clearance problems, but to add a few more horses, and consists of a Citation XI1 air cleaner assembly modified with a reduced diameter cover, open element filter, removed snorkel and late Z28 seal. Underneath all that is the stock Rochester Varajet 2-barrel. There's no room for a conventional fan, so a V8 Monza "pusher" electric unit is mounted in front of the Chevette's stock air conditioning radiator. Air conditioning coils are used for the V6's additional 140 pounds.

We followed along as Chevrolet project manager John Pierce performed the engine compartment surgery. While no kits are yet available for installing the 173-cubic-inch engine these photos at least ought to give you an idea just how to shoehorn the powerplant in.

Below are the major parts required for this swap. Assistance in compiling the part numbers was provided by Baher Chevrolet (18600 Devonshire, Northridge, CA 91324, 213/360-2381) and Courtesy Chevrolet (3610 Thousand Oaks Blvd., Thousand Oaks, CA 91360, 805/497-1651), but any responsibility for error is entirely ours. A "T-car" is a Chevette or Pontiac T1000; "S" is a Chevy S-10 or GMC S-15 pickup; "F" is a Camaro/Firebird.

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