So our pick for a simple, budget, performance V-6 would be an '85-'92 unit without a balance shaft, and we have a slight preference for the earlier units with perimeter-bolt valve covers. They just look better, and based on our inspection of junkyard heads, we suspect that the early ones flow better. But avoid the 200 and 229 heads, which have 1.84-inch intake valves. Speaking of heads, you're sorta stuck with stockers. There was a time when GM Performance Parts had 23-degree, direct bolt-on performance heads and manifolds, but now only the hardcore 18-degree race heads and intakes are available; you can still get all kinds of iron and aluminum race blocks, too, including big-bore capability and priority-main oiling. We learned that Scat Crankshafts still has the very last few sets of Brodix 23-degree V-6 heads, but we were unable to find any others that are affordable. Similarly, intake manifold selection is pretty slim, and while most cam manufacturers can grind anything you want, the only off-the-shelf sticks are pretty mild. We decided to see what we could squeeze out of this thing with readily available parts and the production heads and block, skipping any rocket science. To duplicate every little nut and bolt we used would run about $3,000, including machine work.
Our Chevy 262ci V-6 resulted in 301 hp at 5,500 rpm and 312 lb-ft at 4,700. Puny, but let us remind you that it's still 50 hp per cylinder (a similar 350 V-8 would make 400 hp), which is pretty good for the very mild parts we used. Besides, at 0.060-over, it's just 270ci. Naturally aspirated, our V-6 should put an S-10 into the 14s, and with forged pistons and studded mains, we're ready to nitrous this thing to at least 400 hp or add a Vortech blower for an easy 450 to run in the 12s or better. Even more interesting, Allstar Performance sells brackets to swap a 90-degree V-6 where a V-8 used to be, and the resulting engine setback could make this thing killer for handling applications in, say, a third-gen F-body.
Enough justification. We kind of like our little motor. Have a look at how we conspired with Dougan's Engine to make it run twice as hard as it did stock.
9 The valvesprings supplied by Comp were PN 986, though Dougan's stepped it up to a slightly stiffer 987 because we so often see valve float at 6,000 rpm with hydraulic rollers; as it turned out the power peak was at 5,500 anyway. However, either spring has a 1.430-inch diameter and the V-6 heads need to be machined to accept them, then the springs need stiff shims because there's not much meat in a few of the seats. Dougan's also modified the heads for 3/8-inch screw-in studs since we didn't trust the press-in style above 0.500-inch valve lift.
10 Speaking of lift, we amped the cam's 0.525 lift with 1.5:1 rockers up to 0.560 inch by substituting Comp Cams 1.6: Pro Magnum rockers (PN 1301-12). Next time we'd use the new self-guided rockers (PN 1318-12) and omit the guideplates, as the V-6 heads had some pushrod-angle problems with the V-8-type guideplates. We were surprised that the stock center-bolt valve covers cleared the rockers with no modifications.
11 Because we found no practical aftermarket heads, and because simply cutting one cylinder off a V-8 head won't work, we had our pal Brulio at Westech Performance hog the stock heads for increased flow. These heads are terrible, and even after porting, they only flow about as well as stock 305 Chevy heads. Peak numbers were 208 cfm on the intake and 190 on the exhaust, which was a giant improvement over the pathetic 138/116-cfm baseline. Helping the cause were Milodon Megaflow swirl-polished, tulipped valves in 2.02/1.60 sizes (PNs 45015 and 45045), an upgrade over the stock 1.94/1.50s. Consider these steps mandatory to making any kind of decent power with your V-6.
12 Fel-Pro gaskets were used throughout our little engine, and even though the intake set was clearly marked, we screwed up the first time and put them on backwards. Do so and you block the water passages to the head at the front of the block; they are shown here properly installed. Also note that we blocked off the heat crossover.
13 Header selection is very limited, and while Edelbrock makes tubular manifolds and systems for truck applications, they wouldn't fit the dyno. Instead we used a set of long-tube, coated S-10 headers from Hooker (PN 2842-1) They have tiny 15/8-inch primaries. 26-inch tubes, and small 21/2-inch collectors. We ran all our tests with collector extensions but no mufflers.
14 Ignitionwise, MSD still makes even-fire (PN 8597) and odd-fire (PN 8596) Pro Billet distributors for the 90-degree V-6. We used an even-fire unit with MSD 8.5mm Heli-Core wires and a Digital-7 ignition box. Note that the Demon or Holley-type carburetors will not fit this engine unless a 2-inch carb-spacer is used-otherwise the float bowls hit the distributor and water neck. If you don't want a cowl hood, stick with the Edelbrock carb.
15 Intake-manifold selection is very limited, and we chose an Edelbrock Performer (PN 2111). This is a very low-rise intake, and we made best power with a 2-inch spacer from Wilson Manifolds. The initial carb we used was an Edelbrock 500, which seemed to be jetted perfectly right out of the box. It turned in 288 hp at 5,400 and 303 lb-ft at 4,400. But strangely, the V-6 saw about 1.5 inches of manifold vacuum at WOT, indicating that the carb was a tad too small.
16 We didn't have a 600-cfm Edelbrock to try, so we added a 650-cfm Mighty Demon. It's nearly 300 bucks more than the Edelbrock 500, but kicked the power up to what we were looking for: 300 hp and 316 lb-ft.
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