Originally Posted by Dirt Reynolds
Guys -- it would be great if those who have Vortec heads post their combo.
Here is my old Vortec combo for those who may be interested:
1977 Z28 Camaro - full-weight, all-steel, 3760-3775 lbs race-ready with driver.
Best ET: 12.15 @ 110.52 MPH on a very worn set of BFG 275/60 drag radials, launched off-idle, in the heat of July.
Highlight notes: Home-ported Vortecs with stock valves and stamped-steel rockers, hydraulic lifter cam, dual plane intake and vacuum secondary carb.
This engine was a budget build, since I had already spent a large portion of my original budget for this project purchasing the car as a rolling chassis:
#817 block 400, bored .060"-over for 412.7 ci. The block would not clean up at either .030" or .040" over, so we had to go .060".
11.3:1 CR w/ flat-top 2-valve relief KB pistons, .026" down in the hole, block not decked
ARP rod bolts, resized stock 400 rods, 5.565", rotating assembly not balanced
Crane 'Blazer' hyd. flat-tappet cam & lifter kit, 234/244 @ .050" .488"/.510", 114 LSA
Vortec heads - stock retainers had 3/16" ground off the bottoms for retainer to guide clearance (worked great), Crane single valvesprings with dampner removed, stock rocker arms and valves, fully ported bowls intake & exhaust; some minor runner work consisting of contouring and straightening the runner on the exhaust, and mostly roof work on the intakes with mild contouring of the runner.
Edelbrock RPM Vortec intake manifold, unported; Holley 3310 vac. secondary 750 - milled airhorn, installed #31 squirter, pink pump cam in position #3, secondary metering plate installed with #80 jets (stock #72 in front),quick-change vac.secondary pod installed with the white spring (lightest)
Hedman ceramic-coated 1 3/4" full-length headers, 3" dual exhaust with 2-chamber race Flowmaster mufflers and 18" turn-outs
Stock HEI (recurved), MSD Digital6+ ignition box with Blaster 3 coil, MSD wires, NGK plugs
Misc.: Holley Blue electric pump and regulator (set to 7 psi), sumped fuel tank, Flexalite dual electric fans with control box,TH400 transmission with 2800-3000 stall B&M converter, 4.10 gears, full spool, 33-spline axles, c-clip eliminators, welded axle tubes to housing, aluminum Moser rear cover girdle, Lakewood drag shocks 90/10 front/50/50 rear, no sway bars, 275/60 BFG drag radials rear on 15x8 Weld ProStars; 165/15 tires front on 15x3 Weld ProStars
Other notes:
This combo began as a 13.49/102MPH ride in untuned form on a generic 275/60 street tire, to the eventual 12.15/110.52 performance with the above carb modifications and the drag radials. I feel this particular combo -- had I stuck with it -- would have eventually ended up in the 11.80 - 11.90 range with further testing and tuning. The carb modifications made a HUGE difference in power. I feel there was more in this combo but I got sidetracked with another set of heads, intake, and solid cam. One thing I can state, the 4.10 gear was too much for this combo -- I feel the car would have been quicker and faster with a 3.42 or at most, 3.73 gear. This would enable the engine to pull harder through the midrange RPM band, where it made its best torque.
If you run a dished piston and deck the block, you'll be able to run 92 octane premium. If I did this engine over again, thats what I'd do. In the cooler months of the year, I could run on 94 octane, but in the summer heat I had to add a gallon or two of av gas 100 octane low lead to the tank to keep it happy. The Vortecs will enable you to run right up to about 10.5:1 CR on 92-94 octane without a problem, in my opinion. Maybe more with better quench than what I had.
This shows what is possible on a low-budget engine build, using the Vortec heads. No roller rockers, roller cam, or any trick parts. There are others out there with similar stories of their Vortec builds, so lets hear 'em guys!
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