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Building a 600HP Big-Block for $4000

Blue Collar 454

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Our Blue Collar 454 first appeared in the July '12 issue and consisted of a stock-bore block and rotating assembly from a late-'70s Suburban and a pair of 049-casting oval-port cylinder heads (rebuildable cores can be found on eBay for about $100–$150 apiece). Though the parts were incredibly grimy, the block cleaned up well and showed very little wear in the cylinders. JMS Racing Engines in El Monte, California, rebuilt the heads for us while we reconditioned the block and stock rotating assembly at home. With a tiny RV cam, this combination made 408 hp and 511 lb-ft of torque for the paltry sum of $1,900 carb-to-oil pan (including the machine shop cost!). We were so cheap, we ran out of engine paint and didn't finish painting the heads. All the details can be found in the July '12 issue.

We did a couple more builds with it, adding forged pistons and a tunnel ram, and making 594 hp (naturally aspirated) and 800 hp on nitrous before destroying one of the main bearings. We've brought the Blue Collar 454 back this month to try to duplicate that feat, but without the pricey tunnel-ram/dual-quad setup. We achieved that goal—exceeding it by a few ponies, in fact—and in the process, we laid a good foundation from which to proceed. Our plans are to fully maximize the potential of these lowly cast-iron cylinder heads before seeking an aftermarket solution.

On the Dyno

114-octane Rockett Brand gasoline, 36 degrees total timing

RPM TQ HP
3,600 443.1 303.7
3,700 447.7 315.4
3,800 456 329.9
3,900 463.6 344.3
4,000 471.3 359
4,100 478.5 373.5
4,200 487.1 389.5
4,300 495.4 405.6
4,400 503.9 422.1
4,500 509.1 436.2
4,600 512.1 448.6
4,700 513.4 459.5
4,800 514 469.7
4,900 513.5 479.1
5,000 512.2 487.6
5,100 511.1 496.3
5,200 511.8 506.7
5,300 513.7 518.4
5,400 515.6 530.2
5,500 516.8 541.2
5,600 517 551.2
5,700 516 560.1
5,800 514.1 567.7
5,900 511.7 574.8
6,000 509.2 581.8
6,100 506.9 588.7
6,200 504.4 595.4
6,300 501.7 601.8
6,400 498 606.8
6,500 493.7 611
6,600 488.2 613.4
6,700 480.1 612.5

91-octane Rockett Brand gasoline, 28 degrees total timing

RPM TQ HP
3,500 391.3 260.8
3,600 394.3 270.2
3,700 404.9 285.2
3,800 417.8 302.3
3,900 427 317.1
4,000 435.2 331.5
4,100 442.1 345.1
4,200 450.8 360.5
4,300 460.5 377
4,400 469 392.9
4,500 475.3 407.2
4,600 480.2 420.5
4,700 483.1 432.3
4,800 484.5 442.8
4,900 484.3 451.9
5,000 483.7 460.5
5,100 482.6 468.6
5,200 481.3 476.5
5,300 480.4 484.8
5,400 480.2 493.7
5,500 481.5 504.3
5,600 482.4 514.4
5,700 481.7 522.8
5,800 479.2 529.2
5,900 476.4 535.1
6,000 474 541.5
6,100 471.9 548.1
6,200 469.5 554.2
6,300 465.5 558.4
6,400 460.6 561.2
6,500 455.9 564.3
6,600 450.7 566.4
6,700 444.6 567.2


Watching Star Trek and assembling big blocks.

Stepping into the Wayback machine, here's what the engine looked like when we first took possession. It's difficult to believe something this gross could make decent power.

Based on previous building experience, we decided to try a bigger cam and slightly bigger intake valves—going from 2.18-inch to 2.250-inch, the same size that performance rectangle-port heads use. The exhaust valves remain 1.88-inch, as used in the last test. We installed Comp Cams' Sportsman stainless steel valves this time, with an 11⁄32 diameter, which is slightly thinner than stock.

We also knew the cam we wanted to use would make peak power somewhere above 6,500 rpm, so we opted for Comp's tool steel valvespring retainers, shown in the foreground. They weigh about 33 percent less than chromoly retainers and are within 4 grams of titanium, yet cost about $100 less. Shedding some weight from the retainers allowed us to rev the engine a little higher and offers better valve control at high rpm.

Fred De La Cruz at HPS Automotive Machining did some basic clean up in the exhaust ports, where big-block heads can use more airflow.

Upon disassembly of the last iteration of Blue Collar, we discovered the spark plugs had been hitting the piston domes in all the cylinders. We were lucky that no damage was done, but this shows the importance of not only selecting the correct heat range spark plug but also the correct reach into the combustion chamber.

We used a carbide cutter to grind the spark-plug gouge out of the pistons. We also took the time to grind all the sharp edges off the piston domes. We didn't remove much material, just rounded off the sharp edges.

We chose a solid flat-tappet cam from Comp with 270/280 degrees duration at 0.050-inch tappet lift and 0.650-inch valve lift with stock ratio rocker arms. Because of the increased lift and duration from the previous build, we needed to check piston to valve clearance again, so we temporarily reinstalled the cam.

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1 comments
jbaird55
jbaird55

Dont you think you lost HP by using a square port intake on a oval port head??? why not use oval port intake.....your HP and torque numbers couldve been alot better.....and with alittle more time and home machining a person can port match intake and heads and get pretty respectable flow, HP, and torque numbers... and with little on no cost.... 

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