Q&A With George Ullrich From Speed-O-Motive
CHP: Which of Speed-O-Motive's big-blocks packs the most bang for the buck?
George Ullrich: I'd have to say our 506 Budget Stroker Engine. It's a 0.100-over 454, so it has a 4.350-inch bore and a 4.250-stroke. We use a 6.385-inch rod.

CHP: What kind of heads and cam do you use?
GU: We use Dart Iron Eagle BBC heads, and most people go for a hydraulic flat-tappet cam.

CHP: OK, what kind of power does it make, and what does it cost?
GU: Our 506s usually make 550-575 hp. A full engine costs about $7,250, turnkey and dyno-tuned.

CHP: Which engine in your best-seller?
GU: Our 540 would be right up there. The Street Master version runs 10.5:1 compression and makes about 700 hp. We use RHS iron heads, with aluminum heads available as an upgrade. It goes for about $10,600.

CHP: You use a Dart block for that engine?
GU: Yes, and all forged internals. It's very heavy-duty.

CHP: Could you make the same amount of power based on a 454 block?
GU: We could bump one up to about 650 hp, but by the time you put on aluminum heads and a roller cam to get there, the cost would be up to about 10 grand.

CHP: So that engine would cost almost as much as one of your Dart-based 540s?
GU: Yes, but without the advantages of the Dart block. The cooling is better, and the priority main oil system makes for a more stable platform.

Q&A With Bill Mitchell Of World Products
CHP: Bill, what's hot at World Products?
Bill Mitchell: I'd say the 572 Hardcore version big-block. Hardcore signifies a 4500-series carb, single-plane manifold, and it runs a solid-roller cam. It's very popular, but at $12,495 it's not cheap.

CHP: What kind of power are we talkin' here?
BM: The iron-head version makes 675 hp; with aluminum heads it makes 20 more.

CHP: Are there any other engines that are doing well?
BM: The 540 Hardcore big-block is among our top 10 most popular products. It comes with cast-iron or aluminum heads and makes 610 or 630 hp. It goes for about $11,000.

CHP: We understand you've just done some cam testing on that motor?
BM: Yes. With a hydraulic cam and lifter swap, the 540 jumped up to 690 hp, along with 618 lb-ft of torque. That's 60 extra horsepower for $600. We anticipate that the hydraulic-roller cam will be a big sell- ing point.

CHP: World Products is well known for its aftermarket blocks. What are the advantages of going to a Merlin block?
BM: The key to making power is displacement. When you've got the architecture to build a big motor, it makes sense to use it.

Dyno Details 454
Heads GM Rectangular/Oval cylinder head
Compression8.8:1
Cam hydraulic roller, 230/236 degrees duration, lift unknown
Induction 850-cfm Mighty Demon carb, Performer RPM intake
Exhaust Hooker Super Comp headers, two-chamber Flowmaster mufflers
Timing locked out @ 38 degrees
Max torque541 lb-ft @ 4,100 rpm
Max power501 hp @ 5,500 rpm
Avg torque483.9 lb-ft
Avg power405.4 hp
RPM Lb-ftHp
3,100526310
3,200523319
3,300524329
3,400526341
3,500528352
3,600530363
3,700533375
3,800536387
3,900538400
4,000540411
4,100541422
4,200540432
4,300536439
4,400533446
4,500528452
4,600523458
4,700518464
4,800514470
4,900510475
5,000506482
5,100501487
5,200496491
5,300492496
5,400486499
5,500478501
5,600468499
5,700460499
5,800451499
5,900444499
6,000434496
Dyno Details 496
Heads AFR 305c
Compression10:1
Cam hydraulic roller, 242 degrees duration, lift unknown
Induction Holley 850-cfm marine carb, Performer RPM intake
Exhaust Westech shop headers
Timing 36 degrees
Max torque621 lb-ft @ 4,600 rpm
Max power613 hp @ 5,700 rpm
Avg. torque591.8 lb-ft
Avg. power516.6 hp
RPM Lb-ftHp
3,100560330
3,200565344
3,300574361
3,400584378
3,500593395
3,600599410
3,700604425
3,800608440
3,900611454
4,000613467
4,100615480
4,200616493
4,300618506
4,400619519
4,500620531
4,600621543
4,700620555
4,800618565
4,900615574
5,000610581
5,100606588
5,200601595
5,300596601
5,400590607
5,500582610
5,600574612
5,700565613
5,800555613
5,900544611
6,000532608
6,100521605
Dyno Details 540
HeadsDart Pro 1
Compression9:1
Camhydraulic roller, 0.566 inch lift, 224 degrees duration at 0.050
Induction 850-cfm Speed Demon, Edelbrock Victor intake, open 1-inch spacer
ExhaustHooker headers
Timing35 degrees
Max torque641 lb-ft @ 4,200 rpm
Max power581 hp @ 5,300 rpm
Avg. torque618.7 lb-ft
Avg. power498.7 hp
RPM Lb-ftHp
3,100612361
3,200612373
3,300616387
3,400622403
3,500627418
3,600631433
3,700634447
3,800636461
3,900637473
4,000637486
4,,100638498
4,200640512
4,300641525
4,400642538
4,500641549
4,600637558
4,700631564
4,800623570
4,900616574
5,,000607578
5,100599581
5,200588582
5,300577582
5,400563579
5,500551577