Chevy Big-Block Engine - Big Time Power

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.