Big-Block Mopar Engine - Pump Gas Thumper

In a world where technology has brought us overhead cams, veritable cam timing, high-powered, small-inch, "efficient" engines, factory offerings with over 10:1 compression made to run on pump fuel, and a whole slew of other titillating innovations, it's nice to see that cubic inches are still the way to make big power and huge torque. But what if you equipped your big-inch monster with one modern concession? What would it be? How about a 542ci, pump-gas swilling, aluminum-headed, asphalt buckler with fuel injection? Imagine no cold-start issues and unparalleled drivability. Now imagine 665 lb.-ft. of torque at a mere 4,500 rpm and 624 eager horses at a low 5,100 rpm! The kicker? All that is available on 87-octane pump dribble.

This Indy Cylinder Head/Milodon-built wonder is the perfect recipe for a modern street engine. With enough torque to turn the Earth on its axis, the convenience of fuel injection, and the ability to run all-day-long on the worst possible gas, we would say that Indy scored a home run, a field goal, and a knockout. All we know is that this is the wave of the future with enough oats to push even a cruise liner into the 10s.

What happens when Indy Cylinder...        read full caption What happens when Indy Cylinder heads and Milodon combine to build an engine? You get 625 hp on 87-octane gas. What's more, it happens under 5,500 rpm.

We know that CNC porting guarantees...        read full caption We know that CNC porting guarantees consistency, but CNC machining the block? All blocks at Indy Cylinder Heads are CNC machined. Everything is located from dowel positions. This MP mega block is bored, stroke clearanced, and lightened. This particular engine received a partial lightening, which means the motor mounts were left in place (the owner did not want to run a motor plate). A full race lightening can remove up to 40 pounds of cast iron. Consider this exercise the Atkins diet of block preparation.

Here the MP Mega Block is...        read full caption Here the MP Mega Block is prepped and ready to fill with speed parts.

A mild Comp Cams hydraulic...        read full caption A mild Comp Cams hydraulic bumpstick was chosen to actuate the valves. This particular cam was spec'd for torque, maintenance-free operation, and street manners, featuring .546/.546-inch lift and 241/247-degrees of duration at .050-inch valve lift, and a wide 112-degrees lobe separation angle. It was installed at 108 degrees to boost the already fat low-end torque curve.

A 112 LSA was specified to...        read full caption A 112 LSA was specified to smooth out the idle and help fight surging, a common malady of EFI engines. It also broadens the power band on large-cube engines.

A Milodon true roller timing...        read full caption A Milodon true roller timing set was pressed into service, and a complete engine bolt kit made cleaning and reusing old fasteners obsolete.

In today's high-tech world,...        read full caption In today's high-tech world, CNC porting is the only way to ensure uniformity from port to port. Every port and chamber is identical. These 440/SR heads are equipped with 2.19/1.81 valves, 75cc chambers, and an intake port measuring 295 cc flowing a whopping 355 cfm. This is the smallest wedge head in Indy's arsenal.

The CNC-ported 440 S/R heads...        read full caption The CNC-ported 440 S/R heads have the stock exhaust pattern, but raised exhaust ports. Some headers will fit, but it's best to buy headers that were designed with this feature in mind, such as those from tti.

The 440 S/R CNC-ported head...        read full caption The 440 S/R CNC-ported head has Max Wedge-size intake port openings. They will correctly mate to the 440-2 single-plane intake, which can be ordered EFI ready or with the provisions to run a carburetor--the choice is yours.

This 4.5-inch stroke Crower...        read full caption This 4.5-inch stroke Crower crank is made from 4340 steel and will purportedly handle in an excess of 2,000 hp. While it's overkill, we like the piece of mind it has purchased. The bulletproof Crower piece utilizes standard 2.375 Mopar rod journals and an 8-bolt flywheel flange.

Don't build another wedge...        read full caption Don't build another wedge or Hemi without this gem. This is a billet rear main seal retainer from Indy, made on a CNC machine...

...It has exact dimensions...        read full caption ...It has exact dimensions to clamp the seal properly and uses two O-rings on each side for end seals instead of paper ones.

Naturally, a Milodon 30930...        read full caption Naturally, a Milodon 30930 street/strip oil pan, their big stroke windage tray, high-volume oil pump with pump cover, static pickup, and adjustable relief valve ensure reliable lubrication. We cannot over emphasize the importance of a good oiling system--particularly in a high-horsepower application such as this.

When you use a big stroke,...        read full caption When you use a big stroke, you can't use the internal pickup anymore as space is limited, so an external system is needed. Everyone thinks of a full race system when you say that, but this is a nice little package. The external system comes out the side of the pump cover instead of the back. You just loop the line around the K frame, and you can still use motor mounts. It's so simple.

Ross forged pistons were chosen...        read full caption Ross forged pistons were chosen for their light weight, strength, and quality. This setup used the manufacturer recommended street clearances, a 4.380 bore, 1.460 compression height, .990-inch wrist pin, and a 40cc dish. The Crower rods are 4340 steel, 7.00-inches center to center, and will take nearly any punishment thrown their way. Rods are one area where you do not want to skimp.

One look at the big 40cc dish...        read full caption One look at the big 40cc dish and you'd think it's too much, and better for a blower or turbo application. But this is a big engine, and we only wanted a 9.5:1 compression ratio.

Piston volume was checked...        read full caption Piston volume was checked to ensure that we had done our homework right. Since this engine will be fed a steady diet of sub-par California unleaded fuel, the compression ratio was kept on the low side, squeezing a 9.5:1 ratio.