Torque to me, baby. When the digital twist-o-meter reads out 640 lb-ft at 4,100 rpm, some type of supercharger is usually involved. But not with this 505ci wedge. Combine that normally aspirated grunt with 583 hp and you have a bitchin' street engine.
The password to enter the bad-boy world of big-inch street motors is "stroker." While everyone always wants to talk about horsepower, the big-block Chrysler wedge engines have enjoyed a long history of stout performance based on their excellent torque numbers. And the easiest way to make even more torque? Just add displacement. That led us to a question-what would happen if we stuffed a longer arm in a 440 RB engine? Our candidate started out as a '71 Dodge 11/42-ton truck motor found cast away at our local Pick Your Part recycling yard. After $130 changed hands, we soon had the greasy short-block cleaned up and ready for a stroker crank to up the inches. A stock 440 combines a sizeable 4.320-inch bore with a tiny 3.75-inch stroke to produce 440 cubes. Tom Lieb, the owner of Scat, saw this as a wonderful opportunity to put a ridiculous 11/42-inch additional swing on the crank to create a 4.250-inch stroke that along with a 0.030-inch overbore would push the displacement needle just past the magic 500ci mark to 505. How cool is that?
To ensure that Federal-Mogul bearings live a long and happy life, the key is precision measurement. Engine builder Taylor strives for a little over 0.002-inch clearance for both the rods and mains for a street engine that will not see excessive rpm.
What we created was nothing short of a torque monster. At 3,500, the first test with an Edelbrock Performer RPM intake made so much grunt the dyno couldn't hold it. With a little tuning, this beast made 640 lb-ft at 4,100 rpm, and the lowest we could pull the dyno was 3,500, where it twisted up 614 lb-ft. The horsepower wasn't as impressive at only 562, so we added an Edelbrock Victor single-plane and watched the horsepower jump to 583 at a mere 5,700 rpm, while losing almost no torque with a peak of 634 at the same 4,100 rpm. Check out how it all went down.
RB Block Building
You would think that stuffing a 1/2-inch-longer stroke crank in a motor would require hours of grinding and a lifetime subscription to Iron Lung Monthly. But the truth is, the Scat rotating assembly was one of the easiest parts of this assembly. Scat chose to use off-the-shelf 6.700-inch big-block Chevy rods combined with JE forged and dished pistons to complete the rotating assembly. Engine wrangler Ed Taylor took on the job of putting it together after Jim Grubbs Motorsports performed its usual precise machine work, which included magnafluxing or boring and torque-plate honing to 0.030-over, align-honing the stock two-bolt mains, and then configuring the deck to get it as close to square as possible.
Final short-block assembly involved installing the ATI balancer. Always use a balancer installer tool. Leave the 10-pound sledgehammer in the corner of the shop where it belongs.
Oil System Details
Most production engines have fairly bulletproof lubrication systems that can be used with great success even for high-output situations. The 440 Mopar needed a little attention in this area. We went with a complete Milodon oil pan, windage tray, and single-line, remote-fed pickup assembly that required some extra work.
The Induction And Exhaust
Displacement is the easiest path to making torque, and since we weren't out to make this engine spin very fast, the original-design Edelbrock Performer RPM aluminum 440 heads were the choice. The intake and exhaust ports are both in the stock location as opposed to the Edelbrock Victor heads, which offer more flow but also raise the exhaust port by 1/4 inch, adding expense for custom headers. For the first test of this engine, Taylor assembled the engine with an Edelbrock Performer RPM dual-plane, but we also brought along an Edelbrock Victor 440 single-plane to evaluate the differences in the power curve.
With the Speed-Pro 1/16-inch ring package in place, Taylor used these nice ARP chopsticks to guide the rod over the crank and not scratch the journal. The rods use ARP 8720-grade 7/16-inch capscrews but can still be measured for stretch the same way as standard ARP rod bolts.
Flow Chart
Edelbrock 440 Mopar PN 609292.14/1.81-inch valves84cc chamber210cc port volume (214cc measured)Tested on 4.385-inch bore
Cam Selection
The plan here was to make excellent overall power. With a large-displacement street engine, it didn't seem like any fun to just stick an average hydraulic cam in this beast, so we elected to step up to a complete Comp Cams mechanical flat tappet cam just to make it more interesting. The Edelbrock heads are designed to retain the stock Mopar rocker shaft valvetrain, but we opted to include a set of Comp Magnum roller rockers that gave us a lash adjustment system on the pushrod side.
The Comp Cam custom grind is based on the Comp MM solid flat tappet profile family, which is designed to take advantage of the larger Mopar 0.904-inch-diameter lifter by giving the profile more valve velocity. To duplicate this cam, order PN CRB3 6583/6585 S 109.0.
Camshaft Advertised Duration
Part of the mockup procedure involved installing the crank, piston, and rod assembly on all four corners, both to measure for piston deck height measurements and to check for piston-to-valve clearance. Even with the 0.585-inch lift on the exhaust, clearance was more than adequate. A minimum clearance on the exhaust side is 0.080 to 0.100 inch.
Dyno Testing
We wrestled the big-block Mopar motor out to Westech Performance and bolted it to its SuperFlow 901 dyno. After warming the motor up and running through a quick series of pulls to optimize the timing at 32 degrees and jetting set for best power, the big 505 made so much torque that Westech's Steve Brul had difficulty getting an accurate read at 3,500 rpm. This test eventually saw a massive 640 lb-ft of grunt and 562 hp. While the torque was impressive, we considered just how difficult it would be for a street car to manage all that tire spin.
Because we had so much torque to work with, it seemed a good idea to sacrifice a little for perhaps a bit more horsepower by switching to a Victor single-plane intake manifold. After the swap, the engine wanted more jetting, moving the primaries to 84 and the secondary, with the power valve in place, to 91 jets. While we lost as much as 20 lb-ft of torque at 3,700 rpm, the swap to the single-plane added a solid 30 hp at the top end. Despite the loss of torque, the big Mopar still pushed out 634 lb-ft at 3,400 rpm, which is close to where the stall speed would probably be on a mild street automatic-thus losing torque below that point costs nothing in terms of acceleration. At a peak of 583 hp, this 505 is shy of the max horsepower generated by the 440 we ran earlier this year ("New Victor 440 Heads," May '07), but this is a much milder, totally streetable pump gas package that makes amazing power at very reasonable engine speeds. This torque would be especially useful in a B-Body like a Charger or Super Bee with a Torqueflite and a streetable 3.30- to 3.50-series rear gear. Even at 3,500 rpm, this 505-incher is pullin' a massive 601 lb-ft of torque. All that torque is guaranteed to push even a heavy B-Body well into the 11s at 115-plus mph. Better find some sticky tires, because on the street, torque rules.
Test 1 Test 2 Diff RPM TQ HP TQ HP TQ HP 3500 614 410 601 401 -13 9 3700 {{{626}}} 441 606 427 -20 -14 3900 639 474 620 460 -19 -14 4100 640 500 634 495 -6 -5 4300 631 517 637 522 +6 +5 4500 623 534 629 539 +6 +5 4700 609 545 622 557 +13 +12 4900 594 554 607 567 +13 +13 5100 577 560 593 576 +16 +16 5300 557 562 572 577 +15 +15 5500 533 558 550 577 +17 +19 5700 514 558 537 583 +23 +25 5900 484 545 512 575 +28 +30 Peak 640 562 634 583 Avg. 589 522 595 529Torque Forever
Test 1 consisted of the 505 engine combination fitted with an Edelbrock Performer RPM intake manifold and Mighty Demon 850-cfm carburetor.
Test 2 was exactly the same as Test 1 with the exception of the change to an Edelbrock single-plane Victor Jr. intake manifold.manifold.
PARTS LIST DESCRIPTION PN SOURCE PRICE 440, used Dodge truck n/a Pick Your Part $129.99 ARP head bolts 145-3606 Summit Racing 55.95 ARP engine fastener kit 545-9801 Summit Racing 109.95 ARP flywheel bolts 200-2804 Summit Racing 67.95 ARP main bolt kit 140-5001 Summit Racing 31.95 ATI Super Damper 917470E Summit Racing 419.95 Autolite spark plugs 85 Rock Auto 11.28 Centerforce flywheel, 143 tooth 700-440 Summit Racing 325.95 Comp Cams custom grind camshaft 23-000-5 Summit Racing 163.69** Comp Cams flat tappet mech. lifters 821-16 Summit Racing 105.88 Comp Cams pushrods 7791-16 Summit Racing 159.69 Comp Cams rollerized timing set 3125 KT Summit Racing 221.39 Comp Pro Magnum rockers, 1.5:1 1321-16 Summit Racing 495.95 Edelbrock Performer RPM intake 7193 Summit Racing 199.88* Edelbrock Victor 440 intake 2954 Summit Racing 245.88 Edelbrock Performer RPM heads 60929 Summit Racing 1,359.00 Edelbrock Victor water pump 8814 Summit Racing 125.95 Federal-Mogul rod bearings 2320CP Summit Racing 9.95 Federal-Mogul main bearings 119 M Summit Racing 89.39 Federal-Mogul freeze plugs 3818011 Summit Racing 11.69 Fel-Pro gaskets full set KS2110 Summit Racing 57.99 Fel-Pro header gaskets 1414 Summit Racing 16.88 Fel-Pro intake valley pan 1215 Summit Racing 21.88 Fel-Pro oil pan (2) 1808 Summit Racing 16.16 Fel-Pro valve cover gasket 1612 Summit Racing 21.95 Billet Fabrication valve covers 3-1903 Billet Fabrication 351.00 March pulleys 10010 Summit Racing 189.88 Mighty Demon 850-cfm carb 5563010GC Jegs 549.99 Milodon oil pump drive 21505 Summit Racing 89.39 Milodon oiling system 21010 Summit Racing 319.95 Milodon oil pan 30931 Summit Racing 225.99 Milodon 160 thermostat 16400 Summit Racing 12.95 Milodon windage tray 32005 Summit Racing 65.39 Mopar water pump housing P4286900 Westoaks Dodge 172.80 MSD Blaster coil 8202 Summit Racing 39.88 MSD ProBillet distributor 8546 Summit Racing 295.88 MSD wires 31189 Summit Racing 80.88 Oil, 7 qts 10w30 Auto parts store 10.43 Oil filter Auto parts store 7.00 Scat rotating assembly 1-48051-1 Summit Racing 2,345.95 Scat 4.25-inch 4340 steel crank 444016 Summit Racing 1,399.95* Scat BBC rods, 6.7 inches 2-454-6700 Summit Racing 429.95* JE forged pistons 194915 JE Pistons 950.00* Speed-Pro rings R-9798 35 Summit Racing 139.99 TTI headers 440-200C4 TTI 824.00 Engine balancing labor JGM 250.00 Bore & hone w/ plate labor JGM 224.00 Align-hone, two-bolt labor JGM 150.00 Clean and magnaflux labor JGM 88.00 Deck block w/ fixture to index labor JGM 150.00 Grand Total $11,089.64
*Not included in the grand total**Similar to CCA-23-362-5 listed on Summit Racing
