STEVE DULCICH AND ROSS MARTINDALE
5567 Rd. 148, Dept. PHR
EARLIMART, CA 93219
Steve and Ross' approach to the Engine Masters Challenge was based on their years of experience with big-block Mopar engines. We inaccurately printed that they based their build on engine-modeling software, which was untrue. We had notes on many builders, and the wrong notes were used in reporting their entry. For this we apologize, and Steve made a point to say he doesn't even have engine modeling software. They designed and built this engine purely from experience, which is a credit to their talents.
The low-deck stroker combo for the Mopar Wedge has become a popular option, and they chose this architecture to build upon. Obviously it worked, and now stands as a great example for Mopar enthusiasts to duplicate. Steve told us how it went down.
"I had looked with interest at the first year's event, and recognized that PHR had a winner with this extravaganza. Looking at the restraints imposed by the rules, I was confident that a big block Mopar could post good numbers, if not sweep the field outright. The factory configuration has an exceptional surface-to-volume ratio with the tight wedge chambers; highly stable shaft-mounted rockers; bore, stroke and rod ratios that are dead in the zone for making power; and with the flat tappet rule, the possibility for more camshaft velocity than other makes with less lifter diameter. The Mopar Wedge seemed to have what it takes, and that was fortunate, since as a diehard Mopar guy, I wouldn't have considered anything else.
"We delivered the block to Jim Grubbs Motorsports in Valencia, California, for machining. For precision work, Jim is a top man and I wanted the best. He squared the decks, milling to allow the pistons to have a positive .005-inch deck. At this deck, the 470 would have a tight .034-inch quench clearance, and a 12.7:1 compression ratio. That's a lot for 92-octane, but I was confident. The secret would be in the quench, cam timing, and the use of thermal barrier coatings. Boring and decking were the only machining done to the block, and the factory main caps were retained, buttressed by ARP main studs."
The block is a factory 230 400 H ('72) block, with stock main bearing caps. This low-deck 400-inch unit carries Chrysler casting number 3614230-2, and has a 4.375-inch bore. The crank is an Ohio Crankshaft forged steel 440 unit pushing a 3.90-inch stroke. Mounted to the front of the crank is a TCI Rattler balancer with a 7.2-inch diameter. The block features homemade and elaborate sheetmetal internal baffling for windage control. The internal baffling including enclosing the camshaft--something we also saw on Kaase's Ford. Oil control is becoming a huge factor in dyno racing, and should be in your street engine too.
The connecting rods are by Manley, and are steel. Pistons are from Ross, and boast coated skirts and full-floating pins (2.915-inches in length). Rings consist of a 2-piece gapless 1/16-inch top ring with a standard-type 1/16-inch second ring. The oil control ring is a typical .180-inch arrangement. Bearings are by Federal-Mogul, and are standard 2.2-inch diameter on the rod journals. The 3.9-inch stroke Ohio forged crank was reworked by Dulcich with an 8-inch angle grinder, then balanced. The Tech Line thermal barrier coatings were applied at Dulcich's shop and cooked in his kitchen oven. The coated bearings are from Calico Coatings, and require no prep work to install.
"The plan was to have a custom flat-top piston made to specs, with lateral gas ports and low-drag .043-inch ring package. Time was short, and there was no one I could find to make such a piston in time. Fortunately, Ross offers a shelf piston for just this combo, except with 1/16-inch ring grooves. I hated to have to give up my preferred ring combo, but to make the best of the situation, I ordered a Total Seal gapless top ring in the 1/16-inch width, but specified a special second ring to reduce friction. The second ring was back-cut for lower tension, and was given a Napier Scraper face to enhance its oil-scraping efficiency. I was uncomfortable with the back-cut second ring in a standard-depth groove, due to the potential for oil pooling behind the ring and making its way into the chamber, but alternatives were thin."
The cylinder heads are Chapman CNC-ported Mopar Performance Stage VI heads (PN 4532885), with Max Wedge port sizes. For big-block Mopar guys, this is about as good as it gets in a factory-replacement head. When teamed with the Ross pistons, compression checked in at about 12.5:1.
"Right from the onset, I already had the cylinder head in mind. Chapman Racing Heads revised the Stage VI castings, and offer a beautiful CNC-ported version. I examined these heads before the Engine Masters Challenge, and I knew it had what it takes. The runner volume is 285cc (large version), which is pretty moderate, yet the flow is in the stratosphere at over 380 CFM. That flow efficiency is practically unheard of. With the broad power range required to be competitive in the Challenge, this head would be hard to top. I used the Mopar/Chapman heads as delivered, with no additional modifications."
Dulcich chose a custom-ground Comp Cams solid-lifter cam, teamed with Harland Sharp 1.7:1 rockers and 1.550-inch diameter springs. "I realized from the start was that the valve action would have to be as rapid and aggressive as possible, while maintaining reliability and stability. This is accomplished with the lobe profiles and the rocker ratio. The EMC rules limited ratio to 1.7:1, so that's what I used, getting needle bearing roller rockers from Harland Sharp.
"For lobes, Competition Cam's 'MM-series' solid flat tappets fit the bill, as the quickest practical lobes designed to take advantage of the large .904-inch Mopar lifter diameter.
"My calculations pointed to a profile in the mid 250's at .050-inch lift, and a 105-degree lobe separation. The 3-inch muffled exhaust rule threw me a curve, since almost all my previous experience was in testing engines with open exhaust. I decided that the solution was to add a few degrees of duration, widen the centers a bit from what I initially intended to run, and roll the installed centerline forward to blow the engine down earlier, while maintaining similar overlap. I figured that a single pattern cam with 259-degrees of duration at .050-inch and a 108-degree lobe separation would be ideal, and I had exactly that cam leaning against the bookshelf in my office for another project. Completing the valvetrain were standard Comp Cams solid lifters, custom Smith Brothers' pushrods, and a regular Comp three-piece roller timing chain set to provide a 102.5-degree installed intake centerline. A belt drive was outside my budget.
"For induction, I needed an intake manifold to match the Max-Wedge port window of the Chapman heads, and I wanted to run an intake with a 4150 base topped with a 4500 carb via a tapered HVH spacer. I feel this maintains a consistent cross sectional area, as opposed to a 4500 base intake. I used an Indy 383-13 intake manifold, which required spacer plates to mate with the slightly raised Stage 6 ports. A standard raised-block intake would have bolted right on, but I already had the low-deck piece. I extensively ported the manifold in the plenum giving a rolled continuous radius from the runners into the carb base. The manifold had plenty of meat to work with and was really nice. I chose a Barry Grant King Demon RS carb fitted with blue venturi sleeves with #20 air bleeds and #96 jets.
"To provide oil pressure at a minimal requirement, I opted to use a stock pump, actually a 35-year-old piece scavenged off a '69 440 engine core. I polished the rotors and ported it, and added Milodon's adjustable external regulator. A Milodon windage tray and deep sump provided additional oil control."
The front of Dulcich's Mopar was armed with a Meziere electric water pump and a TCI Rattler balancer. These well-engineered parts work great, and look good too. We saw plenty of Meziere pumps in the Challenge, and we expect electric water pumps to begin showing up in more street machines. While some manufacturers still only recommend them for racing, the increased flow volume and durability of the newest designs should be fine for street machines.
"As for the exhaust, previous experience had shown me that the TTI Inc. 2 -inch-2 1/8-inch step header offers about the broadest power band of any chassis headers in high-horsepower applications, so that's what I used. The rules stated that 3-inch mufflers were required, so I ordered a pair of Hooker's high flowing Max Flow mufflers (PN 21606), and joined them to the 3.5-inch collectors with some tapered pipes I welded up. To mount to the muffler's exit, I made some tapered megaphones to try and psyche-out the competition."
The ignition system was all MSD, from the 6AL box (borrowed from a friend) to the Blaster II coil, distributor and wires.
"Before assembling the short-block, a few more tricks were employed. The flat tappet cam would be pushing the limits on aggressive valve action, and needs fairly stout springs to work, pushing the load limits on the cam/lifter interface. To directly oil the cam's lobes, I cut grooves in the un-bushed stock lifter-bores from the oil galleries downward. This was done by hand with a chopped-off hacksaw blade and a homemade jig. Above the cam, the center two lifter-valley windows were sealed from drainback with some standpipe plates fashioned from sheetmetal and tubing and epoxied in place. The outer two windows were fitted with screens, cut from an old metal '70s Jensen speaker grill and likewise epoxied in. Beneath the cam, I cut some sheetmetal baffles to close the cam bore from the crankcase. Tunneling the cam bore in this way from above and below would have the cam swimming in oil, to help ensure the flat tappet's survival, and also allowed me to control drainback.
"The engine was completed only days before qualifying, allowing only one day for pre-competition dyno testing at JMS Machine in Monrovia, California. Really, there wasn't any time for parts swapping or experimenting with the combo. We just hooked the beast up, ran it to break in the camshaft, bunged in the inner valvesprings, jetted it, and ran some trial pulls. The engine worked really well...well enough to qualify First in the western region, and sweep the field in outright peak horsepower. Considering the limited development time, and a virtually untested combo, I was pretty pleased with this Mopar." --Steve Dulcich
So, there you have it. The reason we developed the Challenge competition was to be able to show readers some great 92-octane performance engines and see tips and tricks not seen elsewhere. These three engines are outstanding examples, and we credit their designer/builders for outpowering everyone else in the nation. They have proven to be the best this year, and we hope you'll be able to use their work as inspiration for your own project. The formulas work, the engines perform, and the dyno doesn't lie.
The Engine Masters Challenge is proud to crown its three kings, and the tension is already building toward the 410-inch battle to be fought in 2004. Will you be there? If so, we look forward to seeing your best efforts. If not, look to the pages of PHR for all the action, and the results of the world's premier engine competition: The 2004 Jeg's Engine Masters Challenge, presented by Popular Hot Rodding magazine!
|CYLINDER HEAD AIRFLOW|
|(Measured on the Westech Performance Group flowbench after Engine Masters Challenge completion, as part of Teardown inspection) |
|INTAKE VALVE||EXHAUST VALVE|
|Valve opening (inches)||Airflow cfm at 28 inches depression||Valve opening (inches)||Airflow cfm at 28 inches depression|
|.050||36 cfm||0.50 ||30 cfm|
|0.100||73 cfm||0.100 ||60 cfm|
|0.200 ||148 cfm||0.200 ||107 cfm|
|0.300 ||214 cfm||0.300 ||158 cfm|
|0.400 ||270 cfm||0.400 ||210 cfm|
|0.500 ||308 cfm||0.500 ||232 cfm|
|0.600 ||332 cfm||0.600 ||250 cfm|
|0.700 ||350 cfm||0.700 ||265 cfm|
|0.800 ||385 cfm ||0.800||278 cfm|