Considerable attention was paid to the stock Mopar crank. After reshaping the throws and c
The oiling system on Adney's 318 block received treatment that should be standard operating procedure on any performance-oriented LA buildup. Problems start at the oil pump pickup tube. As it comes from the factory, the oil pumps are designed for a 3/8-inch screw-in pickup tube. That might be adequate for grandma's grocery-getter, but not for an engine making big power and turning a bunch of rpm. One might think the first response is to bolt on a high-volume pump, but in the 1970s, Chrysler engineers tested the flow volume with standard- and high-volume pumps, and found almost no flow difference until a second pickup tube was added to the bottom plate of the pump. Adney's version of this was to block off the stock oil inlet in the pump, and build his own pickup, threading it directly into the bottom pump plate. "I drilled straight through the oil pump cover, and I just plugged the normal place where the pickup would go in."
On older blocks with a ton of mileage, worn-out lifter bores can be a major source of oil pressure loss, as the passage that feeds the main bearings partially intersects eight of the lifter bores. The block that Performance Crankshaft was working on was in good shape here, but there are two options for those not as fortunate. The first and easiest is to "tube" the block. That is, drill and ream out the oil galleys that intersect the lifter bores, install a copper tube down the galley, run a broach down the lifter bores so the copper tube doesn't affect lifter operation, then re-drill the oil passages going to the main bearings. The tools and tubes necessary for this are available from Mopar Performance. The second option to fix the aforementioned problem is to have a machine shop install lifter bushings in the block. Although significantly more expensive, it is the recommended procedure for a race engine, especially for flat-tappet cammed engines, as the fixturing locates the lifter more precisely and accurately than the OEM tooling. As mentioned above, Adney's block was in good enough shape that just using an out-of-the-box Melling pump with the modified pickup provided a solid 55-60 psi from the hit all the way up to 6,500 rpm.
Something to consider if you plan on slapping together a combo like this is the fact that earlier non-Magnum blocks ('64-92 model years) send oil to the heads differently than the Magnum engines. The early blocks, like the one we're dealing with, shoot oil from the No. 2 and No. 4 cam bearings through holes in the cam, up through a passage in the block and the head, ending up at the rocker shaft where it is distributed to each of the rocker arms. The Magnum blocks and heads are not drilled with that passage, as they get oil through the lifters, then up through the pushrods like Chevy and Ford engines. When using Magnum heads on early blocks, the easy way to get oil up top is to use AMC lifters (which are dimensionally the same) but with pushrod oiling provisions, and use hollow pushrods like the pieces from Trend that Adney has. When setting up an engine this way, you can block the unused oil passages by either clocking the cam bearings so the holes don't line up with the passages, tapping the block passage in the deck, and installing a 5/16-18 setscrew in it, or simply using the Magnum head gasket that doesn't have the oil holes.
Adney plugged the original 3/8-inch NPT entry to his Melling oil pump, then built his own
Moving up higher on the engine, Adney used a set of Mopar Performance R/T Magnum cylinder heads, sourced from friend Randy Malik, owner of RM Competition. Randy "knew a guy who knew a guy," so they ended up with a set of former Super Stock heads that were in great shape. When asked about modifications, Adney responded: "They were ported when we got them; we just touched them up a little bit." Apparently, they were ported pretty well. (If we were to duplicate this buildup, we'd reach for a set of Engine Quest's iron Magnum heads, which will get you in the ballpark with minimal machinework and porting.) LS1-style Chevy valves were installed, along with a set of COMP Cams beehive springs and retainers. The combination worked great, as there were no signs of valvetrain instability with the tach climbing to 6,500.
The brain of the engine was a COMP solid flat-tappet camshaft with 247/247 degrees of duration at .050-inch lift. A mix of Harland Sharp and Crane rocker arms (1.7 intake and 1.6 exhaust, respectively) brought the lift to an impressive .622/.597 inches. The R/T Magnum heads were designed as basically an upgrade to the later-style Magnum heads, and the nonadjustable pedestal mount rockers wouldn't cut it with an aggressive solid lifter cam. A Crane rocker stud adapter kit was used that also incorporates a set of built-in pushrod guideplates. The kit goes a long way toward improving the valvetrain on the R/T heads, but with the 5/16-18 threaded holes that the studs live in, there is not a whole lot of stability there. Being a machinist, Adney solved this dilemma by making his own stud girdle.
The engine uses a Professional Products dual-plane intake sandwiching Fel-Pro Performance intake gaskets. Regarding the use of an early-style gasket on the late-model heads, Adney set the record straight: "They say the Magnum heads are supposed to use a different gasket from the regular heads. I found out that the regular gaskets, the 1243 Fel-Pro's, work just fine. The only thing you have to do is slot the boltholes. It works better than any other gasket they've got." The slotting is necessary due to the fact that the Magnum intake boltholes go straight up and down, whereas the early-style holes are perpendicular to the intake manifold face.
The R/T Magnum has an already efficient combustion chamber that was cleaned up during port
Topping the engine is a Holley 950 HP and a pair of Jomar carb spacers. "The carburetor was done by Randy Malik. Randy's about the best carb guy I've ever met." It was apparent that he knew what he was doing, as the fuel curve was nice and flat.
On the periphery, MSD provided the spark with a venerable 6AL firing the Champion Racing plugs. A set of Hooker headers bolted to Magnaflow mufflers kept the exhaust moving at a steady clip after exiting the combustion chamber. The power created by the Shell V-Power 91 octane passed through a Hays flywheel before ending up at the DTS dyno.
After the dust had settled and the Challenge had ended, Adney reflected, "318s don't have a very good following or a very good name." Like the Rodney Dangerfield of the performance world, the 318 gets no respect. The LA engine was in production for 39 years with variants ranging from the baby 273, to the 360s, and several in between. Of all the Mopar small-blocks created, the 318s were always referred to as the wheezing, slowpoke, economy engines, but Adney Brown truly believes that even on a modest budget, that little engine can be made into a stout performer. And the dyno-the great lie detector-agrees!
Milodon provided the oil pan and windage tray for the 318. Similar to early Chevy II's, th
With the super-aggressive COMP Cams MM and MHF solid-lifter cam lobes designed for the big
The 318 has LS1-style lightweight Ferrea valves. The COMP beehive springs are set up with
Fel-Pro doesn't currently offer a performance intake gasket for the Magnum heads; however,
With the small cubes, a small, dual-plane intake ended up making the average torque and ho
This innocent-looking carb started life as a generic Holley 950 HP, then was modified by R
Combining a two-hole with a four-hole spacer effectively increases plenum volume while ret
Bombproof as ever, an MSD Pro Billet distributor backed by a 6AL box and MSD plug wires pr
Displaying their ingenuity once again, Adney and the crew from Performance Crankshaft came
Adney Brown has reason to smile. In addition to his own entry into the 2007 Jegs Engine Ma