Even with a 4.125-inch stroke, the rotating assembly fits neatly between the oil pan rails
The car that this engine is going into is equipped with a remote oil filter, so we needed a way to connect the external oil lines. The previous engine used an adapter on the oil filter pad to direct oil to the external lines, but the adapter was bulky and prone to leaking, so we wanted a different solution. After a little investigation, we decided to drill and tap the engine block itself, so we could attach the oil lines directly to the oil passages in the block.
The main oil passage that sends oil from the pump to the filter-pad area is accessible from the side of the block. If this oil passage is drilled slightly oversize and tapped, an oil fitting can be screwed right into the side of the block. There isn't much room in this area, so a 3/8 NPT fitting was the largest that we could install. When tapping the block for this fitting, we learned-the hard way-that the oil passage in the block was not drilled exactly parallel to the back of the block. Fortunately, we didn't ruin anything, but we did learn that it's best to verify the angle of the existing hole before trying to drill it oversize.
The Milodon 7-quart street pan fit perfectly over the rotating assembly without any interf
The 3/8 pipe threads in the block were smaller than what we wanted to use for oil lines, but there wasn't enough room to use anything larger. After a little research, we found a set of special fittings from Bo Laws Performance (BLP) that gave us a smooth transition from the pipe threads in the block to our -12 AN oil lines. On the return side, we found that a -10 to -12 AN O-ring fitting could be installed directly into the oil filter boss without any additional machine work.
As one would expect, the rear main cap on the 340 resto block is designed to use a 340 style oil pan. While it seems obvious that a 340 block should use a 340 oil pan, it isn't necessarily the best design choice. The newer 360 style oil pan is less likely to leak than the original 340 design, so an argument could be made that the race blocks should all come with the later design. Of course, if Mopar wanted to do us all a favor, they would make these race blocks compatible with the one-piece oil pan gasket used on the Magnum engines.
Milodon pickup 18346 cleared the rotating assembly without requiring any modifications. So
We originally wanted to use a Milodon windage tray on this engine but we quickly found out that a windage tray was not compatible with the four bolt main caps. Our attempt to modify the windage tray for clearance around the main caps wasn't pretty, so in the end we just left the windage tray out. We also noticed during the trial-fit stage of the engine build that some oil pans were too narrow to fit over the big main caps. The Milodon pan that we eventually settled on fit just fine, but one oil pan that we tried had to be knocked on and off the main caps. Evidently, the aftermarket hasn't fully embraced these Mopar race blocks quite yet!
At this point the short-block is fully assembled and ready for the top end. We have CNC-ported heads from Hughes Engines on order, as well as a ported intake from Shady Dell and a custom roller cam from Comp Cams. We certainly learned a few lessons about the Mopar race blocks during this project, but overall it has been a lot of fun. With any luck we'll have the engine finished and strapped on the dyno in time for the next article. Stay tuned as we finish assembly and hook our 427 to the lie detector.
One main stud had to be cut down to clear the body of the oil pump. ARP supplied us with a
Unfortunately, the Milodon windage tray would not fit over the four bolt main caps. We pro
We designed this engine around a hydraulic-roller camshaft but came to find out that the h
We thought we might be able to get lucky and use an older set of lifters that we had on ha
....We then thought we would be clever and use a set of lifters from a Magnum engine compl
Comp Cams saved the day with their brand-new 8043-16 lifters. These are solid-roller lifte
Once we had the lifter situation under control, we were able to quickly finish up the shor
The short-block assembly was finished up by installing a set of ARP cylinder head studs. W