Oil System
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 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.

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.

1863 Eastman Avenue
CA  93003
JE Pistons
15312 Connector Lane
Huntington Beach
CA  92649
Hughes Engines
23334 Wiegand Lane
IL  61571
Competition Cams (Comp Cams)
3406 Democrat Road
TN  38118
K1 Technologies
889 76th Street SW Unit 6
Byron Center
MI  49315
Mancini Racing
33524 Kelly Road
Clinton Township
MI  48035
Milodon Inc.
2250 Agate Court
Simi Valley
CA  93065