Oil line - lifter valley

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   I bought a 401 from a Jeep.  All stock, all original.  The last rod journals were slightly scored and the bearings had more wear.  I take this as evidence that even on a stock engine the line would be of benefit.  Most of the pictures I see the line is 3/8, often with multiple crappy fittings.  I use good fittings and -8 AN line.  If the pressure is the same at the back with and without the line then two explanations are possible.  One is as I said above a cobbled up restricted small rump line won't help much.  The other is if the pressure drop from front to back is the same but the flow area is larger, then the flow is higher.  Roughly proportional to the area increase.   Pressure is not flow.  BB

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BassBoat Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Aug/29/2008 Status: Offline Points: 1719	Post Options Post Reply Quote BassBoat Report Post Thanks(0) Quote Reply Posted: Apr/28/2015 at 7:55pm
	I bought a 401 from a Jeep. All stock, all original. The last rod journals were slightly scored and the bearings had more wear. I take this as evidence that even on a stock engine the line would be of benefit. Most of the pictures I see the line is 3/8, often with multiple crappy fittings. I use good fittings and -8 AN line. If the pressure is the same at the back with and without the line then two explanations are possible. One is as I said above a cobbled up restricted small rump line won't help much. The other is if the pressure drop from front to back is the same but the flow area is larger, then the flow is higher. Roughly proportional to the area increase. Pressure is not flow. BB

SKeown Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jul/30/2009 Location: Texas Status: Offline Points: 3085	Post Options Post Reply Quote SKeown Report Post Thanks(0) Quote Reply Posted: Apr/28/2015 at 8:38pm
	When there is a momentary loss of pressure the rear journals are the first to be effected and the last to recover weather or not one has installed the auxiliary oil feed line. I spun the #7 rod bearing in my 68 AMX's original engine. That was caused by extended high RPM operation with only 4 quarts of oil in the system. I had the #6 rod bearing get trashed on a more recent engine. That was traced to a tight #4 main bearing that fed debris to that rod journal. A larger capacity oil sump is critical for higher than normal engine operation. SKeown

Aljav Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jul/18/2007 Location: Wisconsin Status: Offline Points: 1037	Post Options Post Reply Quote Aljav Report Post Thanks(0) Quote Reply Posted: Apr/29/2015 at 2:09am
	The one thing we always forget to talk about is the holes drilled from the mains to the lifter oiling hole. You need to get a drill and run it thru the hole. Chances are you feel that the hole was not completely open. I did two 401 blocks in the same day and 8 of the holes were not completely open. I fell this probably a bigger issue than many know about. The main problem is you can't see it.
	69 AMX 9.86 132 mph 71 JAV/AMX and 69 Javelin, .. NAMDRA member #1106