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Debating oil mods for a 401

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gremlinsteve View Drop Down
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    Posted: Oct/06/2017 at 8:28pm
I'm debating whether I need to do the typical oil mods for my 401 or not
It's going to probably make 500 hp but the kicker is I rarely race or run them hard

I won't be seeing but 5500-6k rpm on very few occasions

So should I do the mods or not. That's the debate going on inside my head

Maybe I can do some? Leave others off the list since it's not a race car

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Post Options Post Options   Thanks (1) Thanks(1)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Oct/06/2017 at 8:42pm
As long as you have the engine guy correct the crank oiling as there is a known problem since the beginning of the 401 and it's ending. You won't need any oiling mod. Just be sure your builder builds it within AMC spec. The critical issues are clearances. Should I reiterate? Clearances. You can have a slightly tighter clearance for thinner oils, but racers have more open clearances and require thicker oils.

The oil pump is critical, be sure the chamber, gear mesh, adapter housing and bypass functions properly. I recommend obtaining the Jeep oil filter pipe end for use of the Ford FL-1A oil filter as it has a built in oil feed bypass, which is better than he original built into the adapter. The adapter requires a slight mod to seal the bypass along with the Jeep pipe end.

I will search and post a couple of threads to assist with further details on what I have quickly posted.

71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Oct/06/2017 at 8:45pm
http://theamcforum.com/forum/oil-pressure-problem-resolved_topic74349.html

http://www.theamcforum.com/forum/401-crank-oil-passages-wrong_topic72917.html

It is about time for the end of my day... will post a thread that has some simple mods to assist with crank and journal oiling.



Edited by 304-dude - Oct/06/2017 at 8:53pm
71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
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gremlinsteve View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote gremlinsteve Quote  Post ReplyReply Direct Link To This Post Posted: Oct/06/2017 at 8:46pm
Define crank oiling

We talking about the lifter valley oil line?
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304-dude View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Oct/06/2017 at 8:57pm
Originally posted by gremlinsteve gremlinsteve wrote:

Define crank oiling

We talking about the lifter valley oil line?


The main issue with 401 over all other cranks is that it was drilled incorrectly on some of the oiling to the journals. 390 on down are all correctly drilled.

The upper valley bypass line is not a fix but many run it. Most don't need it, but it helps mostly on the 401 without directly addressing the issue.

71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
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gremlinsteve View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote gremlinsteve Quote  Post ReplyReply Direct Link To This Post Posted: Oct/06/2017 at 9:00pm
So we need to chamfer the crank oiling hole to aligne with the block better
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Post Options Post Options   Thanks (0) Thanks(0)   Quote gremlinsteve Quote  Post ReplyReply Direct Link To This Post Posted: Oct/06/2017 at 9:05pm
I guess I can cross drill them to
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Oct/07/2017 at 2:29am
Cross drilling is old school and most now don't even bother. Chamfering is a common and good option. Fully grooved bearings work well with oiling.

There are other areas to make sure oil is properly channeled to lubricate.

Re drilling the block carefully through the oil passages is a hidden mod that is not really a mod. Many blocks were not fully drilled and create restriction at the rear bearings. It's really a clean up that I would think many builders do with all blocks, but my reasoning is not what has been done through the years. So that must be done as a request or can be done carefully as not to drill any further than cleaning up the junction to the oil galley, from the center holes at the mains, on the block.

The front cam bearing, and cam gear need to be addressed as it can wipe out cam and distributor drive gears if not checked.

Adding a nut to the bottom of the oil pickup for clearances sake. Believe it or not the pickup can create an issue with oil starvation if the gap to the pan is too close.

Will add the link to crank oiling fix... IIRC, Skowen or SC397 (i could be wrong, fuzzy with profile name) had pointed out when explaining the critical areas for oiling.

Here is the link... sorry Photobucket has taken away images, so you will hae to carefully read and search further on details. I would focus on what I explained, most of the mods are for extreme use and may not have any benefit for most engines. Once you dig into the issues I addressed, you will find it is mostly making sure every detail has been checked as for removing any restrictions that the factory left during machining, or should I say lack of machining.

http://www.theamcforum.com/forum/oiling-modswhos-done-em_topic34008_page1.html

Edited by 304-dude - Oct/07/2017 at 2:49am
71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
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Post Options Post Options   Thanks (1) Thanks(1)   Quote SKeown Quote  Post ReplyReply Direct Link To This Post Posted: Oct/07/2017 at 10:12am

 There has been a lot of negative talk about the AMC V8 oiling system. Much of the talk was in an effort to sell unnecessary parts. The system is plenty adequate for it's initial intended use. However if one wants to extend their engines operating range then alterations are called for.

 Assuming the engine is fitted properly. The first thing you should do is increase the oil supply capacity, bigger pan. The next thing is to devise a means to adjust the oil pump pressure relief tension, some just shim the spring to obtain the desired amount of bypass. I've found the oil pump to be more than adequate and not that sensitive end play clearances. It would be nice if someone would design and market an adjustable pump bypass tension means.

 For racing if roller rockers are utilized then reduced feed pushrods should be implemented. If roller lifters are used then Johnson brand will prevent pressure bleed off around the rollers. By bushing the lifter bores with small oil feeds then any roller lifters can be run and the need for reduced feed pushrods is eliminated, but then and only then the auxiliary internal oil feed should be installed. The simplest and most practical approach is Johnson lifters with Smith bros. reduced feed pushrods.

 My recommendations are based on the 49 years of off and on racing of my 68 AMX. I believe the most often overlooked area is the oil pump bypass, it's critical.





 SKeown


Edited by SKeown - Oct/07/2017 at 10:38am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote gremlinsteve Quote  Post ReplyReply Direct Link To This Post Posted: Oct/07/2017 at 1:30pm
Remember

I'm not racing this motor
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