Debating oil mods for a 401
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Category: The Garage
Forum Name: AMC V8 Engine Repair and Modifications
Forum Description: AMC-made V8 engine mechanical, ignition and fuel from basic repair to high-perf modifications
URL: https://theamcforum.com/forum/forum_posts.asp?TID=90175
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Topic: Debating oil mods for a 401
Posted By: gremlinsteve
Subject: Debating oil mods for a 401
Date Posted: Oct/06/2017 at 8:28pm
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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 |
Replies:
Posted By: 304-dude
Date Posted: Oct/06/2017 at 8:42pm
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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 |
Posted By: 304-dude
Date Posted: Oct/06/2017 at 8:45pm
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http://theamcforum.com/forum/oil-pressure-problem-resolved_topic74349.html" rel="nofollow - http://theamcforum.com/forum/oil-pressure-problem-resolved_topic74349.html http://www.theamcforum.com/forum/401-crank-oil-passages-wrong_topic72917.html" rel="nofollow - 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. ------------- 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 |
Posted By: gremlinsteve
Date Posted: Oct/06/2017 at 8:46pm
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Define crank oiling We talking about the lifter valley oil line? |
Posted By: 304-dude
Date Posted: Oct/06/2017 at 8:57pm
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 |
gremlinsteve wrote:Posted By: gremlinsteve
Date Posted: Oct/06/2017 at 9:00pm
| So we need to chamfer the crank oiling hole to aligne with the block better |
Posted By: gremlinsteve
Date Posted: Oct/06/2017 at 9:05pm
| I guess I can cross drill them to |
Posted By: 304-dude
Date Posted: Oct/07/2017 at 2:29am
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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" rel="nofollow - http://www.theamcforum.com/forum/oiling-modswhos-done-em_topic34008_page1.html ------------- 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 |
Posted By: SKeown
Date Posted: Oct/07/2017 at 10:12am
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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
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Posted By: gremlinsteve
Date Posted: Oct/07/2017 at 1:30pm
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Remember I'm not racing this motor |
Posted By: Airdrie AMX
Date Posted: Oct/07/2017 at 2:19pm
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5500-6000rpm sounds like a relatively mild performance build, personally I would fit a larger capacity pan and forget about the rest. As an example my current 401 is similar, 6200rpm max hydraulic cam etc... and it gets driven hard every time I drive it the only thing in the way of oil "mods" are a milodon 7qt pan and swinging pick up. I have never experienced oil pressure issues as in pumping the pan dry and momentarily loosing pressure. So far in the 8 yrs I've been abusing it LOL it seems pretty bulletproof. At your intended rpm goal I wouldn't get caught up in crank oiling "problems" if that were the case 401 everywhere would be self destructing. Just my opinion. ------------- 72 amx javelin 401 4spd |
Posted By: gremlinsteve
Date Posted: Oct/07/2017 at 2:25pm
| I agree. I've decided to keep it simple |
Posted By: Boris Badanov
Date Posted: Oct/07/2017 at 4:21pm
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In my experience the biggest problem with high output AMC V8s is all that oil staying in the valve covers and rear of the lifter gallery. A high capacity pan can mitigate this very real problem. AMC like Buick (Nearly identical oil system in most respects) did a lousy job on returning the oil to the pan. ------------- Gremlin Dreams |
Posted By: gremlinsteve
Date Posted: Oct/07/2017 at 5:17pm
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Jcisworthy and I where just talking about that I think I'll be putting a canton oil pan onto this motor also |
Posted By: JERSEYJOE
Date Posted: Oct/07/2017 at 5:39pm
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I have to put in a few words here. If you check out my project AMX you will find that I have a lot oiling mods NOW. When the AMC factory guys put it together in 1970 to race SCCA B production they had very few oil mods. The car raced up until 1975 with NO engine failure. The only mods were: Oil drain back from the valve covers to the pan. Basic stuff, keep the oil in the pan and not upstairs. 2 quart Accusump in case there was a cavitation the Accusump supplied the system with oil for a couple of seconds. Blueprinted oil pump and external feed from pan. Oil cooler. There was no valley oil line ever, don't think that in 1970 anyone discovered this yet. NO camshaft anti-walk set up or distributor gear oil mod. Of course it has all this stuff because I felt compelled to do so!! After I bought the car in 1981 and thrashed it on the street for a couple of years I took the motor apart and there were zero issues. When I redid the motor for the current project of course I replaced the bearings after the crank was inspected and only polished. The valley line does work but for your needs I would say not needed. Spend the time and money and put at least one oil drain back from the valve covers to the pan and maybe a cooler and call it a day ------------- 1985 J-20 PLOW TRUCK 1977 CJ 7 360 T-18 D 300 1970 AMX ex-SCCA car SPEED COSTS MONEY HOW FAST DO YOU WANT TO GO? |
Posted By: gremlinsteve
Date Posted: Oct/07/2017 at 6:02pm
| Awesome input |
Posted By: wantajav
Date Posted: Oct/07/2017 at 6:47pm
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For me (343 build), I'm planning on adding 1 extra quart of oil, that seems to mitigate a lot of the issues... step two: making sure the oil pump is factory tight for clearances and the timing cover is straight... step three -making sure the block factory passages are clear. No flashing or restrictions.
...and using both high zinc oil (Joe Gibbs or similar) AND zinc additive at all times. That's what my machine shop guy recommended, the oil and the additive both. |
Posted By: BillyBobsAMX
Date Posted: Oct/07/2017 at 7:53pm
I recently read on youtube that the 401 is a truck engine and will eventually blow apart due to bad oiling. So I advise you not to run an AMC motor.
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Posted By: JERSEYJOE
Date Posted: Oct/07/2017 at 8:06pm
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Well I can tell you there are a lot of 401's running around that put out a lot of HP without exploding, but I may agree the rod ratio is not as forgiving as a 390. Still with proper assembly they are very reliable. ------------- 1985 J-20 PLOW TRUCK 1977 CJ 7 360 T-18 D 300 1970 AMX ex-SCCA car SPEED COSTS MONEY HOW FAST DO YOU WANT TO GO? |
Posted By: 304-dude
Date Posted: Oct/08/2017 at 6:01am
From what I gather, above 5000 RPM the 5&6 rods will run drier than the rest and spin a bearing. This is due to an improperly drilled crank. No other AMC crank is done that way. That is why I stuck with a 390 in selecting a build. Actually I am reversing the lifter valley mod, as it is not required. I truly think due to the 401 being raced brought up such a mod, and peeps were using it on all builds thinking their non 401 needed it. Though there are a few who have had the 7 and 8 rod bearing issues with stock 2nd gens, are mostly with the 401. To be honest a factory oiling system with a stock oil fill does well at no higher than 5000 RPM with a 304. Believe me I abused my mostly stock 304 like a mad man back in the day. I can't say that a 401 could handle a lot of 5000 to 6000 RPM with out correcting some of the inherent issues with the incorrectly drilled crank. ------------- 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 |
Posted By: 73hornut
Date Posted: Oct/08/2017 at 7:41am
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The biggest head ache you will have related to oiling issues will be from the timing set. MOST aftermarket sets are just slightly better then junk and need work to make them right. Save yourself much stress and buy a Rollmaster set.
------------- 71 Javelin 74 Gremlin 79 Spirit AMX Rogue Valley Rumblers Like Us on FB https://www.facebook.com/groups/1602825606650796" rel="nofollow - https://www.facebook.com/groups/1602825606650796 |
Posted By: Hurst390
Date Posted: Oct/08/2017 at 7:50am
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I would just finish drilling out the main feed passages, switch to a ford oil filter and its required bushing(Mopar Part No.: 53007563AB CONNECTOR-OIL FILTER) that the filter threads onto in your adapter...and a large capacity pan...all you need ------------- SC/Hurst Rambler 11.62 120 100% Street Legal |
Posted By: gremlinsteve
Date Posted: Oct/08/2017 at 10:27am
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Ok So I've purchased the parts to swap to the ford filter I've also inquired about a new oil pan. Not sure my stock starter will work though Do I drill the small oil hole into the drivers side oil passage plug to feed oil to the timing set? I have a good timing set also I've seen the grooved main bearing saddle mod. I might do it Or should I just run grooved main bearings Or both |
Posted By: 304-dude
Date Posted: Oct/08/2017 at 10:49am
Fully grooved bearings, chamfer the crank journal passageways, check and make sure cam, timing gear set and front cam journal has proper machining. Don't bother with an oversized oil pan, your not building a race motor. Just have the engine guy swap out the nylon buttkn and weld a nut at the bottom of the oil pickup, to keep the pickup clear if the button should come loose. Adding an extra quart will not hurt and it will keep oiling from running dry. There is a cam and gear set discussion about after market parts not oiling properly. Do not assume quality stuff will fit and function, even if it states made for AMC. Checking clearances and proper fit and function is part of a good builder. That is what you are paying for outside of machine work. |
Posted By: SKeown
Date Posted: Oct/08/2017 at 3:38pm
I never switched to a different filter, but it's probably not a bad idea. When Hurst corp. converted 50 AMX's for S/S competition it wasn't long before it was realized that an additional 2" depth to the oil pan was needed to prevent oil starvation and blown engines. I've seen the Western Union first hand that called for that sent to AMC dealers. In an attempt to see more than 45 PSI hot pressure with 20/50 racing oil I tried everything including bushing lifter bores and saw no difference at all. That was until I fitted an adjustable pressure bypass spring, once I did that 70 PSI or more was no problem. I had tried different relief springs early in the process with no change either. Remember, I tried everything possible to enhance my engines oil pressure without any change until the increase in bypass pressure proved that much I had done was unnecessary. SKeown
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Posted By: mixed up
Date Posted: Oct/08/2017 at 11:33pm
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one simple mod is cleaning up the oil passages in the back of the head smooth out the hole and area around the hole help aid in oil drain back to lifter valley and look around all the push rods a lot of flash from casting is in this area ------------- 69 amx 290 auto 65 220 290 4spd 80 ford fairmont |
Posted By: 67 Marlin
Date Posted: Oct/09/2017 at 9:16pm
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Lots of good info in this thread. I remember seeing some of these tips in BJ Builds an AMC. http://www.ifsja.org/forums/vb/showpost.php?p=1678620&postcount=5" rel="nofollow - Here's what a forum member did to my cam and timing set to help make sure my rebuild will be oily in a good way. For the Ford filter swap, is all that's required is the mopar part # that was referenced or is a different stud necessary for the Ford filter to screw onto? |
Posted By: 73hornut
Date Posted: Oct/09/2017 at 9:23pm
------------- 71 Javelin 74 Gremlin 79 Spirit AMX Rogue Valley Rumblers Like Us on FB https://www.facebook.com/groups/1602825606650796" rel="nofollow - https://www.facebook.com/groups/1602825606650796 |
Posted By: farna
Date Posted: Oct/10/2017 at 6:08am
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The deeper pan was for a full bore drag racing engine with the car pulling the wheels off the ground -- remember that!! For a good street performance/bracket race engine an extra quart in the pan is all you really need. That's what AMC specified for police/severe duty engines -- n extra quart in the SAME pan. The police pan has a rudimentary baffle which helps on hard braking, but that's all. The pan is large enough to hold the extra quart without fear of the crank hitting oil and causing it to foam. No other oiling mods are really necessary for a street/occasional bracket race engine. If you're running the dog crap out of it, like all-out drag racing, it may need a little help (like most other production engines). ------------- Frank Swygert |
Posted By: BillyBobsAMX
Date Posted: Oct/10/2017 at 8:00pm
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You mean the oil pressure relief was opening so you only got 45psi? |
Posted By: AZ_chip
Date Posted: Oct/29/2017 at 4:15am
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All great info! I am starting a 401 rebuild myself. I saw the adjustable oil relief spring idea elsewhere. Maybe here. I read somewhere the idea of painting the valley with a product called Glyptol. Any thoughts on that? ------------- 1981 Jeep Cherokee AMC 360 Holley Sniper |
Posted By: Boris Badanov
Date Posted: Oct/29/2017 at 7:24am
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Personally I do not like the idea of coating anything inside of an engine. ------------- Gremlin Dreams |
Posted By: mixed up
Date Posted: Oct/29/2017 at 8:15am
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I have seen lifter valley painted but im with boris not a fan possibility of it flaking always crosses my mind but one thing that can be done is to smooth the vally to promote drain back ------------- 69 amx 290 auto 65 220 290 4spd 80 ford fairmont |
Posted By: gtoman_us
Date Posted: Oct/29/2017 at 11:32am
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My 327 came with the Red Glyptol from the factory with no signs of flaking or chipping. ------------- Moderator - Emeritus Used to collect trophies, now I collect gas receipts and put on miles 1964 Rambler Ambassador Cross Country Wagon 1965 GTO 1931 Model A original survivor "Flat Roofs are Cool" |
Posted By: pit crew
Date Posted: Oct/29/2017 at 8:09pm
Glyptol and other types of coatings have been used for many years both on and off the track. Even AMC used it on "factory" engines in the Rambler days. It is like any other product that someone might use. Done it right all is fine. Screw up and you pay the price. Don't blame the product, blame whomever did not follow the proper procedures, instructions, or recommendations. -------------  73 Hornet - 401EFI - THM400 - Twin Grip 20 |
Posted By: dbomb
Date Posted: Nov/08/2017 at 3:52am
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cam bearing oil holes are huge in this motor bleed off a lot that can starve other areas and you can put a restrictor in line to the lifter bores if needed without bushing the bores cam bearings can be reclocked upon installation and re drilled smaller like .070 I like to do this instead of running internal line or restricted pushrods I've never run an internal line actually is make sure you're crank is drilled right and that supply to rear main is drilled and put that little nut on the oil pickup to space away from pan Some other brand engines have little plastic button on oil pickup but not amcs. 6 quarts ------------- rebuiling 73 amx need parts |
Posted By: jcisworthy
Date Posted: Nov/08/2017 at 4:10am
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Bleed off is a function of clearance not the size of the feed hole. ------------- Specializing in dyno services, engine building, and cylinder head porting rbjracing.com Phone Number 518-915-3203 |
Posted By: dbomb
Date Posted: Nov/08/2017 at 4:13am
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True Jc but they are much larger than many others I've installed ------------- rebuiling 73 amx need parts |
Posted By: dbomb
Date Posted: Nov/08/2017 at 4:15am
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Probly non issue for him anyway ------------- rebuiling 73 amx need parts |
Posted By: Red Devil
Date Posted: Nov/08/2017 at 12:14pm
... maybe some years don't, but the few I've taken apart do have a plastic button. |
Posted By: Boris Badanov
Date Posted: Nov/08/2017 at 4:07pm
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I have two engines with the lovely little plastic button in place. Both are Nash Cans... (AMC) They will not go together without them being replaced by brazed in steel. ------------- Gremlin Dreams |
Posted By: ruphianh
Date Posted: Jun/12/2019 at 9:35am
I have a builder building a 401, I’d like to send him this screenshot. For my own education, what is an adjustable pressure bypass spring?
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Posted By: Red Devil
Date Posted: Jun/12/2019 at 10:53am
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The relief valve is the spool & spring under the hex-head cap on the filter housing. Stock is a fixed setting, since the spring is not adjustable. The relief is the primary control of oil pressure at higher rpms (pump flow vs. clearances limits lower rpm pressure) ... assuming decent clearances and correct oil viscosity. Most are fine with the fixed spring. Some shim it. Some make it adjustable with various means - e.g. thread the spring retainer and use a bolt with sealant and jam nut or a sealing nut. Some fit a different spring. Some run tight clearances to dump more oil over the relief effectively displacing the spool further raising system pressure. Mine is like this:  No kits available that I'm aware of, so simplest to run the stock setup and adjust only if you feel the need. Stock works for most with stock clearances. Hope this helps, RD. |
Posted By: JERSEYJOE
Date Posted: Jun/12/2019 at 11:03am
  ------------- 1985 J-20 PLOW TRUCK 1977 CJ 7 360 T-18 D 300 1970 AMX ex-SCCA car SPEED COSTS MONEY HOW FAST DO YOU WANT TO GO? |
Posted By: 73hornut
Date Posted: Jun/14/2019 at 9:49pm
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My new oil modification. 5W30 Renewable Lubricants, Super High Performance Passenger Vehicle, Bio-SynXtra, motor oil = 130,436 psi This patented biobased motor oil uses agricultural vegetable oil base stock, and is biodegradable. It claims to provide optimum performance in newer High Output Turbocharged and Supercharged “GASOLINE” engines. It also claims to have been formulated with the latest additive package components added to that base stock. It has no Motor Oil Industry certifications, but claims the formula passed the tests required for API SN. And it claims superior wear protection and high temperature stability, both of which proved to be true in my Engineering tests. In addition, it also claims to have a very high Viscosity Index value, which helps against fuel dilution concerns. The higher the Viscosity Index value, the less the oil’s viscosity is reduced as it heats up. zinc = TBD phos = TBD moly = TBD This oil was tested Summer 2018. The psi value of this oil, which came from testing it at the normal operating test temperature of 230*F, put it in the FANTASTIC Wear Protection Category. I also went on to test this oil at the much higher temperature of 275*F. At that elevated temperature, any hotter and thinner oil is expected to experience a drop in Wear Protection Capability. This oil had only an extremely small 0.7% drop in capability. Even at that elevated temperature, it produced 129,486 psi, which still kept this much hotter oil in the FANTASTIC Wear Protection Category. I also tested this oil for its onset of thermal breakdown point, which was 275*F. This was the first biobased motor oil I ever tested. And its performance was EXTREMELY IMPRESSIVE. These results probably surprise a lot of people, since this oil wasn’t even made from petroleum base stock. So it appears, there could be a very bright future for biobased motor oil, if they are formulated well. And the test data produced by this biobased oil, further backs up what I have said about a motor oil’s “base stock” NOT being all that critical, it is the “additive package” that IS critical. ------------- 71 Javelin 74 Gremlin 79 Spirit AMX Rogue Valley Rumblers Like Us on FB https://www.facebook.com/groups/1602825606650796" rel="nofollow - https://www.facebook.com/groups/1602825606650796 |
Posted By: billd
Date Posted: Jun/14/2019 at 10:07pm
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And 5w-30 is a proven good "viscosity" to use. Even at 275 degrees - which is pretty hot for oil - it performed far far better than what most folks use and call "good oil". Impressive........... hmmmmmm update - looked up some reviews - and lab testing supports the "less wear" testing. This oil provided better wear readings in my track car (based on used oil analysis), and longer useful service life than any of the commonly available synthetics (and I've tried most of the others). -------------  http://theamcpages.com" rel="nofollow - http://theamcpages.com http://antique-engines.com" rel="nofollow - http://antique-engines.com |