Final days of the 401 on the dyno

Blown7

Well the last three days have been long, 15+ hrs
I have just about learned all I ever will about the newly built engine, FAST ECU, timing, retarding The need to take time building a engineand using the best parts. I have learned all I can about the infamous AMC engine oiling mods, Bulltear/Crown timing covers, 534 plates, oil pump gears, gaskets, the valley bypass line, and oil pressure drops in the system. (Interesting findings there I can tell you!!!)

I have many opinions, observations, and factual data to sift thru.
Not many pics or video as I was usually oily, dirty and just straight out modifiying, machining parts,and removing and installing. Or cleaning the dyno cell of what seemed gallons of Valvoline 20-50 racing oil. ( More to come on that.)

Heres the cell after 2 hrs and 4 guys cleaning oil off the ceiling, walls and everywhere.

Some of the highlights.
Fuel Used
54 gallons of 93 octaine, 100LL Avgas, and 104 octane racing fuel.

Oil
4 cases (48 quarts)

Oil Filters
11 Filters used (various types)

47 separate engine pulls

Well I gotta get going for now but we did 4 pulls with this stuff

Let me tell you, has anyone seen a 401 AMC turning a 30 old crankshaft and inputting 900 ft lbs of torque on two bolt mains?

It's damn scary :shock:

Heres a vid
http://www.youtube.com/watch?v=DmvzACSpQVM

Jeff

Blown7

BTW this thread is will I will post the disassembly and inspection of the engine to inspect it when I get it back to the hanger. And the Ken Parkman mods? "Not really the final answer" Jeff

1980_Cj7

Anxious to see and hear the gory details, Jeff, as we are getting ready to start the second go around on ours. Not shooting for the kind of power you're fooling with, but still interested in any findings that might benefit us, like oiling stuff.

82Waggy

Can't wait to hear. Nothing like imperical data.

radamx

Not sure what was coming up in front of the engine during the dyno pull .Oil or steam but it was going right in the butterflys. maybe a little contamination during a test don't you think. And yes I have seen 900 ft torque on 2 bolt caps after awhile you kinda forget about it. Hope all is still going well and you get to play in the jeep soon . Good luck. =D>

jeepsr4ever

Jeff looking forward to your report :wink:

Blown7

radamx wrote
Not sure what was coming up in front of the engine during the dyno pull .Oil or steam but it was going right in the butterflys. maybe a little contamination during a test don't you think.

Yes that was water vapor/steam comming out of the oil fill tube.
(Good observation!)
I've got a small coolant leak under the left bank of the head at the valley pan gasket. I'm going to change the valley pan gasket to the separate gaskets. I didn't like the way it fit initially installing the blower manifold. Also when I do the chassis install I'll do a crankcase evac system.

And yes I have seen 900 ft torque on 2 bolt caps after awhile you kinda forget about it.

I hope I can and not be reminded someday by having a custom by crash two piece crankshaft. #-o

That is one of the most amazing things I've ever seen. Alot of people never have seen a Nitrous engine and it was my first time. The video doesn't even do it justice. A few have asked me to describe it and the best anaology I can come up with is once the Nitrous lights off at 3000 RPM it's like a whole other engine inside of this one comes to life. The sound and depth of vibrations and engine sound quality increase dramatically.
If your watching the dyno screen on a typical run when the dyno loads the engine, it hangs there at 3 K for a couple of seconds until the dyno unloads the engine allowing it to accelerate. You can easily follow along on the screen the increasing RPM and torque figures.
Conversely on a Nitrous run when the Nitrous is injected there is no hanging at 3 grand, and the screen numbers ( and graph display) increase so fast all you see is a blur of numbers until you get to the rev limiter then they start slowing enough to be understandable and till it sinks in, believeable.

Hope all is still going well and you get to play in the jeep soon .
Good luck. =D>

Everything I think went very well and I am pleased.

Jeff

Blown7

For my first post on observations and findings I cannot remember if I have ever read or seen addressed on this board or any other AMC board under "Tech" the oil pressure drop induced by the oil filter or filters itself.
When we first started the engine a couple weeks ago the oil pressure steady held at 60 PSI cold.( A testement to MC and his plunger/spring inspections) After the engine warmed up the pressure would drop at idle a few pounds less after every run till it would settle at around 27-30 PSI steady at idle oil temp around 210-220 degrees F.
Greg didn't like it and I tried to legitimize it by saying "well it is a AMC engine"
He didn't want to do any more pulls as the oil pressure wasn't to his satisfaction.
Last week when he called to tell me that the cam bolt backed out and thru the timing cover I told him to remove the cover and weld it and reinstall. As I knew the logisticis of MC overnighting me a new cover on a Saturday nite was impossible.

While he had the cover removed he disassembled the 534 plate and the oil pump gears. He made the decision to modify the assembly by discarding the gasket between the pump housing and 534 plate using silicone as a sealer and turning the gear height down till they where .002 thousandths below the pump housing ( the imfamous .007-.008 height or whatever above the pump cavity allowing for gasket thickness)

(During this time MC contacted me and on his own Nickle overnited a new improved 534 Tri flow second generation plate to install.
A big public "Thanks Matt" your good people.)

Well all was reinstalled,
Damn if the same indicated readings where observed.

Thats when the drilling and tapping 1/8 pipe tap holes everywhere decision was made by me to get to the bottom of the damn AMC oiling questions once and for all. (Or at least on this engine)

(Disclaimer your actual oil pressure variations may change from mine, but I would bet my family farm that it won't be more than 3 percent and it won't matter if alot of oil goes to the rockers, cam bearings or wherever people say it goes too much to in a typical AMC engine.) :lo1l:

After seeing the flow volume of oil under 50 PSI out of our little AMC gear pumps all over the test cell for myself at idle I have determined flow ain't a problem :t:

All kidding aside.

Seriously lack of pressure is or pressure drop at various locations to be specific.
(Indicated engine oil pressure was taken at the front galley right side conventially where it is usually taken.)

The first fitting I tapped was at the oil filters to indicate what the filter/s looses from the pump pressure.
I already had drilled and tapped the 534 plate to find the pressure relief plunger will hold a steady 60 PSI hot at any rpm(not too bad with a 15 LB spring on a .562 dia plunger with approx .25 square inches of surface area.

All filters will loose between 10-15 PSI each right there depending on the filter. Add two in series like I did and you will loose double.

Everybody following?
Tomorrow everywhere else.'
Enough for today.

Looking over my notes I noticed that the engine Guru's mentioned that the engine acceleration under no load was one of the best they have seen ever, meaning the time from idle to 5500 RPM was following the TPS accurately. (Basically as fast as you could move the throttle lever the engine would corrospond.) No one has a answer for that.

Jeff

jeep_man_401

If a person looks at the AMC block and follows all the turns and obstructions there are many places for a pressure drop.

First and foremost is the oil pick-up tube location...with the long hole drilled going to the pump in the oil pan rail.

Another one is straight out of the cover to the block, a D shaped hole in the cover going to a round hole in the front of the block. #-o

From there it takes a 90 degree turn to go up to the Y in the valley with the 2 screw in plugs. #-o

At the Y lies 3 90 degree turns. (1 over the Y to the other lifters and 2 more turns to go down the block to oil the mains and cam bearings + the lifters the other to oil the lifters side only).

Then there are the 90 degree turns it takes to oil the main bearings. :shock:

While at Tech. College we learned about the pressure drop of a 90 degree turn flowing fluids. Ask any plumpers...

the AMC V8 has at LEAST 7 of these turns... 111!!!

The only way to minimise the turns is to take a small die grinder with a long bit (6" or more) and radius these turns. You can get at all of them except the main bearings with a small bit.

The front of the block in the valley with the 2 plugs should have all the sharp edge raduis with a die grinder.

Grind the front of the block the same as your cover...

I spent many hours just looking for these restictions and grinding them away as much as possible before the block went the the hot tank. I then ran long cleaning brushes through them and cleaned it myself again with parts wash and high pressure air.

I have always had lower oil pressure at idle than most built Chevys...Every dyno guy has ran thousands of these and MAYBE one AMC. They are used to seeing high idle oil pressure...but the oil pump uses HP.

Any more pressure than needed is just robbing HP from the motor and wearing the cam gears and can in some cases can cause timing spark scatter on the dissy.

I even port matched the Indy cover I used to the block...MC I hope your new cover has a matching hole :? (cool stuff at the shop also!!!)

As to the oil mess, I made a big one also when the oil filter gasket went south (or was it west??) on my motor...oiled the ceiling and walls of my grarage. :t:

Going against most chevy guys I wanted more oil on the cam also. So I drilled a few more hole above the cam lobes to drop oil onto the cam. Most races block these holes off to keep the oil from falling on the crank and rods...thus robbing HP. My view was I run my motor on the street and it sees alot of idle time at stop lights. I wanted the cam to have plenty of oil while idling...a good cam will always make more power than one with a flat lobe! :lo1l:

Mudrat

Blown7 wrote
Heres a vid
http://www.youtube.com/watch?v=DmvzACSpQVM

And another one of his...
http://www.youtube.com/watch?v=SX8ALp1I7AQ&NR

jeep_man_401, cools stuff!!! Makes me want to pick up another one and 'try so stuff' - #-o 'Course I'd probably become single and living in the shop, but hell .... :mrgreen:

fuzz401

jeep_man_401, cools stuff!!! Makes me want to pick up another one and 'try so stuff' - 'Course I'd probably become single and living in the shop, but hell ....

I will try it on the next motor but I will still be in the house 8) due to it will be her gremlin :t:

jeepsr4ever

Chris you are correct! The fastest way to the oil galley without creating a new feed from the top would be from the pressure port. Alot of racers including Hemmy Adtkins and John Garland use our 534 plate and use that port to feed their race motors.

Blown7

So this was my first problem

Anybody see whats wrong with the design?

Moving on, I did all the mods jeepman401 did in regards to the oiling system.
But one of the most interesting things that was discovered was the pressure drop of the left side galley rear. And the lack of drop at the right ( where the valley oil line is connected.)

The left rear read approximatly 10 PSI lower thru all the RPMs than the right galley input. (at the conventional gage port) Which sounds reasonable. What was interesting was the right rear had the same reading as the convential gage port. MEANING the valley oil line is doing what it was designed to do.
MOVING OIL AND PRESSURE.
HOW MUCH?
I don't know I didn't have a flowmeter handy but I think I'll install one later in the valley oil line with a one way check valve.

Now I know ol' 82 Waggy will disagree, but my evidence is given the pressure drop of all the 90 degree bends (which jeepman401 described so elegantly above and which BTW drop about .6 inches of Mercury per each bend or about .25 PSI per 90 degree bend ) I should have noted a pressure drop at the right rear galley even for the distance involved not including the actual pathways of the galleys off the main galley there should be a pressure drop, but I was reading the same pressure as the main feed galley from the pump output.

Now I calculated long ago I needed about 1/2 gallon per minute oil flow thru the main bearings ( I drilled the main feed to the bigger size drill and have a cross drilled crank) to keep the bearing heat radiating capacity temperture rise under 20 degrees F with 190 degree incoming oil with a SAE 50 weight oil. Given a friction HP loss of about 1/2 HP at each main not including the thrust bearing which takes more given it's length to diameter ratio. BTW I calculated the mains at .24 with a full oil groove. But maybe thats why it accelerates so well
Actually now that I look back I could have use solid bearings with just a oil hole on the last two mains to get the l/d ratio double thereby increasing the torque parameter vs Eccentricy ratio by double.

My main journal bearing lubrication analysis indicated a bearing load of 593 lbs/sq in at 6000 RPM with a surface speed in inches per minute of 47118 inches per minute or 3926.5 feet per minute. That little journal travels 3/4 of a mile in one minute at 6000 RPM (2.500 journal diameter x pi x 6000 RPM)
My clearnace modus was .0012
Main clearanace was set to .003 giving me a actual hydrodynamic flow of .1926

Bottom line for me
Valley line works period.
Oil filters suck (but what can you do? )
There is no such thing as a magic number of a certain engine RPM per what oiling mod to do. You have to look at each design parameter then decide what or if.
I think all the "big names" in the AMC engine building world knew all this 30 yrs ago but they still ain't tellin'
and damn Ol' Smokie Yunicks dead.

The rear main bearing problems alleduded to in so many posts and articles is real but it may not be from lack of oil or pressure but from bearing friction heat rise, crank whip, assymetrical torque loading, hydrodynamic flow or lack therof or even line bore/crank error.

BTW next segment discussing the oil filter adapters.

Jeff

fuzz401

could it be the passage between the 2 filters necks down tomuch

Blown7

On a entirely separate note many have asked me why I didn't use 4 bolt mains given the HP output. 1. I don't think they are needed given the size ans strength of the webbing. 2. I have seen aftermarket 4 bolt splayed caps break a block given how they "pull" the casting and create new fatique lines and stress risers. 3. It is my belief that the two bolt mains will never give me any heartburn given everything has been seasoned and relieved for 30 yrs. 4. If I did it again I'd prolly use dowel pins instead. Jeff

Blown7

fuzz401 wrote
could it be the passage between the 2 filters necks down tomuch

Yep thats a series flow filter, the oil has to flow thru both filters till it gets to the output side. 10 psi loss thru each filter then add 10+10 lbs =20 PSI pressure drop right there.
I thought it was a parallel filter I didn't look close enough.

Jeff

82Waggy

Sorry Blown7, but until you run it without the valley line and measure the same drop on the right side I won't be convinced. Sounds to me like you have a restriction on the left side to me.

jeepsr4ever

82Waggy wrote
Sorry Blown7, but until you run it without the valley line and measure the same drop on the right side I won't be convinced.

Sounds to me like you have a restriction on the left side to me.

Yep its called cam bearings

1980_Cj7

Blown7 wrote
So this was my first problem

Anybody see whats wrong with the design?

Jeff

YES! It's blocking the picture of the girl on the calendar. No wonder you can't get the juices flowing!

82Waggy

jeepsr4ever wrote
82Waggy wrote
Sorry Blown7, but until you run it without the valley line and measure the same drop on the right side I won't be convinced.

Sounds to me like you have a restriction on the left side to me.

Yep its called cam bearings

How do cam bearings interfere with the flow down the left hand (drivers side) lifter gallery? For that matter, they cannot be interfering with flow down the right side gallery either.