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

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

[Blown7]

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.

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.)

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

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.

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

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.

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...

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.











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!

[Mudrat]

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' - 'Course I'd probably become single and living in the shop, but hell ....