Final days of the 401 on the dyno

Blown7

Waggy, the oil circulates around the chamfer, under the washer. Jeff

Blown7

82Waggy wrote
BTW: though obviously used, neither of the two of my over 100k milage stock gears show the depth of wear exhibited in Blown7's gear.

Thats why I'm concerned, I shouldn't have this kind of wear running 50 gallons of gas thru the engine. Unless I really loaded the oil pump. Or some other explaination I just don't have.

Jeff

82Waggy

Blown7 wrote
Waggy, the oil circulates around the chamfer, under the washer.

Jeff

Well, I'm sitting hear staring at a gear and washer. You think that was the intention of the chamfer, eh? Guess I'm gonna have to assemble the snout of my cam and put a closer eyeball on it as I don't remember if the two non-keyed holes hang off the front enough to allow oil to get too them, nor do I remember if the woodruff key blocks the hole under it.. Hmm.

jeepsr4ever

Jeff I think it may be reasonable to blame the mis-alignment for the wear. If you have more oil to the gear it is possible for less wear however these gears do need to find a pattern and you just may have found the pattern your set needs to live on. Worst case scenario is that the gears didnt get enough lube. This could be caused by alot of different variables but I do agree that those slots will undoubtably improve the lubrication of both gears. After our phone conversation it got me pondering taking a air grinder to every single (65pcs) camshaft gear we have in stock. :idea: :t:

82Waggy

OK. I can see that the crown in the slot for the woodruff key may allow oil to get to that hole, I guess. You don't think there would be enough windage in there to coat the gears as well? I would also think that these helical cut gears could deal with a good bit of misalignment. I dunno Jeff, too much oil pump load?

1980_Cj7

Matt, you need to modify one of your timing covers so there is a window in it so you could observe the oiling going on while an engine is running and really see what is going on. Of course, the oil would probably get sprayed on the inside of the window right away and keep you from seeing anything. The other thing that could be done is to take an old cam and thread a fitting into the oil hole in the circumferance of the front journal, then attach a line to it and feed some pressurized oil to it with a timing gear, fuel pump eccentric, and dizzy gear all installed on the front of the cam. You'd see pretty quickly where the oil was coming thru. I'm just looking at a cam here. The snout of the cam has a champfer on it too, so between it and the champfer on the dizzy drive gear, they form a "V" and provide about twice the volume for the oil to flow thru that the champfer on the gear alone would provide. For a minute I thought the champfer on the cam snout might be deep enough to let oil get to the two "dry" holes, but I don't think it is.

jeepsr4ever

Amc camshaft gears dont sit down all the way so they have oil to all the oil holes. Sorry Jeff it may be another issue.

Blown7

MC, I think I have a guess after thinking about it today, I know when I primed the engine the first time once the oil pump got its fill of oil my drill would bog down, and after releasing the drill chuck, the oil pump shaft would turn back by itself (counterclockwise) about 4 full turns, and with the original Hamburger dual in series oil filters I probably had alot of resistance caused by the pump itself then add the adjustable oil pressure screw and spiking the oil pressure a few times, the gears might have been trying to push 100 ft lbs of torque (my W.A.G) to spin the oil pump. After removing the timing cover it was covered in oil, so I think oil flow for lubing the gears wasn't my problem. High resistance caused by the oil pump was. My best guess for now. Jeff

1980_Cj7

jeepsr4ever wrote
Amc camshaft gears dont sit down all the way so they have oil to all the oil holes. Sorry Jeff it may be another issue.

Ah ha. Didn't think to put all the pieces on the front of the cam and check that. That explains it. Couldn't imagine all those engineers at AMC could have missed something so obvious.

Well that's good news, Matt. At least now you don't have to modify 65 dizzy gears, ha, ha.

82Waggy

jeepsr4ever wrote
Amc camshaft gears dont sit down all the way so they have oil to all the oil holes. Sorry Jeff it may be another issue.

That makes more sense. The chamfer alone is not much area for flow.

82Waggy

Blown7 wrote
MC, I think I have a guess after thinking about it today, I know when I primed the engine the first time once the oil pump got its fill of oil my drill would bog down, and after releasing the drill chuck, the oil pump shaft would turn back by itself (counterclockwise) about 4 full turns, and with the original Hamburger dual in series oil filters I probably had alot of resistance caused by the pump itself then add the adjustable oil pressure screw and spiking the oil pressure a few times, the gears might have been trying to push 100 ft lbs of torque (my W.A.G) to spin the oil pump. After removing the timing cover it was covered in oil, so I think oil flow for lubing the gears wasn't my problem. High resistance caused by the oil pump was.
My best guess for now.

Jeff

With the pump resistance you had, maybe you did not get much pre-lube either. Initially dry gears and high load.

I don't think it was an alignment issue.

Blown7

Soooooo MC was correct, the holes are open to recieve oil

And as I surmised late yesterday lube doesn't seem to be my problem. I think alignment could be plausable as when you get into gear theory and pressure angles, pitch depth, etc. alignment and clearances can prematurely make gears fail. However I cannot prove or disprove or accurately measure what those dimensions are on my engine with this cover unless I bandsaw the cover up to allow me to take some measurements. I don't feel that motivated at this point to make all those checks. I'll wait and install the new cover with new gears and see where I'm at then. I believe my problem was excessive oil pressure resulting in the cam gear trying to turn the dizzy/oil pump shaft beyond it's designed operating torque input.

I will make a insert of Aluminum to install in the washer or Silicone the washer side to keep a oil tight seal under the cam gear.

Jeff

Blown7

I also have two slots on the cam timing gear (at approximatly the 9 and 3 o clock positions that bleed some oil off to lube the timing chain but I don't think they are bleeding off too much (sorry for the lousy pic)

Jeff

82Waggy

You also have the drainback from the lifter valley getting slung all over the place.

AMX69PHATTY

Hello, may I ask a "silly" question ? Did your Rod Bearings have the Oil Squirter Hole notches or no ? ( duck to avoid the items thrown at me )

Blown7

AMX69PHATTY wrote
Hello, may I ask a "silly" question ?

Did your Rod Bearings have the Oil Squirter Hole notches or no ?

( duck to avoid the items thrown at me )

No need to duck, a reasonable question. I have Carrillo rods which have no provision for the notch. Nor did I add any.
Maybe this week I'll get into the bottom of the engine.

Jeff

73hornut

82Waggy wrote
Blown7 wrote
MC, I think I have a guess after thinking about it today, I know when I primed the engine the first time once the oil pump got its fill of oil my drill would bog down, and after releasing the drill chuck, the oil pump shaft would turn back by itself (counterclockwise) about 4 full turns, and with the original Hamburger dual in series oil filters I probably had alot of resistance caused by the pump itself then add the adjustable oil pressure screw and spiking the oil pressure a few times, the gears might have been trying to push 100 ft lbs of torque (my W.A.G) to spin the oil pump. After removing the timing cover it was covered in oil, so I think oil flow for lubing the gears wasn't my problem. High resistance caused by the oil pump was.
My best guess for now.

Jeff

With the pump resistance you had, maybe you did not get much pre-lube either. Initially dry gears and high load.

I don't think it was an alignment issue.

Yep, sounds like alot of strain on the distributor gears.

Blown7

Oh boy look what I did....

Guess I got motivated.....

Jeff

jeepsr4ever

Way to go Dr, Jones you pulled its heart out :?:

ironman_gq

when that thing chewed through how much coolant ended up in the motor and how long was it therebefore you noticed. :shock:

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