solved:help needed with oil system problem

brokenjeeper

O.K., so I messed with this some more. I thought maybe the gauge line might be partially obstructed. Took it off and blew it clear w/ carb cleaner. While off, I ran the drill and got a nice flow of oil out of the block fitting. Re-installed and no oil flow out of the small line to the gauge. Somehow or somewhere it seems to just not be building any pressure even though the flow is there.

ironman_gq

are all block plugs installed in the oil gallery holes on front back and top of the engine? two in front behind the timing gear. two in back behind the flywheel and two on top in the front of the valley above the cam

brokenjeeper

All plugs are in and tight. Also, in the picture of the valley above there is evidence of oil flow the length of the valley. That was what was pumping out of the lifters as it was also being pumped into the coolant passage. At the time, I assumed that I had not gotten oil to the rockers because of the line into the coolant passage and subsequent lack of pressure build up. The pump was definately moving oil. At this point, the only possibilities I can think of are: timing cover is too far out of spec and simply not building pressure, lifters bores are too large, or something else that is bleeding off pressure faster than the pump can make it.

ironman_gq

did the right size bearings get used. If you had your crank turned and standard bearings were used you will have a lot of bleedoff.

brokenjeeper

I will have to disassemble again to check that. It came as a short block from a respected shop. At my next opportunity, I plan to pull the manifold and run the drill to get an idea of what sort of flow is going on at the lifters and elsewhere that I can see. Then drain the pan and disassemble one or more main caps to check with plastigauge. I know that the crank was turned but I will have to verify with the shop how much. if there is a better way, or something else I can check please let me know. At this point, I am taking nothing for granted. I want to have a clear picture of what all is wrong before I confront the shop. To that end, I would also like to find out what acceptable clearances are for the lifter bores.

brokenjeeper

O.K., I pulled the oil pan and removed main caps two and three, so far. The mains were assembled with ARP bolts and moly lube by the machine shop. The ARP catalog lists 3 separate torque values for that size bolt: 95, 107, and 119. I believe factory torque specs are 95-105 so for plastigauge purposes I used factory torque specs on #2, which I believe may be excessive for ARP bolts/moly, and 95 lbs/ft for cap #3. The reading on cap 2 indicates between .002 and .003 clearance (even with the higher torque of 105), and cap 3 indicates .002 at the 95 lbs/ft torque. This seems sloppy for a new build, but the clearances seem to indicate that standard bearings were not used on an undercut crank, correct? Also, the bearings have an oil groove running the entire circumference of both bearing halves, is this correct? Should I also be concerned about connecting rod clearances as it relates to excessive oil bleed off?

ironman_gq

.002 to .003 is perfectly within spec anything between .0015 and .003 is normal. .0015 is on the tight side and you would see that on a new engine .003 is more common and would be seen on a high performance build due to the extra heat and friction created cause as they say a loose engine wont seize when it gets hot. I would say your problem is not related to the bearings unless a cam bearing was put in wrong and the oil holes dont line up with the passage in the block

brokenjeeper

I note that most replacement bearings only have the oil groove on the top half of the bearing. Should this be an area of concern since mine are grooved 360 deg.? If its not bearings what else could it be? Even if the oil pump were way out of spec. I think it would have better output than the 5 psi I'm seeing?

brokenjeeper

Problem solved. Not sure how I missed it, but it rhymes with "heavy shifters".

jeepsr4ever

:?:

tufcj

Hope they didn't bounce around too much and screw up the cam lobes. Glad you found the problem. Bob tufcj

ironman_gq

forgot the lifters? :oops:

brokenjeeper

:oops: On the bright side, I did manage to get another 1/4 qt. of oil out of the water jacket when I turned it upside down.[/list]

ironman_gq

chevy lifters? :oops: :-|

tufcj

The mains look OK in the pics. Good thing you didn't lose them. That .062" difference would sure bleed a lot of oil that should have gone to the rods/mains. Bob tufcj

brokenjeeper

The engine was never run. This was all on the stand so everything is fine. The lifters shipped with the cam.; not the fault of the maching shop-they have been great and willing to fix any problems. It was totally obvious once I was looking at the lifters specifically for fit, but .06 is easily missed by the naked eye when its a foregone conclusion that the parts are matched and ones attention is elsewhere. I don't do this for a living or even on a regular basis, so it is a perfect example of the difference between knowledge and experience. I'd like to say it will never happen again,.....but I like beer.

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