lost all oil pressure but not flow

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UDUST81 said:
well heres my list so far

1.no other pushrods are bent (checked against known straight edge)

2. dont believe any valve to piston interference (pulled plug in cylinder and saw no metal shavings on or inside plug)

3.checked lifter and cam, (no irregular wear, lifter was just sitting in valley right to the rear of its home no damage that i could detect)

4.rockers oiling holes are in correct position, no irregular wear on rocker or shaft and side plugs are still intact

5.put lifter back in hole, put bent pushrod back in place and noticed if i pulled the cup back up to how far out of the pushrod it was sitting when i pulled valve cover (about 1/2 inch out of pushrod) it fit right up on the ball of the rocker. camshaft in this posistion for this cylinder just happens to be on the base circle where the valve would be shut

Now i dont want to assume because this is a critical problem and i need to go over every possible thing but could it be the 440 source 3/8 pushrod just flat out failed me? idk im no expert on valvetrain geometry but when i first assembled the motor everything seemed within reason, small sweep, pretty well centered on valve stem... of course it could be better but other than possibly needing more clearance for pushrod, or geometry issues i didnt see, i dont think theres anything else to it than maybe where the pushrod and the cup mate there was a failure with the higher rpms

any suggestions i may have missed?
Click to expand...
what about clearance between retainer and valve guide/seal? what about possible coli bind?
How many threads of adjuster are exposed under the rocker arm? You don't want too many, because that's not good, but you don't want too few either because the cup edge on top of pushrod may contact rocker bottom at extreme lift and come out of the rocker socket.
There is one very remote possibility I can think of: if you had too high of an oil level the crank could whip the oil in the sump, and aerate the oil, collapsing a lifter. Conversely, if you pump the sump dry at high rpm's, you can collapse a lifter(among other things).
 
Might have to check if the cam bearings are properly installed..there are holes for oiling that need to be properly aligned...
 
it's funny, I was just thinking about this thread, today. I just got my latest issue(September) of Hot Rod mag and they have a trouble-shooting story of a stroked RB engine, which has a reputation of breaking rocker arms, etc. It turns out the engine assembler mixed up two pistons, so that the eyebrows in the pistons were incorrectly matched to the particular valves in those cylinders. The intake valve(s) were colliding with the exhaust valve relief(s) in the pistons of two cylinders.
 
OP. Did you happen to miss a hairy shift and possibly over-rev it ? ?
That would be a simple solution in my mind. Save a lotta speculating. jmo
Been there, same result. lol
 
hey update for everyone sorry i havent been back on much lately life getting in the way and all....
new pushrod is installed and engine reassembled, havent driven it on the street but have ran it a few times in the driveway, oil pressure acts exactly the same as before and engine seems to run just as good, only thing i changed while reassembling was i changed my valve lash from what i originally set up with.

i had read before that when breaking in a cold engine to set the valve lash .002 looser than what your hot lash will be, aparently this is true.... for an iron headed iron block, for an iron headed block with aluminum heads aparently you should set the lash .006 TIGHTER... so i did that and am seeing no issues so far...

im hoping the issue possibly did just come down to an overev or possibly a faulty pushrod or myself just setting up the lash far too loose and beating up the valvetrain too much we will see when i actually have time i will run it for a good while and pull the valve covers and check my lash when hot

BTW heres a good article i found about setting valve lash Valvetrain Tech: Lash Is Much More Than Just A Little Gap
 
UDUST81 said:
hey update for everyone sorry i havent been back on much lately life getting in the way and all....
new pushrod is installed and engine reassembled, havent driven it on the street but have ran it a few times in the driveway, oil pressure acts exactly the same as before and engine seems to run just as good, only thing i changed while reassembling was i changed my valve lash from what i originally set up with.

i had read before that when breaking in a cold engine to set the valve lash .002 looser than what your hot lash will be, aparently this is true.... for an iron headed iron block, for an iron headed block with aluminum heads aparently you should set the lash .006 TIGHTER... so i did that and am seeing no issues so far...

im hoping the issue possibly did just come down to an overev or possibly a faulty pushrod or myself just setting up the lash far too loose and beating up the valvetrain too much we will see when i actually have time i will run it for a good while and pull the valve covers and check my lash when hot

BTW heres a good article i found about setting valve lash Valvetrain Tech: Lash Is Much More Than Just A Little Gap
Click to expand...


It's NOT true. I've never seen any engine loose lash as it warms up. Never. I don't know where that started, but I've never seen it happen.
 
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