Oil Pump spin up Question

[DNK]

On a 6, when you spin the oil pump by drill, should oil seep out of all the rocker holes?

 

[DrEntropy]

I'd expect to see ~some~ oil up there but likely not a lot. Do you have a "hard" gauge you can view as you spin the pump? That'd tell you more than visually "measuring", methinks.

 

[DNK]

It's for a friend. Says he has beem spinning the heck out of it and only getting oil from 6 of the 12.
I think this is about right.
Think he wants to make sure everything is correct up top
Doc with a drill how much oil pressure could you expect?

 

[hondo402000]

I believe you spin the oil pump counter clockwise

Hondo

 

[DrEntropy]

Too many variables, really. But, considering the pump/cam gearing to be close to 1:1 and engine idle speeds in the 1K RPM area, if you can 500+ RPM from the drill you should see something near "normal" for pressure at idle... 35~40 PSI, mebbe. With 1K~1500 drill speeds the thing would read 60-ish, up to pressure relief valve pop-off. Somewhere "north" of 75 to 80, IIRC.

 

[M_Pied_Lourd]

Yep, make sure the drill is in reverse. Don, I was able to see 60 on mine.

Cheers,
Tush

 

[TR3driver]

I suspect it may depend. At least on the TRactor motor, the head is not fed from the oil galleries but from a hole off to the side of the rear cam bearing. The cam journal has a flat on it that acts kind of like a metering pump to allow only a small amount of oil to flow to the head with each cam revolution. With the cam not turning, you might not get much flow to the head, regardless of the main oil gallery pressure. And since the rocker shaft is tilted, it takes a certain minimum flow to fill it and force oil out all the weep holes.

Not sure if the 6 works the same way, but it seems likely.

 

[DNK]

My friend rotated the motor a little bit at a time and tried in each position

EDIT

His remarks

♠spun the pump up for many minutes. Rocker # 3; counting from the front of the engine, positions # 5&6 immediately started seeping oil. After some minutes, position #3 and then # 1 came on line and some minutes later position # 8 followed a good while later with position # 7. For reference positions 1&2 are cylinder # 1, then 3&4-cylinder # 2 etc. Rocker # 2, 9,10, 11 and 12 have yet to produce oil through the little hole, but oil came out around the rocker on #9, but 11 & 12 show no evidence of any oil anywhere. I spun the sucker for 20 minutes or longer and rotated the crank every 4-5 minutes through 22 degrees or so until I had a complete rotation of the rockers through a complete combustion cycle. Still no oil on 11 and 12.

 

[TR3driver]

Well, what are the other circumstances? Might be worth pulling the shaft apart, to be sure all is well inside. They do get clogged with sludge sometimes.

But I would probably start it first and see what happens. Unless the rockers are totally dry, running for a few minutes isn't going to hurt anything.

 

[DNK]

Brand new motor and shaft so hopefully no sludge in it
EDIT
Who was it that just had a shaft go bad. Wasn't it a fairly new shaft?

 

[TR3driver]

Who was it that just had a shaft go bad. Wasn't it a fairly new shaft?

I forget who that was offhand, but the post-mortem was that the shaft had been made wrong.

 

[DNK]

That's what I was afraid of.

 

[Brosky]

If you're worried about it, then it's worth pulling off and checking completely before starting the engine, IMHO.....

ACTUALLY...if you do pull it and spin the oil pump you will see how much actual oil is coming out of the small galley hole at the back of the head that feeds the rockers.

EDIT: as in this little guy shown here:

 

[DrEntropy]

ACTUALLY...if you do pull it and spin the oil pump you will see how much actual oil is coming out of the small galley hole at the back of the head that feeds the rockers.

That'd be a 'next step' in my opinion. FWIW. :wink:

 

[TR3driver]

Thing is, he knows he's getting some oil out the port in the head, because there is at least some oil coming out of most of the rockers. And unless he's parked on a hill, the dry rockers are also the lowest rockers (11 & 12).

So it seems to me the problem must be oil not getting from the center hole in the shaft, to rockers 11 & 12; rather than any problem with oil getting to the pedestal.

At any rate, that's where I would look next.

 

[DNK]

It's been a while. How many ped holes are there?

 

[poolboy]

One from the head, the one Paul photographed

 

[DNK]

So one hole feeds the whole shaft?

 

[poolboy]

Yeah. And as Randall explained, it's pumped up there by the cam, not the oil pump per se, so the oil is not under a lot of pressure in the valve train.