Hi everyone! I just got my 440 built and I went to prime it and I only see 25psi. However all the rockers on both sides are oiling just fine. I made sure when I built it that the NPT plugs in the timing cover area and bellhousing cam area were installed. It has a HV oil pump, 15w40 oil, pickup was measured at 7/16" away from bottom of the pan. It has retrofit roller lifters, each lifter felt nice in each bore. Rod bearings were measured at .0025" and mains were 0.003". However I did NOT install the fuel pump pushrod as I have a electric fuel pump, would that make a change in oil psi? It does have a mechanical oil pressure guage. I will say, due to my hurt shoulder I cannot prime AND turn the motor at the same time. I did turn the motor over a few times and then prime again but I cant do both at once. Any help would be greatly appreicated!
Thanks

Aftermarket pickup?, because stock pickup should lightly contact pan bottom.

Otherwise, I think that's the pressure I saw on ours
primed and when running, 70 PSI with 10W30

Joe

An oil pump is a constant volume pump, meaning it puts out a certain volume of liquid for every revolution. Oil pressure builds when the pump's output is higher than will leak out of the engine's many leaks at a low pressure. It's really very simple. If your drill is spinning the oil pump shaft at 600rpm the oil pressure should replicate cold oil pressure at 1200 engine rpm.

As you prime the system with your drill, at some point the pressure builds high enough that the drill can't spin the pump any faster. It depends on the drill power, the pump size and the amount of the leaks in the engine. Starting from oil pickup tube empty, it should feel like at some point the drill bogs down.

That's all you really need to see. You're not performing diagnostics, you're simply making sure all the oil passages are full before you start the engine. The thing to watch out for is when you start from zero and the drill fills the lines BUT DOESN'T BOG DOWN. This is a clue that your oil pump has a problem, or else that you have a really big leak in the engine.

In my case it meant the oil pump I had installed had a problem. 10,000 miles later I got to take the engine apart again.

R.

What size electric drill motor are you using and what RPM will it turn priming the pump?If your using a battery powered drill motor at 200 to 400 RPM your fine If your using a 1/2 inch electric drill motor at 550 RPM your not As already pointed out I would get the pickup closer to the oil pan bottom I like to see no more than 1/4 inch maximum from the bottom on a stock pickup, I rather have it touch On the aftermarket pickups like the Milidon with the strap covering the screen I make sure the strap touches the pan or has no more than 1/8 inch off the bottom. I remove the drain plug and use the oil dipstick throuh that hole to measure, if it clears flat or sticks between the bottom of the pickup I'm fine, if it clears sideways I adjust the pickup down si it doesn't clear that way Please let us know what you find and do

agreed 7/16" is too much & I like to have it touching to avoid stress cracking from it hanging suspended over time (I add spacers on the circumference so it is touching & still have ~1/8" at least (depends on RPM range/oil mods). What Cab said you should have way more than 25 & even with that distance with no slosh on a stand it wouldn't be sucking air to cause a low reading (if in doubt toss in another 2 qts just for a test, you can drain that amt when done). Holler how it goes/turns out.

Please don't take this wrong but is the drill turning in the right direction?

You guys are overthinking this one. A drill will pull down to a fraction of its rated speed if presented with a decent load, and no-one can really tell how fast it's going. I repeat, the main reason to spin the pump is to fill all the oil passages with oil before startup. AND, many many many engines are started up without this step and live just fine.

The guy getting 25 psi should thank his lucky stars and move on to other things that need more attention. For the kind of question asked, plus the information he gave about clearances, things are OK. At 10 lb per thousand rpm, his engine could be turning 2500rpm and that'd still be OK.

As there isn't a problem, any the effort trying to "figure it out" is wasted.

In my case I didn't have an oil pressure gauge and the fact that the drill DIDN'T pull down should have been an indication that something wasn't right. In my hubris I ignored that fact, and paid for it later.

If everyone who was starting out building an engine were to read all the warnings and fulminations on this board, the entire population of gearheads would quit the hobby and take up knitting.

It's not brain surgery.

R.

Well, what Dog said we might be OCD ing this. Ori what I'd do (in order/as needed if the prior one dont help) is (1) have a known correct gauge (2) grab a fast(er) drill (3) toss in 2 more qts & see what you see. 25 just seems low

You get no oil pressure turning it the wrong way.

After building a few big blocks I finally figured out the easy way to prime the engine. I use a speedwrench rather than a drill so I can feel the oil pump priming. There is no need to rotate the crankshaft, it just needs to be moved once. First put the camshaft in position to lube the passenger side valvetrain and then once you see oil at the rocker arms rotate the crank until the camshaft hole lines up with the driver side. Fill the driver side rockershaft and the job is done.

25psi with a 75+psi relief spring? you got an internal leak.

I


I borrowed a new 1/2" drill but it still said around 20-25psi. I took the intake off and saw that the lifters are dumping oil on all of the can lobes, thats where my pressure is going. Is this normal? I have a some photos of not priming along with priming.

sounds like the tappets are exposing the lifter galley. the tappets may have a cut out on the body that is dropping below the galley creating a leak. take a tappet out and give it a good look. another thought is there are four pipe plugs. two in the back of the block and two behind the timing cover; did you install all four?

Yes all 4 galley are plugged. Sealant tape as well.

The lifters do have a tiny hole from the galley which feeds on top of the roller. Is this okay to run like this?

What is the clearance between the lifters and the lifter bores? Might be too loose, in which case it's a problem.

call whoever's tappets you have. you may have a small base circle on the camshaft letting the tappets drop down to far,....? you won't solve this on this website.

Get someone to help you test this, prime the motor while slowly turning the crankshaft through two full revolutions and watch the oil presure If it changes for the better, higher pressure, your lifters are exposing the lifter main oil galleys on one side or the other when rotating it If that is the case you will need to change the lifters to a taller body type lifter that won't expose the oil galleys or have the lifter holes bushed. I had one 426 Street Hemi motor that I had to block the oil off to the left(drivers side) lifter gallery due to the solid roller lifters on that side exposeing lifter oil galley at max lift, the right side was fine Do not run the motor with 25lbs cold oil pressure Figure out what the problem is and fix it IHTHs I primed a motor last week with hydraulic lifters, it flowed a lot of oil out the sides of them also, it did have over 70 lbs oil pressure cold when priming it with a 1/2 drill motor at 400+ RPM with 10W30 Wt oil in it

UPDATE!
The motor is running strong and is well. My solution to this oil pressure problem was simply going with CompCams solid roller lifters, they have a solid type body instead of grooved like I had before. My oil pressure is now 75psi cold and can idle it hot around 40psi. Just wanted to inform others of my discovery and fix for the problem!

and if you prime it by hand now I'd bet its still only 25 psi !

Nope! Priming by hand gets me 75psi!