pop23235

Interested to see the outcome. I think you corrected the low pressure leak. High? Not sure. When I was young and foolish I ran a 283 wide open for several miles. After probably 10 minutes the oil light came on and scared me good. Immediately killed the engine and coasted to the side of the road. Could find nothing. I assumed the oil pumped up and became too low in the sump.

pop23235

Interested in your outcome. I believe you've fixed your low oil pressure, but not sure about the 4K issue. Once when I was young and foolish, I ran a 283 for about 10 minutes wide open. The oil pressure light came on and scared me good. Immediately shut down the engine and coasted to the side of the road. Checked everything and found nothing. My assumption was the oil was pumped out of the sump faster than it returned to the sump.

C4toC2

That is good to know - Is the L79 the 350 hp and does it have the same pan I do? (300 hp) I had heard that the Fuel injected car had a longer pan that held 5 quarts in the pan and would not fit with power steering. Having said that, if we assume at least a quart is in the system on it's way back to the pan, filling to pan to 5 quarts should be fine - that is 5 quarts in the 4 quart pan + a quart in the filter.

I assume you are running a HV pump with the 70 psi bypass spring?

The engine is back in the car, may get it running this week. Next weekend being mother's day, will not see much car work.

C4toC2

Yep - mixed stories - With the leak in the front fixed - I should be able to do that? I guess I'm going to find out

63 340HP

Let us know how it works?

My '63 runs 4000 rpm for extended trips of an hour or more. The 4.10 gear and 220/60s can make 80mph freeway travel buzzy. I run an 8 qt winged pan with no pressure loss. A windage tray or screen helps.

I keep about an inch and a half oil depth in the sump. More oil, and the engine during a high rpm trip wants to use it. It will blow vapor, enough that I fabbed an external oil separator for the pcv line to recover and minimize the loss.

Too much oil can be a problem.

A question, for all, how much oil depth is needed in the pan?

Jackfit

Hi, regular Melling Pump....they tend to run high on pressure....Yes L-79 is the 327/350 . Don't know size of pan. but 5 plus a little more will put it at full. When I rebuilt the engine, we put the front plugs in (first builder forgot) but also we found that the rear oil passage near distributor was full of gump sludge.


Jack

C4toC2

Primed the system and fired up the engine last night to set the timing. Warmed up the engine to water temp 190 and the got the oil temp to 190 measured via a laser thermometer on the pan. With oil temp of 190, I have 23 psi of oil pressure at 950 rpm.
Need to see what the oil psi will be at a temperature of 220 degrees - which will require harder workout than just idling in the drive way

pop23235

I think I'd take the tube off the back of the gage and flush it with the engine pressure before continuing. It's difficult not to spill oil in the interior, but would be worth it. Pull the coil wire, crank it over.

You'd be OK with that, but I'm surprised it isn't about 30.

Westlotorn

I believe two gauges were tested and two oil pumps were used.
Idle oil pressure Hot should be well above 30 PSI based on the information provided.

Can you clarify one thing and I am not intending to insult just to clarify.

Was the plasti gauge used for your measurements placed in the direction of travel on the crankshaft or perpendicular. It should lay across the direction of rotation and should be measured at the crown of the caps, the highest point which is also the place with the least clearance. Placed anywhere else you get a bum read.

Based on what you tested and we read here it sounds like your Mains and Rods are loose, maybe .003 or greater. I know you stated they measured .002 but that is not consistent with your gauge.

Are your bearings stock profile or racing profile? Race bearings have much more clearance and would need a high volume pump.

I wish I had asked these questions a couple weeks ago.

C4toC2

I think I got that right - the plastigauge was opposite the piston/bottom of the bearing - center of the cap in all cases. The Plastic was laid front to back with respect to the engine/across the bearing.

I will take no offense - I find that I'm learning things constantly -

Aaron

C4toC2

Also - I should add - this is with the standard pump back in. Based on past experience, the HV pump would probably have 30 psi for this scenario.

jimh_1962

I had a similar issue when I installed a standard melling pump. During the first rebuild (other problems than the pump) I installed a HP/HV pump. The drill almost burned out with the load while priming the engine during the first attempt to run the engine.

I pulled the engine due to rings not sealing and wanted to do some more work on the heads. During the second attempt I bought a new standard melling M55 pump. During startup I only got 7 pounds on the oil gauge. Quickly, I shut down the engine. Then went here to ask some questions. I received a lot of good suggestions.

I disassembled the engine and check all of the clearances once more. I found nothing wrong so I decided to install the the old HP/HV pump which was barely used (300 miles on the engine) back on. Sure enough the extremely low pressure was caused by the standard melling pump. Oil pressure problem was fixed.

My symptoms was only getting 7 lbs of pressure at idle it would climb up to 12 lbs. There was hardly any oil reaching the top of the rockers. I should noticed the problem during the rebuild since the drill did not have any load while priming. Plus, I did not check the pressure (rookie mistake) the an oil gauge. The extra gauge/tester was sitting on a shelf while I was priming the engine on the engine stand. Mistake on my part since had to pull the engine once more and check all of the clearances.

Check your pump. I had a bad melling pump right off the shelf. The pickup was brazed and at the correct position as the old replaced HP/HV. We took apart the pump and tested it. Sure enough it was defective. It happens...

Put the old HP/HV and now get high pressure and some small leaks which is the downside.

Westlotorn

In the early 90's we had a production issue with oil pumps, an entire run had low oil pressure.
When you plastiguaged the clearance between the gears and gear cover on these it was almost .005. These all had terrible low idle pressure. < 10 psi.
You cuould remove the cover and take .003 off the pump and the
Same pump would jump to 40 si at idle. I did one on a piece of glass with valve lapping compound with same result. These all had good internals and good pressure relief springs.

Westlotorn

In the early 90's we had a production issue with oil pumps, an entire run had low oil pressure.
When you plastiguaged the clearance between the gears and gear cover on these it was almost .005. These all had terrible low idle pressure. < 10 psi.
You cuould remove the cover and take .003 off the pump and the
Same pump would jump to 40 si at idle. I did one on a piece of glass with valve lapping compound with same result. These all had good internals and good pressure relief springs.

jimh_1962

The pump I bought probably was from the 90s knowing the person who sold me the "new" pump.

Westlotorn

Did you get to test drive this yet? Curious how the Oil pressure is at 3,000 RPM hot after your repair. Hope it is much better.

C4toC2

The latest - with the plug in the front of the engine re-set such that there is no leak and installation of
the standard pump with a new pickup - I need to remember to go back and Tig welded it.

Oil is Valvoline 10/30 standard, about 5.5 quarts - I was instructed by the shop to run non synthetic for the first 4K miles.

1. Cold oil pressure at idle is 55 - 60 psi.
2. Oil pressure at normal operating temp 190 degree F and 850 rpm idle = 23 psi
3. Oil pressure hot 220 degree at 850 rpm idle = 14 psi. I guess I'm now OK with that.

4. Oil pressure cold(starting to warm up) at 2000 rpm 65psi
5. Oil pressure hot at 2000 rpm 40 psi
6. Oil pressure hot at 4500 rpm 47 psi

looking at these numbers, although the pump is new, it is possible the pump is a bit sloppy. I'm also
curious to see what the pressures are when I switch over to synthetic.

So that is where I'm at today - and I think I'm going to run with these numbers for a while.
One thing about the HV pump, the pickup tube needs to clear the internal baffle in the pan and
because the actual pump is longer (sits lower in the pan), for the pickup tube to clear the baffle, the pickup itself needs
to sit higher in the pan - I didn't like this and would modify the pan prior to using the HV pump such that the pickup
is 3/8 of the bottom where it needs to be.

I have looked at the Allstar 6 quart pan - anyone out there ever used one of these. What I'm after is more capacity without
making the pan deeper and putting it in harms (speed bumps) way.

Thanks to the group for all the help as I worked through this. Now - on to the air-conditioning.

Aaron

jerry gollnick

I use an Aviad pan in the road race car. It does not reduce your clearance.

427Hotrod

I always take mine down to .0005-.001". Work great!

JIM

snoopybob

Maybe your oil pump pickup tube fell off. I have seen that.