Need help 427 low oil pressure ?

[priobe]

Thanks for your help

I guess I will look for a oil adaptor on ebay unless someone has one they want to sell

[FFR428]

You can buy them new still. DSC and other vendors sell them. Get the later C8 adapter. Those have larger passages than the early std C0 adapters.

[lineslinger]

If you only have 30 psi or less driving you are going to damage that motor, pressure is too low.

[olddog]

Since you said the engine was ok on the dyno, it is most likely the external plumbing.

Put a pressure gauge on both lines at the block. That's two gauges. One gauge will read higher than the other. The higher gauge is the oil coming out of the oil pump. It is quite possible you will find the pressure there is exactly what is was on the dyno. I'll guess it was 50. If you have 50 coming out of the engine and only 25 coming back to the engine, then you have the proof that the plumbing is creating a 25 psi pressure drop, from resistance to flow some where, and that there is nothing wrong with the engine.

On the other hand if you have 25 psi on both gauges, you have proof the the plumbing is not the problem and that the problem is indeed somewhere in the engine.

This will at least let you narrow the search. Prove this first! Everything else is a guess.

[2KWIK4U]

I agree with Olddog. The gauge pressure port on my adapter plate is on the return side of the plate, after the oil has passed through the filters and cooler. I would first verify the gauge is reading properly, then I would remove one hose from the filter and loop it back to the adapter plate to bypass the filters and see if that makes a difference. The oil won't be filtered, but would probably be safe as a test for a few minutes. Are the pressures your quoting with the oil cold or hot?

Brad W.

[427 S/O]

No Priobe, the top oil hole on the block is 'to' the engine, the bottom oil hole is from the oil pump. I mounted a boss 429 oil filter adapter plate to my frame (pics), the two SS hoses clamped together are the in-out from the engine.

[jimmymac]

I had oil pump bolts work loose. With about the same pressures as you have. You could check by pulling the distributor. If you can move the oil pump at all problem solved. Jim Dove can supply the adpt you need. I run it. Still you could try stock adpt. an filter. Just for testing. Be Patience

[priobe]

Hello All,

Ok update I spoke to the Engine Builder and he told me that the mains are : .0022 and the rods are .0025

I think that this falls with in specs.

I pulled the pump and everything looks fine. I called Melling and they told me to determine if it is a Hp pump the gears will be 7/8.

A HV pump will have 1 3/32 tall gears. I will check measurement tonight.

I pulled the pump apart and everything looks fine. I am thinking of replacing the spring in the pump or would you guys recommend replacing the entire pump?

I guess next stop will be the bypass at the back of the block. I really dont want to pull the tranny

[xlr8or]

Have you tried bypassing the external plumbing yet?

[priobe]

Yes and there was no difference

[lovehamr]

I may have missed it in the thread but have you tried a different gauge?

Steve

[patrickt]

Originally Posted by priobe

Hello All,

Ok update I spoke to the Engine Builder and he told me that the mains are : .0022 and the rods are .0025...

FWIW, the clearances on my SCAT Stroker Crank are greater than that (.003 and .0028, respectively). With the Melling M57 HV Oil Pump, remote Moroso filter and oil cooler open all the time, my pressure (with the oil as hot as it ever gets in the low 90s on the Smiths gauge) at idle is around 20 or even a couple pounds below. It comes immediatley up when the throttle is applied and is in the high 50's at anything above 3000 or so. Cruising at 2000 or less it might be in the high 40's. BTW, it's a a solid lifter cam and all of these numbers are just fine.

[vettestr]

Priobe,
You have bypassed the filters and thus bypassed the external relief valves. I read your posts a couple of times but may have missed what cold start up P was. What is cold pressure at idle and say 2K RPM? I see you live in Miami so it is plenty warm there and could be thinning oil with heat a bit. If Pressure cold is OK I would try straight 50 WT and check at operating temp. If a big difference then a lot of suggestions. This pressure at oil temp of say 230 to 250 degrees on a stock pump would be normal with 30W of the 10w/30W. Hope it is an easy fix.

[priobe]

Lovehamr,

I have tried 3 gauges:

Stewart Warner -Electrical - does not move cold or hot (gauge does not rest at zero. Sits between 0 and 25)
Moves pass 25 when you hit the gas.

Cheap Advanced auto gauge - Mechanical - 15 psi at idle cold & hot - 2000 RPM 30 psi

Snap on mechanical gauge- with drill spinning counter clockwise 28 psi cold did not try hot or with motor running

Vettestr,

I dont understand how I would bypass the external relief valve ? This relief valve is in the back of the block.

Cold startup is around 15 PSI and I am measuring the pressure before it enters back into the motor like most of the people on here. I have not yet connected my oil cooler because of this problem nor do I have thermosat to control the oil flow. It is basiclly 2 lines from the adaptor plate to the dual remote oil filters and back into the motor. I am using 20/50 Valvaline synthetic oil.


Update:

I spoke to Doug at Precision Oil Pump to purchase a pump even though I dont need one. Doug stated that synthetic oil's will cause you to lose pressure compared to Dino oil as long as all else remains the same. He also stated that idle oil pressure should be 15-20 PSi warm @ idle and should climb to 45-60 depending on clearances.

I have read many articles /threads with people having very simular problems and never posting what the problem was. Also, I have read people mentioning that they get 30 + psi @ idle (assuming idle = 650 - 900 RPM) and Doung mentioned that the spring in the pump does not control pressure at idle.

The pan that I am using is a Armondo Pan with a total of 11 QTS of oil.


I dont know what else to include. I am waiting for a response from my engine builder to find out what restrictors were placed in the head. (would this make a difference.


P.S. I have also check the plug inside the distributor and can not find it. But before disassemble of pan and pump with a drill I did not see oil gushing in that area. I am assuming the plug was installed : I also verified with the builder and he recalls the plug being installed.



Note:

Boy those pistons sure look nice when looking underneath and the pan off.
If I continue to disassemble more things I might as well rebuild the motor

[patrickt]

Originally Posted by priobe

I am waiting for a response from my engine builder to find out what restrictors were placed in the head. /

The general consensus (and I'm using that term loosely) on the FE forum was to use .060 restrictors for solids and .090 for hydraulic lifters. I have .060 restrictors in mine (again, solid lifter cam).

[priobe]

Thanks for the response, I too am running a solid lift / cam.

Question,

Is there a way to check and see if the restrictors are in the head by removing the valve covers ?

[patrickt]

Originally Posted by priobe

Is there a way to check and see if the restrictors are in the head by removing the valve covers ?

No, not just by looking. I remember that Luke-44 wrote a really nice, detailed thread about restrictors and it had a lot of photos as well. I did a quick search and found a reference to it, but not the thread itself. But here is a picture that he posted that shows you where the restrictor goes before you bolt down your rocker assembly.

[vettestr]

Priobe,
You have tried or answered any of the things I would suggest. I do see you are running a 20w/50w oil and its readings were hot and cold as you mentioned. You asked me about (external bypass possibilities I refered to.
Oil filters manufactured for GM, Chrysler and others have an internal bypass disc built into the filter (this bypasses the filter element) but the #8A does not have this and is in the housing. Some remote mount base mounts have a pressure operated bypass built into them and this is more common with a non-bypass type filter application like the 8A used on Fords. I have seen the in/out reversed on a remote filter mount causing the engines bypass to open.

[olddog]

Priobe,

Since you already have the pan off, check the gap between the rods. You gently push the rods apart and carefully use a fealer gauge. Do not stick it in and score the rod journal. Too much clearance here could cause your problem. It wouldn't hurt to check the end play in the crank. That should be checked before the rods are connected, but I think an excessive amount would still show up - not sure though.

Whoever said that the pressure relief valve does not control the oil pressure at idle is correct, but that is kind of a microsoft type answer. Technically correct but useless in this case. In a normal functioning engine, at idle the pump is not pumping enough (volume of) oil to generate enough back pressure to cause the relief valve to open, therefore it does not control oil pressure at idle. However if the relief valve malfunctioned and does not close completely, it will cause low oil pressure at idle, as not all of the oil the pump is pumping is going out to the engine.

You should be able to watch the oil pressure climb with rpms until the pressure reachs the point where the bypass valve opens. From that point on the oil pressure should stay pretty much the same.

What is the oil pressure at 1000 rpm, 2000 rpm, 3000 rpm, 4000 rpm - hot and 1000 rpm & 2000 rpm cold?

[Iceberg]

Do you have a Pond block? I had the same problem and Keith Craft fixed it. It something to do with a part shifting and blocking a port..

Ask Keith.

Good luck,

Kurt