ah64pilot

Hey guys, I wanted to ask any of you that have high performance engines and use a Melling High Volume, High Pressure pump what your normal oil pressure is.

I have a 455 .060" over, Edelbrock heads, oil restrictors in 2,3,4 mains, and CB IC886 pistons with zero gap rings, and a Melling HVHP pump...I am running about 75 psi oil pressure cold/cruise and 50 psi warm at idle.

Is this normal for these pumps or is this oil pressure too high? I have a freeze plug blocking off the hole where the filler neck normally goes and I have oil seeping UP from around the freeze plug and collecting in the "CUP" of the plug. I am wondering if the high oil pressure is the culprit or if I just have a bad seal around the freeze plug...the car doesn't leak anywhere else.

I saw a few posts talking about blow by but I don't know how I would have blow by after making 492hp on the dyno and not a single hint of smoke out of the tail pipes...please give me a clue

J-(Chicago)

Mine is about 65 cold and 45 red hot&in gear now, but I run Mobil1 15w-50.
You could try running 0w oil. How good is your gauge?

I had a gauge once that I wrote +15 on, because it didn't read correctly. Said 2psi oil pressure, but valve covers were swamped. Switched gauges, and got 17psi

coppercutlass

I only get blow by once its at running temp usually on the street. At the track i never see that little puff of smoke . My psi is 50 cold 20-25 idle and 15-20 in gear, 40 crusing . 75 seems a tad bit high. I would try a thinner oil .

ah64pilot

Are you guys using high volume / high pressure pumps or just high volume?

gregvm

There is no high pressure pump, per se.....
The pressure on the high end is set by the bypass spring.
Add shims to the spring, increase bypass pressure.

50 seems a little high at hot idle. What weight oil and what are your main/rod bearing & rod side clearances?

Greg

svnt442

Is the baffle in the hole below the freeze plug? It could be oil is getting up to it because the baffle was left out as I think the chain gets lubed from the other side of the block and I don't see where any excess pressure would cause seepage there.

matt69olds

I'm agreeing with the missing baffle theory. There is nothing pressurized under the freeze plug you installed. The oil is splashed up from the timing chain rotating. Even then, how is it seeping UP past the press fit of the plug? Are you sure its not leaking from the intake? From the oil pressure sending unit fittings?

507OLDS

Pressure is also dictated by your bearing clearances,so you can't exactly compare your pressure to another engine.I have to run 20W50,no way around it.I have 50-60psi cold/idle,and 10-15psi hot/idle.We knew that before the engine was even finished.The real concern is oil volume.You need to oil a 3" main bearing.Pressure is not going to do as much as volume will.The 507 also has restrictors in it,but I haven't put them in anything else.I have not seen any benefit from those.I also have Total seal rings in it,but will not,and have not used that type of ring again.Nothing convincing there,except that a ring like that "can" create more pan pressure.I also have the large freeze plug on my oil tube hole,but it has never leaked,nor has anything else.
As for my friend that had the severe blowby problem,his car didn't smoke,which is why we couldn't figure it out at first,but it still went 11:80's.When it was repaired & back together,it went 11:73-11:75 from there on out.
Do you have the front timing chain plug,with the small orfice in it,to oil the chain?Do you have the stock plug in behind the distributor gear,or is that hole larger?I enlarged that hole to add more oil to the bronze distributor gear.That will have a small effect of pressure as well because a larger hole will relieve some pressure versus a smaller hole.Have you done an oil change yet,or do you still have the dyno/break-in oil in there?There is also a small,square baffle/deflector,below the oil fill tube,in the block.Did you remove that,or is it still in there?Leaving it in can help keep oil away from the plug,like it keeps oil from climbing up the tube.How do you have your engine vented up top?

cutlassefi

Good stuff Brian as usual.
And to add to that, when you go with a "high volume" pump, everything else being equal, it will automatically become a higher pressure pump as well. You're trying to push an increased amount oil thru the same passages and bearing clearances, plain and simple.

Yes, 50 at idle is exteme imo, 25-30 is plenty. As mentioned oil volume is just as important as pressure, use a thinner oil if possible. It's costing you hp/tq too.

Run to Rund

There is good advice above.
You need enough pressure vs. rpm to overcome centrifugal force from the crank journal diameter. I like to see 45 psi plus by 2000 rpm, 55-60 at high rpm with moderate clearances and warm to hot oil. I run 15-40 weight oil. Bearing clearances, rod side clearance, and especially the metering system in the lifters have significant effects. I ran a set of solid lifters once that didn't have metering plates under the pushrod buttons, and got 37 psi hot. Adding plates fixed the problem. I used the 4 offset hole type plates; single hole (offset from center) plates meter less oil, and stock plates have no holes.
As stated above, this has nothing to do with oil seepage around the cup plug. It isn't sealed well (did you use RTV?) and lack of the baffle under it can make that worse.

coppercutlass

I disagree with the missing baffle theory . Mine is in and I blew my oil filla cap off oil spewed all over the engine compartment. Oil will push up past the baffle at high rpm mine does it usually at the track when I'm at high rpm. I just needed a new cap .

507OLDS

Nate's engine had the baffle in,and it still popped the cap off.Then he dusct-taped the cap on,and it pushed the whole tube out.The baffle will help,but not when you have a blowby issue like he had.

coppercutlass

If its blow-by then yeah can't aid that with a new cap . But if his blow-by was sever wouldnt he see the smoke coming out the breathers. I usually see a puff under acceleration. And a slight smoke in idle but not enough to really worry about . I was mainly saying oil can still get past the baffle .

ah64pilot

I figured I'd respond to Brian because he hit most of the points everyone else was hinting at...and because I text him last night and he never responded

Using 20W-50 (still have the break in/dyno oil in there...planning an oil change this weekend)

I have the oil galley plugs (holes and no holes) in the right places, front and back

Stock hole plug for timing gear

Baffle is below the freeze plug

PCV passenger side, breather driver's side

And...there are NO leaks anywhere, only oil on the engine is in the cup of the freeze plug. It looks like it is pushing up from around the plug and collecting in the plug itself. I don't have the specific bearing clearances so I'm no help there...I'm also using a K&N oil filter, opinions?

I guess I should add that the day I saw the oil in the freeze plug it was 38 degrees outside, I cruised about 35 miles at 2800 RPM...do you think the cold weather and the high RPM combo might have cause oil to seep up around the plug? I drove the car around the neighborhood (< 2500 RPM) last night and there was no oil in there -Keep in mind, I am being **** here...the amount of oil in there amounts to a 1/4 of what would fit in a oil bottle cap. It's not spraying or anything...

507OLDS

Nate's car didn't smoke at all,not even going down the track.

I don't think the temperature would result in the oil leaking around the plug.It could easily be a burr ir scratch along the wall of the fill tube bore,and the oil is wicking through there,between the side of the freeze plug.

coppercutlass

I might add it puffed out the breathers in my case never exhaust. I think mine is just spent gasses going past the rings. Wouldn't a little gasgasinch work to seal the freeze plug .

cutlassefi

You probably should have included that info from the start, it may have alleviated a bunch of speculation.
I believe it will drop 10psi or so with a 10W-30 and no break-in lube

Bill in NC

We have similar builds and share some of the same internal parts. My fresh oil psi runs very close to what you've posted during the cold weather months. My rod and main clearances are .003 (can't recall rod side clearance). You will notice a difference between running new 20-50 in 38 deg weather and running 20-50 with 2,000 miles on it in 100+ deg weather. After cruising for a couple of hours in 100+ deg temps my oil pressure will get down to 20psi at idle in gear and around 50psi at cruise. I think Brian is probably right on track with a slight groove being the cause of that oil seepage.

67Olds442X2

I'm running a Melling HV pump. Pressures at 60 psi cold/cruise, 35 to 40 at idle / warm. (20W-50) Got a PCV in right VC and breather in left VC, no baffle and at high RPM's, get oil out the filler. Before putting in PCV, would blow breather from VC.

67Olds442X2

This may be a little off from the major topic of this thread but it deals with oil from the filler tube. I get oil at high rpm's coming out the filler even with a PCV setup but I don't have the baffle in the block. I have a few spare valve cover grommets that are baffled and they just fit in the filler tube. I'm going to give it a try and put one in since it will still let air out but hopefully will keep the oil in. It's too large to fall in the engine since the tube is tapered. I have a breather for the cap.
I'm in the middle of changing my front oil seal, waiting on a HB installation tool, but once that's done I'll check it out. I figure it can't hurt to try.

ah64pilot

I'm using Valvoline VR1 20W-50 with no additive...that was what we broke the engine in on...that was September...about 100 degrees outside, and the oil pressure then is the same as it is now. That is the same oil I will continue to use, just a lighter weight.

cutlassefi

Correct, you'll need to with a flat tappet. Your pressure will go down if you use a 10W-30 or so.

ah64pilot

Update...I have driven the car on the same trip 80 miles round trip and have no evidence of oil in that location. All I did was clean out what was in the freeze plug. When I got home, I checked it and there is no evidence of oil anywhere. I think the cold weather may have had something to do with it, but I'm not sure. Odd indeed.

Gonna change the oil tomorrow, I'll let you know what the pressure is with some 10W-30 in it. Merry Christmas all!!!

ah64pilot

Thanks Joe! A ton of info, probably too much! lol! But I do feel better about my oil pressure now.

Steve

WoofWagon

Here's a thought, go to NAPA and pick up their oil leak detector dye, you have to use a UV light but it will show up any leaks coming out of an engine. I've used these in the past to track down little oil leaks in diesel engines that were driving the operators nuts.