stock oil pressure?

Anyone know the stock oil pressure range on the 3.0?
I don't want to turn this into an oil debate, but we endurance road course race. Car runs 3-6k rpm in 3/4 gear constantly. Was running 10/40 but after burning a 1/4 to 1/2 qt of oil every 2-4 hours and then a rod bearing failure, inspection showed bearings were taking a beating. Bored .040 over w racing mains and racing rod bearings. Switched to mobile 15/50. Oil psi at startup is 60-70 as expected with that thick of oil. After 5-10 min, runs about 35 or so... Wondering if its a bit too thick though and should drop back to 10/40 or stay with 15/50? Thoughts??

5-10 psi hot idle, 10 psi for every 1000rpm. This is considered minimum but can be higher. I would try a 10w40 oil and see what happens. In my 2.5 I set all bearing clearances to 0.002 and I run a 0w40 synthetic. Cold idle is still 60 psi.

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Originally Posted by notbob

Anyone know the stock oil pressure range on the 3.0?
I don't want to turn this into an oil debate, but we endurance road course race. Car runs 3-6k rpm in 3/4 gear constantly. Was running 10/40 but after burning a 1/4 to 1/2 qt of oil every 2-4 hours and then a rod bearing failure, inspection showed bearings were taking a beating. Bored .040 over w racing mains and racing rod bearings. Switched to mobile 15/50. Oil psi at startup is 60-70 as expected with that thick of oil. After 5-10 min, runs about 35 or so... Wondering if its a bit too thick though and should drop back to 10/40 or stay with 15/50? Thoughts??

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So what were you reading on 10w40 hot idle? I run 20w50 cheap stuff on one 6g72 with a loose rod journal and ran 20w50 with Lucas in a nasty oil burner. It would maybe be 25-35 I cant exactly remember. I still have the loose journal motor in my Duster with 20w50 in it that I could warm up and see what it reads. What 6g7x road race guys really seem to worry about is what your oil pressure does after you do a couple long hard pulls on the motor. Does oil pressure drop or remain good? Some of the circuit racers have found that the cheaper oil choices that work for drag racers don't work when superheated. They lose and lose and lose oil pressure until things are unsafe. You really shouldn't be having problems if those guys can run higher rpms. I think most of them run Motul or Amsoil. Hit them up on 3si.org, there are a lot of old threads on the subject, especially the oil analysis threads that never lead anywhere for the average non racer who shouldn't bother with oil analysis. Is this the car recently running dry sump or another endurance 3.0?

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Originally Posted by shackwrrr

5-10 psi hot idle, 10 psi for every 1000rpm. This is considered minimum but can be higher. I would try a 10w40 oil and see what happens. In my 2.5 I set all bearing clearances to 0.002 and I run a 0w40 synthetic. Cold idle is still 60 psi.

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IMO short version, quit the thick oil and lucas, switch to "high mileage" oils correct grade, = new motor. Not sure for racing though. Try racing oils (offroad use only) more zinc I believe, modern spec leaves a lot out. Oh and btw, had a different grade mobil in my 3.0 a while back, sounded like it was going to sh!t a bearing at idle, really loud, changed it out quick, same grade castrol, pennzoil is quiet. Sounded like arse in another motor too, it's on my avoid like the plague list now.

The 10-40 ran around 20-25 hot idle and would change from 5psi to 35 depending on turns an acceleration. The 10/40 was rotella... The mobile 1 15/50 stays pretty consistent and I haven't seen it drop below 20. This is a different endurance car. No dry sump...

I tend to think that oil is slow to return from heads in 3.0s for some reason, leading to partial responsibility for oil burning in exhaust from getting forced down guides (inadequate PCV a culprit also) and taken to extremes this could lead to aeration/starvation in the sump. That's a large part of why I tend to think "thick oil isn't the answer" in these motors.

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Originally Posted by notbob

The 10-40 ran around 20-25 hot idle and would change from 5psi to 35 depending on turns an acceleration. The 10/40 was rotella... The mobile 1 15/50 stays pretty consistent and I haven't seen it drop below 20. This is a different endurance car. No dry sump...

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If 10w40 got you 20-25 hot idle and inconsistent pressure when it was beat on then I think you are doing a good thing moving up in the oil world. If that oil thins out and you get a quart low at high rpms you might suck air or just have the oil thin out too much under extreme heat. Goodbye bearings. There are still better oils if you need them.

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Originally Posted by RoadWarrior222

I tend to think that oil is slow to return from heads in 3.0s for some reason, leading to partial responsibility for oil burning in exhaust from getting forced down guides (inadequate PCV a culprit also) and taken to extremes this could lead to aeration/starvation in the sump. That's a large part of why I tend to think "thick oil isn't the answer" in these motors.

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Oil does have problems returning. I hog out the return passages but I do that because I also try to pull blowbye from the crankcase through the heads and that causes even more drain problems. I once had my lower intake manifold valley filed with motor oil that backed up out of the valve covers and went to the center instead of down the sides of the block. Easily could have lost a motor there.

Since you are talking road course, have you considered adding baffles to the pan to try and keep oil near the pick-up on long turns?

Many race oils are 50 weight for a reason...

Having said that, there's a 101 opinions on what weight, type and brand of oil to run. Personally in an endurance car I would run a full synthetic, regardless of what weight you choose. Also an oil cooler may be a worthy addition.

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Originally Posted by Force Fed Mopar

Many race oils are 50 weight for a reason...

Having said that, there's a 101 opinions on what weight, type and brand of oil to run. Personally in an endurance car I would run a full synthetic, regardless of what weight you choose. Also an oil cooler may be a worthy addition.

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I think a lot of people run the thin oil to eek out the last bit of HP but the increased work that the oil pump has to do in an endurance event to move thick oil is probably worth it as long as the oil doesn't get too hot. I know nothing about oil gaining heat from friction vs just soaking up heat from the block/pistons.

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Originally Posted by Ondonti

I think a lot of people run the thin oil to eek out the last bit of HP but the increased work that the oil pump has to do in an endurance event to move thick oil is probably worth it as long as the oil doesn't get too hot. I know nothing about oil gaining heat from friction vs just soaking up heat from the block/pistons.

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From what I know, I think the trick is to use the thinnest oil possible for your application that does not lose viscosity. Thicker oils are harder to pump and rob hp, and IIRC are more prone to aeration. I run 5w30 in my Lebaron now, and it gives me no problems, even on mountain runs.

Endurance racing is much harder on oil though. The main enemy of oil is heat, which is why I suggested the oil cooler. A) it will help save your oil from breaking down, and B) it will help cool the engine.

You are monitoring oil pressure, but what is to oil temperature? That is just as important and can help you determine how to move (up or down) the viscosity scale for your oil. Remember you can also mix viscosities to get what the engine likes.

Also, can you post pictures of the rod/main bearings? I'm interested to see what they look like.