Oil Pressure

[cv70chall]

I did a starter upgrade several years ago to the smaller hi-torque style starter for my Challenger and have noticed that the oil pressure on my aftermarket gauge seems to be high- 70-80psi for about 10 minutes and then settles down to between 40-60psi. I was initially "told" to start the car, shut it off- wait about 20 seconds and start it again before driving. (?) Would this have anything to do with the starter?
Thanks

 

[pschlosser]

Whomever gave you that advice, out of context, it seems a tad psycho, to me. I cannot think of any way the starter motor would impact operating engine oil pressure. I don't think the starter has anything to do with the oil pressure.

What you describe with oil pressure, I've seen many, many times on older and wearing engines. When the engine is cold, varying tolerances in the engine may be tighter than when warm. Further, as the engine oil heats up, it (thins and) flows differently resulting in a slight drop in pressure. Add those things together, and at idle, the oil pressure can read quite a bit lower on a warm/hot engine compared to a cold one.

 

[Steve340]

I would not bother to start the engine twice - most wear occurs when the engine and oil are cold during the first 10 minutes of running.
The starter should in no way affect the engine oil pressure.

 

[Xcudame]

Sounds like normal start up pressure and warm pressure to me. Starter has zero affect on oil pressure. Now if it dropped to single digits after warming up, you've got a problem. So drive your Challenger and enjoy!

 

[Steve340]

What grade of oil is in the engine for example 20W-50?

 

[WFHDANB426]

I did a starter upgrade several years ago to the smaller hi-torque style starter for my Challenger and have noticed that the oil pressure on my aftermarket gauge seems to be high- 70-80psi for about 10 minutes and then settles down to between 40-60psi. I was initially "told" to start the car, shut it off- wait about 20 seconds and start it again before driving. (?) Would this have anything to do with the starter?
Thanks

Like the other replies said the starter has nothing to do with the oil pressure. Your oil pressure readings sound reasonable to me.
I raced my Chrysler Kit Car in 1980 and it had 100 psi cold oil pressure with the dual pickup oil pump with Hemi rotors & Quaker State 30 WT Racing Oil and prob 60 psi hot oil pressure idling but I ran that engine at 7,500 RPM. The synthetic oils are so good these days that less oil pressure is probably fine. I used Mobil 1 synthetic oil for many years and now I use Pennzoil Ultra Platinum but these are just my personal choices and opinions. Now I write songs and on youtube if you search:WFHDANB426 you can hear my three Cuda songs.

 

[aussiemark]

Cold oil is thicker then hot oil once the oil is up to operating temperature the pressure will be a bit less this is normal for any engine. Old engine builder rule is you want 10 psi per 1000rpm for so yours is good for around 5000rpm sounds good to me.

 

[aussiemark]

I do remember reading about a special race engine that needed the oil and coolant to be pre heated before start up they said if it was started with cold fluids it would cause engine damage very interesting.

 

[rogue]

formula one engines have the fluids pre-heated

 

[TIMINATOR]

I modify (port) the oiling system on every engine I build. Then the cold/hot disparity is less and I can run a stock oil pump to higher RPM dropping pumping HP losses. Modifying oiling to me is EVERY passage intersection, pickup tube entry and exit, main cap on small blocks too. Cavitation and aeration happen at every sharp edged intersection.
I made a tester with a pressure gauge with a "T" and feed the bare block with old cam bearings for testing. Check the back pressure first, then after the mods. You will be amazed. And that's with air, not even thick oil!
Don't believe me? Stick an oil pump in a 5 gallon bucket, turn it at 3000 RPM, that's 6000 engine RPM. See how fast the bucket empties. Then do the test with a bare block. Before and after oiling mods.
Things pros do that others don't.
TIMINATOR

 

[540HemiCuda]

You have more oil pressure than you really need. Warm oil pressure of 15 pounds or so at idle and 10 pounds for each 1,000 RPM thereafter till a high of about 60 is PLENTY. Cold oil will have more pressure than hot oil even with synthetics or multi grade oils. What are your hot oil pressure readings? If higher than the above recommendations, just reduce your oil weight till you get the pressure in that range.

There is also the issue that oil that results in pressure that high is thick enough that it will slow the oil getting to all points of the engine during those cold starts. In other words, for our street oriented cars, excessive oil pressure has NO advantage, but actually has disadvantages. Pressure is a measurement of the RESISTANCE to flow. After the appropriate pressure is achieved, higher pressure is NOT higher volume. Much may just be directed right back into the oil pan due to the pump's bypass valve being opened.

Since I may not get to drive my car for a couple of weeks at time and know that most wear happens at start up and during warm up, I have an AccuSump that I use to pressurize the oil system. The engine has oil pressure BEFORE I even hit the key. No dry starts. If the car is driven almost every day, then that action is not as necessary.

Why most engine wear occurs during cold start up?

What is phyisical reason for 75%-90% wear engine occurs on cold start up? I can't find exact reason.. Is that beacuse ? 1) rich fuel mixture on choke, splash oil film from cylinder wall? 2)corrosive wear on cylinder and piston rings? 3)cold oil don't lubricated well?? (but oil when is cold...

www.physicsforums.com

And the previous posters are correct that the starter has NOTHING to do with your oil pressure. I would add, that you need to seek someone else for that kind of advice.

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