oil pressure gen 2 stock

[gen2lover]

is 50 normal for a stock gen 2 rt-10? it stays about 50 all the time regardless of weather or driving etc...

 

[dave6666]

My '01 runs 60 psi on Mobil 1 10W-30 at speed. Idles around 45 psi hot. I've read these gauges are not that accurate.

 

[bvk]

mine is 40-50 most of the time, drops to 30ish at idle when hot.

 

[GreyKnight]

60 all the time. I checked in about 98 degree weather.

 

[chimazo]

Mine also stays pretty much the same regardless of the temp or RPM, leading me to believe (as someone already mentioned) that it's not very accurate.

 

[RedSrt007]

mine is 40-50 most of the time, drops to 30ish at idle when hot.

Mines about 35 idle, 40-50 warm, and 50-60 cold

 

[triblk6spd]

Mine runs around 70 most of the time. dropping slightly at idle and raising slightly when revving. Should I be worried. How would oil pressure get be too high? I run Royal Purple 10-30.

 

[dave6666]

60 all the time.

With the key off too? Damn man, get a new gauge!!

 

[dave6666]

Mine runs around 70 most of the time. dropping slightly at idle and raising slightly when revving. Should I be worried. How would oil pressure get be too high? I run Royal Purple 10-30.

Yes I would be worried. However fellow Texan, as your proximity to me is close I'd be happy to examine your car for free of charge. Please leave it at the Wendy's with the key under the mat. We'll be watching from across the way, and will fax a report when finished with the car.

Really though, some engines have an internal bypass valve back to the pan to prevent over pressure to the journals. Maybe someone can clarify if the Viper Gen2 engine has this feature. Heck, my dune buggy with 50's technology has 2 bypass valves. One at the pump and one at the front main (engine is backards...).

 

[gen2lover]

so is 40 all the time bad? near 45 when hot? does oil amount affect pressure? low or right on (full)?

 

[dave6666]

so is 40 all the time bad? near 45 when hot? does oil amount affect pressure? low or right on (full)?

40 does seem average compared to some, but what concerns me is why you would say 45 hot and 40 all the time. You usually have a lower number when hot, and how do you have 40 all the time and 45 when hot, when it's 40 all the time???

Your question about oil pressure... First an explanation of what pressure is. It is the resistance to flow.

Things like this typically affect pressure:

-> Pipe size, or in the case of an engine, oil passages. Bigger pipe or passage, less resistance to flow and lower pressure.

-> Flow rate, or gallons per minute, as more flow in the same pipe size generates more resistance and more pressure.

-> Fluid viscosity is a player, but more than likely the difference between thick or thin oil does not affect pressure until it reaches the ultimate reduction in pipe size, the bearing journals. Yes, that's where the passages get tight, where most of your pressure is built, and where thicker oil gives you a higher pressure.

It is important to note about the pump itself. Most if not all oil pumps are positive displacement. Meaning for every revolution or cycle they take a predetermined amount of fluid and move it through the pipe. Period. Well, with the exception that there are slight mechanical clearances that can have internal leakage. This positive displacement phenomena is also why many of them have a relief valve in them so that if the oil passages get blocked or if the oil is too thick to pump, it just dumps back into the pan.

A little more on pumps, in regards to fluid viscosity. In simple terms, the thicker oils pump at the same rate as thinner oils. Thicker oils just take more power to run the pump (robbed from the engine...) as this is a positive displacement pump and both oils will flow at the same rate at a given pump or engine rpm.

A note on thicker oils and the warm fuzzy feeling of more pressure as read on the gauge. Remember that part about the majority of the pressure drop is at the bearing journals? And that thicker oils will give you better pressure trying to get by those tight clearances? That is not all good, especially if the Viper engine has any internal relief or bypass valves (I do not know this fact or not). Reason why this "good" pressure with thick oils can be bad is that yeah, you got great pressure, but little flow past the bearings. Bearings are now running with great pressure but less lubrication. The oil has to go somewhere though, and if the engine has internal relief features built in then that is where it goes. Otherwise, the pump and V10 engine powering it must work it's ass off pumping that thick stuff wasting your hp.

I think you asked about oil level, didn't you? Without another technical speech, which I could dive in again, the oil level only affects pressure if the pump starves for oil and flow stops or becomes intermittent. Flow of course being one of the constituents of pressure. Lower flow, lower pressure. And yes, lowering your pressure by lowering flow due to pump starvation is B-A-D! I doubt you have that problem, and depending on the movement dampening bult in to the gauge, the gauge would bob up and down all the time. Yours is stuck on 40 right?

 

[PDCjonny]

Were you at a Holiday Inn last night, Dave?
Damn impressive.....

 

[dave6666]

Were you at a Holiday Inn last night, Dave?
Damn impressive.....

After 27 years in chemical engineering & maintenance, I can't help myself.

 

[bvk]

yes thankyou, very informative.