PDA

View Full Version : Oil PSI with Valvoline VR1 20W 50


GTFD244
07-11-2013, 10:44 PM
Hey guys and gals running Valvoline VR1 20W50, after reading positive reviews on this oil here and in other places on line, I have switched my 1995 Prostar 190 diet to this. The engine is the 350 TBI. Today was the fist day in the water with this oil and I noticed higher oil pressures with it. I did expect a slight increase being I switched up from 10W30 however, I didn't expect this much. With the 20W50 oil I am reading about 35 to 40 psi at idle and 70 psi or even a little higher at 3600 RPM. With the 10W30 I was around 15 to 20 at idle and 45 to 50 psi at 3600. I like the idea of the higher oil psi when the motor is running hard however; I am not a mechanic and wanted to run this by you guys for your input...

CruisinGA
07-11-2013, 10:52 PM
Higher pressure is not always a good thing. Flow is important to remove heat from the components being lubricated by the oil.

At the risk of diving ino another "oil thread" 50wt seems a little on the thick side to me. Your engine is already running at a much lower temp than an automotive application so the oil is not going to thin as much from heat. Personally, I run 40wt

jhall0711
07-11-2013, 11:01 PM
Hey guys and gals running Valvoline VR1 20W50, after reading positive reviews on this oil here and in other places on line, I have switched my 1995 Prostar 190 diet to this. The engine is the 350 TBI. Today was the fist day in the water with this oil and I noticed higher oil pressures with it. I did expect a slight increase being I switched up from 10W30 however, I didn't expect this much. With the 20W50 oil I am reading about 35 to 40 psi at idle and 70 psi or even a little higher at 3600 RPM. With the 10W30 I was around 15 to 20 at idle and 45 to 50 psi at 3600. I like the idea of the higher oil psi when the motor is running hard however; I am not a mechanic and wanted to run this by you guys for your input...

I have similar readings running the VR1 20/50.

j.mccreight@hotmail.com
07-11-2013, 11:20 PM
My 351w has similar readings with Valvoline VR1 20W50, zddp is necessary for flat tappet camshafts, I'm unsure if your gm 350 tbi is flat tappet or not. BTW 351w specs is 35-60 psi @ idle.

JMann
07-12-2013, 12:02 AM
I'm 40 - 60 psi with the same 20/50 in my 91.
Could the 70psi be due to being over filled a little bit? With the dip stick problem (not reading correct) I'm always concerned about over or under filling.

GTFD244
07-12-2013, 01:09 AM
Thanks for the info guys. I did check it before running it but will again tomorrow, that is a good point on the oil level.

GTFD244
07-12-2013, 01:14 AM
My 351w has similar readings with Valvoline VR1 20W50, zddp is necessary for flat tappet camshafts, I'm unsure if your gm 350 tbi is flat tappet or not. BTW 351w specs is 35-60 psi @ idle.

I am also not 100% sure but by reading other posts in this forum it sounds like the Chevrolet 350 in my 95 most likely has flat tappet camshafts. This is a great forum!!!

mikeg205
07-12-2013, 07:07 AM
you should have been running a minimum of 15w40 like rotella - not 10w30 - the 95 has a flat tappet engine. I run the Synth VR1 20w50 and my engine runs much better and gets a bit more RPM.

GTFD244
07-12-2013, 08:59 AM
you should have been running a minimum of 15w40 like rotella - not 10w30 - the 95 has a flat tappet engine. I run the Synth VR1 20w50 and my engine runs much better and gets a bit more RPM.

Yep, I see that now looking at the oil posts on here and am happy to have discover this being the manual says nothing on viscosity. I went with "it's a car motor" when I bought the boat and did my first oil change and always thought the oil PSI was a little low. I bought the boat new so it is a one owner 95 with less that 250 hours on it so I know it's full history and am happy to have discovered the true viscosity range I need. I do agree with the run better, my boat seemed to run very smooth yesterday through the full RPM range. Thanks again for all the info.

By the way Mikeg205, what oil psi do you see on your 95 with the 20W50?

mikeg205
07-12-2013, 09:48 AM
I will have to look - next time I am in the boat.... 40-idle and 80 skiing speed is what I remember...

GTFD244
07-12-2013, 10:36 AM
I will have to look - next time I am in the boat.... 40-idle and 80 skiing speed is what I remember...

Thanks, I would appreciate that.

east tx skier
07-12-2013, 12:22 PM
Thanks, I would appreciate that.

Different engine (PCM GT-40), but that's in line with what mine does 40/70.

GTFD244
07-12-2013, 01:15 PM
Different engine (PCM GT-40), but that's in line with what mine does 40/70.

Great, I did check the oil level and it is good so those oil pressures are what I will have. Glad to hear they are consistent with others running that oil. Thanks!

ricford
07-12-2013, 02:05 PM
I was going to ask the same question at some point. My 96 LT1 runs similar numbers, or even higher when the engine is cold. Glad it's normal.

GTFD244
07-12-2013, 05:52 PM
I was going to ask the same question at some point. My 96 LT1 runs similar numbers, or even higher when the engine is cold. Glad it's normal.

Yes, the numbers I questioned are readings when warm and as you said, they are higher cold. I have always let it warm up good before running any passes so I have no idea what the cold pressures are. I would guess cold it would peg the gauge at 36 mph.