X-40 with no VIIs? Redline?

[ringmaster]

I am looking for a very shear-stable X-40 oil. My current fill is Pennzoil Conventional 10w30 (break-in oil) and when the oil gets to the upper range of the motor's operating temp my oil pressure is dropping too low which has me looking for a 40wt for the new fill. My hope is that the strong synthetic 40we will give me at least 5psi more oil pressure.

So far I am down to Redline 5W40 or 10W40 or Esso XD-3 0W40.

Is there a clear winner in this group that offers shear-stable high temp performance?

 

[buster]

Redline clearly has the best shear stability of all synthetic oils. No contest.

 

[TallPaul]

I heard that all of Redline's oils are without VII, except for 5w40. Still probably not much VII at that.

 

[ringmaster]

quote:

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Originally posted by TallPaul:
I heard that all of Redline's oils are without VII, except for 5w40. Still probably not much VII at that.

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This info could be the deciding factor! The car won't see any really cold weather starts so if the 5W40 has VIIs and the 10W40 doesn't I would probably buy the later. Is this logical or are there other factors I am overlooking?

Redline
5W40 15.1 cSt @ 100C
10W40 14.6 cST @ 100C

So they should both help to raise oil pressure vs the Pennzoil 10W30 I have in the engine (10.4 cSt @ 100C).

 

[TallPaul]

Can call Dave at Redline and ask him. I doubt the 5w40 would ever be a problem, but like you say, if no real cold weather, might as well go 10w40.

 

[Auto-Union]

Delo 30, 12cSt, no VIIs. $4/gal.

 

[JHZR2]

I wouldnt discount GC... my operating pressure has increased about 4-6 psi over what it has always been since I bought it new, running conventional and synthetic 5w30s.

JMH

 

[TooSlick]

I'd add the SL/CF rated Amsoil 10w-40, Motorcycle oil to this short list....A VI in the 150 range and completely shear stable in auto use.

TS

 

[ringmaster]

quote:

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Originally posted by 427Z06:
I'm curious. What kind of temps and oil pressures are you seeing?

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When the oil (5w30 conventional)is around 265F I get approx 22# at idle and 40# max. I want to see at least 50# max when the oil is hot and I think a good 40wt synthetic should get me there.

 

[427Z06]

quote:

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Originally posted by ringmaster:
I want to see at least 50# max when the oil is hot and I think a good 40wt synthetic should get me there.

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What is the oil pump's relief valve relief pressure set at?

 

[ringmaster]

quote:

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Originally posted by 427Z06:

quote:

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Originally posted by ringmaster:
I want to see at least 50# max when the oil is hot and I think a good 40wt synthetic should get me there.

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What is the oil pump's relief valve relief pressure set at?

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Good question....not sure but I think all the hi-flow LS1 pumps are set over 50#.

 

[427Z06]

quote:

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Originally posted by ringmaster:

quote:

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Originally posted by 427Z06:

quote:

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Originally posted by ringmaster:
I want to see at least 50# max when the oil is hot and I think a good 40wt synthetic should get me there.

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What is the oil pump's relief valve relief pressure set at?

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Good question....not sure but I think all the hi-flow LS1 pumps are set over 50#.

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I guess you'll probably find out when you stick that 40wt synthetic in there. A flush run with some 15w40 HDEO would tell you too, as when it's cold it should bump right up to the relief pressure at anything above a fast idle.

 

[427Z06]

I'm curious. What kind of temps and oil pressures are you seeing?

 

[DeaconBlue]

Although the Amsoil’s SL rated 10w-40 Motorcyle oil (MCF) is an excellent choice, the additive package (IIRC, heavy zinc and phosphorous) is NOT very catalytic converter friendly. So if the vehicle has cat-cons, stay away from the Amsoil 10w-40 M/C oil.

 

[Jason8691]

quote:

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Originally posted by DeaconBlue:
Although the Amsoil’s SL rated 10w-40 Motorcyle oil (MCF) is an excellent choice, the additive package (IIRC, heavy zinc and phosphorous) is NOT very catalytic converter friendly. So if the vehicle has cat-cons, stay away from the Amsoil 10w-40 M/C oil.

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Unless your vehicle is an oil burner it wont matter.

 

[ringmaster]

quote:

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I guess you'll probably find out when you stick that 40wt synthetic in there. A flush run with some 15w40 HDEO would tell you too, as when it's cold it should bump right up to the relief pressure at anything above a fast idle.

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I did a change and used 10W40 Quaker and now the pressure is up about 6-8# across the whole RPM range.

My research shows that the K&N filter might flow better and give a bit higher oil pressure.

 

[va3ux]

quote:

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I did a change and used 10W40 Quaker and now the pressure is up about 6-8# across the whole RPM range.

My research shows that the K&N filter might flow better and give a bit higher oil pressure.

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If you get higher oil pressure from an oil filter, you probably don't want it.

Bear in mind that an oil pump is a positive displacement pump with a relief valve and some slippage within the housing. If the discharge pressure increases (for a given speed), then the flow has decreased. Is this really what you want ?

 

[TallPaul]

The filter should not affect overall pressure. The 10w40 definitely would increase pressure over a 10w30. It did for me by about 5 psi.

 

[Gary Allan]

I don't think any filter offers anything but marginal alterations to pressure. It's virtually transparent to oil flow. It's next to nothing compared to the engine. If it adds up to 2psi ..it would be alot. Once the relief is open ..there is no longer that mandated relationship between the engine resistance and the filter's resistance in line. That's when I see all excessive (assuming a fairly new filter) PSID readings.