FC3S Murray's never ending build.

[FC3S Murray]

OK I found my spec notes on all my internal parts. I thought I didn't spec out my oil pump BUT i did lol...it was all a blur last summer trying to squeeze in engine time in with the new house and family.

Anyway: Between lobe measurement was .003 , FSM says between .0012-.0047

Between body and outer rotor: .009 , FSM says .0079-.0098

So it is good, not perfect BUT good. I keep researching standard oil pressure and I keep coming across 15psi (RETed). The FSM only states standard oil pressure at 3K...no idle. WTF lol? I thought i found factory oil pressure in the fsm......hmmm?

I am not too worried since it now reads 17-18 psi @ 1K. I will watch it though.

[RETed]

Anything above 10psi is okay.
If it starts dropping under that, I'd worry.

Here's the problem...
Unless you have a pressure gauge that is "certified" for low psi in the 5...10...15psi range, your gauge is probably not that accurate that low.
As a rule, gauges are most accurate in the middle of their range...
So a 0 - 100psi pressure gauge is most accurate around 50psi.
Trying to get a 0 - 100psi pressure gauge to read accurate down to the 5 - 15psi range is just not reasonable.

Yes, your oil is diluted from all that rich running.
Your oil pressure is going to go up.
How much is it going up? I doubt it's going to be much...
I'd be surprised if it goes up from 10psi to 15psi.
It doesn't hurt, and changing oil isn't that much of a big deal.

Now, going from a 10W30 to 20W50 *is* going to be much more of a difference.
You're basically doubling the viscocity of the oil, and that's going to change your numbers significantly.

I think you're being a little paranoid about the oil pressure, but, on the flip side, I don't blame you.
I've been through an OPR failure and an o-ring failure, and I know what the symptoms look like - you're going to see a significant drop in *max* oil pressure at higher revs; idle oil pressure is practically "0".
Remember, the engine is under very little load at idle - 10psi doesn't sound like much, but it's enough to keep everything lubed and happy.
An engine revving under load at 3k+ RPM's is going to fail a lot faster when you cut the oil pressure in half versus at idle.
Now, I'm not talking about catastrophic oil pressure loss like...NO oil pressure, which is obvious the engine is going to kill itself in short time no matter under what conditions, but I hope you get the point of this long reply...


-Ted

[FC3S Murray]

Originally Posted by RETed

Anything above 10psi is okay.
If it starts dropping under that, I'd worry.

Here's the problem...
Unless you have a pressure gauge that is "certified" for low psi in the 5...10...15psi range, your gauge is probably not that accurate that low.
As a rule, gauges are most accurate in the middle of their range...
So a 0 - 100psi pressure gauge is most accurate around 50psi.
Trying to get a 0 - 100psi pressure gauge to read accurate down to the 5 - 15psi range is just not reasonable.

Yeah I am running prosport gauges...they are nice qaulity BUT I am pretty sure their low range is not as accurate as I would like and I doubt they are as accurate as a 150.00 Greddy gauge. Can't complian for a 50.00$ gauge though.

Yes, your oil is diluted from all that rich running.
Your oil pressure is going to go up.
How much is it going up? I doubt it's going to be much...
I'd be surprised if it goes up from 10psi to 15psi.
It doesn't hurt, and changing oil isn't that much of a big deal.

Now, going from a 10W30 to 20W50 *is* going to be much more of a difference.
You're basically doubling the viscocity of the oil, and that's going to change your numbers significantly.

That is what I hope for. My idle will never drop beyond 1050 rpm so I think the pressure will be there EVEN if I have a long period of WOT pulls and get that oil thinner

I think you're being a little paranoid about the oil pressure, but, on the flip side, I don't blame you.
I've been through an OPR failure and an o-ring failure, and I know what the symptoms look like - you're going to see a significant drop in *max* oil pressure at higher revs; idle oil pressure is practically "0".
Remember, the engine is under very little load at idle - 10psi doesn't sound like much, but it's enough to keep everything lubed and happy.
An engine revving under load at 3k+ RPM's is going to fail a lot faster when you cut the oil pressure in half versus at idle.
Now, I'm not talking about catastrophic oil pressure loss like...NO oil pressure, which is obvious the engine is going to kill itself in short time no matter under what conditions, but I hope you get the point of this long reply...


-Ted

Thanks man and I am glad you understand my parinoid reasoning. I am keeping in mind the "golden" rule of 10 psi for evry 1000rpm and I am DEFINITELY getting that!



Thanks for the encouraging post man.

[RETed]

Originally Posted by FC3S Murray

Yeah I am running prosport gauges...they are nice qaulity BUT I am pretty sure their low range is not as accurate as I would like and I doubt they are as accurate as a 150.00 Greddy gauge. Can't complian for a 50.00$ gauge though.

Even if the GReddy stuff costs more, don't expect better accuracy.
My rule about the gauge accuracy holds true for all gauges unless you can show me a certified accuracy certificate.
If you ever have experience with any scientific meters for biological / chemical experiments, you'd know what I mean.
With accuracy comes price; if you want truly accurate pressure gauge from 0 - 100psi, with, let's say + or - 1psi error range, I would expect it to cost closer to $1,000 when it's all said and done with.


-Ted