OK, 1st oil change (be nice please..lol)

[JESSEGG]

Hey guys, what about "oil pressure" for this engine? I'm aware it is a "wet sump" but what is a good reading on the gauge? When you are at a light idling? Or when you are going 110 on I95? Reason I ask is because my mind likes to think "5" is always a good reading..lol.

[HondaDustR]

Originally Posted by JESSEGG

Hey guys, what about "oil pressure" for this engine? I'm aware it is a "wet sump" but what is a good reading on the gauge? When you are at a light idling? Or when you are going 110 on I95? Reason I ask is because my mind likes to think "5" is always a good reading..lol.

Factory manual says 4 bar at 5000 rpm and at least 0.5 bar at idle. I like to see at least 1 bar at idle, but 1.5 bar is typical. If the oil pressure relief valve is working correctly, you'll never see much more than 4 bar once the oil is up to operating temp...maybe 4.5 bar at redline. It's entirely rpm dependent, but you'll typically see the oil pressure relief valve start regulating to 4 bar around 4000 rpm.

[VirginiaF1]

Originally Posted by HondaDustR

If the oil pressure relief valve is working correctly, you'll never see much more than 4 bar once the oil is up to operating temp....

Thus, if seeing 4 bar @3,000rpm (and 180F coolant for at least 20 mins), the OPRV is failing?
Or the OP sensor is suspect?
If neither, is it time for ATF or SeaFoam in the crankcase 100 miles prior to next Oil Change?

[HondaDustR]

Originally Posted by VirginiaF1

Thus, if seeing 4 bar @3,000rpm (and 180F coolant for at least 20 mins), the OPRV is failing?
Or the OP sensor is suspect?
If neither, is it time for ATF or SeaFoam in the crankcase 100 miles prior to next Oil Change?

Well, that's where it starts depending on whether you're using regular viscosity oil or pancake syrup in your car.

But seriously, how soon you hit 4 bar depends on oil temp and viscosity. Right now, I don't see 4 bar until 5000+ rpm. Back when I ran 20W-50, I'd see 4 bar as soon as 2500 rpm. Wherever you hit 4 bar, if it stops there and doesn't increase appreciably with increasing rpm, the OPRV is fine. It might run up to 4.5 or slightly higher by the time you're at redline, especially with a thicker oil, just because the bypass port of the OPRV is posing some resistance that increases the pressure slightly at the high oil volume flow of high rpm, but if it increases substantially across the remaining rpm range after it hits 4 bar, i.e. hitting the peg at operating temp when the revs increase far enough, the OPRV may be sticking or the oil cooler housing is not aligned well, preventing the valve from fully opening. Now the valve sticking open should be obvious with an unusual/unsafe drop in oil pressure at low rpm/idle. If the oil pressure behaves erratically, like hitting 4 bar at wildly varying rpm and/or randomly dropping oil pressure too much at lower rpm, it's possible it's the pressure sender, wiring, or bad grounds, but also an indication of a worn, gummed up, or misaligned OPRV. The original 3 piece OPRV had issues with sticking until it got updated, and then eventually replaced with a one piece retrofit part.

Oh, on a side note about oil temps, since I have installed an oil temp gauge, I have found that it takes roughly 5 times longer for the oil to come up to full operating temp than it does for the coolant to come to temp.

[JESSEGG]

Originally Posted by HondaDustR

Factory manual says 4 bar at 5000 rpm and at least 0.5 bar at idle. I like to see at least 1 bar at idle, but 1.5 bar is typical. If the oil pressure relief valve is working correctly, you'll never see much more than 4 bar once the oil is up to operating temp...maybe 4.5 bar at redline. It's entirely rpm dependent, but you'll typically see the oil pressure relief valve start regulating to 4 bar around 4000 rpm.

Thanks HondaDustR, I have a better understanding of this now. It's been a lot of discovery for me since I bought this 2 months ago. I guess I should get an owners manual.

Thanks man,

Jesse

[VirginiaF1]

Originally Posted by JESSEGG

Thanks HondaDustR, I have a better understanding of this now. It's been a lot of discovery for me since I bought this 2 months ago. I guess I should get an owners manual.

Thanks man,

Jesse

Yeah, it is nice for us new owners to learn from the more technical blokes on this forum.

To draw from & add to Honda's and 333's discussions:

I'm trying to focus on the requisite oil properties for our engines rather than brand:

For flat tappet/ sacrificial boundary protection:
Zinc > 1100ppm but < 1500ppm per LN Engineering
Phos > 1000ppm

For cold flow & hot hydrodynamic bearing protection:
Pour point < -30F
Viscosity at 100°C (212°F) ASTM D445 > 13 mm²/s

For extended (>3,000 mile) OCI drains:
Total Base Number > 10

More than a half dozen oils fit these parameters.. some synth and some dino.
If there's an oil property that I should add, please suggest.
Ultimately, my aim is to build an online searchable database of all solutions 944...
parts, fluids, repairs, noises, failures, etc..

[samevansjr]

By far the best oil for my 1984 944 20-50w VR1.

[princej]

Originally Posted by samevansjr

By far the best oil for my 1984 944 20-50w VR1.

I agree 100%, my 1987 944 loves 20w50 VR1.

never sounded so good.

[333pg333]

I guess the bottom line is what oils seem to work best for our cars under more extreme circumstances. I can't include sub zero temps as I have very little experience of this sort of climate. So for us, stop-start traffic is bad but of course running on the track is by far the hardest condition for a car, any car.

As someone has mentioned, 99% of us run wet sumps. I have a dry sump in the race car but I'm not including this in the discussion. As oil gets hotter, it gets thinner. Even the Race 25w/60 we run on the track is pretty much like hot water in terms of it's viscosity after some laps. Running 10w/40 or lower visc is basically suicide under these conditions. If 25w/60 is watery when hot, a 10w/40 or worse, 0w/30 is more like vapour when hot. Essentially you have lots of spinning metal parts working within very tight tolerances and all they really 'want' to do is smash the crap out of each other (technically speaking!). The only hope you have in those extremely sudden and brief moments where you might have some oil starvation to the big end bearings is for the oil film strength to provide the last bastion of protection and save you from spinning a bearing...or worse. We have read of many people who have spun a bearing or worse and more often than not they are using a lower visc synthetic oil.

I agree that you need to change your oil regularly and utmost in protection is making sure you have sufficient oil cooling for your circumstances. Comparing a car on a track to a street car isn't entirely valid, granted. But I will sacrifice a couple of hp and this supposed cold start wear due to running say a 20w/50 dino oil, for peace of mind both on and off the track. Sure, if you live in parts of Europe and North America, then the Winters can demand a lower weight oil than I run...but then again, many of you guys don't even drive your 944s in Winter anyway. You've all got those big ass Trucks!! :-)

[VirginiaF1]

Patrick,
For daily driving 944's, would engine longevity be increased ( all other factors being equal) by using synthetic / Group IV oils vs. Dino?
Provided both had >1100ppm ZDDP AND sufficient high temp viscosity ie: 40)

PS: Loved your racing video from 2010 vs. that green 997 GT3RS..

[333pg333]

I don't claim to be an oil expert by any means even if I do tend to question other people's opinions on this matter in the many number of threads that proliferate all the forums. I only know what I've experienced and what my Porsche factory trained mechanic has found through 30+ years working on these cars and specialising on the front engine models. Google Bruce Buchanan / Buchanan Automotive (the Aussie one) and you will find some of Bruce's detailed replies on matters involving oils for these cars.

I'm not belittling H-Dust at all. He might be correct and I'm espousing 'old school' info. The only thing I'd say to that is the old addage of "If it ain't broke, don't fix it". By this I don't imply that old is always better, more, that it's been shown to work very well in this matter. Bruce has opened up motors with over 300,000kms that have always run on VR1 or similar and they look brand new inside...or very close to it. Conversely, there was a stage in Sydney where the workshops were finding a real increase in top end wear and this was specifically due to the continued adoption of M1 after Mobil had lowered the level of ZDDP markedly without telling anyone. Sure, this may have been due to California pollution requirements but try telling that to some guy down here who has to pay for a partial or full rebuild...or the Workshops that paid for these motors.

Not sure if you're aware of a monumental oil thread on this forum. Well worth checking out....just allow yourself a couple of days...

http://forums.pelicanparts.com/porsche-911-technical-forum/367300-ultimate-motor-oil-thread-why-we-hate-cj4-sm-oils.html

Anyway, I'm sure there are some new oils that are very good for a street driven car. I'm even considering trying some of the new Nano-tech Millers racing oil myself.

Thanks for the compliment on the video. Gee that seems like a long time ago. A lot of money and time has passed since then. I hope to have some videos with the new car in the coming months that will significantly raise the bar. ;-)