Mr.Matchbox

Interesting read:
https://blog.k1technologies.com/bear...sity-explained

Thomas Guide

To add to the oil controversy, I used Eneos 0W-50 (with the yellow label) for over 10 years in my daily driven S until they changed formula/branding and I could no longer be sure if the new products were the same as old. That 10 years included 2,500 miles of track time (mostly the Big Track at Willow Springs) and the top speed achieved was 149 MPH (on a desert straightaway not on the track)...could have gone faster but I ran out of road. The Eneos was recommended and sold by my Honda dealer, where many S2000 were owned and tracked by the mechanics, advisors and staff. There's a lot of old data on it I can dig up if folks are interested, and it was used a lot in several groups and communities, like the Subaru STI folks, but also it was very well known in Japan.

In the last 4 years been running Redline 10W-40, last Blackstone Oil Analysis engine was healthy, just sent in for another analysis last week and am awaiting results.

If I could find the Eneos 0W-50 with the yellow label I would use it without hesitation.

Car Analogy

Interesting. How long did the top speed run last? How long was the engine run at sustained near redline rpm?

windhund116

Is this the Eneos oil you are referring to?

Thanks!

https://www.ecstuning.com/b-eneos-pa...SABEgK_0PD_BwE

windhund116

That is a LONG time, at or near redline. What was the WOT combat limits for that Corsair?

Thanks!

Thomas Guide

The run lasted until we ran out of straight road. It's the long stretch in the desert that leads to the exit for the Willow Springs track in Rosamond. We would travel in groups from LA leaving before sunrise, with no one on that road with miles of forward visibility, for some reason me and a friend kept egging each other on until we went full throttle. We completely blew past our exit and kept going. At 149 MPH there was about 1500 RPMs left and she would have kept going to the max listed speed limit of 155 mph. The S is fairly quick up to 125 (the front and back stretch at Willow Springs it was typical to achieve 122 mph). It was definitely starting to grind past 135 but she kept pushing through. I don't recall how long the drive was but looking on a map it was a few miles from the exit to the bend in the road when we let up. She handled surprisingly well, it was quite a rush, which is probably why some details escape me (i.e. I was white knuckling it at that point), and I haven't done something like that since lol.

The S is 100% OEM stock with no mods.

Thomas Guide

So that is it however it's not available in the US anymore (unless there are some old cases floating around from 5 years ago) and most vendors have not updated their pictures or websites (even in years). I reached out to countless vendors and had the misfortune of having to send back two cases because they were sending the Sustina version.

The Sustina has now also been discontinued in the US and they released an Eneos Street Racing line that contains a 0W-50. But I also reached out to Eneos several times to try and get clarification on the differences between the old 0W-50, the 0W-50 Sustina and now this Racing 0W-50 and I was not able to get satisfactory technical information. In fact when the Sustina line launched they didn't have a technical data sheet for it, and I kept reaching out to the US group for one, they finally slapped one together and it was just a cut and paste of generic info. I do see a version in other world regions that looks like the old Yellow label I used, and it appears the Sustina is available in other parts of the world too.

All this confusion and brand changing coupled with lack of technical data and information did not instill confidence to keep using. I haven't looked much into it lately TBH.

Here's the old Sustina 0W-50:

https://www.oakos.com/3210-300.htm

and here's the new racing line 0w-50:

https://www.eneos.us/product/eneos-racing-street-0w-50/

twohoos

Yes, it was sustained high-rpm, wide-throttle operation (i.e. high-speed) that caused the cyl 4 scoring. The 2-hole jet bolts could not provide sufficient (or sufficiently consistent) oiling to the cylinder wall. OP's story of 10 miles at Vmax would have lasted about 4 minutes, which is the shortest failure period I've personally heard about, but then it's also by far the most stressing condition. The "typical" scenario for these failures (again anecdotally) involves 20-30 continuous minutes of 110-130mph. As others mentioned, since the car that failed here would have had the updated bolts, the 50-weight oil could certainly be a factor. (One of the early observations about the 4-hole bolts was that the total *area* of the 4 holes in the updated bolts is slightly *less* than the total area of the two holes in the original bolts - so it's not just a question of quantity, but of flow efficiency.)

@Mr.Matchbox you recently posted in my banjo-bolt upgrade thread that a German owner had found many stuck/seized 4-hole bolts while rebuilding some damaged engines. True, those failures leave the holes *open* all the time, not closed, but they do cause low oil pressure at idle. Is it possible that over time, low oil pressure while warming up might have caused/accumulated enough "light" scoring that, when stressed by a 4-minute Vmax run with 50-weight oil, the motor finally let go?

Mr.Matchbox

@ twohoss: You could read my mind?

I am also a little bit concerned about the Banjo bolts. When the springs inside the bolts are broken, is it possible that some oil is dripping back into the pan when the engine is sitting, that the oil channels are emptied over time?
When i start the engine, it takes roughly one second until the oil warning light gets off, while the engine spinns with 2.000 RPM. That annoys me to death.
And remember that the oil pressure switch only needs 0,2 Bar / 5psi to switch the warning ligth off.
Can this cause lightly scoring on the bearings over time? Maybe. Can idle with low oil pressure due to damaged banjo bolts can score the bearings lightly? Maybe.
Add to this that all the guys that have knowlegde in engine oil will tell you that a thicker oil create more heat in the engine because of more friction and reduced oil flow.

Maybe i am ovethinking it, but:
- Using only oil with -30 or -40 viscosity grade,
- Add a Oil pressure and Oil temperature gauge,
- Avoid long high speed runs,
- And maybe check the banjo bolts

Seems like a good idea to me.

As a side note, i was allways doubtfull that this engine, with this extremly high piston speed, is really bulletproof on the autobahn, e.g. drive it for lets say 50 Km/ 30 Miles with 8.000 RPM +.
This is just to much stress in my opinion. The recomendation from rpg51 to keep it under 100 MPH / 160 Km/H / 6.000 RPM make sense to me. Beside short sprints to higher speeds, of course.

cosmomiller

Not to hijack but there are no limits to the jet engine. You could slam the throttle even in high angle of attack modes or full blown departures on all 3 axis. We had Pratt engineers show up and attached monitors to the planes and they had a hell of a time. Said they did not know why they were recording so many throttle movements. (These guys were commercial engine guys) We gave them a ride in a 2 seat airplane for ACM (air combat maneuvering) and their eyes were opened. They had no idea we slammed the throttle from idle to MRT (Military Rated Thrust-full power) so many times.