cold oil pressure, 500 RPM idle, startup experience.

[flapman]

Hey guys,

Love the work you're doing, and the regular updates to this hot rod! Unfortunately my Mustang has been under the weather since the Accusim updates released with the T-6.

First squawk:
Upon manually starting a cold and dark aircraft, oil pressure immediately stabilizes in the green range. After the 3_27_16 update this functionality was totally inoperative. You could fire up a cold engine then immediately power up to 60 inches MAP with no oil over-pressure. Now, after 4_7_16 core Accusim update, a cold engine can only produce 150 PSI (the idle limit) at 40 inches MAP. Perhaps the problem relates to oil viscosity?

Second squawk:
My beautiful 12 cylinder Packard Merlin can happily idle forever at 500 RPM. This doesn't appear to realistic for this type of engine. A lot of the soul of the engine seems to be missing. Startup is very quick, and the engine "accelerates" up to idle very quickly. This engine hardly sputters at all, and it used to take almost 20 seconds to get all the parts going.

Other notes:
I had another issue in the previous update, in that my mustang starter acted like the inertial starter in the Texan, but that seems to have been resolved. I'm not sure if it's because I installed the 4/7/2016 update, or I switched starters a couple times in the T-6 and set something within the Accusim module.. but that's working fine. Also, since the 4/7/2016 update I've had both my P-51 and Spitfire both start tipped on their nose after selecting them from the MS Trike with engine running (on the ground). Thankfully the mechanics said my engine was fine each time, but every minute the sim would repeatedly switch to the "close program" dialog box. Taking the hint, I closed FSX and these problems have been resolved.

My setup info:
P-51 Accusim Military
4_7_16 update installed.
T-6 Accusim installed.
Spitfire and others installed, other than the first load after update, appear to be working just fine.
FSX Acceleration (not steam).
Windows 10.
TrackIR, Saitek throttle, sometimes ASN, CumulusX

Any other questions let me know! Thank you for the continued support!

EDIT: I forgot to add some other notes.
I tried deleting my .log files to no avail.
Normal Oil (1100..has been changed after update), 100 Octane fuel.

[flapman]

Bump with the latest 4_16_2-16 update.

No changes.. problems still exist. I have reinstalled the Mustang with Accusim and have had no luck.

Here is my first ever youtube upload to show the problem.

[youtube]http://www.youtube.com/watch?v=lz5qQPjIEgc[/youtube]

[Scott - A2A]

flapman,

Having high oil pressure with cold oil in the Mustang is normal.

You will also notice in your video how rough the engine was running when cold. The engine will run smoother as all of the cylinders warm up. Also, the Mustang will idle at 500rpm but you should't idle it this low for extended periods of time, as the plugs could foul.

Scott.

[flapman]

Thank you for the reply Scott,

My issue is that I cannot get the mustang to experience the high oil pressure phenomenon that you have described unless I demand 2500 RPM and 40" MAP. Before 3_27_2016 this feature was working normally, and care had to be taken to keep the engine idling before the temp stabilized.

Thanks,

[Molly - A2A]

If you are using real weather, the ambient temp affects how thick the oil is. If it's very cold then oil pressure will be higher, and if it's warm out then pressure will be lower.

[flapman]

If you are using real weather, the ambient temp affects how thick the oil is. If it's very cold then oil pressure will be higher, and if it's warm out then pressure will be lower.

Thank you, In my video the oil temp is 15C with "Clear Skies (Clears all weather)" profile selected. No real weather is used.

For comparison, here is how the engine functioned up until the release of the Texan. If the code doesn't work, the startup is at 13:28
https://youtu.be/cUOmJzxoaCA?t=808

[robert41]

A2A changed the oil pressure with the March update, it is no longer sky high with a cold start up.

[flapman]

Hello! A quick update on my concerns since 5_1_2016.

No changes to the oil pressure situation. It's no longer necessary to carefully warm up the oil to reduce high pressure before starting taxi. Cold oil is no longer a hazard to the Packard Merlin. As other replies have mentioned, this appears to be the new normal for the Mustang. I'm willing to accept that.

Scott mentioned that the engine is just fine idling at 500RPM, and I think this situation has shown some improvement. Since 5_1_2016 there is a noticeable increase in cockpit shaking when the engine drops below about 6-700RPM. I do also experience fouled plugs (according to hangar) from idling this low (been experiencing this since the Texan release). Also when bumping up the idle to what I would consider an ideal range of 7-800RPM there is a marked change to the exhaust, with an increased "growl" which I find most satisfying. I can say that while not all of my issues are fully corrected, you guys did something which brought the "life" back into this engine. Thank you.

The first patch after the Texan release appeared to increase the cranking torque from the starter, and has been an improvement. It's still not the whirring monster that it was before the Texan update, but it's usable and feels like it has some force to it. Some online videos show Mustangs which have the exact starter behavior as the current update. The Packard Merlin is substantially easier and quicker to start than previous versions, but even as my video showed, there is the slightest roughness before all cylinders start producing power. Before, it felt like maybe 2-4 cylinders were working when the engine first catches. Now, my uninformed guess would be 6-8. This is a change that I'm willing to live with.

I think I am most pleased with having the "life" breathed back into the engine, and would consider my concerns mostly addressed. Thank you for the feedback.