The A2A Simulations Community

Hi Everyone

Well where do i start? Well first of im guna say this is just a super dopper aircraft 15/10!!! Sounds Great fell Great! Its been worth the wait may i add.
Now im guna say whats wrong.... I fly the spit mk 1 with 2 pitch prop done about 10 hours on airframe, Going to have to replace engine for the 4th time now?? I'm a little concerned about that fact.

"Average Engine life 100 hours"


Now i don't have the slightest clue why because im Letting her warm up to about 90 to 100 rad temp before takeoff oil comes up to 40c i never let the oil pressure go Bellow 25psi. Takeoff on 4 psi climb out retract undercarriage Rad temp about 110 by that stage, maxing out 115. I bring her back to 2200rpm -2.5psi. climb up to about 3000 feet. level of bring rpm back to 2100 - 2000 ruining -3psi, rad temp 112-114, doing about 175mph, cant really do much more.
Now Killratios guide said you want to bring rad flaps back to normal flight so you decrease drag. So i bring them back to normal flight, i get the slightest speed increase maybe 3mph rad temp then slowly increase so im forced to fly with them open. So i fly around for around for half an hour on those settings. Rad comes back to 104 - 99 if im lucky. So i head back in, come on to base lower gear below 160, finals about 100 lower flaps rad temp 105. Now im already to land start to flare about 90mph and gease her on, most of the times i cant tell iv landed. Rewarding!!! then i make a quick taxi in park her let idle for maybe 20 secs on 33psi oil pressure, pull the shut down ring. Now comes the depressing part!


Shift+7 now the mechanic tells me shes "runing ok" I do a compression test lost about 6-8 psi. I do about 3 flights like that and i get told need new bearings and on the 3rd hour of engine life She fails to pass inspection.


Does anyone have a clue to what im doing wrong? Is this pilot error or is this a bug? Iv got 400 hours of flight experience with over 180 of that in Accu-sim aircraft. Please somebody help me!!!



P.S. i never let her go over 90c oil and very really let her go over 120 Rad temp. Day temp 20c And i never push her to hard nothing over 4psi. Iv been thinking to myself how could this be such a great war machine if its got 3 hour engine life? lol

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If your rad temp hits 100°c on the ground you need to shut her down and cool off. The radiator will be boiling by the time you get to any altitude if you warm it up that much. You should be airborne in as little as 5 - 6 min from contact. By 10 min on the ground you are cooking it (OAT causes variables of course).

You should read the advice sticky, and the radiator tutorial thread.

viewtopic.php?f=77&t=23604

viewtopic.php?f=77&t=23834

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If you look at the Shift+2 it says to climb with +6 boost and RPM no lower than 2000
The spit needs cool air & flow so the higher you can get her the better
All so the quicker you get her moving the better
Look at this post
viewtopic.php?f=77&t=23845

Ron

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Ron
B-17 AIRFRAME 710 HRS PLUS AND CLIMBING




GIGABYTE X58A-UD5 MB, INTEL I7 950, 12GB DOMINATOR-GT DDR3 RAM, WIN7 64, GIGABYTE SUPER OVER CLOCK GTX 560 TI 1GB GGDDR5 1000Mz, CORSAIR 850W PS, NOCTUA NH-D14,
TRACKIR 5 & TrackClipPro

I have found that even if I take off with radiator temps at 100, the "steps" climb will work and allow the engine to cool a bit. Even if you are very low on the throttle you can fly well... I just flew from Seattle to Alaska with no problems (except for an emergency landing cause I needed more fuel ) On my most recent engine overhaul I now have over 10 hours... all I had to fix was a small coolant leak, and a little oil leak, no big deal. In fact, with a little practice I can make a full, long range flight with my radiator temp never going above 100.. even taxi after landing is no problem at all if the flaps are up and the radiator is open full...

My first several flights I went through a ton of bearings, but being conservative on the throttle and RPM's have entirely fixed it for me.

If you are even at 500 feet and 1/3 throttle you can level out and let things cool off before you climb if you need to!

I love this plane!!!

Joe

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Hi mate,

Glad you like the Spit...she is a beauty
Two things to note.

Killratio's tutorial also says


1. Don't fly around below 180mph at least.

2. Don't carry out extended operations below 5,000 or 6,000ft.

It appears from reading your flight plan that you are doing both. Go back and have a read through the tutorial again and adjust your technique..you should be right.

In addition, the emegency minimum oil pressure is 30psi and normal minimum is 45 , so if you are using 25...that is where a lot of your damage is coming from.

Have a go mate, then post back your results.


Darryl

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...Some say he never blinks, and that he roams around the woods at night foraging for Merlin parts...

Hi everyone thanks for replying. Iv taking all your advice and it sorta helps took her for a 40min flight and in the end i thought she would be damaged but no its how i left it before i took of I think the key is to keep it fast and keep watching that rad temp keep the rpm up a bit but not to much cause when i drop it to much she seems to fly way to slow then = HOT TEMPS ! Managed to keep the rad temp bellow 105 most of the time which is a start.

Can you guys please post your settings and heights and temps at that time? If you could it would help just that bit more

Thanks guys

Regards

Alex

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Did a flight yesterday, about 80nm (short really), and got my temps down to 80 and pretty much kept them there. All thanks to Killratio and his tutorial and advice. Like you was concentrating so much on keeping my RPM's down it was keeping me too slow.

My flight was, take off with temps of oil 40, rad 80ish, throttle back straight away, slow initial climb until I got all my gear up, landing light off, canopy closed etc. Set rpm's to 2600 ish, and climbed to 6000 at around 190 knots. I think I levelled off at one point to set the rad flaps to normal and check the temps properly, oil just under 80, and rad was 115. Increased speed a bit to 225-240 knots and watched the temp on the rad. it came down to 100, so I continued the climb to 6000-7000. Once up there I was able to throttle back and reduce rpm 1800-2200, maintaining a speed over 220 was the key for me. I climbed at +6 boost mostly, and boost was zero or below in the cruise.

By the time I landed, after doing some turns, rolls and other flash stuff, my rad temp was 80 on landing, and oil below 80. Best flight I've had (temps wise), I think I've cracked it. Taxied to parking, shutdown, put trolley on, and temps were 100 on the rad, just a smidge over 80 on the oil.

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Tony

Intel core i7-2600 3.40GHz, 16GB DDR3-1600 Ram, GT430 1GB Graphics, Windows 7 Premium 64bit, FSX Gold Acceleration. REX 2.0 overdrive, TrackIR 5, Saitek X52Pro, CH Rudder Pedals, Saitek Cyborg X.

Brilliant Tony...

Well done!



Darryl

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...Some say he never blinks, and that he roams around the woods at night foraging for Merlin parts...

Well it's all thanks to you Darryl, now I have to transfer all my new found ability to the Mk II, but to be honest, I think that shouldn't be a problem now I understand what I was doing wrong.

What surprised me was how quickly that extra speed brought down those temps. Of course going faster makes my scenery blur with addon scenery, but that's a whole different issue I have to over come

It was truly an amazing flight though. Now to hone my battle manoeuvres, after all, I don't want all those Cessnas' shooting me down do I

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Tony

Intel core i7-2600 3.40GHz, 16GB DDR3-1600 Ram, GT430 1GB Graphics, Windows 7 Premium 64bit, FSX Gold Acceleration. REX 2.0 overdrive, TrackIR 5, Saitek X52Pro, CH Rudder Pedals, Saitek Cyborg X.

I think the main question is still "open"

How come that, if i very careful with the operations mostly above 10000feet the MKIa engine life is so short...

is it possible that back then the old days, the early spitfires after let's say 2-3 combat sorties (many with agressive combat usage), the mechanics must had to change the MAIN BEARINGS , the pistons the rings, overall set the hole engine to peaces..

and for this at every single on of them... (more than 500)

iv started to fly the mkIIa just right now.. if i know correctly, the merlin XII is more rugged... i hope this is modelled as it should be;)

it's so cool in this plane, that you must really see and understand what the gauges showing to you...

not just for the checklist, and do it for just "realistic" way...

if someone who red some old maintance books... or was mechanics that time (ancestro maybe) and saying that is pretty normal was back at the days
it's really fine for me! just a bit... strange for me

i would really happy if the 6-10hours go way up the 30hours (with realistic combat usage) lifespan

Detonation is your biggest offender when it comes to damaging the internals of the engine. It can tear a good engine down in a very short order.

If you are having issues with a short engine life, just take a step back and treat your plane, not like a wartime aircraft, but an aircraft you own and is in your hangar today. Try this:

1. Use 100 octane fuel
2. Use lower power takeoffs (+2 to +4psi)
3. Use lower power climbs (0 psi)
4. Avoid pro-longed negative g maneuvers
5. Keep coolant temps less than 120 deg

Be aware, engine wear accelerates with power. Here are the TBO times for a wartime early mark Merlin:

+6 psi – 100 hrs
+12 psi – 10 hrs
+18 psi – 2.5 hrs
+24 psi – 15 min

Keep in mind, you can’t reach the +18+ psi in this mark, as the above tests were done with water injection, but the table shows how rapidly an engine takes wear as power increases. If we were to use 87 octane, disable your boost limiter (red lever in front of the throttle), lower your RPM below 2000, and apply full power, your engine would start detonating and likely destroy itself in minutes.

So just be aware, quick errors that cause detonation do their damage and over time, build up. So use gradual throttle rather than just trusting your limiter and throwing the throttle forward.

Scott.

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A2A Simulations Inc.

I must say Daryl "instructions" help a lot preserving my engine.

3rd Engine have served me well with over 5 hours now and still looking good so far. But the first two was disastrous until I read the manual properly and follow all the postings here and advice. it really helped me

BTW no parts yet replaced on the current no3 engine. only a bit of glycolyne and little oil.. and some fuel naturally

Thanks Scott for the tips. I think a big question that you brought up would be "Detonation" This could well be the problem. But im not sure how because im not over doing the rad temps and i now keep them bellow 110 but still get damage to the engine. I know detonation is brought on by an over heated cylinder leading to pre ignition . But what is a sign? Im now going to try and do some testing in the mk II and see if i get the same results. Hopefully not.

Best Regards

Alex

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Just read in Wikipedia now....

Detonation can be prevented by any or all of the following techniques: the use of a fuel with high octane rating, (Scott mentioned) which increases the combustion temperature of the fuel and reduces the proclivity to detonate; enriching the fuel/air ratio, which adds extra fuel to the mixture and increases the cooling effect when the fuel vaporizes in the cylinder; reducing peak cylinder pressure by increasing the engine revolutions (e.g., shifting to a lower gear, there is also evidence that knock occurs more easily at low rpm than high regardless of other factors)

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I just want to clarify if I may. The Accu-sim manual states: "the Mk Ia, fitted with a Merlin III engine designed for 87 octane fuel".

Are you saying we should ignore that and run 100 octane? I have been using the 87 just because of that line.

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