Huricane Mk I 100 Octane perormance tests 1.07.18301

[TomcatViP]

Originally Posted by phoenix1963

[ BTW: the conditions for detonation of the fuel-air mixture are not really to do with a particular temperature. Detonation happens because the sound-speed is higher on the high-pressure portion of a pressure pulse, so the pulse gradually sharpens-up until it becomes discontinuous - a detonation. So I'm afraid the run-length of the pressure pulse (i.e. the geometry of the cylinder) is a big factor. ]

56RAF_phoenix

Great point. But in the case of changing the fuel of an engine without modifying the design, the geo of the cylinder is fixed. Tht's why I am talking about T=f(octane grade) that is becoming the prime factor for the E you can output from the fuel (I might have the formula somewhere... In Canada, damn !).

My answer was to this :

Originally Posted by CaptainDoggles

If you're talking about switching from 87 up to 100 octane, you need to go look at what the definition of an Octane number is. Octane number does not mean the fuel has more energy in it.

If you change the fuel, the minimum you wld need is to modify the compression volume and material of the pistons/cylinders that you have an equivalent heat flux. Today, tuner can play with the injection para to artificially reset the volume or modify the air compression ratio playing with the boost ratio (carburated and injected) .

But this imply modifying extensively the engine. Especially if your daily hobby is a long and lonely flight in a single engine plane above the sea!

[Igo kyu]

Originally Posted by TomcatViP

If you change the fuel, the minimum you wld need is to modify the compression volume and material of the pistons/cylinders that you have an equivalent heat flux. Today, tuner can play with the injection para to artificially reset the volume or modify the air compression ratio playing with the boost ratio (carburated and injected) .

But this imply modifying extensively the engine. Especially if your daily hobby is a long and lonely flight in a single engine plane above the sea!

You need to understand the difference between detonation and deflagration.

http://en.wikipedia.org/wiki/Detonation

http://en.wikipedia.org/wiki/Deflagration

Lower octane fuel detonates.

[TomcatViP]

Originally Posted by Igo kyu

You need to understand the difference between detonation and deflagration.

http://en.wikipedia.org/wiki/Detonation

http://en.wikipedia.org/wiki/Deflagration

Lower octane fuel detonates.

I don't see where I said the contrary but thx for the refresh. Pls explains what you mean instead of this mystic answer. I am not here to show off any knowledge but because I like others to understand better what this sim is emulating.

Again my reply was about the assumption form D. that octane grade had no link with the E that you can output. Damn do we really read each others ? Or is nailing and plinking becoming a sport here ? Because if you still don't know we have the ATAG server to that

[CaptainDoggles]

Originally Posted by TomcatViP

If you change the fuel, the minimum you wld need is to modify the compression volume and material of the pistons/cylinders that you have an equivalent heat flux.

No. You are wrong.

If your engine was designed to run on a particular octane, at a particular compression ratio, and you put fuel in that has a HIGHER octane than before, the minimum that you need to do is nothing. The octane number is just a measurement of it's anti-knock performance. Octane number does not mean the fuel burns hotter, or has more energy in it, or has a "greater heat flux". You don't need to modify the engine if you want to put higher octane fuel in it.

On the other hand, if you want to run at a higher compression ratio, then you are required to increase the octane rating of your fuel.

[dnr]

Results of my comparision demonstrate a marginal increase in performance of the 100 octane over the 87 octane Mk 1 Hurricane when using the boost cut out. There does not appear to be any increase of performance other than slight improved acceleration for the 87 octane when the boost cut out is pulled. What is demonstrated is that the 100 octane Mk1 is very prone to failure soon after employing the boost cutout. Works best at low altitude, but you have only 1 minute to engine destruction. At 20,000, the 100 octane will hold a steady at 210 mph +2.5 beyond 6 minutes whereas the 87 octane at +3 210 mph blows up after two minutes. Otherwise, you can run the 87 octane at +5.5 lbs all day at 240 mph. So my assessment is that the 87 octane is a better option for combat operations (e.g. very slight trade off in performance, versus substantial improvement in reliability)

Mk1 Hurricane Comparison between 87 and 100 Octane Rotol

100 Octane
87 Octane
Wind: 0 mph/0 % deflection
Boost Start 0 psi
Weight 3177 lbs
Fuel 100%
Start Speed 180 mph
Rad 100% Open
X engine failure

2,700 RPM SPEED & ACCELERATION
Altitude 1 min 2 min 3 min 4 min 5 min 6 min (BOOST)
5000 ft 240 mph 260 mph 260 mph X Goveror failure X +8
5000 ft 210 mph 230 mph 230 mph 240 mph 240 mph 240 mph +6.2

10000 ft 240 mph X Gasket failure X X X +8
10000 ft 220 mph 240 mph 240 mph 240 mph 240 mph 240 mph +6.1

15000 ft 220 mph 240 mph 240 mph 240 mph 240 mph 240 mph +7.2
15000 ft 230 mph 230 mph 240 mph 240 mph 240 mph 240 mph +6.1

20000 ft 190 mph 200 mph 210 mph 210 mph 210 mph 210 mph +1.5
20000 ft 200 mph 210 mph 210 mph 210 mph 210 mph 210 mph +3

3,000 RPM SPEED & ACCELERATION
Altitude 1 min 2 min 3 min 4 min 5 min 6 min (BOOST)
5000 ft 260 mph X Gasket failure X X X +8
5000 ft 220 mph 240 mph 240 mph 240 mph 240 mph 240 mph +5.5

10000 ft 240 mph X Gasket failure X X X +8
10000 ft 220 mph 240 mph 240 mph 240 mph 240 mph 240 mph +5.5

15000 ft 220 mph 240 mph 240 mph 240 mph 240 mph 240 mph +8
15000 ft 230 mph 240 mph 240 mph 240 mph 240 mph 240 mph +5.5
no BCO 220 mph 230 mph 240 mph 240 mph 240 mph 240 mph +5.5

20000 ft 190 mph 200 mph 210 mph 210 mph 210 mph 210 mph +2.5
20000 ft 200 mph 210 mph X Burnt intake X X +3

All engine failures were confirmed with a second test
All tests conducted with Boost Cut Out pulled

__________________________________________________ _____________
CyberpowerPC Gamer Ultra 2063 120mm LQ, AM3 Phenom II X6 1090T(3.2GHz), ASUS M4A87TD EVO MB, G.Skill Ripjaws PC3 12800 DDR3 1600 16 GB RAM, 2TB HDD, Dual 1 GB AMD Radeon HD 6870 (Crossfire) GPUs, Windows 7 Home Premium 64-Bit, Saitek X52 Pro stick/thrust/ rudder, Cyborg, 70” Sharp Quattron, TrackIR 5

[TomcatViP]

Originally Posted by CaptainDoggles

No. You are wrong.

If your engine was designed to run on a particular octane, at a particular compression ratio, and you put fuel in that has a HIGHER octane than before, the minimum that you need to do is nothing. The octane number is just a measurement of it's anti-knock performance. Octane number does not mean the fuel burns hotter, or has more energy in it, or has a "greater heat flux". You don't need to modify the engine if you want to put higher octane fuel in it.

On the other hand, if you want to run at a higher compression ratio, then you are required to increase the octane rating of your fuel.

Ok next time you take a Diesel, I suggest yu might try to put some 95 or 98 gasoline while I'll try myself to put diesel in a gasoline car. We will see who has the biggest bill.

[Seadog]

Originally Posted by TomcatViP

Ok next time you take a Diesel, I suggest yu might try to put some 95 or 98 gasoline while I'll try myself to put diesel in a gasoline car. We will see who has the biggest bill.

What the hell does diesel have to with this?

[CaptainDoggles]

Originally Posted by TomcatViP

Ok next time you take a Diesel, I suggest yu might try to put some 95 or 98 gasoline while I'll try myself to put diesel in a gasoline car. We will see who has the biggest bill.

Thanks for confirming you have no idea what you're talking about. Diesels use compression ignition. Gasoline engines have a spark plug.

I'm done talking to you now, have a nice day!

[TomcatViP]

Damn the Diesel have a low eq octane number. This is an example. An illustration. Ok got it now?

I will remind you that you slipped the purpose of our conversation from : "the octane does not rate what E you can output in a compression work" to "detonation and deflag."

But as always simplistic argument and quick assumption on individual are the way to go with the 100octaner. One more in a long series.

Do you really think that I don't know the diff btw Diesel and gasoline? If such salute and have a good day back to your black and white world.*

What i was showing you is that with higher grade you hve higher energy in the same volume of the cylinder hence more heat hence (what I was expecting you'd understand by yourself) more wear since the eng is not designed for that amount.

We are not talking about a 2L 90Hp car but 1000HP with primitive engine technology with low compression ratio (a lot more fuel flow).

Thx for loosing my time too.

*I hve to admit that writing this my blood was boiling up to its flash point. Sry for being rude

[phoenix1963]

Back on topic....

"British Performance Reduction Methods for Modern Aircraft", D Cameron - A. & AEE Report No. Res/170, 1942.

Is cited by papers on googlescholar. Spitfireperformance.com has many references to test data from later Spitfire marks being normalised using this method to some standard atmosphere.

I've looked on "Web of Knowledge" and some other places but have not been able to get a copy.

I suspect that, since Cameron felt it necessary to write a paper in 1942 to standardise the methods, other variants were probably used before. I'll continue trying to find it.

56RAF_phoenix