Running a 4agze with no exhaust manifold, or stump type.

[mr_monkey]

do you worry about reliability running at high rpm for extended periods?

[kiwi4agze]

That has always been my concern, hence why i was going to run it super rich.... Thats what destroys most auto engined planes

I was going to run a huge radiator, place the intercooler in the air stream, and run the engine very rich. I am getting a water injection setup and sprayers for both the intercoolers and radiators.......

Any other ideas????

[Mr Revhead]

do you worry about reliability running at high rpm for extended periods?

People use rotarys and subaru engines in these things.... I don't think he has a lot to worry about

[MAGN1T]

You won't run super rich with water injection, all it will do is misfire.
You've been spending too much time in the interweb without any real life experience.

Steve

[kiwi4agze]

Geez thanks for sugar coating it!!!!

[Mr Revhead]

Don't pay too much attention to him

[RomanV]

Man, I'd really look into this more considering your life might be on the line!

Running mega rich, fouling plugs or something and then falling out of the sky does not sound ideal.

[kiwi4agze]

I only thought that cause lycoming engines run super rich for take-off to prevent detonation... so i thought hmm that might work.. now i realise.. nah it wont

The biggest issue i have with running a 4a engine is that in its car life it was maybe taken to redline for 10-15sec at a time! In its new life it will be required to be at max-power for 5-15 minutes to get to 15,000ft which is a huge strain on it.

Any ideas would be great......

[Mr Revhead]

You really do need to talk to some who have converted car engines to light aircraft.
When you say the lycomings run super rich, what ratio are you talking?
All things are relative!

[mr_monkey]

What i just cant get my head around is that every car engine converted to aeromotive use has been more suited to the job than the 4age. Eg, lighter and producing more than adequate power rather than cast iron water cooled and running its balls raw to make power. For something so important it just seems so very much less than ideal.

Why not just take the financial hit and go with something proven and purpose built for the task? Resale, performance, reliability.. Everything wins.

[QikStarlie]

because that would be boring

engine isn't going to just fail because its at high load for x amount of time. if its all setup correct, cooling system and tune wise. why will it fail? unless the cooling galleries cant pull enough heat away for the heat its producing, over extended periods. but doubt this would be the case on a standard 4agze. im sure toyota beat down on these engines for extended periods, on an engine dyno trying to destroy them.

i'd be paying allot off attention to cooling system and the tune, both ignition and fuel wise. over the entire operating range you'l be using. as thats whats going to kill it.

[kiwi4agze]

put it this way.. lycomming 160hp flat 4cyl aero engine is around $30,000
Rolex rotary or 4cy engine of100-125hp is about 23,000
4agze is about $900 plus rebuild

the 4agze has a tried and tested performance record in light aircraft... hence why I am using it.. just Toyota never makes things easy

[matt dunn]

i'd be paying allot off attention to the tune, both ignition and fuel wise. over the entire operating range you'l be using. as thats whats going to kill it.

Both what I was thinking.

How do you plan on mapping an advance curve without an ECU,
as anything from a non forced induction won't work ignition wise,
and how do you adjust the mechanical injection if it is not right as they are all pre set from factory??

[Grrrrrrr!]

Megasquirt with custom software that takes barometric pressure as well as rpm and load into account would be the go I reckon.

[kiwi4agze]

How do you plan on mapping an advance curve without an ECU,
as anything from a non forced induction won't work ignition wise,
and how do you adjust the mechanical injection if it is not right as they are all pre set from factory??

Mechanical injection is very easy to adjust, increase the fuel pressure, increase the injector size or fuel line size all equal more fuel, go the opposite way for less fuel.

Ford CVH turbo engine injectors flow enough for 200hp
Volvo Injectors enough for 180hp
Ford RS1600 enough for 210hp

all which use the same fuel system.. volvo has a higher flow rate at the metering unit so would flow more then the fords...

not sure on timing as was just going to use a 4K-e one or work out an other option... if you have any ideas as I will be usine the gZe and the others used the ge.. There is a electronic device out there to use, would that work?

The lycomming engnes at take off run a a/f of 7.8:1-9.2:1 depending on the engine, rolex's about the same with cruising a/f of 10.7-12.4:1 again depending on engine .

[mr_monkey]

wouldnt any MAP ecu essentially do the same thing automatically? its pressure in the manifold that matters.

[kiwi4agze]

Its the atmosphere pressure which makes EFi crap itself, air is thinner at 15,000ft then sea level, Efi cant compensate, Mechanical doesn't need to..

Most aero engines use a electronic mechanical setup for that simple reason or a really expensive bar pressure setup with air density reader etc etc etc which is out of my budget

[mr_monkey]

ooooooooh.. thanks. I learning

[kiwi4agze]

In piston aircraft engines, continuous-flow fuel injection is the most common type. In contrast to automotive fuel injection systems, aircraft continuous flow fuel injection is all mechanical, requiring no electricity to operate.
Effectively there are 2 types of setup:
1) Bendix RSA system, this is basically an improved pressurized carb with fuel fed to fuel lines and injectors instead of the bowl
2) TCM system which is basically an improved Bosch's K-Jetronic which is what i am using. Most aircraft using the TCM fuel injection system feature a fuel flow gauge which is actually a pressure gauge that has been calibrated in gallons per hour or pounds per hour of fuel...

The stock Toyota computer can either shut off the injectors if certain things fail such as a water temperature sensor to protect the engine from a perceived or real overheating condition or go into a very low power limp home mode. Either of these scenerios mean that I am coming down in an aircraft. The designers of automotive ECUs did not take aircraft use into account during the design phase obviously. Their considerations were likely as follows, in order of importance: 1. Reliability- keep the engine from destructing ( shut the injectors off if necessary), 2. Emissions, 3. Fuel economy, 4. Driveability, 5. Power.

Modern EFI systems, sensors and ECUs are VERY reliable. But again it is not a continuous fuel system which can also be deadly.

[kiwi4agze]

Oh and one more big point..
Automotive oxygen sensors don't work with avgas which has a high lead content plus most Aero Fuel systems are dual systems, in that they contain a backup controller which can be selected by the pilot in the event of a failure of the primary system. The K system has that ability with a bit of modification