Ej-22 SOHC manifold.

[Aussie_Paul]

Again RFI Don or anyone.

Boy are there a lot of bits wired into the loom operating on/into the manifold of these latest Ej-22 SOHC engines.

One seems to drive some sort of butterfly through a plastic gear.

I would imagine that we blank off all these bits when using a simple after market ECU, and just use the Throttle Position Sensor(TPS), the water temp and possible vacuum with the the crank and cam sensors.

Aussie Paul. :)

[rfi]

Paul,
I thing what you are referring to is the bypass air control valve on the throttle body. You probably wouldn't use it with an aftermarket system such as the Link.
The engines that you guys get are a little different from ours here in the USA.

[Aussie_Paul]

Paul,
I thing what you are referring to is the bypass air control valve on the throttle body. You probably wouldn't use it with an aftermarket system such as the Link.
The engines that you guys get are a little different from ours here in the USA.

Thanks Don. There are several more "things" on the manifold in addition to the bypass air control valve on the throttle body.

So... more pics in order I think. Better than a 1,000 words.:confused:

Aussie Paul. :)

[rfi]

Paul, there is a pressure sensor (MAP) and inlet air temperature (IAT) sensor on the throttle body along with the bypass air valve and throttle Position sinsor, plus the new ('05 and later models) have the electronic throttle. It's getting complicated.

[Aussie_Paul]

Don, both of my two new engines have electric throttles. One has variable valve timingand the other has what appears to me to be extra butterfly's in each inlet manifold tube just above the heads. They are connected with a shaft, and each side of the engine, cylinders 1 and 2 work together, and cylinders 3 and 4 work together. One end of the shaft has an electric motor that rotates the shaft connected to the loom. The other end has a potentiometer connected to the loom.

The engine number for the variable valve timing engine is Z25 3L 122 and for the other D25 3B 313

Attached are some pics

Aussie Paul. :)

[Aussie_Paul]

Potentiometer end.

Don, are the exciters built into the coils these days?

Aussie Paul. :)

[Aussie_Paul]

RFI Don, any thoughts as to what I have here???

Aussie Paul. :)

[Aussie_Paul]

..I just noticed that I have writted ej-22 instead of ej-25 SOHC in the name of this thread.

Don and all, I have found out what these manifold "butterflys" just above the heads do. They are closed during start cranking. I wonder why they need toi do that??? All I need to do with them is leave them disconnected. Easy.

Aussie Paul. :)

[rfi]

Paul,
Sounds like what you have is the new SOHC EJ25 with variable valve timing that develops 173 hp. At least that is what we are getting here in the USA.

I don't have any experience with these late model engines. In fact, the latest engine harness that I have modified is a 2004 Legacy. I don't have manuals for the newer engines either. I order them when I have a need since they cost over a hundred bucks each and there are six models of Subaru autos here in the USA. I don't do enough harness conversions to justify spending a lot on manuals any more. The demand has dropped considerably. I think I only modified four harnesses this past year.

[Aussie_Paul]

Paul,
Sounds like what you have is the new SOHC EJ25 with variable valve timing that develops 173 hp. At least that is what we are getting here in the USA.

I don't have any experience with these late model engines. In fact, the latest engine harness that I have modified is a 2004 Legacy. I don't have manuals for the newer engines either. I order them when I have a need since they cost over a hundred bucks each and there are six models of Subaru autos here in the USA. I don't do enough harness conversions to justify spending a lot on manuals any more. The demand has dropped considerably. I think I only modified four harnesses this past year.

Hi Don, one engine is the variable valve timing engine and the other does not have the variable valve timing BUT has these extra butterflys in the manifold just about the inlet ports. I have found out that the car ecu closes these butterflys during the start up cranking. A correctly set up ECU system requires no throttle for start up.

This could be to make them start easier for the people who just have to put their foot down on the throttle to start. I guess a lot of people who grew up with carbys cannot get out of the habit.

I have made a simple and neat throttle arrangement to convert the electric throttle to cable.

The NZ Link ECUs have developed the software to make use of the variable valve timing. They are AUD$ 600 dearer than the standard ecu. It is worth it for the gain in HP when it is already fitted to the engine.

I hope have the ECU by the end of this week, and next week the wiring can start on FB 001. With some luck all the mechanical stuff on FB 001 with be completed ready for inspection this Sunday, especially if I get out there now and get working :):)

Aussie Paul.:)

[OzyRuss]

Interesting.......my new soob has variable cam timing etc.......block is stamped

"EV25". Runs as sweet as, in the test cradle, using a 4 pin soob pewtar.

With the expected HP and torque of these engines, bolting on the "Ivo" magnum inflite adjustable when it is ready to take to the air, has got me salivating.

Stan............heard no more from you re.......your further tests with the prop, any news updates please.

[rfi]

Paul,
Forgot to answer your question about the coils. All SOHC EJ25 engines have the igniter (driver transistors) incorporated into the coils. The late model DOHC EJ25 engines have individual coils on top of the plug with built-in driver transistor. Those engines are turbocharged. The H6-3.0 DOHC engine also has individual coils for each cylinder.

[PW_Plack]

In an aircraft application, isn't VVT just wasted weight?

If I recall, the major benefit is enhanced low-speed performance by reducing overlap below a certain RPM. Since low-end torque is not a requirement for turning a prop, why would you need it?

For reliable starting?

[Aussie_Paul]

In an aircraft application, isn't VVT just wasted weight?

If I recall, the major benefit is enhanced low-speed performance by reducing overlap below a certain RPM. Since low-end torque is not a requirement for turning a prop, why would you need it?

For reliable starting?

Good point Paul. We have been told that the VVT is more for emmissions than anything else. I have also been told that the valve timing is one belt tooth different to the non VVT engines and if we change the valve timing to the non VVT setting we have all our power back without using the VVT. Does that make sense Don???

Aussie Paul. :)

[mceagle]

Paul, the butterflys that you referred to are called flutter control valves. They are driven by the ECU and set their position on a mumber of factors, not just rpm. When closed they direct all the manifold airflow through a small by-pass hole, over the injector nozzle. This helps fuel mixing and consequently, low down torque and efficiency. It also reduces valve overlap "blowback" into the manifold, meaning that a higher performance Camshaft can be used without the normall associated rough idling. They have no bearing on performance within the rpm range that gyros operate. The idle is smooth enough with the butterflies disconnected but some method must be used to ensure that they do not close in flight - ie they must be locked in the open position.
There is no variable valve timing with these engines - they probably do not need it (pretty hard to do on shoc engines anyway).

[automan1223]

All of these improvements are nice but they add complexity and more failure points. Gyros fly on the KISS principal. VVT is a nice concept suited for cars and trucks that require the best power at any given throttle setting and power requirement. In our aircraft unless you were using an IFAP the added complexity of the system would not be worth it.

Adjustable Intake runners are throttled and bottled to make use of the VVT. It helps extend the power curve from down low to up high. Electronic throttles scare me. They have no business in a gyro or any experimental / GA aircraft. The extra power or percieved extra power you may get from a finely tuned VVT motor is just not worth the possible problems you could run into for our apps.

I work on these for a living and love tech but KISS still rules my tool box. I submit that a fresh non vvt 2.5 with mild milled heads, mild port job, cam grind, CORRECT EXHAUST setup. CORRECT TUNING / FUEL flow. Could easily turn 180 hp. This is more than enough for what we want and the reliability we require. Unless you are flying at high alts or high DA with heavy loads I just cannot fathom why you would want all the b.s under the hood to go and bite you. Turbos are a simple way to demand lots of power ON DEMAND. A single lightweight turbo on a stock 2.5 would easily push a 2.5 into the 220+ realm without the added complexity of such other systems.

Parts cost lots of money. I frown on junkyard parts unless they are hard parts. Sensors and actuators cost bucks. I would guess most of you would choke given the replacement costs of most of those sensors and actuators that you would in good concience have to replace to keep your engine safe. It all looks good on paper until you have to pay the piper.

Jonathan.

[Aussie_Paul]

Thanks Tim, Jonathon and others. I am great KISS believer. It is getting more difficult to get simple auto engines with the pollution laws etc.

I believe that the best bet is to lock the flutter control valves open and not worry about connecting the VVT.

The question now, "Is the base valve timing of a VVT engine the same as the engines that do not have the VVT"?

Aussie Paul. :)

[automan1223]

I will have to investigate in the repair info I have in my alldata system. Rule of thumb is advancing the camshaft increases cranking compression and puts more torque down low in the powerband. Retarding the camp puts the powerband in the upper rpm range. If you can see how its setup if not the service info may tell...

Monday.

Jonathan

[Aussie_Paul]

Ok, another question. What does this electrically controlled water flow thingie do and can I blank it off or do I need to let the water flow around between the holes.

Pic attached.

Aussie Paul.:)

[automan1223]

Paul,

I dont think thats a water flow anything.

Looks like an electronic EGR * Exhaust Gas Recirculation Valve to me....

Yes you can block it off EGR is only used for part throttle high / higher load to reduce cylinder pressures / temps by introducing some exhaust into the intake charge, thus contaminating the charge and cooling it. You recognize the Ping or detonation when it stops working and you are going down the highway.

I do not imagine we would need it turning a prop, or at the higher rpms we cruise at. .

Jonathan

[Aussie_Paul]

Paul,

I dont think thats a water flow anything.

Looks like an electronic EGR * Exhaust Gas Recirculation Valve to me....

Yes you can block it off EGR is only used for part throttle high / higher load to reduce cylinder pressures / temps by introducing some exhaust into the intake charge, thus contaminating the charge and cooling it. You recognize the Ping or detonation when it stops working and you are going down the highway.

I do not imagine we would need it turning a prop, or at the higher rpms we cruise at. .

Jonathan

Oops:hail: :hail:

I was incorrect as I am never wrong.:tape:

Thanks Jonathan.

Aussie Paul. :)

[Papa Smurf]

Retarding the timing improves idle and startability. Advancing timing improves power at speed. You sure that's a SOHC engine? Some features imply it DOHC... Maybe with AVCS.

But I don't know..

[StanFoster]

Jonathon: Thanks for your inputs. Its nice to know if I ever run into a technical problem with my 2.5, that you are here ready to help.


Stan

[Aussie_Paul]

Retarding the timing improves idle and startability. Advancing timing improves power at speed. You sure that's a SOHC engine? Some features imply it DOHC... Maybe with AVCS.

But I don't know..

Papa Smurf, are you talking about ignition timing?

I am sure my engines are definately SOHC, but you have made me wonder.

One has "VVT" and the other the "Flutter control valves"

And Stan, Jonathan should remain our best friend. :lol:

Aussie Paul. :)

[Papa Smurf]

Mr. Paul,

On timing,,, either. Well I guess it depends on base timing but generally speaking retarded improves idle and starting, advanced improves power at speed. I'm speaking in relation to TDC or BDC which is the beginning of the exhaust cycle. As you advance the timing the intake valve opens earlier in the exhaust cycle which improves scavenging or the volumetric efficiency hence improved performance at speed.

The AVCS uses oil pressure to advance the timing as engine speed increases via a proportional solenoid. The actuator is located just behind the cam drive sprocket.

On further reflection, I believe the AVCS system is only used on turbod 2.5's and 3.0 Six cylinder in the states. I'm not sure about the Asian market.

Cosworth has lots of goodies..... $$$$

[mceagle]

Paul. the igniters are built into the coils which is good because separate igniters are expensive little suckers, and it simplifies the wiring. The engine you pictured is a single overhead cam EJ25 and as far as I know, they do not have VVT. What you have done to the exhaust gas recirculation system is the best way - remove the valve and cover with a plate.
The later model SOHC motors are lighter, simpler and develop as good HP at the equivalent RPM's so in my opinion are a better proposition.

[Aussie_Paul]

Thanks Tim, Don said they were. I have 4 engines with the VVT, and one with the Flutter Control Valves. I wonder what I will get next time :):)

Papa, they are definately SOHC.

Both these engine types are quite different than the ej-25 SOHC engines of 5 or 6 years ago where they had an almost identical manifold to the ej-22.

My NZ "Link" ECU is in Melbourne and should arrive Wednesday. I should have the rest of the engine ready to start by then.

I spent quite a bit of the day installing the electric trims. These fiddly bits sure take some time. :help: :help:

Aussie Paul. :)