Building a 10,000 rpm NA engine.

[svxfiles]

Originally Posted by Dessertrunner

My question,
I am flat as a lizard drinking and don't have time to look so can anyone tell me the following,
Size of standard injectors?
Fuel pressure in PSI?
If possiable maxium duty cycle of our injectors?Other updates,
- Rear drive lock for 5 speed transmission for dyno arrived so I have to get on that soon so we can run some tests.
- My mind is thinking and I wonder how much pain a standard SVX engine can take, in other words can the standard valves, pistons & rod run a lot higher revs that we have all assumed possiable before. I need to find out so it maybe time to distroy a engine.
- Anybody know how many stage pump in a porsche engine and if some one has a oil flow diagram it would be very help full.


Any ideas on engine loads for a turbo engine, in other words its a 3.3l engine what boast number do I need to get to acheive a 6.6l equlivant. If this sounds stupid, go with me for the minute.Tony

About 270cc.
36.3 PSI with the stock regulator.
I believe about 80%.



14.7 PSI, or 1 bar.

[icingdeath88]

Originally Posted by Dessertrunner

Changing to that pump won't give much benfit and will creat to many headaches. The concept is good but,
To get around the cavitation problem you need to have a seperate oil tank and to do that you have to have a minium of 2 stage pumps, one suction one pressure. The other issue is there is not much room between the front of the block and the timing belt to get the suction past everything.

For the mid engine car I am building I have lowered the engine and gearbox by about 100mm and also aim to lower car by about 50mm. My aim being to drop the CG of the car lower.

Okay Bazza and I have been having a debate about the dry sump. I personally think that we should use a 2 or 3 stage pump and forget about pumping oil back from the heads. One of the stages needs to be pressure.

In the mid engine thread I will post a image of the engine block sitting in the subframe with the new engine mounts etc and you can see how low it is, not sure were I will discuss the simpler dry sump set up but will explain it in the near future.

Tony

Where does the pressure one go to and from?

[Dessertrunner]

Originally Posted by icingdeath88

Where does the pressure one go to and from?

In the stanadard type dry sump you need to have a tank to get rid of the air, so the low pressure suction from engine sump would go to the tank. From Tank to inlet of high pressure pump then out of pump and into the oil line on the block which could be were the oil filter is.
I may have miss understood you question if so yell.

Thanks Tom much appricated.
Tony

[icingdeath88]

Is the tank to get rid of the air separate from the reservoir tank?

I was thinking to retain the stock oil pump to supply the block, and just use the 1-stage pump to pump oil from the pan to a reservoir tank, which then would supply the stock oil pump. So there will be 2 pumps total.

[Dessertrunner]

Correct. You may have issues getting the oil from the sump to the other tank and back to stock pump.

[icingdeath88]

Originally Posted by Dessertrunner

Correct. You may have issues getting the oil from the sump to the other tank and back to stock pump.

So it ought to be pumped to the stock pump?

[bazza]

Tony, I'm still running stock regulator with the turbo setup - I assume the pressure is raising with boost.

As for injectors, the 80% is a figure used by tuners to sell you a bigger set of injectors but in reality you run up to 100% and when you see the AFR's not responding you know you've maxed them out and the power figure or boost or whatever to keep well under.

[Dessertrunner]

Originally Posted by bazza

Tony, I'm still running stock regulator with the turbo setup - I assume the pressure is raising with boost.

As for injectors, the 80% is a figure used by tuners to sell you a bigger set of injectors but in reality you run up to 100% and when you see the AFR's not responding you know you've maxed them out and the power figure or boost or whatever to keep well under.

I remember having a discussion about the 80% and the case with the BZ how it is running 2 injectors per cyclinder. I beleive to get a better mix of air and fuel the number has to come down to 40% so the fuel isn't stilling on the side of the intake manifold in liquid form.

Tony

[bazza]

Originally Posted by Dessertrunner

I remember having a discussion about the 80% and the case with the BZ how it is running 2 injectors per cyclinder. I beleive to get a better mix of air and fuel the number has to come down to 40% so the fuel isn't stilling on the side of the intake manifold in liquid form.

Tony

You asked about EJ/EG injectors... and the EG33 / EJ2X all run standard sequential injection setup and which is what we were talking about and with this setup you can run the injectors at 100% duty.

The fuel doesn't actually sit on the valve, it's a mist, never liquid unless cold starting - hence why you need twice as much fuel when cold as much of it doesn't vaporise and at race rpm, say 3500rpm+ the mist is there for about 5-10 ms. It's actually beneficial as it helps cool the inlet valves on the way in - batch fire is also nice to ensure nicer cooling on the way into the engine. Batch fire is when all 6 injectors fire at once.

As for the 40% duty, that means the injector is open for about 288 degrees - which means if you want the valve open the entire time - you need inlet cams with that duration. Standard SVX cam is about 236 degrees, means you'll need to run max of 33% duty if you want the injector open only when the inlet cam has the valve open. However it doesn't work like that in reality... they usually finish injection 300-400 degrees BTDC, about 300 degrees before the cam is even thinking about opening.

[dynomatt]

Originally Posted by bazza

Batch fire is when all 6 injectors fire at once.

Or when groups of 2 or 3 are fired together.

M

[bazza]

Originally Posted by dynomatt

Or when groups of 2 or 3 are fired together.

M

Or you can fire them two or three times per 720 degrees. Didn't want to go into to much detail to confuse people lol

[Dessertrunner]

Originally Posted by bazza

You asked about EJ/EG injectors... and the EG33 / EJ2X all run standard sequential injection setup and which is what we were talking about and with this setup you can run the injectors at 100% duty.

The fuel doesn't actually sit on the valve, it's a mist, never liquid unless cold starting - hence why you need twice as much fuel when cold as much of it doesn't vaporise and at race rpm, say 3500rpm+ the mist is there for about 5-10 ms. It's actually beneficial as it helps cool the inlet valves on the way in - batch fire is also nice to ensure nicer cooling on the way into the engine. Batch fire is when all 6 injectors fire at once.

As for the 40% duty, that means the injector is open for about 288 degrees - which means if you want the valve open the entire time - you need inlet cams with that duration. Standard SVX cam is about 236 degrees, means you'll need to run max of 33% duty if you want the injector open only when the inlet cam has the valve open. However it doesn't work like that in reality... they usually finish injection 300-400 degrees BTDC, about 300 degrees before the cam is even thinking about opening.

I understand all the theory but you miss the point that I am trying to make and that is the need to get better air mixing of fuel when it goes into the cyclinder.
It is a known fact that if you got perfect airfuel mixing you will get maxium burn and therefore maxium power is all other factors are equal.

The idea that you are getting sequencial injection when the duty get close to 100% is crazy.

What we know as facts are:-
Sequencial injection is better then group or batch firing.
The better the fuel air mix the better the burn.
Air velocities in the intake manifold change based on when the valve is open.

The way I see it we want to take those knowns and build on them.

[SVXRide]

Hi Tony!

How goes the engine dyno?

Cheers
Bill

[bazza]

Originally Posted by Dessertrunner

I understand all the theory but you miss the point that I am trying to make and that is the need to get better air mixing of fuel when it goes into the cyclinder.
It is a known fact that if you got perfect airfuel mixing you will get maxium burn and therefore maxium power is all other factors are equal.

No I get the point but it won't work with the old head design and port setup. The issue that remains for high powered turbo and NA cars is that if you get a better burn you get a bigger bang and with a bigger bang comes more heat and temperatures. So even if you get the mixture burning 5-10% more efficient, you're still up **** creek as you'd need to richen it back up to keep the temperatures down or you'll melt exhaust valves or pistons - this is exactly why my mixtures are very rich - purely safety. Even if the mixture was burning more efficiently the limiting factor is the burn temps. If you told me that the more efficient burn would reduce burn temps then that's different but if you burn it more efficiently, you reduce the "unburnt" fuel in the chamber which helps keep things cool.

You'd really need to investigate a new head design (like the BRZ) and direct port injection and thermal coatings to make this work.

The idea that you are getting sequencial injection when the duty get close to 100% is crazy.

Why is it crazy - it makes no difference to power or AFR's. People just get carried away with this number on so many forums and magazines and spend a fortune based on the bad advice they read and upgrade 100 things they shouldn't but in reality if the AFR's are where you want them to be and they're steady who cares what the duty cycle is.

[Dessertrunner]

Bazza I don't agree at all,

You are totally missing my point but thats the way life is.


Hi Bill,
Okay part arrived for the gearbox now it just a matter of finding time to do the welding mods to be able to fit the gearbox and tail shaft. I think there is a couple of days work to fire it up so hopfully I can find the time in the next couple of weeks.
Pretty exciting really. Have to put the mid engine on hold till I get the dyno running.

Tony