F-1 Cylinder Head Design

[Kevin Johnson]

Many years ago we used a very, very aggressive "texturing" on the intake for a very wet fuel, worked wonders...

So, soapy low surface tension fuel?
Along those lines, anyone know anything about the additive(s)/surfactant(s) used in military jet fuel to reduce friction and speed in-flight refueling?

https://www.google.com/search?q=jet+fue ... e&ie=UTF-8

... following the dissemination of:

https://www.sae.org/publications/techni ... 7/preview/


http://www.dtic.mil/dtic/tr/fulltext/u2/405052.pdf

[gunt]

I had the privilege of having a section of that head in my hand , the biggest item I noticed was the valves opening to the center of the bore to eliminate shrouding of the air flow , but on foot of that was the incredibly design of the cam shaft lobes which as a result required the use of thrust washers

[MadBill]

...Along those lines, anyone know anything about the additive(s)/surfactant(s) used in military jet fuel to reduce friction and speed in-flight refueling?

https://www.google.com/search?q=jet+fue ... e&ie=UTF-8

... following the dissemination of:

https://www.sae.org/publications/techni ... 7/preview/


http://www.dtic.mil/dtic/tr/fulltext/u2/405052.pdf
[/quote]

Thanks for coming through again Kevin!
Doesn't directly address refueling flow rate enhancers (also used I believe for increasing the range of fire hoses) but does mention that one likely candidate (surfactants) cause filtration problems.

Now back to our regularly scheduled program...

[midnightbluS10]

With 50 bar fuel pressure (100 bar in later V8 and 500 bar in current DI V6) the droplets are pretty small.

What kind of non-di V8 engine uses 1400 psi of fuel pressure? Or even 700psi? LT4's have 2900 psi for example. Don't know of any non-di engines running fuel pressure that high(700 psi or 50 bar). 50 psi? Yes. But not 50 bar.

You only specify that the V6 in your post is DI. I've never seen anything non-di with 700psi of fuel pressure. V8 or not.

[Brian P]

F1 uses that range of fuel pressure. (Even though it's not direct injection.)

[Brian P]

With 50 bar fuel pressure (100 bar in later V8 and 500 bar in current DI V6) the droplets are pretty small.

Until it hits a wall

The injector is centrally located in the airbox pointing straight down the middle of the intake runner, which is straight until the slight bend towards the intake valve. The injector has a narrow spray angle. Even the portion injected while the intake valve is closed, the penetration depth of the spray won't be far enough to reach the valve. Combine the fine atomisation, and the geometry of the intake runner and the spray pattern, and the strong flow pulsation which would act to further break up and evaporate any droplets, and very little of the fuel will hit a wall.

[digger]

if you look at the renault F1 video on youtube there is fuel going everywhere and it is far from a narrow spray pattern. if you read the honda papers the injection event was always partly occurring when there is reversion as well, this means there is low velocity which is a great way to get the walls wet. the spray angle in one of the papers was a upto 60* included angle. for sure the walls wouldnt be as wet as some systems buts its still going to be wet

[Brian P]

Certainly, but with all their resources, I'm quite sure they have researched and established the optimum texture for the intake runner walls, and it was not rough, and it was not a mirror finish.

[Kevin Johnson]

Thanks for coming through again Kevin!
Doesn't directly address refueling flow rate enhancers (also used I believe for increasing the range of fire hoses) but does mention that one likely candidate (surfactants) cause filtration problems.
...

https://physics.aps.org/story/v4/st32

https://patents.google.com/patent/US20060236597A1/en

[MadBill]

Thanks for coming through again Kevin!
Doesn't directly address refueling flow rate enhancers (also used I believe for increasing the range of fire hoses) but does mention that one likely candidate (surfactants) cause filtration problems.
...

https://physics.aps.org/story/v4/st32

https://patents.google.com/patent/US20060236597A1/en

[apm]

I know its mechanical fuel injection and not efi and its not even close to F1 but the top fuel car I tune uses just over 700psi of fuel pressure

[midnightbluS10]

Thank you. I looked at mech inj pressures before I posted but wasn't seeing anything like that.

[gunt]

would the high rpm range have anything to require the pressure or varying pressure

[Brian P]

It means it's a benefit to get the atomisation and vaporisation and mixing done to the greatest extent possible before the mixture enters the cylinder (i.e. in the intake runner), because there's not a whole lot of time between intake valve closing and spark plug firing, and the combustion itself has to be complete within an extremely short time. That means not waiting for evaporation and mixing has to be a good thing.

Synchronising the fuel injection period with the time in which air is flowing into the bellmouth makes sense from that viewpoint, too.

Several production motorcycle engines are using two injectors per cylinder, one close to the cylinder and downstream of the throttle (remember, individual throttle bodies!) in the usual location for part throttle and lower revs, and another in the airbox spraying down the center of the intake runner in the same place where F1 puts it, for high load and high revs.

[mk e]

I read something years ago that talked about optimal injector location vs rpm...below like 6k by the valve, below 11k in the center of the track, above 11k outside the runner... something like that.

But then I remember (I think) Ducati went to shower injectors on a 9500 engine and made me question the article. I saw some test data on a couple different engines that showed power loss with shower injectors, including 1 sport bike that came with them....so back to believing the original article .

The real key seems to be in the pulse length of around 35%dc.........I think you need to test to know for sure on any new application.