90 S-4

Ryan,
Injectors closer to the valves are for oem applications, better low rpm response
& emission And going further up makes more power...

Jim bailey - 928 International

Some of the F-1 engines mounted the injector ABOVE the bell of the air horn ! and the storm going into the engine carried the fuel... Porsche race engines they moved them up down pointed up and pointed down

JEC_31

I packed a lunch.

Would love to hear the 100 details.

Awseome strumpets!

Mike Simard

We could have a long, interesting discussion on the subject of injector placement as well as throttle opening direction but in the end it's not as important as you might think. If you're using a stock ECU then it's batch firing which makes injector placement even more irrelevant. The fuel is going to be puddling on the walls and it doesn't matter too much because it will be evaporating anyway.

Hammer,

6.0-928S

Thanks Joe. If you pull out an injector & look down the hole you can see the backs of the intake valves. I'd call that perfect placement. Besides, if you reverse the throttle bodies so the injector is on the outside the fuel spray would wash down the short side radius of the port floor. Also I wanted (although small) a ram effect & having the injectors up higher adds the weight of the fuel into the intake charge hence increasing the ram effect.
Hammer

RyanPerrella

Jim

Most F1 teams run two sets of injectors, you only see the ones in the middle of the trumpet

6.0-928S

Thanks Mike. You are (as always) correct about the minutia, but as long as I'm designing something from scratch I have always tried to take advantage of physics regardless of how small the advantage may be. I don't have to tell you that everything adds up.
Hammer

RyanPerrella

It was just a comment. I have never designed an intake manifold so i trust your judgement.

I guess the longer track to the combustion chamber allows the fuel more time to mix with the air more completely. It looked fromt he pic that the injector is pointing at the wall of the runner though.

I know suzuki used twin injectors on some of its more recent GSXR's and one injector was pointed at something like a 45 degree angle to the runner as this caused some sort of fueling anomality that they found best for power. I am sure they know allot more about this then i do that for sure.

RyanPerrella

Hey if your doing it from scratch, best to take advantage of whatever you feel will work best. Thats half the fun of making your own stuff.

When will you finish this engine and run it? Youve been doing this for at least the past year now right?

6.0-928S

I started with the base plates & ported them to start the transition from the oval head to the round throttle bodies. I countersunk (machined) the underside of the top plates that the bodies are mounted on to accept the tubes & keep them round. Then I crimped the head end of the tubes(you can see the taper in the tube in one of the pictures) in a press to an oval to match the porting I did in the bottom plates. (I also ported the heads myself) Then had the 968 valves installed. Ed Quay welded the manifold assembly for me & this was the result.
Hammer

6.0-928S

It's been more than a year. However long it takes to do it right is how long it will take. (right Mike?)I'm in no hurry.

largecar379

HAMMER------!!!!!!

now I'm really jealous......first an A990, now this......


I want some of those for my 16V heads.


--Russ

90 S-4

Hammer,
This pic is to Bitchen not to use for a new avitar

6.0-928S

How's this Joe?

Hammer

90 S-4

Yep, that'll work -- PURDEE !!!