Injector location/angles on a intake

[blk00z28]

I've talked to a few engine builders and tuners before about the location of injectors in the runner of the intake. Lower in the runner vs higher and on a normal under 900hp motor it really made no difference, once over 1000hp they said it started to matter.

My question now is, does anyone know if the angle of the injector matters when installed in a intake? Normally they are in a pretty straight line to the valve. But what if you position them at a 90 to the runner? Are their any gains/losses in flow by doing this? Has anyone done something like this before? If so any advice? I'm looking into this not for real gain if any, but to make the intake look better and not have everything so tightly packed on the intake.

 

[MRKING]

Re: Injector location/angles on a intake

is he giving you options on where you want the inj bungs welded ? i just held my stock rail up to the manifold and got an idea where the general area should be . then with a micrometer and drill press , marked and drilled each the exact same . stock rail fits perfect and I saved $$$ using parts I already had .

you really planning on 1k plus hp ? if so, you probably have alot of other things to worry aboot as well . and that doesnt sound like fun
At least try to get it running for your kids 16th b-day ..

 

[JSM]

Re: Injector location/angles on a intake

Ideal angle is pointed at back of intake valve. Most of the time that can't be done though unless it is designed into the intake. Retrofit carb intakes make it hard to get that ideally.

 

[turbodig]

Re: Injector location/angles on a intake

Big RPM motors want them upstream more, gives the fuel more time to mix effectively.
The information you were given is consistent with the current thinking - motors in the realm of the average guy aren't gonna see much of a difference.

Place the bungs such that they don't intrude on airflow too much, and be done with it.
Packaging drives it as much as anything else.

 

[blk00z28]

Re: Injector location/angles on a intake

Mike; its not a shop asking. I'm doing the work on the intake for my truck with a fellow friend who's going to weld them in however I want them for free.

I just wondered if by installing the bungs at a 90* to the runners will it wash the runner walls with fuel rather then just spray into it. I've kind of hinted at this with a few turbo Buick guys with alky/meth kits. They have no problems installing the nozzles at a 90*. Granted a alky/meth system doesn't flow nearly as much or often as a fuel Injector at a high DC. .

Air is being forced into the intake most of the time rather then drew in by normal compression on a forced motor. So would it really make a difference? I've seen some wild street/track cars that have a dual injector at a 90* above the normal one, but those are probably for when they run wot at the track with lots of psi or nitrous.

Like I said, I'm asking this only because I want to open up some room on the intake and not have everything tightly up on the plenum. If it will possibly wash the walls of the runner then ill just install them like every other kit.

 

[MRKING]

Re: Injector location/angles on a intake

I'll put up a pic of how my setup turned out later , you may be able to get some * to it but off hand i dont recall . You going forward facing tb or side like stock ?

 

[blk00z28]

Re: Injector location/angles on a intake

Going to the side. Which side though, I'm not sure about yet. I kind of like the idea of the ic piping routing cleaner into the drivers side. So it might face that direction. But please shoot me some pictures.

 

[MRKING]

Re: Injector location/angles on a intake

90* inj mounting is deff possible with forward facing and I dont think L or R side would make a diff . my question is , is 90* really the optimal angle . Ive never given it thought before and I am curious . A little late for me now though .:lol:

 

[blk00z28]

Re: Injector location/angles on a intake

Two reasons I like the side facing better in my case, I'm keeping the stock radiator, court support, a/c, brakes(minus abs). So hopefully by facing it towards the drivers side I wont have to get the IC pipes wrapped around the A/C lines. Of course, I havent figured out the throttle cables yet if I go that way. I have the plate to go towards the pass side, but not sure how I'll get them reversed. I didn't realize you brought the cross over up like that, are those the twin headers that you bought a while back and couldn't sell?

When the intake and bungs show up this week in the mail I'll start mocking things up to see how they will look. I have a buddy that I can grab some used fuel rails from off another v6 style motor and see how much/close they will be in contact with the plenum. I have to make spacers for the intake to fit my Bowtie heads as well (which I'm going to weld onto the intake so I don't have to screw them on and worry about leaking in the future) so it'll be a fun project to say the least. Might not beat the flow of a sheet metal intake, but my only other option aside from the work I'm doing to this intake was a Daytona Dash. Which I still had to make spacers for..

If I can get away with the injectors being 90* to the runner, I'll run the wiring on the inner side of the rail vs the outside like stock. Keeping it cleaner as well. (Just little things that hopefully will make it easier on me in the future for cleaning, as well as looks you know.)

 

[MRKING]

Re: Injector location/angles on a intake

yeah , I couldnt bring myself to sell the rpm tt headers . they looked too good to let go and I only got a few offers since a x-over had to be fabbed .most wanted a bolt on and drive setup .

i now have to redo my exhaust since the rpm dp will hit my tire when hard turning the way the minigate hangs low to the left side . with switching to all elec accessories , its been a solve this , now what do i do about that type of thing . after the fixing the exhaust and getting a new upper radiator hose , I can take it off the jackstands and start it up . i really wanted to make the shindig with it .I was going to ride out with dennis in his ty at the last minute , but had to work on sat and sun that weekend . disappointment was an understatement .. time to start planning for our annual jan wrench meet .

 

[blk00z28]

Re: Injector location/angles on a intake

Yeah, wish someone could answer the question about the injectors being 90* to the runners if it'll wash them or not. I don't have access to make something to do like a flow system to test it. So I'm left asking questions or doing it and realizing it doesn't/does work. lol.

Now that you mention it. I wonder how the belt would run on a truck with all the accessories, but with a electric water pump like you have? I don't think the alt would have a lot of contact with the belt then because it would just run straight across the top of it and down from the ac..

 

[turbodig]

Re: Injector location/angles on a intake

Thing ya gotta remember is, the flow of air will actually bend the spray a bit. You'll never really see perpendicular to the runner. Hold a garden hose up in a high wind, and you'll get a pretty good demonstration of this.

I'd angle cut the bungs, and lay them as flat as you can with available fuel rail clearance.

 

[SY2932]

Re: Injector location/angles on a intake

Two reasons I like the side facing better in my case, I'm keeping the stock radiator, court support, a/c, brakes(minus abs). So hopefully by facing it towards the drivers side I wont have to get the IC pipes wrapped around the A/C lines. Of course, I havent figured out the throttle cables yet if I go that way. I have the plate to go towards the pass side, but not sure how I'll get them reversed.

That's what I'm talking about ! I was kicking around this idea last year so that I could retain a somewhat stockish W2A setup. I wanted a "mirror image" upper intake to keep the IC and everything else away from the heat of the downpipe. Never did figure out how to address the cable problem since I have since changed the direction of my future build. I figured that I would have to go with an electronic setup to make it work since wires make bends easier than cables do...

I'd angle cut the bungs, and lay them as flat as you can with available fuel rail clearance.

Yep, that's why I'm gonna make my own fuel rail so that I can do what I want :lol:!

 

[Windedv6]

Re: Injector location/angles on a intake

Keep the injector angled into the runner. Our bank to bank setup is batched fired and fires twice before the valve opens. You will wet down the walls spraying across the runner Firing close to the valve as possible allows the valve heat to help atomize the fuel which helps at idle and low rpms. You can have a Idle/drivability issue wetting down the runners as once the fuel spray hits the wall it will cause dropplets that will not mix as welll with the air. Under high air flow at WOT or higher boost you can clean the "Wet" walls and not notice the problem. That is why you will see the second injector on some setups at the 90* angle.

John

 

[blk00z28]

Re: Injector location/angles on a intake

That's what I'm talking about ! I was kicking around this idea last year so that I could retain a somewhat stockish W2A setup. I wanted a "mirror image" upper intake to keep the IC and everything else away from the heat of the downpipe. Never did figure out how to address the cable problem since I have since changed the direction of my future build. I figured that I would have to go with an electronic setup to make it work since wires make bends easier than cables do...!

Yeah, I've only seen one truck with it facing the drivers side. And thats just based off memory. I know I've seen pictures but cant find them.

Thanks for the reply John, again you seem to answer most of my questions lol.