'Stealth' EFI

kev_the_mole · Post by **kev_the_mole** » Thu Mar 04, 2010 8:39 pm

Can I rip the NOS pipes out of this and do port injection from inside the manifold or will it be too hot? I can blank off the cavity to stop/reduce oil contamination.

Is this crazy?

gelmonkey · Post by **gelmonkey** » Thu Mar 04, 2010 8:44 pm

Mad as a box of frogs I would say.
I think that you would be evaporating the fuel before it got to the cylinders and that would be melted piston time.
IMO.
P

kev_the_mole · Post by **kev_the_mole** » Thu Mar 04, 2010 9:10 pm

It's kev_the_box_of_frogs then

gelmonkey · Post by **gelmonkey** » Thu Mar 04, 2010 9:20 pm

kev_the_mole · Post by **kev_the_mole** » Thu Mar 04, 2010 9:48 pm

OK so no stealth but this is what I've got to work with

I can probably squeeze eight injectors in to the manifold but they'll be firing at 90 degrees to the airflow. Any comments from the experts?

Cheers,

Ian

gelmonkey · Post by **gelmonkey** » Thu Mar 04, 2010 10:25 pm

Ian
I am no expert on this kind of thing as I have yet to fire my system in anger but am thinking, could you weld some bosses to the bases of the inlet tracts at a 45 degree angle and then use Fogger nozzles?
This would alleviate the need for seperate pipes and keep it fairly simple ish.
I don't think that firing in at 90 would be that effective as the venturi effect would drag the charge down the side of tract rather than into the center which is better.
I may be talking poopy plop here but am sure someone will come up with a more informed opinion.
cheers
P

stevieturbo · Post by **stevieturbo** » Thu Mar 04, 2010 11:00 pm

If you can physically install them in there, then it will work. Get some shorty "pico" injectors

It may not be ideal, but it will still work.

Only big issue there might be, is if the injectors are not spraying into a unique port.

ie, some fuel may end up in the wrong runner. At low speeds it could be a small problem. At higher rpm it wont.

kiwicar · Post by **kiwicar** » Fri Mar 05, 2010 6:01 am

I have heard of people stripping out all the internals on webbers and and blocking up the air passages and installing the injectors through the float bowles, firing in at about 60 degrees, the other way would be to install the injectors up stream of the throttle plates by mounting a plate at the top of the throttle body and hiding everything in the air filters.
Mike

ian.stewart · Post by **ian.stewart** » Fri Mar 05, 2010 1:20 pm

Ahh the street racers perfect friend

I love the Idea d a hdden systm but as Gelmonkey says, fuel evap could be a real problem.

Heres one I started last year, All well and good ----until tried fitting the rocker cover, Did anybody realise RV8 rocker covers do not sit on the heads squarely????? an run out about 4mm end to end, DOH

kev_the_mole · Post by **kev_the_mole** » Fri Mar 05, 2010 2:47 pm

OK a box of frogs suggestion then!

I mill the hump containing the NOS stuff away, plate over the hole and put in injector bosses firing at the back of the valves.

Am I going to have enough room using 'pico' injectors or am I going to ruin (I have form on this

) a perfectly good old-skool manifold?

kiwicar · Post by **kiwicar** » Fri Mar 05, 2010 4:18 pm

Hi Ian
on the principle of there is nothing that a little thinking about the problem won't solve, here is another surgestion.
As you said originally strip out the NOS set up, iinstall injector bungs and install pico injectors from unberneath with the fuel rails and everything out of sight (simple so far!). Now you only have the heat problem to deal with. Having had a look on mine you have 2 to 3" below the manifold base in the valley where you can put in somthing to keep the whole lot cool, so make up a cover for the bottom of the manifold out of ally with a hole in either end and a fitting that is accessable from the cavity you have all the injection gubbins in say 1/2" diamiter and run a pipe from this out to the outside world.
Below the cover make up a spacer about 1/2" thick that seals to the manifold bottom cover and put a second cover over this. Now you have a flat cavity under the injection kit with a feed in and out that you can run cooling water through, rig up a radiator and electric pump that will cool this water and add another heat deflector under the whole lot and it should keep it all nice and cool and stop the fuel vaporising. Hide the exits of the pipes from the manifold top and no one will be any the wiser.
Best regards
Mike

topcatcustom · Post by **topcatcustom** » Fri Mar 05, 2010 4:58 pm

It looks like there are threaded bosses to bolt into underneath your manifold to take a heat sheild already- one in thin stainless could go in- you could always rig a couple of cheap computer fans in there as they push a lot of air and draw nothing, they should keep it cool as it will be open-ended with the valley shape.

You cant ruin that lovely manifold!!!

Mark · Post by **Mark** » Sat Mar 06, 2010 2:34 pm

If height is not a problem you could get some ali blocks made up that fit between the carb and inlet and mount the injectors in them ?

Mark

kev_the_mole · Post by **kev_the_mole** » Sat Mar 06, 2010 6:12 pm

If height is not a problem

Sadly it is.

Currently I'm looking at some very high-tech pipe insulation (think NASA) so once the fuel is moving it will not matter if the pipes are inside the manifold. May need a fuel cooler but that's another matter.

stevieturbo · Post by **stevieturbo** » Sat Mar 06, 2010 6:30 pm

It will not matter. The fuel will be fine.

The only way it may become a problem, is if you do not installl the fuel rails in a full flow setup. ie, the fuel rails dead end inside the manifold.

But most efi systems arent like that ( although a lot of modern stuff is )