Converting odler mechanical FI intakes to EFI

[Bill]

Hi ho-

Got a few older Hilborn/Crower intakes collecting dust and would like
to convert them to EFI. Trying to avoid welding in the injector bungs as the
heat causes distortion, which will likely require the intakes to be remachined
in order to straighten them out. However- I'm wondering why you can't machine
an intermediate adapter to hold the injectors and bolt in place underneath the
ram tubes. I'm sure this will work ok at part and full throttle. My concern is
that, at idle with the throttle blades closed, the injectors will be positioned
above the blades (instead of below them like most setups) so it might not
idle so well. On the other hand, tbi's & carbs work that way, and the two Crower
mechanical intakes I have also work that way (but I DO realize these weren't
meant for cars who's main purpose was idling!). Still, the more I think about
it, the more I think it will probably work.

Has anyone tried this?

cheers,
Bill

[PeterD]

Post by Bill
Hi ho-
Got a few older Hilborn/Crower intakes collecting dust and would like
to convert them to EFI. Trying to avoid welding in the injector bungs as the
heat causes distortion, which will likely require the intakes to be remachined
in order to straighten them out. However- I'm wondering why you can't machine
an intermediate adapter to hold the injectors and bolt in place underneath the
ram tubes. I'm sure this will work ok at part and full throttle. My concern is
that, at idle with the throttle blades closed, the injectors will be positioned
above the blades (instead of below them like most setups) so it might not
idle so well. On the other hand, tbi's & carbs work that way, and the two Crower
mechanical intakes I have also work that way (but I DO realize these weren't
meant for cars who's main purpose was idling!). Still, the more I think about
it, the more I think it will probably work.
Has anyone tried this?
cheers,
Bill

I think they called this throttle body injection...

[Bill]

Post by PeterD

Post by Bill
Hi ho-
Got a few older Hilborn/Crower intakes collecting dust and would like
to convert them to EFI. Trying to avoid welding in the injector bungs as the
heat causes distortion, which will likely require the intakes to be remachined
in order to straighten them out. However- I'm wondering why you can't machine
an intermediate adapter to hold the injectors and bolt in place underneath the
ram tubes. I'm sure this will work ok at part and full throttle. My concern is
that, at idle with the throttle blades closed, the injectors will be positioned
above the blades (instead of below them like most setups) so it might not
idle so well. On the other hand, tbi's & carbs work that way, and the two Crower
mechanical intakes I have also work that way (but I DO realize these weren't
meant for cars who's main purpose was idling!). Still, the more I think about
it, the more I think it will probably work.
Has anyone tried this?
cheers,
Bill

I think they called this throttle body injection...

but that had a plenum. CanAm cars that used Lucas metering did the same.

[*]

Post by Bill
Hi ho-
Got a few older Hilborn/Crower intakes collecting dust and would like
to convert them to EFI. Trying to avoid welding in the injector bungs as the
heat causes distortion, which will likely require the intakes to be remachined
in order to straighten them out. However- I'm wondering why you can't machine
an intermediate adapter to hold the injectors and bolt in place underneath the
ram tubes. I'm sure this will work ok at part and full throttle. My concern is
that, at idle with the throttle blades closed, the injectors will be positioned
above the blades (instead of below them like most setups) so it might not
idle so well. On the other hand, tbi's & carbs work that way,

If you look closely at carburetors, you will see that there is a slot -
part of which is below the throttle plate when it is closed.

This slot provides idle and off-idle fuel.

[Bill]

Post by Bill

Post by Bill
Hi ho-
Got a few older Hilborn/Crower intakes collecting dust and would like
to convert them to EFI. Trying to avoid welding in the injector bungs

as the

Post by Bill
heat causes distortion, which will likely require the intakes to be

remachined

Post by Bill
in order to straighten them out. However- I'm wondering why you can't

machine

Post by Bill
an intermediate adapter to hold the injectors and bolt in place

underneath the

Post by Bill
ram tubes. I'm sure this will work ok at part and full throttle. My

concern is

Post by Bill
that, at idle with the throttle blades closed, the injectors will be

positioned

Post by Bill
above the blades (instead of below them like most setups) so it might

not

Post by Bill
idle so well. On the other hand, tbi's & carbs work that way,

If you look closely at carburetors, you will see that there is a slot -
part of which is below the throttle plate when it is closed.
This slot provides idle and off-idle fuel.

fuel or just air?

[.boB]

Post by Bill
Hi ho-
Got a few older Hilborn/Crower intakes collecting dust and would like
to convert them to EFI. Trying to avoid welding in the injector bungs as the
heat causes distortion, which will likely require the intakes to be
remachined in order to straighten them out. However- I'm wondering why
you can't machine an intermediate adapter to hold the injectors and bolt
in place underneath the ram tubes. I'm sure this will work ok at part
and full throttle. My concern is that, at idle with the throttle blades
closed, the injectors will be positioned above the blades (instead of
below them like most setups) so it might not
idle so well. On the other hand, tbi's & carbs work that way, and the two Crower
mechanical intakes I have also work that way (but I DO realize these weren't
meant for cars who's main purpose was idling!). Still, the more I think about
it, the more I think it will probably work.
Has anyone tried this?
cheers,
Bill

Will it work? Yeah, it probably will. But you'll
have some idle and low rpm performance issues. I think
it would be fine for a race car. But a street car will
have some real annoying derivability issues.
When the fuel hits the nearly closed blades, it will
puddle a drip off.
Have the bungs welded in below the throttle plates.
have a pro do it so there's no distortion. It will
cost you, but worth it.
Take a look at how Kinsler does it.

[Bill]

Post by Bill
Hi ho-
Got a few older Hilborn/Crower intakes collecting dust and would like
to convert them to EFI. Trying to avoid welding in the injector bungs as the
heat causes distortion, which will likely require the intakes to be
remachined in order to straighten them out. However- I'm wondering
why you can't machine an intermediate adapter to hold the injectors
and bolt in place underneath the ram tubes. I'm sure this will work ok
at part and full throttle. My concern is that, at idle with the
throttle blades closed, the injectors will be positioned above the
blades (instead of below them like most setups) so it might not
idle so well. On the other hand, tbi's & carbs work that way, and the two Crower
mechanical intakes I have also work that way (but I DO realize these weren't
meant for cars who's main purpose was idling!). Still, the more I think about
it, the more I think it will probably work.
Has anyone tried this?
cheers,
Bill

Will it work? Yeah, it probably will. But you'll have some idle and
low rpm performance issues.

I think you might be right but I'm still wondering if anyone has done this. . .

I think it would be fine for a race car.

But a street car will have some real annoying derivability issues.
When the fuel hits the nearly closed blades, it will puddle a drip off.

That what I thought at first but it doesn't do that with tbi (maybe because tbi
works with less pressure?). I don't know that it will actually hit. It might
depend on how far above the blades the injector tip is. And it sprays so little
at idle that I think the atomized fuel might just find it's way around the
blades (vaccuum) and work ok. Sure the spraying fuel is under a lot of pressure
but it's also atomized and there is a fair amount of vaccuum at idle. Maybe the
tip of the injector will have to be some minimum distance above the blades to
allow for a smooth flow around them.

Have the bungs welded in below the throttle plates. have a pro do it
so there's no distortion.

Talked to a couple of pros about this. Depends where you want them welded and
how thick the metal is there.


It will cost you, but worth it.

Take a look at how Kinsler does it.

I have. And talked to them on the phone. They do it a few different ways: One,
with Lucas metering (not EFI but makes no diff in this case), bungs welded into
the ram tubes and sprays fuel down onto the throttle blades. Another (most
common for Kinsler) is below the blades BUT spraying from the outside at the
opposite side of the intake runner wall instead of toward the valve. According
to the theory above, the fuel would then splash off the opposite wall and drip
into the cylinder. But I'm not sure it really does. Yet another (actually own
one of these) is a 3 piece magnesium intake from a chevy SB (well actually
"Pontiac" but in name only) turbo gtp car. The throttle blades are way high
(maybe 10 inches high) in the runners with the injectors just below them on the
inside of each runner- so there is still probably a good 9 inches of wet flow
before the fuel makes it into the head...(quite a contrast with the direct port
injection used on some sprint cars) I called kinsler a few weeks ago and asked
if this adapter method would work and they said they had done it using a Hilborn
setup on a hemi and it worked great. But admittedly that was a race car.

I guess there's no way to know without actually trying it. . .

thanks for your input it IS appreciated!!

b

[*]

They might be worth more "As-Is" at an antique auto flea market than they
would be butchered up.

[Bill]

2 things here- the original post said adapters were going to be used in order to
avoid welding. ie...so it wouldn't have to be "butchered" as you put it. 2nd-
there are a lot of modern efi manifolds that are virtually nothing more than
these "antiques" with cast-in provisions for efi.

So I gather from your responses that you haven't done this?

cheers
Bill

Post by *
They might be worth more "As-Is" at an antique auto flea market than they
would be butchered up.