Would this work

boomer · Post by **boomer** » Wed Nov 28, 2007 6:55 am

[IMG=http://img187.imageshack.us/img187/3199/itbne8.th.jpg]

I left a post on HybridZ but it's almost dead, so I try my chances here!

I have a set of 3 delortos on a cannon style manifold. The carbs are not in good shape, corrosion inside, but the barrel are in top cond. They have been ported to the manifold and it would be shame to bin them!

I also have a rebuild engine bloc F54 with a milled and shimmed P90 head, fast road cam, 6/2/1 exhaust.

I would like to convert my DHLA into ITB, the easiest way would be to fabricate a fuel rail with the injectors aiming in the barrel of the carbs!
I could secure the fuel rail to the air box.

How far inside the plenum should I go, witch injectors are slim enough to restrict air to the minimum still giving around 20/25 lbs/h ????

I would like to keep the 3 carbs setup without giving too much clues about the ITB conversion

FridgeFreezer · Post by **FridgeFreezer** » Thu Nov 29, 2007 4:50 am

Short answer - it should work. BMW did this on touring cars as a second bank of injectors, and my cousin is building a similar setup on his BMW. Many TBI setups fire onto the throttle plate.

boomer · Post by **boomer** » Thu Nov 29, 2007 5:00 am

life is so simple

FridgeFreezer · Post by **FridgeFreezer** » Thu Nov 29, 2007 5:15 am

Starter for 10 courtesy of BMIHT Gaydon:

Apologies for bigness of picture!

Post by **efahl** » Thu Nov 29, 2007 6:00 am

I was going to say F1 has been doing it for decades, and Fridge's picture of the Hart motor bears that out. Here's a video (5 meg) of the 2004? Renault V-10 motor on the dyno, where you'll see essentially the same setup.

Crank up the volume!

http://www.not2fast.com/f1/renault_v10.wmv

boomer · Post by **boomer** » Thu Nov 29, 2007 6:51 am

Aren't we in business now!
Thanks a lot, I know my options now.
Still: which injectors would be best suited?
No need to go farther into the plenum?
No risk of back-firing?

This is nice!

bionicbelly · Post by **bionicbelly** » Sat Dec 01, 2007 6:40 am

That is freakin awesome!

Mk1rocco · Post by **Mk1rocco** » Sat Dec 01, 2007 8:05 am

I've seen systems like that before but always on all out racing engines. I'm wondering if there's a reason for that, could such a system be made streetable? I'm sure these system are great at or near WOT, but what about at or just off idle, especially during warm-up?

78Spit1500Fed · Post by **78Spit1500Fed** » Sat Dec 01, 2007 5:34 pm

Okay, so air velocity isn't such a concern at 15,000 RPM... how about at a tenth of that, say at idle?

I just wonder how that would work at low RPM's?

-Brian

boomer · Post by **boomer** » Sun Dec 02, 2007 1:15 am

This is one of my main concern!
My guess (I have only a PHD in WDYDTF - [why did you do that for] is that it should work like an SU where the fuel come from behind the butterfly all the time.
I do know that the idle on Dual Barrels is a bypass of the main jet IN FRONT of the butterfly, yet it work wonder on the SU.

My second is that vapour of dustirezed (?) fuel could work their way close to the exhaust! I Need a tight airbox, maybe vented to the outside of the car?

If your'e OK to help me on the thinking of this thing I have more questions: One at the time and one on a post

boomer · Post by **boomer** » Sun Dec 02, 2007 1:23 am

Question 1:
I plan to gut the aux venturi.

I don't need it as it's only a high tech jet, right?

So I will slice it, I want to keep the ring in the center to use it as a base for the injector nose, inside the barrel. And use turbo ZX barbed inj. on a custom made steel fuel rail.

boomer · Post by **boomer** » Tue Dec 18, 2007 7:55 am

I have almost everything figured out now.
Yet I still have other options I need to consider:
Welding some injector bosses on the intake manifold would be the easy way

But I don't have enough room to fit injectors at the std 45Ã‚Â° angle, is it all wrong to use the injector at a 90Ã‚Â° angle at +- 3 inches away from the intake?