Hilborn 8 stack efi injection on BB Chevy

[Nilater]

Thinking of switching to Hilborn 8 stack efi injection on my 69 BB Camaro. Anyone running this type of fuel injection on the street? Looking for real world examples.

[camcojb]

I ran one on a small block years, ago, ran fantastic. Getting the throttle blades synched is the most critical part of the whole deal, other than that it tunes fine. Mine liked to be a little richer at idle than a normal setup......... mid 13's a/f as I remember. It was fine at 14.5-15 a/f cruising down the road.

Throttle response is awesome, looks of course are another benefit. It will also "tame" a camshaft. My small block had a solid roller with [email protected] duration. You could literally not touch the throttle in first gear, just let the clutch out slowly and it would cruise in first gear with no jumping back and forth like most big cams do in a low gear with the throttle closed.

One caveat....... make sure your blades are large enough to support the engines needs. Mild engines, no big deal, but on higher horse setups it can cost power. There is no plenum to "borrow" from like a carb'd single plane setup, so what each blade can flow is all that cylinder will see.

[BBPanel]

How much under 3K rpm do you think you gave up if you had run something on the order of mid-240's @ 0.050? What LSA did you run? -Bob

[camcojb]

Originally Posted by BBPanel

How much under 3K rpm do you think you gave up if you had run something on the order of mid-240's @ 0.050? What LSA did you run? -Bob

That cam was .625 lift and [email protected] on a 110 lsa as I remember. It was spec'd for a Victor single plane with a 1000 cfm throttle body. 10:1 406 with iron heads, made 480 rwhp and 480 rwtq.

Probably more cam than it should have had, but it ran great. I had the 2 3/16" throttle blades, and they were too small, still had 2-3" of vacuum at WOT.

240's on a big block is fairly mild, but it should run great. Depends on your power goals, and what the car is going to be used for. The IR setup adds a bunch of torque down low, so you're not going to give up low rpm power. I picked up 30 ft.lbs down low over the single plane, and the same HP. Also the cam sound was completely different; the single plane was pretty choppy, great sound. The IR setup was much milder, sounded like a small street/strip cam. So a big block with a small cam might not have much chop if that's an issue for you.

[supremeefi]

What Jody says is correct. They are a win-win in my book. Just make sure you get a good EFI system. I've tuned a bunch, even via email.

I did a 408 Chevy with the Hilborn setup on it. In fact it's on my video. https://www.youtube.com/watch?v=RnSi6FgMXjE
Before that it had a dual quad tunnel ram on it with Brodix heads and a 260/[email protected] Crane solid roller on a 106 lsa with .675 lift. It wouldn't idle at anything below 1100 and used a bunch of fuel.

After we installed the Hilborn intake it idled at 750 all day. The reason? No more dirty air. With the individual runners every hole gets clean air unlike a shared plenum like Jody mentioned. He was actually a little pissed because it idled so smoothly afterward. But with 10.25:1 and that big roller it didn't have any cylinder pressure down low, therefore no bang sound.

But even with that the throttle response was excellent. I'm a big fan of the IR stuff when done right. In fact I'm fabbing one for my Olds. Let us know what you end up with.

[Nilater]

Thanks for the responses. Leaning toward a Hilborn system with a Holley controller.