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.

[Revved]

I deal with these on a regular basis... mostly on SBF strokers. As the guys said above setup is EVERYTHING. The majority of them that come in running poorly have throttle plates that are out of sync.

Spend the money on a good EFI system with someone that knows how to tune it. #2 problem I see coming in the door is guys that tune them to run like crazy at WOT but can't tune them for part throttle operation or drivability. The MAP signal on these systems is narrower than on a common plenum manifold so the part throttle driving runs through the same spots as hard throttle. It takes a lot of experience to dial in the enrichment tables to get the drivability right.

Mark will tell you that ACCEL is the way to go... I have great luck with FAST XFI systems.... most importantly is that you have a competent tuner to set it up for you. I've done a couple with EZ-EFI gen1 and not had good results- my theory is that it goes back to the "bubble" running through the same spots on the fuel tables and the system tunes in glitches. I've been talking to David Page at FAST about the Gen2 EZ systems and the Sportsman systems and almost pulled the trigger on a Sportsman for a current ITB Windsor project but they won't be releasing them for another month and I can have an XFI on it by the end of the week.

Another thing I highly recommend but I know it comes down to visual personal preference is the filtration. The UP cars were built with DC&O ITB manifolds with the spun stacks... the filter media they used was horribly restrictive and breaks down over time. On a Keith Craft 427 SB stroker we gained 40rwhp simply by taking off the filters. We developed adapters to bolt on KN filters that only cost 5hp and never break down.

They are good if done right and short of dropping a couple turbos under the hood it's hard to beat the cool factor.

[supremeefi]

Let me explain why I like the Accel, especially for this type of setup.

Accel has 5 transient fueling tables, XFI has 2. That's very important to get the very best in drivability. As you mentioned Sean, wot is easy. It's the part throttle stuff that's more difficult. The more tables you have ultimately the better it will drive.
And the XFI has individual fuel and spark control but it's all or nothing. It's not adjustable by load and/or rpm like Accel and others. I've had 2 Hilborns that I had a really hard time getting the blades synced. Because of that it would pop out of the throats that were opened more. We can richen those throats at idle to fix that. But on the XFI that change would carry thru the whole rpm/load range, when maybe it doesn't need to.

They are tricky but worth it imo.

[Revved]

I've had DC&O manifolds that didn't want to balance so I had to remove the blades and hand sand them to fit. There is always another answer if you think outside of the box.

Didn't need 5 fueling tables... Got it done with 2




Messing with you Mark!

[supremeefi]

Originally Posted by Revved

I've had DC&O manifolds that didn't want to balance so I had to remove the blades and hand sand them to fit. There is always another answer if you think outside of the box.

Didn't need 5 fueling tables... Got it done with 2




Messing with you Mark!

Well then you're a better man the me!!Lol!