breathial

Ok, the summary: 427 BBC, built to run with a 6-71 GMC supercharger on top. Initially, I ran two 600-CFM Holley carbs, but had serious issues getting the idle correct (ran WAY too rich, but smoothed out when I got off the idle circuit). Finally, after being a bit disgusted with this issue, and after reading about the Megasquirt EFI computer that you can build yourself (and download all software for free, off the internet), I decided to take the plunge, and do an EFI on my blown engine.

The big problem has been packaging: HOW do you fit the injectors above the blower inlet (for cooling of the rotors), and yet maintain that "clean" look, without looking like a cobbled-together mess (like BDS, Force Fuel Injection, et al.) with injectors hanging out the side? And, the aftermarket suppliers are charging $4500+ for such a system... I thought, there MUST be a better way! And there IS...

So, let's go to the pics. I didn't bother to throw in pics of building the computer, as there's not much to see...

Initial pics with the carbs. As you can see, they sat so high that there was no way to see around them...



Compare the above photo, to the next one, with the injector hat I'm using. Note the partially completed hood (blister) that will cover the majority of the engine.


For housing the injectors, I eventually went with a 1/2" aluminum plate, and used two 1 1/2" thick pieces of aluminum, that I machined with an end-mill to house the injectors.

breathial

How does it fit inside the Enderle (bug-catcher) hat?



So, with the injectors mounted...



Now the problem comes up- how to route fuel and control wires to the injectors? Simple, really... The bug-catcher has four holes at the base of each side of the scoop, for the mechanical fuel injection... I'll use hard-lines from a fuel distribution block on one side, and an identical block on the other side, routing the wires through the tubes. This way, I achieve the "hard-line" look, get everything routed where it needs to be, and have a very "clean" finished look...

The two blocks, mounted on the back of the scoop. The one on the right will be fuel, the left is electrical. Note, the -AN fittings. They are highly expensive, very fragile. Plus, the -3AN fittings are too small to run the wires through. The tubes (in retrospect) will not fit the dual blocks I have made, and I'm unsure they'll flow enough fuel to feed this engine at max boost/RPM.



I found McMaster-Carr carries 1/4" type 316 stainless steel line and compression fittings. Add in the 2000-degree wire heat insulation, extra fittings to route the fuel to the injector tops, pigtails for wiring...? Total cost is $207. So, waiting for the hardware to arrive.

As it looks now...?

DC118us

Wow, that's impressive.......

ZD75blue

Beautiful.

How does it run for you? As much as I dislike fuel injection (black box... murphys law!) that setup sure makes me drool.

How will your system register airflow/temperature?

Wow.

breathial

Also working on a hood "blister," to cover the engine so that the scoop is the only part visible from the outside. Since I intend to drive this car quite frequently, I wanted to shield the engine from as much dirt and rain as possible.

So here's the pics of the hood scoop, taken yesterday:

SteveG75

Nice work.

As for the scoop, the 4" Vanacor L-88 hood may work well for you.
Discussion here:http://forums.corvetteforum.com/show...160&forum_id=3

breathial

It's not running yet. Just posting pics as I go along. I thought others might be interested, because this can be done for about.... around $1500-2000, versus at least $4500 from the cheapest aftermarket supplier. It should run very nicely, much better than carbs, since I'll be using a wide-band O2 sensor to provide real-time feedback to the computer, to dial the exact air-fuel ratios needed. (didn't put in pics of the O2 sensor bung I welded onto the passenger-side header)

The cool thing about the megasquirt, is that the software is all public-domain. Which means it's free. It has enough capabilities to run the most sophisticated engines you can think of, yet, can be dialed-in easily using a laptop computer.

So, as it comes together, I'll be posting more pics and my impressions on this... It seems that nobody has ever taken this approach before (injector packaging) as I have, so I'm having to design everything from scratch.... The next guy should have a much easier time of it....

As for airflow, I have a throttle linkage I built, that incorporates a throttle-position sensor. Also, the computer has a built-in vacuum/boost sensor. So between these two, I will be able to feed the computer everything it needs for the airflow computations. I just bought the inlet air-temp sensor, and I'll be working on that, this next weekend. I haven't determined yet, how I'll include it in the scoop.... but it'll be interesting...

breathial

Actually, I decided against the aftermarket hood manufactures, because the scoops available carry the higher height all the way to the back of the hood. If I get one that covers everything the way I want, then it'll be so high at the back that I simply won't be able to see. (Forward visibility is one of my pet-peeves about cars- I like to have the maximum available.)

The real limitation, is the height necessary to adequately clear the blower pulley. To get one so agressive to cover it, I'd be looking at about 6" of height....

I did this, so I could hide pretty much all of the blower, yet still give me plenty of front visibility. From inside the car, the visibility is almost unchanged, because the hood blister is flat, and will mold right into the back edge, about 1/2" above the stock hood height...

But thanks for the feedback. I just hope it doesn't look too bizarre when it's finished....

I'm off to bed... I work the night shift ( ), so I need the rest... God knows, I'm too old for it to be "beauty rest" any more...

ZD75blue

Sounds like fun!

Can't wait for some more pictures of this beast...

Now you've got an audience...

Twin_Turbo

I wouldn't want that 4" tall hood either..that doghouse looks so much better

76custompaint

That's really cool

How easy is the megasquirt to set up and and get configured right? I'm thinking about it for another car... When I look at the cost of getting a chip for it at 300$ and getting 20 hp and still having to run cats, and getting a megasquirt with all the accessories for 400$, and being able to tune it however I want.. Well there is really no comparison

So when are you going to start selling the injector housings? I'm sure there are people here on the forum that would be interested, especially if they were looking for the reliability of fuel injection with the raw power of a supercharger

Very clean install, keep up with the good work, and the pics too

ZD75blue

Seeing how you are giving us this great piece of tech, and I'm procrastinating... I've set out to ponder how you can get away with a smaller blister. I dont think dropping the engine is an option... unless you want a to do a crossmember delete.

I think norval just had a how to for the blower pulley. He put the blower at the back, and the accessories at the front. That might take a few inches out of the required blister. Theres also a french guy on www.jalopyjournal.com that turned a custom pulley for a blown flathead that has promise.

The other thing I'd look into is running the same ratio pulley, but reducing the diameter out of both. Problem being the radius can get smaller than the belt works with... requires some further research!

The last one I'd ponder, would be taking some meat out of the blower manifold. Who knows, might be able to knock a 1/4 inch off of it... but since the hood/blower makes a triangle, and the pulley sits on the hypotaneuse, a little height reduction goes a long way.

PatsLs1vette

Very trick setup im impressed.

Kalway

I want one!

Z-man

Looks good!

Did you look into adding injectors directly into the manifold?

stickboy

Are you using the bug catcher as a throttle body? Have you modified the butterfly area at all? If not, I would think that you throttle will be fairly unresponsive. Also have you given any thought to idle? Most EFI setups I have seen use an idle air controller and not the throttle body to control idle.

stingraymaniac

everything looks really good except that hood scoop..
Why cover up such a beatiful thing as a supercharger?

Monty

Cool. I love seeing other guys' fabrications. Nice work, I'm looking forward to seeing more of it as it moves along.

Yellow73SB

I whould just cut a hole in the stock hood and let the blower stick out. Looks like your pretending to have a blower with that hood.

SuprJames

I don't know much about your blower's manifold, but the fuel going directly into the cylinders seems like it would be the way to go. Is the only reason you're putting it up there is so that it will cool the air in the blower? Also seems like it would restrict airflow. I'm far from a supercharger expert so I might be way off base here.

Still looking.