Thread: Fuel Injection

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If I started with a chevy 350 that already has fuel injection, and then I add 150 hp to it, with the stock fuel injection still work? What would I need to do to make it work?

Thanks

How did you add the 150?

Need more info about the setup.....there are several factory Chevrolet Fuel Injection systems and a boat load of aftermarket setups.......What is yours? Is it electronic?
IF so, what is the controller (ECU)?

http://www.chevyhiperformance.com/te...ild/index.html

stock vortec
GM Performance Parts dual-plane Vortec intake manifold.
Stinger electronic ignition distributor to trigger the MSD 6 box
GM Performance Parts HOT cam, and 9.75:1 compression ratio

I have a 72 sbc 350 now. There is a brand new vortec long block for sell close to me for 700. I'm thinking of getting that and selling mine. I'd like fuel injection for offroading (it's in a jeep), but I don't want to pay for an aftermarket unit. So it's cheapeset to buy a used motor with the fuel injection already on there, but if I have to change it anyway because of the increased power, then I might as well get that good deal on the brand new vortec motor.

Thanks

With a wet sump oiling system, there is only so far you can go out of plumb anyway. Check out this article. Looks to me like the Q-Jet is the way to go for performance and also light on the checkbook compared to EFI.
http://www.4wheeloffroad.com/techart...iew/index.html
My best advice would be to purchase it from Cliff Ruggles and have him set it up for your particular application before he ships it....
http://www.cliffshighperformance.com/
Use GM aluminum vortec intake manifold #12496820. This Vortec manifold was designed for ultimate horsepower and torque to be used with Vortec cylinder head, P/N 12529093, 12558060, 12497186 or 12464298, will accept Holley or Quadrajet carburetors and is EGR equipped. Use intake manifold gasket P/N 12529094 and (8) special manifold bolts P/N 12550027. Can be sourced from Scoggin-Dickey....
www.sdparts.com
Alternately, use an Edelbrock Performer Vortec Q-Jet. I have not been able to find a dual-plane, high-rise, Vortec, Quadrajet intake manifold. Edelbrock makes the Performer RPM for a Q-Jet, but not for Vortec L31 heads. Same with Weiand. Seems like someone would cast one up.

OK, I did the same thing for my jeep....I bought a stock '96-2000 vortec long block
for a truck with the idea of using a brand new vortec injection unit that I bought on the bay. I gathered a stock GM Vortec ECM and sent it to Fuel Injection Specialties in San Antonio TX to reprogram for my 4:56 gears and 37" tall tires (back then, now 40"). They also made me a nice harness for the engine/controller. As I worked thru the project, the stock vortec controller had several limitations that proved to be a pain....stuff like VATS and the upstream/downstream oxygen sensors on two cats. After seeing this would get really complicated, I stopped the direction that the project was going and went to a fuel injection system from Arizona Speed and Marine. They used a GM vortec intake, welded injector bungs in the proper locations and topped it with an MSD air meter. The computer is a MEFI unit. It required the proper MSD distributor (for a fuel injection engine) but, when we got it all together and turned the key, it fired immediately and has run great ever since.

We are in Tucson at 2700 ft and the jeep has been to about 12000 ft in Colorado without a hiccup....FI is great, I can be tilted sideways at 45 deg and the thing runs.....the FI cost me about $3800 with the harness, manifold, injectors, air meter and MEFI. It idles great.

mike in tucson

Sorry, I'm not a mehcanic at alll. I'm just getting into this.
"With a wet sump oiling system, there is only so far you can go out of plumb anyway."
not sure what this means, but I'm assuming with a vortec motor you wouldn't be able to fuel that much hp?

Originally Posted by whabamdo

Sorry, I'm not a mehcanic at alll. I'm just getting into this.
"With a wet sump oiling system, there is only so far you can go out of plumb anyway."
not sure what this means, but I'm assuming with a vortec motor you wouldn't be able to fuel that much hp?

What I was saying is that with a wet sump system, which is what you have, the bulk of the amount of oil in the motor is put into the oil pan, then sucked out by the pump and distributed within the motor. When the oil has done its job, it runs back down into the oil pan to be picked up again by the pump to do it all again. With oil just sitting in the pan, you cannot lean the motor very far one way or the other left to right or very much to the front or rear without uncovering the oil pickup in the oil pan, so that the oil pump begins to suck air. Once that happens, it's only a very short time to the end of the ball game with a seized-up motor.

It just sounds like to me that the Q-Jet would be ideal from a performance and cost standpoint.

I'm not sure what you mean by this.....
"I'm assuming with a vortec motor you wouldn't be able to fuel that much hp"

Our Tucson associate said he spent $3200 for his EFI system. To each his own, but to me, that is unacceptable. You have to remember though, I'm CHEAP.

how do people offroad those motors then? Are the pre vortec blocks better?

Tech, I said I spend $3800, not $3200 on the FI......but then, it's a $100K vehicle.

I also agree with you that a properly setup Q Jet is fine for most vehicles that are driven street and off road.....anything but an old AFB!!!

I have used Holleys off road but they had terrible float problems in the whoops (center hung floats). The nice thing about FI is that it is always adjusted.....at our house (2750 ft), we can go to 9000 ft in less than 20 miles.

mike in tucson