Thread: Natural Aspiration vs. Fuel Injection

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I thought I'd renew an (almost) age-old debate. Which is better for a new street rod, fuel injection or carburetion? I'm building a 427 tall block for my '41 Ford Pickup, and although two 4's look good sitting up on top, Fuel injection system can look pretty sweet as well. What can anybody tell me about fuel injection on a 427T? It's not going to go to the track, but it will be built pretty beefy for street legal. Thanks!

I think you're a little confused about this "aspiration" thing, although I want to thank you for using the correct "naturally aspirated" instead of the incorrect "normally aspirated".

Naturally aspirated means a motor breathes by the pressure of the ambient air alone pushing air/fuel mixture past the intake valves. It makes no distinction between carburetor or fuel injection. Both methods are used to naturally aspirate a motor.

A motor can also be aspirated by the use of an air pump such as a supercharger or turbocharger. Then it is no longer aspirated by nature. It is "blown". You can further use a carburetor or fuel injection with the blower to measure air and fuel in the proper proportions to facilitate efficient burning.

Hope this helps.

Last weekend, we drove a road that hit 13,114 ft above sea level. The 350 Chev engine started just the same as it does at home (2650 ft elevation). It never coughed, sputtered or missed; the altitude effected me more than it did the motor. This setup is a GM manifold with injector bungs, an MSD body, and a Mercury Marine controller.

Personally, I will never again own a carbureted motor unless it is a drag-race only engine with a Holley or Holley variant. Otherwise, the driveability of fuel injection has too many advantages. For your motor, there are several options, the Cobra guys have the stack injection setups available. For a more traditional look, there are the MSD body styles that use injector bungs welded into the manifold. For a nice manifold setup, you should be able to do one for $3K-$4K including the computer.....the stack injection will be a couple of grand more for a nice looking setup.

mike in tucson

Naturally aspirated means a motor breathes by the pressure of the ambient air alone pushing air/fuel mixture past the intake valves.

i'm a little tech, I though nat. aspirated was air being sucked in.

Hey! It's good to find you checking in again, Techinspector1!

There's been a serious shortage of wisdom lately. I'm glad to see you showing up to keep guys like me out of trouble.

Jim

I was taught that "Vacuum" was a created word (leaving outerspace aside) to over simplify the process of a high pressure area flowing to a low pressure area, ie the action of the piston traveling down in the cylinder creates a low pressure area, so then anything outside the cylinder is a higher pressure and flows into it.

Originally Posted by Littleport22

I thought I'd renew an (almost) age-old debate. Which is better for a new street rod, fuel injection or carburetion? I'm building a 427 tall block for my '41 Ford Pickup, and although two 4's look good sitting up on top, Fuel injection system can look pretty sweet as well. What can anybody tell me about fuel injection on a 427T? It's not going to go to the track, but it will be built pretty beefy for street legal. Thanks!

The fuel injection is great for tune-ability, but it is a lot more money.Even with a rad. cam they will start better and idle a little better.On the dyno I doubt you will see much of a hp. gain.The last one I priced out was 5K from a company called Force fuel injection.Yes,it was very trick but with the thousands of dollars saved you could install a blower.

holley made a really cool setup for a few years that might be a little difficult to find but you still can, its a fuel injection system with a blower built right on top of it, they made were a good system but they didn't sell too well... one of my buddies happened to pick one up for his 427 and that thing roars

Thanks for clearing the aspiration deal up Tech. I love to learn. As much as I may know about the guts of a motor, I'm a little lacking in the carburetor and transmission department.

I'm not too worried about price because this is a truck that will never be sold. I never thought much about the blower or supercharger option. That's something to consider as well.