EFI vs. Stack fuel injection system

Wondering if someone can tell me the difference between a factory EFI set up and one like the stack system shown at the below URL. Benefits of one over the other. Principles behind how the stack work vs EFI. Any other bits of info you might think of to throw in there.

Thanks,


http://www.verycoolparts.com/Stack.htm

I don't know much about the stack other than what is on that page, but I'm a big fan of factory EFI for the following reasons:
1) you can walk into any parts store and buy parts for it.
2) the cost of doing the conversion is less that 1/3 of the cost of the stack(I'm only into my EFI conversion about $5-600, just say $1000 if you want to do it really nice)
3) there is tons of aftermarket/tuning support for Stock EFI
4) you can pull into any shop and have them plug the scanner in and tell you what's wrong
I'm sure there's more.....

My questions on the stack system would be:
How is it controlled?
What are the details on its air fuel monitoring/controls, etc?
I'm not sure how it does all the necessary things needed to properly control a fuel injection system.
Or is it just a direct bolt in replacement for a stock EFI setup?

Good;

looks really cool (great for show car)
air flow support to 9000 rpm

Bad;
really exspensive
air cleaner? how
MAF sensor? probally have to use speed density
short runners/huge throttle opening - no low end torque

jjwtwice said:

Wondering if someone can tell me the difference between a factory EFI set up and one like the stack system shown at the below URL. Benefits of one over the other. Principles behind how the stack work vs EFI. Any other bits of info you might think of to throw in there.

Thanks,


http://www.verycoolparts.com/Stack.htm

Click to expand...

THE PRICETAG! OUCH!

I'm very likely to use the factory set up. For all of the reasons mentioned above I think it's the way to go.

I'm just looking around at what else is available and trying to learn what the differences are. This is why I ask the questions here, there is such a wealth of knowledge.

Your right, I can think of better ways to spend $6K on my Bronco.

that's an apples to steak comparison.

Broncobowsher - I was hoping you might jump in. I'm assuming by your response that it might take too long to explain? Can you break it down into a few simple bullet points.

We used stack injection on drag cars back in the 60s , they are a constant flow pump with barrel valve co-ordinated with the butterflys with adjustable linkage . A bypass metering jet controlled the A/F mixture as did the port nozzles and the spool inside the barrel valve . No electronics ! Very simple in theory and tuning -However- I don't think it would be worth a dime on a trail rig . I do have a friend with a sprint car style Hilborn stack on 30 % Nitro and 70 % methanol mix , he has this on a 406 SBC in a rear engined sand rail and it will haul the mail but is not for everyone .

Stock EFI
Set up for daily driver type use.
Fuel economy
matched to a mild cam
choke up at high RPM
Single throttle body, all flow is even between all cylinders (or close enough)

That EFI is still computer controlled, but has the appearance of the old school hilborn stacks. The large bore short runner (much shorter then Ford EFI) is better tuned for high RPM power. It starts making power after the Ford EFI has already run out. Those 8 throttle butterflies need to be balanced for airflow. Low speed drivability will suffer for a number of reasons. The big one is the cam needed to get the engine into the powerband needed for those stacks to flow will not run that good at low speeds. Another is that much throttle butterfly is difficult to regulate small changes in airflow.

http://www.morrisonmotorsport.com/enter.html (there website is down at the moment, but this should work later) is the same idea as the stack EFI manifolds. Super workmanship. IF I was doing a road racer where the engine spent all day between 5000 and 9000 RPM one of these manifolds would be the only way to go.

Simply put and engine to run good has to have matching parts. Mismatch and it will run bad, get horrible economy, pathatic power. While it is EFI, it is like claiming a Dominator carb is the same as a normal 4 barrel. You just can't mix parts that are that for off balance from there intended application and expect good results.

Thanks, Good information.