A Stupid Engine Management Question

[Anonymous]

I know this sounds dumb, but I've been asked 3 times last week.

Can you convert a modern EFI engine to carbs with out changing the entire engine management computer system?
They want to run carbs and keep the stock ignition system.

The three engines are:
LS1, wants to run 4 webers..........'35 Ford Coupe
Navigator 5.4 Triton with 4V heads, sheet metal tunnel ram...'32 Ford rdstr
5.4 Triton with 2V heads, wants to run a B&M 250 blower....'40 Ford sedan

I told them they would have to use some thing like a SDS system that was a dedicated ingition system.
But now I'm not so sure.
Any thoughts?

They want the look and feel of real carbs on thier Hot Rods :roll:

John

 

[rbohm]

8) all three engines will need a crank trigger ignition system to tell the coil packs when to fire.

 

[Anonymous]

I thought that was what they have now?

John

 

[Anonymous]

They do..but the computer changes the ignition timing....the crank trigger sends a signal to the ECM to tell the ECM where the engine is at and how fast its going....then with all the other parameters like engine temp, air temp and etc. it detemines when the coil packs should fire the spark plug.

So it wouldbe kinda dificult.....i think if you wanna use carbs on a perfectly good engine, then your kinda defeating the point using a EFI motor to begin with....might s well go and get yourself an engine made for the carb....a cheaper one at that...

But i think a fuel injected 5.4 with the supercharger off of a Ford Lightning would be pretty sweet in a '32 Ford roadster orf a '40 Ford sedan.

You can get high performance parts for those 5.4's and lots of performance parts for the LS-1...

 

[rbohm]

8) i guess i should have said that when you change from efi to carbs, you are changing th entire fuel management system. unless you install a throttle position sensor on the carb's, you need to get rid of the efi system completely as it no longer has the right signals for adjusting ignition timing. thus the need for a new ignition system. and since the 5.4 never had a dist in the first place, you have to use a crank trigger system from msd or holley, or other ignition manufacturer. the other problem is it will have to be adapted to the engine, which means more fabricating.

 

[Anonymous]

OK, so I was right when I told them to look at a SDS (Simple Digital Systems) stand alone ingnition system.

This isn't my idea, I wish I had that kind of money to throw around!

John