ursus

Actually your reasoning should be the other way around.

What is the really good reason you want to change and what do you hope to gain, can you gain that and what is the cost and is it worth it. Im not saying efi is better I would give you same advice if you were thinking of switching from carb to efi.

I bot a 502 long block to replace the tired 330hp I had and stumbled accross a complete efi from a 1999 502mag included: plennum,manifold,fuelrail/injectors/distributer/coil/ecu/fuelpump/sensors and wires for about $700, you can find efi systems for around this price and less depending on completeness. This was the mag efi system and used one season pulled off by someone who went to a blower/carb msd ignition.

I wouldn't have bothered with the 7.4 mpi but a hot roder might be interested and who knows on ebay . I was originally planning to go carb but I couldn't have bot a manifold/carb fuel pump and ignition for that price and it was bolt on and turn the key.

P.S. and I did, bolt on turn key and spent every weekend and several weeks on the water this summer without problems/headaches, setting up, tinkering etc etc and thats worth a lot to me, more than 3 mph

ursus

An afterthot, the increased fuel economy I saw was more likely due to the change in comp ratio, 8:1 with the 330 to 8.8:1 with the 502 than the carb/efi

DonMan

The MAIN reason I would like to swap to a carb is, I am planning on doing several different upgrades, both large and small over the winter and perhaps on into next season. With the EFI you must recalibrate the ECM each time you change something. I am very familiar with carbs, not that educated on EFI. My ultimate goal is to build a much larger, more powerful engine when this 7.4 gets tired. So I will definately be switching to carb at that time anyway.
As far as costs, I have estimated that I will need about $600 to swap from injection to carb, all new parts. I am hopeful that I can get somewhere near that for my MPI. So the actual cost would be minimal. THis is my initial plan, I think it`s going to work out......

Intolerant1

EFI goes bad and so does a piston or worse/. Carb goes bad and you can usually diagnose yourself and fix as well as limp home.

crmax

I was also thinking about going to a carb on my 7.4 mpi, can any of the ignition system be reused? or is it taking info from the fuel injection?

turbo2256

Have you guys ever thought about throttle body FI. Seems to me its the best of both worlds if you aquire one thats adjustable enough.

ursus

The efi ignition is run by the putr which needs all the sensors, map,mat, knock, water temp etc, if you go to carb you will need a tbolt 4 or 5 ignition distributor/coil/ign amp/wireing harness

Whiteknuckle

My .02 is to run what you have right now. I guarantee you will be very disappointed in the gains by changing to a carb. If your ultimate goal is a much more powerful engine in the future, why not run and enjoy your very reliable 310 HP fuelie, and take the money that you would spend on the carb conversion and start building the big, powerful replacement engine. Why not just go through this one time. You can get good performance out of the base 454's but it takes some effort and careful selection of components. My suggestion is buy a 502 long block, put it in your garage and build what you want. Leave the injection on the 310.
Good luck which ever way you go.

cleary73

Does anyone have a cutler mpfi unit for a BBC with rectangular port heads for sale out there? Thanks RC

articfriends

iTrader: (1)

turbojack had one last week,Smitty