5.7 4bbl to MPi or TBi, a project for the winter.

Hi Guys,

On my list of winter projects is to convert my current carbed engine to a more efficient fuel injection system with ecu etc. I work in engine management systems and will be able to datalog engine performance and produce custom software to match but I need to know if there is an oem injection system that will bolt straight to my engine or if I need to build one.

Engine is 5.7 vortec with est ignition and edelbrock 1409 4bbl.

If there is an oem or aftermarket kit that will fit can anyone point me in the direction of where to buy?

Best wishes,


Stan

Re: 5.7 4bbl to MPi or TBi, a project for the winter.

Holley has some TBI set-ups you might like. Its going to set you back in excess of $1,000. Selling the Carb will get a few hundred back but I tend to keep take-off stuff in case I feel the need to go back. Otherwise its hit or miss with automotive stuff. The Holley comes as a marine kit with everything you need.

Re: 5.7 4bbl to MPi or TBi, a project for the winter.

Bubba1235 said:

"to a more efficient fuel injection system"

Umm, easier starting perhaps but you will not see a measurable increase in efficency over a properly tuned carb.

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which is a can of worms in itself. best way to tune is under load. kinda goofy trying to do this on the water and not drop something in the drink on accident. drop a jet on the ground and you just get on your knees and look for it. not so much fun on the water.

hook a laptop up to the diagnostic port on the ecu and tune away.

OP says he works in the engine management field. surprised he doesnt know about megasquirt and VE analyzer?

Re: 5.7 4bbl to MPi or TBi, a project for the winter.

Thanks for all the positive and helpful responses folks, I think the safest way is to go the all new parts route... it's just trying to find a kit that is available off the shelf... the holley TBi kits seem a bit too simple... from a bit more research I think I will go MPi or TPi for the best results. I am considering this - http://www.affordable-fuel-injection.com/ixxocart/products/Chevrolet_Marine_MPFI_System-25-41.html

stackz said:

OP says he works in the engine management field. surprised he doesnt know about megasquirt and VE analyzer?

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Don't know why this comment is even relevant... a bit of a pointless brain fart if you ask me....

I live in Scotland, there are very few cars here with these engines... Most of our work is VAG group, BMW, Mercedes etc

Re: 5.7 4bbl to MPi or TBi, a project for the winter.

I believe that fuel injection system has been discussed here at iBoats in the past. Hopefully, searching will find some pertinent tech info, outside of any fuel savings will never pay for the cost. Good luck, and please post back with your experience and info. Even us carb guys, appreciate the work that goes into a project like this.

Re: 5.7 4bbl to MPi or TBi, a project for the winter.

OUCH.... $2,500.00 to start easier and maybe improve fuel consumption!

B.O.A.T. Break Out Another Thousand.....

Good luck, let us know how it works out!

Re: 5.7 4bbl to MPi or TBi, a project for the winter.

stant1man said:

Thanks for all the positive and helpful responses folks, I think the safest way is to go the all new parts route... it's just trying to find a kit that is available off the shelf... the holley TBi kits seem a bit too simple... from a bit more research I think I will go MPi or TPi for the best results. I am considering this - http://www.affordable-fuel-injection.com/ixxocart/products/Chevrolet_Marine_MPFI_System-25-41.html

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kind of funny how tossed together that kit looks for the price. looks like they just grabbed a thunderbolt distributor, a holley fuelie manifold and a 727/730 series ecu and tossed in some "you cut to length" pigtails and a map sensor.

it really does look like the 727/730(NA engines)/749(turbo) series ecu. GM used it in ALL kinds of engines in the early 90's. if its not actually one of those ecu's then they are at least using the case from one and maybe filled it with megasquirt components. they all have the same primary part number (8 digits ending in 727/730 or 749) and then a secondary number that breaks to the engine size/chip tune. lots of info out there on those. I havent had personal experience with it yet but the thunderbolt distributor is the marine GM distributor that works with an EFI setup. there are diagrams on here regarding it.

If you want to try a cheap OEM used setup to cobble together would be to either rob a TBI setup off an early 90's truck (ecu will be inside the cab behind the glove box door, just pop out the glovebox and there it is on the right jammed in there). Or if you want multiport, grab a tuned port setup from a camaro or corvette. they are dated now and getting super cheap on ebay complete but still very nice. only concerns would possibly be regarding using automotive efi setups in marine applications is making sure you have a marine distributor (kinda weird though since efi virtually eliminates the fume buildup carbs deal with) and proper sealing of the ecu against moisture. and yes, the 727/730 series is based on MAP sensor readings so no mass air sensor to deal with.

http://www.edgesz28.com/edgesz28/suburban/tuning/suburban-tuning.htm#diyintro

in the end though, might not matter if you cant get it working with the thunderbolt distributor...unless its ok to run the auto distributor with the efi setup.

Don't know why this comment is even relevant... a bit of a pointless brain fart if you ask me....

I live in Scotland, there are very few cars here with these engines... Most of our work is VAG group, BMW, Mercedes etc

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didnt mean to sound bad just I find it hard to believe though that there arent plenty of car nuts in scotland who have started running megasquirt in their cars though...and you being in the industry I just assumed you'd hear through the grapevine about it is all.

http://www.megasquirt.info/

very cheap, very very versatile systems. and now you really dont even need to tune them anymore. they VE analyzer software pretty much tunes the engine for you.

http://www.efianalytics.com/TunerStudio/#veAnalyze

Re: 5.7 4bbl to MPi or TBi, a project for the winter.

Stan,
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