Adding fuel injection
 

Have a crate 502 engine with a holley carb. in my formula boat. I've been told that I can change the engine to fuel injection. Is this correct? How is it done and what does it cost? Thanks.

Check out Edelbrock's site

http://www.edelbrock.com/automotive_...xt_chevy.shtml

Anything is possible for a price. You could just use a complete 502mpi sustem and have the ECM calibrated for your engine. There are also many aftermarket EFI systems.

Mpi
 

I will have a completed 502 Mag MPI set up for sale in about a month. The intake has had the short runner conversion and has been extrude honed by ASM. New Mefi 4 computer, new MSD distritutor, compelete with all sensors, injectors and throtle body. Unit has been powdercoated a transpent purple.

you would have to want injection real bad to spend what it's going to cost and what you really are going to gain...not even close in my opinion...Rob

I have the Holley MPI kit, prepare to spend $4k if you do it yourself. You can get the kit itself for about $3k, but there is a bunch of stuff that came with the kit that I had to upgrade right away. If you go that route let me know and I can give you some tips. Or you could find a used merc setup. If it is not stock you will have to have the PCM reflashed.

I just intalled a used Merc Mpi set up on my port engine (carbed 502). It went on easily and once I got everything hooked up right it started right up. Set the timing, good to go. I have put about 4 hours of run time with no problems.

I have instant starts, great throttle response, and a solid idle in gear or not. I can't say that for the engine that still has the carb on it.

The cool part is being able to run twin engines with one carbed and the other EFI. According to the floscan, the injected motor is burning 16gph at cruise and the carbed unit is burning 20 gph. That's huge! I was hoping for maybe 10%.

If you shop around you can find a complete used set up for less than a grand. I paid a mechanic to do the actual install because I can't crawl around on the engines like I used to. I did do the final electrical and fuel connections though.

I am very happy with the results, and I would highly recomend it. We just started converting the other side lastnight. Hopefully it will go as smoothly as the first one.

Steve H

Fuel injection is well worth the effort and in the end what cost difference there is is worth it. I'll never build a carb motor again. Keep in mind you wont get huge performance but it is very respectable and the reliability, economy and ease of service more then make up for it. Complete Merc take offs are not that hard to find these days at a decent price. Heck theres even some good deals on 500EFI stuff if you shop around enough.

Something you might consider, http://www.compperformancegroupstore...Category_Code=

something to also keep in mind with aftermarket fuel injection is service parts availability. When i did mine it was based on all GM/Delco parts so as to never be stranded waiting for the UPS truck to arrive. Any part i needed was locally obtainable at a dealership same would go for using a complete Merc system. :cool:

Wow, I bet you get some head scratches when you pop your hatch. :eek: Do you have to give one more throtle than the other? Does one pull more RPM than the other at WOT? I assume you will be looking for a deal on another setup. I converted from a carb to MPI about 4 years ago. I like the easy starts and better performance. It made the boat much quicker but only about 1MPH gain in speed.

The engines are under the floor, so I don't pop the hatch unless needed. The injected engine defintely takes less throttle. The injected side is more powerful than it was by a small margin. I think that I will gain a mile an hour or two. Top speed was 50 mph if loaded light on fuel. Maybe 52 now? We'll see.
I already have the other side half done now. Just missing a few sensors, so I'm off to NAPA.

Steve