Carb to EFI conversion ?
 

I have some 97 carb 454 330 hp motors in my Seray 330 DA, I see people sometimes selling a complete Mercruiser EFI setups on Ebay and this site.
What would be involved in updating my motors to EFI ?
Can it be done ??


Are the cams in stock Carb motors different ? I think the heads have oval ports and rectangular style ports ? I think i have Oval and efi manifolds are Rectangle ? Could I bolt this intake to my heads and use the oval gaskets and get a proper sealing ?? Thanks for your response..... Davepnola

Lots of work for little benefit in your application. Several thousand dollars each as well for complete setups with ECM's. Plus, if you buy it used, you may end up with pieces that have issues that will need to be sorted out.

You could do a conversion using something like the Accel DFI or the MSD system. They use a throttle plate/injector body that replaces the carburetor. You really won't save any money though. I figure by the time you're done buying parts, modifying components and having a marine EFI tech map the ECM's for you, you'll be about 8 grand deep on a pair. Maybe more.

That would buy alot of carburetors and rebuilds.

I have to agree it would be a lot of work. Not sure if there would be any gains.
I do have a complete 502 mpi fuel injection set up for sale. Make offer. Its off an 01 motor with rectangle ports. If you are interested send me an email and I can send pictures.

What if he used an EFI setup for an oval port motor. The only way it would benafit is the ease of fuel injection. Doubt there would be a performace gain.

The 330 isn't really a good candidate for performance gains. At least any noticeable gains. If you went up by 50 HP per, I think all you'd really notice would be a minor bump in midrange and a mile or two on top. That would take cams and some other work. More power than that and you'd be over-stressing that low-po bottom end.

The EFI will give you a bit better midrange cruising economy and most likely more trouble-free operation. The downside is that EFI isn't bulletproof and when it does fail, it takes alot more time and $$ to get back working than carbs do. You'd also have to cruise around the world sebveral times to recoup the fuel savings. ;)

This could be a deal for someone looking to convert. The Kinsler stuff is first-class.

http://www.offshoreonlyclassifieds.c...-o8143-en.html

I could do the install my self and diagnose it if needed. My concern is not performance but Safety with carb motors . Fuel injection is more of a closed fuel system . Did they make EFI motors with the oval ports. Look at this setup. http://cgi.ebay.com/ebaymotors/ws/eB...244450805&rd=1 would this work . My boat came with the Efi option my year , I just do not have it and would rather the efi setup.

Efi Rocks
 

Running EFI on my 572's with AZSM throttle bodies - its not cheap but either is gas. I think you can save in the long run

All the 454 mag, 502 mag intakes that are that style, are square port. If you are heart set on it, you will need one off of a 454 EFI. The throtle body (if you are looking at it from the top) will be off the center of the right side. All the mag's are off of the front like you have pictured. The picture below is the system you will need.

These are square port.

So can I bolt the square up to oval port ?? Get it to seal with the square gaskets ??

They'll bolt up but you're going to have flow problems. You essentially will have smooth flow right up until it hits that big step on all four corners. The oval is quite a bit smaller than the rectangle port, both shorter and narrower. Who knows if it will flow and how well.

You're going to have to possess some fabrication skills and the equipment to do it. It's more than a device that fits on top of your engine and is generic in application You're also going to have to get a laptop and programming software. This isn't anywhere near as easy as bolting something on.

This is what i took off. Fuel injection is great on stock. When you start making mods, Carb is a lot easier to tune. I've seen the same set up on the 454 MPI. A friend had one in a Baja 24 Outlaw. Not sure about the ports, oval or rectangle though.

I think that if the square are bigger it should work and seal.
Once again I not worried about major hp gains. My motors are 330 hp factory. I think the EFI version are the same 330 . I think though the camshaft would have different specs than the carb cams, though the ECM with sensors hooked up should be able to compensate for the small difference. Now if I were to use the Blue manifolds 502 hp setup, that would be a different story in tuning. My guess is the parameters in the mapping of the chip would be the difference and the CFM of th intake and runners would be larger. Does someone have spec book on the efi engines ??

Safety?????

You said they are 1997 engines. They have been fine for 10+ years.

Seriously, As long as they have the flame arrestors and the carbs are not leaking, they will be fine.

Ok I am looking for this type pf EFI take intake setups ?? Please let me know if anyone has these from upgraded motors . Thanks http://www.offshoreonly.com/forums/a...1&d=1209415296

I have done this same mod to my 84 scarab last winter when I redid my motors and let me tell you it was the best money I have ever spent, turn key and starts every time, it kills the motor when it gets hot and loses oil pressure. I did an hp500 cam and exhaust and a few other mods and I just to sent my computers to Hardin marine and told them what I did and they flashed my computers and then I was on my to trouble free boating. Oh by the way the 502 and 454 setups are the same except for the programing on the computer even the injector flows are the same.

http://i29.photobucket.com/albums/c2...o/DSCF1223.jpg