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m50

It seems to me there is no easy answer some like em, some don't. How about we look at it this way if I found a boat that was everything that I thought I needed but it had carbs on it would you not buy a boat just because it had carbs? Or on the other hand would you not buy a boat just because it was F.I. ?
Thanks RB

MichiMike

Didn't really matter for me,except if it was EFI it would of been 500 blue motor.Wound up with carbs and a blue motor they are great.

14 apache

iTrader: (1)

I would buy either one.

ThisIsLivin

I have a carb and I've done EFI. In the long run the carb has fewer parts and will require less service. On a stock cam motor it is hard to tell the difference between the 2. The new HP Holleys are really tunable you just have to know how to do it. I have a fairly radical cam and I'm running a carb, for the most part it's flawless, I can idle for an hour, get to open water and tromp on it. It's real weak point is trying to maneuver at idle in strong cross winds or currents. It has to idle at 950 rpm to get it to 600 in gear and with a big cam, it's loping pretty good. For me even self tuning is out, because they need 9 inches of vacuum in gear to learn the idle. I'm looking at the FAST EZ-EFI 2.0 for my next motor. It has the benefits of a carb in that you are introducing the fuel upstream to cool the charge and improve fuel atomization. But I can't use the self learn function, I have to do an open loop system. I don't know about anyone else but dumping a bunch of fuel on the backside of the intake and hoping the inrush of air will provide even fuel distribution and atomization doesn't sound optimal. I know it works, it's just when you are looking for every last hp, I look for other solutions. I have seen dyno tests with Fast EZ_EFI 2.0 and it out performed a Holley HP. That is the only time I have seen and EFI system produce more horsepower than a Carb. Cold running and idle is certainly better than a carb and for a lot of people that's worth it. You can also get a lot tighter control on your AFR with EFI. I put an Edelbrock EFI system on a small block Chevy with a Victor Jr intake and everything improved over the stock carb and dual plane intake. The best part I was able to lean out the cruise and add timing to improve fuel economy by 50%. I would do a search on EFI for Everyone, there is a lot of good information there.

hogie roll

The cooling effect the carb provides won't be realized with fuel injection no matter where the fuel is introduced. I think efi systems preheat the fuel to much, or the fuel isn't undergoing phase change in the same location. It's a bit of a mystery, as I've never seen a test where they tried to control IAT on an EFI system by cooling the fuel somehow. Now that would be interesting.

I have not seen a carb vs injection comparo with injectors above stacks. But on normal intakes and tunnel rams the carbs have made more in the comparos I've seen.

ezstriper

why do you think a carb has cooling ? fuel bowls sitting on top of the engine...EFI fuel strait from tank...with return system fuel is going to be much cooler than fuel passing thru carb...

m50

There is a lot of good info here!
Thanks guys
RB

ThisIsLivin

The cooling effect takes place when the fuel goes from liquid to vapor. I believe Super Chevy or Engine Masters did a comparison between the Fast EZ-EFI 2 throttle body and an HP Holley, the Fast EFI actually produced more horsepower than the Carb did. It's the first comparison of this type I've seen.

CDShack

M50---if the motors have nothing, consider spending the extra bucks and go EFI. Generally starts better, a little better mileage (but you have a boat....nuf said) seems less prone to bad fuel/storage. There are some really good threads on some of the self learning systems here.

I firmly believe that well setup carbs in the marine environment provide more bang for the buck than EFI, so if the boat HAS carbs, I would leave them and enjoy OR, if motors have nothing, and price is a consideration, carbs (particularly on a twins) is a lot less expensive to acquire and setup. With carbs, spend an hour or two setting them up, and if you never raised the hatch again, you'd be hard pressed to know the difference. I've had both, build both, still run both, and I like them both.

A lot of talk goes on about the theory of carbs/EFI and what you see on a dyno. I've spent hours over dynos, and thousands of hours in boats, and if I'm at the lake, in the sunshine, my beautiful family and friends by my side sipping a cold one, 12.6 AFR vs. 13.1 AFR is pretty much meaningless. Set either up right and go to the lake and enjoy what ya got!!!