Conversion from Carb to Injection

[I Roll]

I've been contemplating the benefit (and the cost) of converting my engine to fuel injection. I've got a 454 with a Holley 750. Some folks I've spoken to feel that the biggest benefits would be the ability to run regular fuel versus super and also have improved economy. Sounds plausable to me but even if I can source all used parts I expect that the cost would be over $1,000. Not sure it's worth it.

Has anyone converted their 454 from a carburated intake system to FI? I'd be interested to know more about the upside (or downside) and the cost. Would there really be any gain in economy or power using lower octane fuel? If so, is it worth the cost?

 

[Anonymous]

It really comes down to the power level, and what you consider a good investment. If it's a easy conversion AKA factory changeover. the money is low, and the torque/throttle response/fuel economy give awesome returns. Also, if you are running a max-effort engine that see's double duty as a ride boat..Also another great return, but at a much higher expence due to the hardware required (But being someone building a BIG/Expensive powerplant, this tends to fall in line with the overall package). But if you're somewhere in the middle, it will take some research to make the decision. Cheap EFI only comes at low power levels, and big power levels (at this time in the DFI world) aren't so cheap.

So, I would say, if you're running a big block (let's say in the 550-700HP range), and looking to build a more high-tech boat, that has the potential to have the best of all worlds..Spend the scratch and get a good EFI. But if you're running 400-550, and someone who likes things simple, stick with a carb. If you have a smallblock that is either DD or making under 400HP....I would look into a factory EFI conversion, and also if you run supercharged or turbocharged....It's pretty much a no-brainer, unless you buy a proven package that works carbureted.

Both can acheive good results, and many shops other than mine offer these services. It comes down to service/support. If you like to do things for yourself, stick with the carb (If you knew enough about DFI I would assume you wouldn't have made this post, and considering cost-effectiveness being an issue, I wouldn't suspect you care to do a full blown R+D program to learn the ropes)

Examples of a "bottom line"....1 If fuel economy is a concern, and the cost of the system is cheap. money well spent. If the cost of the system is high...Consider money saved in fuel vs your initial investment. 2 If the power level is high, and the ease of maintaining that power level are easier, nevermind the cost of broken parts, then it's a no-brainer.

EFI in the proper hands is awesome. It gives complete control across the spectrum of load and RPM. A well designed EFI package is a win/win no matter how you look at it. But you have to know what you're doing with it.

Last and not least by any means.....The assumption that EFI allows higher compression is a falacy. In a way it's true if compared to a poorly tuned carb. In reality.....About the same time that you saw factory compressions rise, you saw EFI and ALUMINUM cylinder heads, that were actually up to date. The combustion efficiency of a modern OEM engine has much more to do with cylinder heads, and the overall engine design than the fuel injection that gets all the praise. And feel free to quote me on that.

Sorry if I missed many people's application, and I hope, I didn't talk in circles, and at least gave you some reasonable direction.

Felber

 

[I Roll]

Thanks for the information. My engine is crate 454, nothing special. It's supposed to produce 425 hp. No work has been done in terms of modifications or performance improvements. Just standard stuff. It's not working overtime as a tour boat, I just use it for fishing, pleasure and some occasional hunting. I'm putting around 100 hours a year on it.

I wouldn't expect to save more than a couple of hundred a year on fuel so I don't expect the difference between regular gas and premium to pay for the upgrade. The most I'd expect is some savings on fuel as sort of a bonus.

You mentioned that a factory changeover may be somewhat inexpensive and that the torque/throttle response/fuel economy would provide awesome returns. What should a "good" EFI system cost?