Sign in to follow this  
Followers 0
Futzin'

EFI vs. Carb

Fuel Injection vs. Carburetor   48 members have voted

  1. 1. What is your preference?

    • Fuel Injection
      41
    • Carb'd
      6
    • Don't Care / It's a Push
      1

Please sign in or register to vote in this poll.

9 posts in this topic

What is your preference?  New(ish) technology vs. old school . . .. .

I prefer FI; hit the key and go.

Share this post


Link to post
Share on other sites

EFI's ability to adjust fuel mixture to accommodate changes in atmospheric conditions improves both drive-ability and longevity. Carb jets are fixed and represent a baseline average for a particular application based on a theoretical air/fuel ratio irrespective of changes in barometric pressure, temperature, or engine heat. As a result, engine builders need to take a conservative approach to both fuel curves and timing maps running a given engine slightly richer than necessary. EFI's have become extremely reliable and comparing a new EFI to a vintage carb motor does not make much sense anymore as these engines are becoming a rare breed. The newer carb versions are true mixes of old and new as they have electronically controlled idle and cold start circuity and the timing maps are monitored and adjusted by temperature, and limited by knock sensors. The old carb boys may hate the ECM's but they snuck in and are here to stay.  Cy, I may still have a few points and condensers laying around if you want to convert.  Ha...   W

Share this post


Link to post
Share on other sites

 I am solid state now.  Magnetos. The most solid ignition in history. 

Trouble shooting is very difficult with out a hand held reader to collect all the component failure codes.

Share this post


Link to post
Share on other sites

Just moved from carbed Mercruiser to MPI.  No contest. EFI hands down.  Doubly so for 2 stroke snowmobiles. 

No warm up on the lift, just turn key and back out.

Share this post


Link to post
Share on other sites

I'd say it's a bit of a wash to me, but I've also not owned a FI boat.  Comparing the Vortec 350 L31 in my boat, with a carb, to the identical engine (both are 1996 engines) in my truck with MPI, the truck is less temperamental to start.  Beyond that, I can't tell a difference when they're running.  I was able to rebuild the whole fuel system on my boat myself, for a hundred deer, but it had cost a thousand for a new set of fuel injectors for the truck, and the pumps are about six hundred deer apiece in the truck installed.  The fuel pump on the boat is a Summit Racing marine pump that was like fifty deer and runs the boat flawlessly.

It took me a bit to get used to what this carb likes for starting, both cold and hot, but now that I know it it's extremely consistent.  I will say, it's not as mindless as the truck.  It's funny, too, because the Chap this boat replaced had a carb, as well, and it needed a different starting process.  Again, though, once started, it was as consistent as any engine I've ever owned.

Share this post


Link to post
Share on other sites
1 hour ago, jmiska said:

I'd say it's a bit of a wash to me, but I've also not owned a FI boat.  Comparing the Vortec 350 L31 in my boat, with a carb, to the identical engine (both are 1996 engines) in my truck with MPI, the truck is less temperamental to start.  Beyond that, I can't tell a difference when they're running.  I was able to rebuild the whole fuel system on my boat myself, for a hundred deer, but it had cost a thousand for a new set of fuel injectors for the truck, and the pumps are about six hundred deer apiece in the truck installed.  The fuel pump on the boat is a Summit Racing marine pump that was like fifty deer and runs the boat flawlessly.

It took me a bit to get used to what this carb likes for starting, both cold and hot, but now that I know it it's extremely consistent.  I will say, it's not as mindless as the truck.  It's funny, too, because the Chap this boat replaced had a carb, as well, and it needed a different starting process.  Again, though, once started, it was as consistent as any engine I've ever owned.

Huge differences between a FI system from 20 years ago, and an ECM controlled MPFI systems offered today.

Share this post


Link to post
Share on other sites
9 hours ago, Wingnut said:

Huge differences between a FI system from 20 years ago, and an ECM controlled MPFI systems offered today.

If you're talking the newer automotive direct injection systems, I'd agree.  Otherwise, I disagree with the "huge" part of your statement.  The system on the L31 of 20 years ago was an ECM controlled, MPFI system that architecturally is still rather modern (certainly enough for comparison purposes in this discussion).  It used all the same sensor input data that current systems use, and a central ECM to control fuel delivery to each port.  One area in which the system would be outdated was the injector technology itself. The original injector set on that truck was poppet valve controlled.  That had reliability problems, and GM offered a more modern Bosch electronic conversion kit that changed it to the same type of injectors used on the later engines. I've put that kit on the truck.  Having owned that truck concurrently with the much newer 5.3L Vortec for over ten years, I can honestly say there is no real, noticeable, functional difference between the two engines.  One or two MPG, perhaps, which could be attributed to better aerodynamics of the newer truck, and maybe a slight bump in horsepower, but that could be better head and exhaust manifold designs as well.

I go back to my original point.  I have two engines of identical basic design, though in very different applications, and each one runs more or less as well as the design of the engine will allow, and neither seems to be limited by the fuel delivery technology used.  Neither seems as though it would be improved for its application by more accurate or precise fuel delivery.  I recognize that when things like pollution requirements are introduced (as in the automotive industry), fuel injection accuracy can't be beat, but for weekend recreational marine applications that we're talking about here, for me, the difference remains a wash and would not really matter to me in choosing my next boat.  Both have some advantages and disadvantages, but neither seem to me like they would sway me either way.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0