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Has anyone had really good success switching from carbs to fuel injection?  What brand/system did you go with?  What should I be aware of and be on the lookout for?  Any information/experience (good or bad) would be greatly appreciated.  Oh, and the REAL cost when it was all said and done.

Thank you in advance.

Fuzz

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I switched to sequential port fuel injection when I had my Fontana block stroker engine built ten years ago. The system is the FAST XFI 2.05 and it works great. In addition to eliminating carb boil over and issues with elevation changes, what would have been a 12 to 14 mpg engine is now an 18 to 20 mpg engine. It is 390 cubic inches and is making about 550 horsepower at the flywheel. As for cost, I have about $3000.00 in the system, so it will never pay for itself considering how much I actually drive my Pantera. There are simple throttle body systems that cost much less and also do a very good job. The aftermarket fuel injection systems have come a long way and are much better now than they were when they first came out. These systems are getting very popular, so there are a good number of shops that can install and tune them.

I had the Holley throttle body system installed when restoring and modifying my car several years ago.  The good points were that the car would start with a simple turn of the key for the first time in 20 years and the gas mileage was significantly improved.  However, once the car got warm (not hot or overheating) it would vapor lock or at least that's what it felt like, and would leave me in some very dangerous situations.  I would sit there for 15-20 minutes while the system cooled and then could restart and drive away.  But it was terrifying while stuck in dangerous intersections etc.  I had two different mechanics and two shops, both of whom have done a lot of work for me over many years, try and diagnose the issue, install heat shields, wrap fuel lines etc. but it continued to happen.  Holley was no help as they haven't answered their phones since the pandemic began, so there was no technical support.  I wanted to drive the car, so we removed the unit and installed an Edelbrock carb, and I've had no problems whatsoever in the three years since.  Only negative is the gas mileage is about half of what it was.  I have the Holley system sitting in a little box in my garage to someday be revisited, but after 25 years of ownership where I couldn't drive the darned car for most of it, I'm too busy making up for lost time, driving it every single weekend.  I'm not gettin' any younger.  An additional note, when I was visiting P.I.M. one day, I spoke with Jerry, and he told me he has removed fuel injection systems from so many Panteras, he can't even count them anymore, although there are many on this forum who report theirs working great.  This was simply my experience.

When I recently built my 404 stroked cleveland, I opted to retain a blue printed Holley carburetor.

My previous engine also used a Holley carburetor and gave me 50,000 miles of trouble free driving

Seems I hear more tales of difficulty tuning an EFI conversion than I ever hear about tuning a carburetor.

there are some drivability improvements with an EFI conversion, but sometimes the price of actually achieving them requires month after month of efforts to fully dial in the optimal EFI program.

kind of comes down to ……if it ain’t broke, why try to fix it?

Ny 2¢

Larry

Dear Fuzz,

          I have had very good luck with custom Holley carbs built by Bob Oliver of Competition Carbs in Reno, Nevada.

          You tell him what you want (650, 750, vac secondaries, double-pumper,etc).  He will ask you for some specific parameters of your engine and your transmission and you intended use.

           You will pay him about $1000.  He will send you a carb that when placed on the engine for dyno testing is usually within one jet size of being optimal for your engine. 

            All of my custom carbs have been markedly better than off the shelf carbs that required constant fiddling and provided chronic disappointment.

                        Warmest regards, Chuck Engles

I also use a Bob Oliver 700 double pumper Holley and am satisfied with its performance, which surprised me by breaking the rear tires loose in 3rd gear when I did a full-throttle exit of a freeway on-ramp. On a trip to 'Vegas from Carson City NV- a jaunt of some 420 miles, the carb also delivered 21 mpg with frequent triple digits seen on the speedo and no particular effort at mileage.

That said, I probably should have copied Jim Murch's efforts. Jim installed a modified Ford factory EFI system from a 351-W that can be made to fit, itself a copy of an earlier installation done in Sweden by an owner whom I've forgotten, it having happened in the late '80s! Both these cars are still running just fine.

@Fuzz posted:

Wow, this is great information, specifically because my mechanic is recommending the Holley Sniper EFI Self-tuning 550-510K.  After reading what tberg wrote, I am not sure I want to throw away money like that. Which Edelbrock carb did you install?

If you are worried about money, then don't go with EFI. It will never pay for itself on a Pantera because it is doubtful that you will ever drive the car enough. The early aftermarket EFI systems did have problems and when they came out it was very new technology for the aftermarket. In recent years the systems have improved tremendously. There are lots of high horsepower muscle cars that are using aftermarket EFI systems and the owners seem to like them. There are also many more EFI tuners around that actually know how the systems work and can troubleshoot them if necessary. When my 390 cubic inch stroker engine was rebuilt, it was tuned on an engine dyno in 1000 rpm increments when it was hot and cold. I put the engine back in the car and hooked everything up and it runs great. It helps if you have someone that knows what they are doing. FAST makes a nice system monitor which I installed. It tells me everything that is going on with the engine in real time. It also has fault codes that will  be displayed on the screen, so there is no need to hook up a laptop computer to find out what is happening.

Great topic, I've been thinking about going to the Sniper EFI, its self learning and everything I've read seem to say they are amazing and work great.

The Holley Sniper will allow you to use either coil on plug or coil near plug ignition system. It will basically eliminate your spark plug wires. These self learning systems have basic engine tunes, which should be able to get your engine started and running. In my experience what is really needed is to get then engine tuned on a chassis dyno or if the engine is out of the car, then an engine dyno. The number of shops that can do this are increasing because there are lots of older cars that are switching to EFI system.

@jamesolc posted:

Technically they have been running fuel injection in Nascar for the last decade.

Both options work - both have benefits and both have limitations.

The question you need to answer for your car is if you want it to look like a carburetor or not.  Lots of options available - Holley and FiTech are probably the simplest.

I never considered how my system was going to look when I switched over to fuel injection. It came down to how it would make my car run, which after ten years of driving it I am totally satisfied with how well my car runs with it and the gas mileage is great for a 550 plus horsepower car. I can get 17 to 20 mpg on the highway and I doubt that any carb is going to do that for me. Cold starts are great and major changes in altitude don't matter.

@jffr posted:

I never considered how my system was going to look when I switched over to fuel injection. It came down to how it would make my car run, which after ten years of driving it I am totally satisfied with how well my car runs with it and the gas mileage is great for a 550 plus horsepower car. I can get 17 to 20 mpg on the highway and I doubt that any carb is going to do that for me. Cold starts are great and major changes in altitude don't matter.

For the most part, in 2023 all EFI systems provide similar performance and benefits.  There are some folks who prefer a throttle body that looks like a carburetor (ie. the Holley Terminator Stealth) so the car looks "original" while others may not be concerned about it at all.  Ultimately the same gains are there, it's just giving the owner what they want.

Dear Jim,

            Just for the record of carb performance, I calculated my fuel mileage over 1711 miles driving to the Reno Rally.  The engine is 484 hp 351C with a Holley Strip Dominator intake, CR 10:1 ported 4V quench heads, and a custom Holley 4150 double pumper.  The run to Reno included many miles of high speed grand touring driving. 

            The calculated miles per gallon was 18.7 mph.  17-19 mpg can be done---perhaps not often and more often with custom carbs, but it can be done.

                     Warmest regards, Chuck Engles

@cengles posted:

Dear Jim,

            Just for the record of carb performance, I calculated my fuel mileage over 1711 miles driving to the Reno Rally.  The engine is 484 hp 351C with a Holley Strip Dominator intake, CR 10:1 ported 4V quench heads, and a custom Holley 4150 double pumper.  The run to Reno included many miles of high speed grand touring driving.

            The calculated miles per gallon was 18.7 mph.  17-19 mpg can be done---perhaps not often and more often with custom carbs, but it can be done.

                     Warmest regards, Chuck Engles

I doubt that my 550 horsepower 390 cubic inch stroker engine would be able to get more than about 15 mpg with a carb. What I do like is that I can go from sea level to 9000 feet above sea level and never worry about how the car will start or run.  For most Pantera owners the switch over to fuel injection will never pay for itself in increased fuel mileage. The aftermarket fuel injection systems have come a very long way from the time that they were first on the market. Some of them were definitely very bad, but those days are long gone.

So I finally pulled the trigger and bought the new Holley Sniper 2 EFI system.  It is being installed by my mechanic as we speak.  While in there doing the work, I have asked him to get whatever he can off and let's get them cleaned and powder coated to dress up the engine a little bit.  Headers are being ceramic coated too.  Engine block is being painted red, as it was originally when I bought the car.

On a happy side note, Wilwood brakes were built and delivered by SACC Restorations.  Those are powder coated red and should complement the new gold Group IV wheels I purchased from Italy nicely.

I will post photos as the project advances.

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