clive

I have EFI on my Harley and I love it. I wanted to add it to the 400sbc I am doing however the cost difference is huge from what I can tell. I am just at the planning stages of my build and have been trying to compare prices. I am not quite a gearhead and never built a motor so I am not sure yet all the small parts needed for a carb setup that might be included with a EFI example; fuel pump.
I would like to see a part list price comparison so I can be more aware. Oh and where to buy other than Summit.

l88rocket

Efi makes more power easier,better throttle response,the advantage is hands down over a carb.


Then take LSX engine,makes power easier,cheaper to build,don't need high dollar heads,and what not to make the same power.

MotorHead

What's the valve angle on LSX heads ?

big_G

I think it's 15.

427Hotrod

Whew....this one took on a life of it's own!!

Here's my take....EFI is great stuff....I love it on my daily driver stuff. I don't even want to know if there is an engine under there...I want instant starts anytime, no burps or sneezes etc etc.

But I sure like a carb on my Hot Rod toys. Cool is cool.......

If you play around you can get a carb to do pretty decent...

I can't remember when the last time was that I had a Holley PV blow....if you're blowing PV's it ain't the carbs fault..you've got timing issues or it's big time lean for some reason. In fact...can't even remember when I ever had my motor pop back through the carb at all??

Those old Motorcraft carbs actually had fantastic response and ran pretty well. The Holley copy did too..but they sure looked funky!!

So let's see....you use a system with a vacuum signal or a feedback O2 sensor that tells computer how much fuel to send. It gets that info from a table. Someone has to put that table together.....most folks won't spend the time to work out that table. In fact..every EFI guy I know spends more time playing with the tables in the computer than I ever spend messing with a carb. Then they tell you how the EFI instantly tunes for infinite variables. Yes....THEY INFINITELTY TUNE!! What's the difference? You're still constantly tweeking and playing with it...but you're right..no gas smell!!

A well set up carb is an infinitely variable fuel metering device that always responds to ALL the conditions....load, vacuum, heat, altitude etc. Sometimes it operates well out of it's normal range and you have to do something to it..but usually they can do everything pretty well.

Modern OEM EFI setups are a complete package. That includes cams with little to no overlap, incredible flowing heads, higher comperssion, better exhaust, super long runners in many cases and LOTs and LOTS of time tuning those tables. Look at how rotten most late models run at low speeds and idle as soon as you change just the cam. When you move to the stuff that we all like for big power....you're right back to tuning..whether it's carb or EFI.


JIM

Bullshark

Jim.....That post was about as much double talk as I have ever heard come out of your mouth Even after all those Jack's down at CI

Bullshark

Bullshark

Umm.... sounded like a test question Wayne. You aren't challenging l88rocket statements are you I don't have a position on the second comment but he is "right on" with the first. I spent the night at a Holiday Inn so my previous statement about "you guys wore me out" is history.

By the way, was Big_G correct?

Bullshark

427Hotrod

Hey ...just the facts you know???


Different things require different approaches. I personally enjoy watching people walk up to me with watery eyes after sitting behind me at a red light!!

But I *could* throw in a nice little weenie cam and take care of that...NOT!!!


JIM

Bullshark

What chew talkin about Willis

Bullshark

Shark Racer

Go take a look at how the LSX fuel injection system really works.

The PCM is very, VERY intelligent.

There are power modes and cruise modes. There are modes for when you're backing out of throttle or entering throttle. You only need ONE tune, but assuming that tune is done well, it will cover all things well.

Carbs can compensate for these things as well, but to nowhere near the degree that a fuel injection system can.

Two things separate a carb from a FI:
1) Sensitivity (output vs input)
2) Intelligence. Carbs are not.

karioth

i was just saying that what you are comparing isnt really fairly aligned with what we were talking about

Billysvette

From all that has been talked about,it tells me that high tech just isnt worth it,no body has really hit on the cost of these high tech gizmos and parts.The cost out ways old school by far and you really arent getting a MAJOR difference in performance.Thats what i was tring to understand ,why people would spend so much for not a big improvement in hp.I guess it really is just preference,or to be different then the rest.

Bee Jay

I was actually saying that you had a good point. I also did some more old tech to new tech comparisons, just like the title and spirit of the thread. I don't understand what wives have to do with it all. Although when my wife turned 50, I did joke about trading her in for two 25s, but I couldn't handle even one 25. I'll keep her and my '79. I'm not foolin' when it comes to old schoolin'.

cardo0

Mr. Hotrod your comments were right on regarding tunig EFI. My DD is a GEN II LT1 and everything with that EFI costs $300 to improve. Just a hand held scanner for the OBD I is $300. Then the tuning box for the OBD I is $300+. U want a tuning box/scanner combo >>>$300. Now most tuners will opt for a laptop PC for tuning which is $300++ for even a used laptop. U need softeware for the PC tuning also - well this is a break <$300 but u need a custom cable too so $300 here we come again. Higher flow/press injectors - u guessed right = $300. High flow throttle body - again $300. Now a new intake elbow with K&N filter is only $200 - man finally a break. Fuel press reg $$$? Now what is your time worth to verify all you fuel and timing curves let alone install the parts? Yes we do have to make those curves with a carb also but resolution is limited - not so with a laptop and EFI.
IMHO a full EFI upgrade will cost you as much as parts for an entire replacement motor. I would rather spend that cash for a stroker crank, rods, pistons, block, heads and just bolt on a $400 brand spank'n new Demon or Holley carb to have an entire replacement engine ready.

Bullshark i'm sorry to read u see EFI tuning woes as double talk. But u can search here on the forum and easily read plenty of disipointed EFI conversion posts. We see u have had great success with EFI and feel very comfortable using it - but plenty others don't. There is a learning curve for a performance EFI and i congratulate u for achiving good results with yours. IMHO i just cannot recommend a novice to upgrade his C3 to EFI. Not when i can find great carbs for <$300. And really i expect most C3 owners bought a carburated eng for that old tech/somewhat nastolgic attraction. I truley say i didn't buy my carb'ed C3 to upgrade to EFI - i wanted to run a big azz 4 barrel or maybe two.

That's enough of my gass'n for now.
cardo0

Bullshark

cardo.....don't get your shorts all in a bunch I was just pulling 427Hotrods chain. Yep, playing around in this hobby and on this forum is definitely not cheap But I don't think that was the point of this particular thread. The implication was "why go high tech when old school is just as fast" (i.e. good). Better does not come cheap.

Bullshark

By the way, including the cost of a PC was hitting below the belt. Even the old school guys probably have one of those else we couldn't set in front of the TV watching BJ while playing on the forum

427Hotrod

Yep...me and the Bull go way back........way back to the ice chest to mix another Jack Daniels!!

Bullshark has his EFI working great....now if he would just let me talk into some ridiculous cam...I could screw that all up quickly and give him a REAL tuning challenge!!

JIM

Z-man

A big part of it is - Do you like to drive your car, or do you like to fiddle around with it...??

If you are out on a cruise and hundreds of miles from home, do you want to trust your ride to 30 year old parts??

Bullshark

Yeh......I still remember that night when you were "tuning" that carb on the Hampton parking lot between Jacks Now I know how you old school guys get them dialed in so accurate.

Bullshark

bbeck

it's all dependant upon what you're used to and what you want out of it.

bb69

It sounds to me like you made up your mind before even making the post. I don't think anybody would argue that FI makes more peak HP than a carb. I would suggest that FI make more average HP, and I believe Hot Rod had such a comparison in the last year or so. However, those of us using FI did not typically go that route because we wanted more HP. We did it for driveability, cold starts, ease of tuning (I can get a lot more done with a laptop than I can with metering rods and jets), and because we like the idea of fuel injection. If that's not you, keep on using the carb. There are plenty of people that get a carb setup properly and enjoy playing with jets and metering rods. I'm just not one of them.

Ken