Fuel injection with a 6-71 on the street.

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Coyote Jack

Coyote Jack

Member #55, I'm old
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I am in the process of gathering parts for a 340 with a 6-71 on top for 72 Demon, 3102 lbs without me.. I have most of the engine from the heads down. Forged crank, 8.5 to 1 +.030 forged pistons, X-heads (open chamber) with 2.02/1.60 valves. Have yet to decide on a cam. Fuel will be 91 octane as that is the best available here. Boost will be no more than 10 lbs but probably 8 lbs. I will run thicker Cometic head gaskets to lower the compression a little more. The tranny is a 727 reverse manual valve body with a trans brake. Rear is an 8 3/4 with 3.23 shur-grip. Tires are 275-60-15 M/T's. I will also go with some kind of boost referenced timing controller.

I am undecided on whether to run carbs or fuel injection. If it's carbs I will probably go with two 750 holley's, boost referenced. My problem is I don't know much if anything about fuel injection.
What parts are needed to run fuel injection on the street? Is it hard to do? Does it have to be electronic or can it be mechanical? I just don't know what is involved.

If you need any more info on the car, let me know and I will post it.

Jack
 
Jack, the tuning and driveability of fuel injection really cannot be duplicated with carburetion. Although a properly set up and thought out carbureted fuel system can come close, there will always be a difference........ESPECIALLY in the ability of fuel injection to calm down a more radical camshaft and make it more driveable on the street. However, as you've eluded to, there is a learning curve, and unfortunately, it's not something that anyone can really impart, at least not in whole, because each system is different on each engine. These people here though http://www.efisupply.com/fast_ez_efi.htm can probably give you some good advice. I like those units. Much like a carburetor, they are throttle body injectors, but they are complete units with throttle body, injector rails and injectors all in the same unit.
 
Your also going to need a in tank fuel pump. You might what to talk to djvcuda he has this system installed and running (this is the system that I'm going to be using on my car).
 
1970Duster said:
Your also going to need a in tank fuel pump. You might what to talk to djvcuda he has this system installed and running (this is the system that I'm going to be using on my car).
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What am I missing here???

Jack's talking about using a 6-71 Roots blower on a 340, is he not???
Hios words were: "gathering parts for a 340 with a 6-71 on top."

Doesen't the carb or injector body go ON TOP of that blower???

And, if it does, why would he need it boost referenced, or a fuel pump in the tank??? He's not going to need egregious amounts of fuel pressure, IF he runs carbs. If not, I still don't understand why the pump would need to go in the tank, except for cooling it, maybe.

Somebody tell me what I am overlooking here... please. :!:
 
I was under the impression that you could go with some kind of hat, like a bug catcher, that the injectors are in the base of which sits on top of the blower. I have also seen pics of nozzles added to the blower manifold, which I can only guess is a way to add more fuel and cool the air charge some after it has gone through the blower.

Jack
 
don't see anything streetable in that combination the size of the fuel lines alone says that's probably set up for alcohol the other thing that concerns me is why would you need a boost referenced timing controller your boost will be consistent with a supercharger versus a turbocharger so there is no need to pull timing back with higher boost as your manifold pressure will always be consistent we're talking roots style blower not a centrifugal ,centrifugal offer increased boost with rpm similar to turbo chargers roots type super chargers have a fixed amount of displacement for engine revolution there is a guy on here who has an incredible twin turbo fuel injected dart I believe his fuel injection is hand built from the ground up I would definitely seek out his posts it's amazing what he has done
 
Bill Dedman said:
What am I missing here???

Jack's talking about using a 6-71 Roots blower on a 340, is he not???
Hios words were: "gathering parts for a 340 with a 6-71 on top."

Doesen't the carb or injector body go ON TOP of that blower???

And, if it does, why would he need it boost referenced, or a fuel pump in the tank??? He's not going to need egregious amounts of fuel pressure, IF he runs carbs. If not, I still don't understand why the pump would need to go in the tank, except for cooling it, maybe.

Somebody tell me what I am overlooking here... please. :!:
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You're not missing anything. I think what he meant was that EFI simply requires high PSI fuel pressure is all. Maybe he's not aware there are in line EFI fuel pumps available.
 
Coyote Jack said:
I was under the impression that you could go with some kind of hat, like a bug catcher, that the injectors are in the base of which sits on top of the blower. I have also seen pics of nozzles added to the blower manifold, which I can only guess is a way to add more fuel and cool the air charge some after it has gone through the blower.

Jack
Click to expand...

Now you tell us. Look under "Blower injectors" and then "Bug Blown Gas". I think that's what you're lookin for.

http://injectionconnection.com/
 
If you go EFI make sure the 6/71 is set up to not have fuel go through it if you go with port fuel injection, Most modern blowers like that have thin teflon strips on the rotors and will melt from the heat of rubbing against each other if you don't run some sort of fuel past them. I've seen it happen...

Joe
 
Might want to talk to FastManEFI about it....think he has done one with inectors both above & below the blower.....
 
StrokerScamp said:
Now you tell us. Look under "Blower injectors" and then "Bug Blown Gas". I think that's what you're lookin for.

http://injectionconnection.com/
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Yup, that's what I was thinking about. But I noticed that they were very quick to point out that it was not recommended for street use. That's to bad because the price was in the ballpark.

Jack
 
Coyote Jack said:
Yup, that's what I was thinking about. But I noticed that they were very quick to point out that it was not recommended for street use. That's to bad because the price was in the ballpark.

Jack
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I would be calling and asking why. Maybe they could modify one for the street.
 
I've seen systems like that on "street" cars before so either they run THAT on the street, or somebody's modding them.
 
You COULD end all the guessing and talk to Rich, after all he sells EFI stuff and has tuned a blown EFI HEMI.....just saying.....
 
You want MPFI and a dry blower setup. You also want to buy an injector that can support the most HP you think youll get with a blower as that is pretty much a constant if you dont want to raise your fuel pressure. In tank pumps are about 700 to get the tank sumped and the pump, but an inline pump from a ford pickup frame rail is 25 bucks at a yard. Run 2 if you want in parallel or in series (Look at a Mercedes 500 class, 2 in series outside the tank) Carbs would be cheaper, a "pull through" system on a blower is less complicated for a carb becasue its still doing what it was designed to do with all its Vacuum sources still available to it under its base. An EFI setup with intake mounted injectors just needs a "hat" and a MAF that can measure the air going into the blower so it can meter the fuel. Blown EFI also need a dedicated ECU that can do forced induction. Carbs would be way easier unless you get a EFI guru into the conversation. Same with a draw through turbo, just a big carb is needed, preferably a double pump so there is no vacuum pot to deal with. Good luck.
 
Here is some info I got from one of the members at YellowBullet.

have done a few of them .e85 is bout the easiest or alky.gas can be done but has to be dead on.A blower you can be a little fat on tune and it will cover it up.Nat asp is tough but can be done.Take a look at good vibes racing they sell kits with everything but a pump.They sell it cheaper than i can.They can figure what you need for nozzles also.you will need a belt driven pump if no one makes a cam driven cover for your engine.I reccommend 8 nozzles under hat into top of blower.That give you good distrubution and easiest tuning.You will want a nitrous solenoid to spray fuel in hat when engine cold to help get it fired first time until warmed up.hope this answers your questions.
Vinny

I also received a response from Good Vibs on the question as to why you can't run the Bug Catcher on the street. Here it is.

Hello Jack,



We reviewed your email and the reason they are not recommended for street use is because they do not have any partial throttle. Without partial throttle you tend to richen up the fuel mixture so much it floods the motor when trying to get from light to light and so forth. If you have any further questions please feel free to contact us. Thank you.



Kasey Smith
Good Vibrations Motorsports
Whittier, CA
800/576-7661
sales@dragparts.com



Jack
 
Here is some info I received a few minutes ago. I found it very interesting considering my timetable.

Hi Jack,

Thanks for the note!

I am working on just what you need...but it isn't ready for prime-time I'm afraid. I've had very little time to work on it in the last year and the latest tweaks remain untested except in the driveway.

From testing so far, I know it will work - but further refinement is needed. Now I have to wait out winter weather in order to make any real progress on it. Realistically, if everything goes well, I'm probably looking at another year to have units ready to sell. Developing and manufacturing something like this just takes forever.

At this point, the best solution for street duty is still carbs or EFI.

Have you looked into Mega-Squirt? It's a VERY affordable way to get into EFI. You can use various 2nd hand components, hook them up to the Mega-Squirt ECU and dial it in pretty quickly for a small fraction of what an aftermarket EFI system costs. You can buy the ECU kit and do it yourself super-cheap, or buy it assembled and tested for a very reasonable price. Choose your components from the junkyard and away you go.

Thanks again for your interest - I wish I had something for you!

Best regards,
--
Spud Miller
Fuel Injection Enterprises, LLC
541-990-2485
http://fuelinjectionent.com



On 12/20/2011 6:42 AM, Jack Koval wrote:
I am in the process of trying to build a blower engine for my 72 Demon. What I would like to do is run a Bug Catcher on the street. Everybody is running carbs and I want something a little different but the cost of EFI is just to high for my blood. I was told on YellowBullet.com to get in touch with Spud Miller.
I understand that there is a problem with starting a mechanical fuel injection system when cold. I have found an electronic primer pump that takes care of that problem. The other problem I have been alerted to is the part throttle loading of the fuel system when cruising. This is where I stand right now and I was told that Spud has developed a "smart pill" that either cures or minimizes this problem. Can you fill me in on what is available? Also if there are any other problems I should be aware of please inform me of those and any possible solutions. I want to make an informed decision before I puchase anything for the fuel system.

My setup is going to be something like this:
1972 Demon
3102 lbs without me
340, +.030
Forged crank
H-beam rods
TRW l2385 forged pistons
Stock X-heads 2.02/1.60 valves
Solid flat tappet cam (size to be determined)
1 5/8" to 3" long tube headers
2800 stall TQ
727 manual reverse valvebody
8 3/4 shur-grip with 3.23 gears
275-60-15 tires
Manual steering and brakes
Blower 6-71 roots (make to be determined)
Fuel will be gas, 91 Octane

Thanks

Jack Koval
 
i have driven allso in street..............fun :D

340 +6-71 mech hilborn

P5.jpg


499 14-71 elect.injection

IMG_0346.jpg
 
Dartblower, can you post some close-up pictures of the 340-6/71 Hilborn setup.
How does it work when cruising the street?

Jack
 
Coyote Jack said:
Dartblower, can you post some close-up pictures of the 340-6/71 Hilborn setup.
How does it work when cruising the street?

Jack
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Hi, this dart standing on garrage now 6 years, but goint to rebuild it soon.
no more pics right now, just some oldones.

working just fine on street but if hot or cold weather have to tuning it littlebit cos mech system. i think fuelpump can run some 5000 km only, so better to be few pumps ready, cos it damaged on seconds when comes to end and not make any pressure anymore,just for idle only, i have used 2 % 2T oil with gas.
 
Thanks Dartblower,
It appears that you have injectors in the intake runners. It's hard for me to tell, but do you have injectors above the blower as well?

Jack
 
Coyote Jack said:
Thanks Dartblower,
It appears that you have injectors in the intake runners. It's hard for me to tell, but do you have injectors above the blower as well?

Jack
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no, injectors is in hat, I have test and seen, NEVER use offy low model with inj. in intake runners, it NOT work

this was first intake to my 499

Nowbigger.jpg


Problem is, it not flow good to corner runners, maybe some 10-15 % less than to middle, i burn pistons 3,4,5,6, so never try it :)

So i made new model; offy tunnelram, no problem anymore :)

IMG_0284.jpg


IMG_0001-3.jpg


IMG_0337.jpg


Threre is good intakes for sb on indy, planning to buy that to my 340 allso
 
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