Dual Holley snipers on a flathead?

At home sick today so I been thinking what if I was to get an intake manifold that fed both sides of the motor individually. Then set up two EFI 1100’s as two separate systems each responsible for one side of the motor. What problems would that cause?

 

It's a fever, right?
This is a fever dream and once it breaks you will no longer babble incoherently, right?

1. Cost
2. Time and money for little benefit.
3. When you say one for each side, you realize the firing order, which is preceded by the inlet stroke is not even side-to-side.
https://www.jalopyjournal.com/forum/threads/flathead-firing-order.488465/
I am not well versed with flathead intake theory, but I'd go with the front/back locations used thru most of it's life.
4. If you want to look at combining the latest tech on an engine that was designed almost one hundred years ago, look at LSR racing and the engines built for that. Then add in cold start and warmup, idle and part throttle operation, and fuel economy.
5. Does Holley provide a way to sync two separate systems? If not, realize what a feedback loop is aside from just a cool guitar sound.
EDIT: https://forums.holley.com/forum/holley-efi/sniper-efi/8365-dual-sniper

That said, you might be one of those people that thrive on proving It Can't Be Done is wrong.
All the pioneers cut and tried, and some of it worked great. I figure you were bored and wondering, so that's the stuff off the top of my head why not.

 

I’m sure you can get more control of your fuel curve on that flathead than it’s ever had before… manifold selection might be more important because you can tune fuel to perfection. I say go for it!

startup and drivability will be much improved once you get it right.

 

That's $2200 just for the EFI 1 barrels not including manifolds and no guarantee it would work. If you got the dough, I'm in for the show!

 

What started this line of thought was a video of an engine running with 1 head removed. So that got me thinking that an o2 sensor and carburetor for each side instead of the old way of front half and back half. Then the question did anyone ever make a left half right half dual carburetor manifold?

 

I have exp. with snipers. The amount of throttle body area at wide open throttle will be overwhelming. Even one would require some modification to the linkage that opens the 2nd set of barrels. If you wanted to get creative, you could build a throttle stop to control opening to match the velocity of the engine at upper rpm ranges. By not opening the throttle much at low rpm, decent results could be achieved.

 

He was talking about using the 1bbl sniper. It could be made to work but the cost/benefit*****ysis would be tough.

 

Oops. I went to sleep, again.

 

How deep your pockets ?
I can spend your $$$$!
Let's get Creative.
8 ecu's , or One custom ,
A good writer to configure a program,
8 throttle Body's
8 coil packs ect, custom Reluctor wheel.
Tune each cylinder as 1 individually ,
But 2 cylinders share same exhaust port
Per side , so there a balance that would have to experiment with, exhaust side.

Maybe use a 2 in 1 coil set up to have
Just 4 coils .. Ect
May be see the thinking ...

The 2 ecu & 2 TBI's would work,
Then You would Need 2 distributors
Or another way to run engine like
4 cylinder , Or
Custom way to trigger coil's 2 , Reluctor wheel , 2 Distributor . Yad Yada .

Then if you loose one side Kind of dead in water On one side
If you loose a sensor , witch would be multiple duplicates ,, No mater witch way You Go , 2 TPI's or 4 , 8 .
There way's to do all this , $$$$$
Development research,,

Maybe Just Focus On
Custom Equal Length Intake Runner's With Custom
TBI that Looks like twin Carbs
Or Single With regular Snipe/Fuel Tec Ecu
Picture below is just an example for
"" 1 ""coil F -H

 

I have seen a flathead with 2 distributors, 2 coils and 16 spark plugs running mechanical port injection

 

Yes MFI , No big Deal easy !
One throttle body or 2 - 8 ,
& 8 port Nozzles.
One or Two distributors,
Been done I think Pre War or just after off top of head time frame.

Your wanting " EFI "
Totally different way

 

The following is a paragraph that accompanied this photograph that I found on the net. These are not my words;

Most unusual is this prewar high-rise Davies 2x2. I've seen photos of a Davies in use in 1940 on a Flathead-powered '29 Model A. Bill Ewing ran one on his deuce roadster for a time. The tall risers are set up for Winfield carburetors, but you could purchase adapters for the ubiquitous Stromberg 97s or 48s.


I saw this online when I did a search for "cross ram flathead intake". It would be cool to build a cross ram for your idea. This one has an equalizer tube but that could be chopped out or plated actually. This may be the rarest flathead intake on the planet for all I know but it may give you ideas.

 

@Bandit Billy
I seen pics of that intake years ago ,
I would think better flowing
Then Sling shot , because pretty much equal length runners across all eight cylinders.
The only thing maybe would be imbalance if the Two carbs did not flow
Feed identical from Idle to cruise ,wot

A design like that with one single carburetor in the middle would be excellent, & maybe shorter or Taller

 

That Davies manifold is like what I was thinking (without the crossover) and with EFI managing each side there would be no imbalance. I might be able to cobble something together like that.

 

Well, here's a brand new one, just a grand.
https://www.lakeheaders.com/products/2x2-flathead-intake-with-finned-logs

 

That kinda cool.

 

If you use the Davies intake
Run one sniper as main the other piggyback the 2nd with just injector
& make a drive shaft to connect throttle shafts in stead of bell linkage or use Bell.
Adjust & lower fuel psi on laptop support & change duty cycle on injectors & tuning ,
Not done threw hand held keeping Around 70 % with 35-40 psi fuel pressure , & one O2 , One TPS ,
And with thought u can also clean up looks move the TPS to gas pedal on inside ,
You can also take apart And eliminate wires on big bulky plugs many wires most time will not be used , Void's warranty ,
But only has a One year anyways from purchase date
Also if wanting to Hide / clean up & relocate Map , IAC , TPs ..

Also the term self learning Is a
""Vague term"" just to get up running
& a start to help get a base ,,
Then lap top is needed to actually tune
To full potential ..

I have one of the 4500 with 8 injectors
Good for around 1,400 hp
I have a few engine that rang from
500 hp to 1,300 hp
So depends on Hp , the low Hp engine I had to recalibrate adjust on laptop down to 40 psi & duty cycle of injectors to 70%
Originally fuel pressure was set @65 psi
& duty on Injectors where around 30%
& Was way to much fuel .

So On a F -H with 100 -150 hp
Will be same as in Lowering fuel psi from 55-60 psi to 30 ish something then to adjust to keep the duty cycle over 60% With
2 TPI 's body's .

One Sniper 1,100 supports up to
170 -200 hp

 

I am not conversant with a Ford engine. Having said that, I know a man that has two EFI mounted on a 1941 Buick duel carburetor manifold. Probably not what you envision.

Ben

 

A friend who unfortunately is not on the hamb, has done efi on a flathead for the street, using a Hilborn stack injection manifold and Holley electronic components to operate it. It starts like a new car, pulls strong to the redline, idles around 850 rpm, and gets great mileage. Oh, and it breaks Ford 3 speeds easily!

Now for the bad news. It was not inexpensive and took a lot of effort to get it right. Plus a lot of special fabrication for a lot of things we don’t need with a carburetor.

 

Most if Not Just a bolt on & $1,200
Cheap some say Expensive.

But I can say that the Unit You describe
Starting With Key part Hillborn ,
& may be ECU Custom parts fabrication add it All up especially if you doing the work yourself
$3,000 to 4k ish
Vs
Not being able to do $5,500 Up
No parts starting off ,
Hilborn Bare with just*****erflies
$700-1,200
Ecu $700- 3,500
Then the rest needed
Plus custom work / parts
Then Labor this why $5,500 up..

If familiar there's even a cheaper way to do using OBD One First GEN Fuel Injection ECU & some Early OB2 and thinking outside of the box,

Down side of OBD 1 in Hot Rod
Limited to be able to adjust but you can add a super chip Or take Cheep Holley Sinper Remove ECU & adapt to pretty much anything you want .
Snippers start @ $ 1,100 ish up

 

Good info, Eddy.
I wouldn't mind an EFI setup, but cost of entry, steep learning curve and obsolescent by the time you turn the key.
Just like so many things, there used to be a fairly standard***X sensor at a reasonable price but the makers keep reinventing the wheel so who knows if that part you built into your system will be around when it fails later.

 

Unfortunately Now a day's most of us old stuff when brake down & need of right then and there ,Most parts needs to be ordered even from the Big box stores,
Most of parts on Holley is Ls components and sensors.
I do miss the days up until Early 2000 parts on shelf NAPA , That made Long road trips doable, Now pretty much have to stay in Hotel for at least one night until they get the part the next day

 

I have mentioned this , directly and indirectly. I have a re purposed 1990 GM Throttle Body on my 1950 Buick inline eight. Been from NO Texas to Seattle and back. Iowa and back. Many shorter 1000 mile or less round trips. Total of almost 30,000 miles. I have yet to have a break down . Period. Only problems have been from other systems. All sensors available .
Oh, there is a problem with it! I never have anything to do but look at it.

Ben

 

@firstinsteele
Yes OBD 1 pretty reliable even TunePort
I have 6 Gm sb & Bb out of those
Only one lost One injector on TPI 94
With around 160k miles,
Another 90 454 with 34k miles Distributor pick up,
Another with 81k
Another 260k
Another 190 k 93
Pic below around 91 a TunePort pulled off 87 IROC installed on 450 hp sb
& put around 60k on 25 mpg , Pic shows stetting in Snow No Hood , was reliable.
Then Ford OBD1 2.3 200k
86 3.8 stang 190 k

 

I too have a GM LS single throttle body with port injectors on a 300 inch inline six. Holley Terminator, which also controls ignition timing. Solid and reliable.
Before that, I had the Sniper 1100 on it. Nice little unit, all self contained. It has a single 100lb/hr injector.
Knowing what I know about 'em, I'd reckon you'd have to treat 'em as two separate units, tuning each individually, with each having its own O2 sensor, and treating as two four cylinders. The "brain" is integrated into the throttle body. So the question is, is there a way for one to control the other? I dunno.
Treating them as two four cylinder unit, potential problems would be synching. Not so much the injector flow, since it's a single injector and "pretty much" constant flow. There's no timing issue unless you wanted to control timing using the Sniper's built in controls.
Two coolant temp sensors? Two idle air control valves? Or disable one?
It would be interesting, for certain!
There was a guy on YouTube that used throttle bodies from a motorcycle on a flathead, 3D printed his prototype adapters and used a Holley Terminator to control it. The throttle body was a two barrel deal, that looked like two single barrels. The throttle body I believe, had its own IAC.

 

Yeah the idea was 2 separate systems. Each sniper controlling a bank of 4 cylinders unaware that there is also another 4 attached at the crank. The trigger wire from the coil would need to go to both.

 

@Mike Lawless ,
If the snipper 1100 has same program witch I am sure same in all Snippers TBI's, The Snipper 2 I do not Know same ? I have not looked into the
S-2" what was up grade's " difference".
The Snipper 1 on the 1100 says laptop
Tunning should able to adjust fuel psi requirements & change duty cycle on the injector in this case 2 the Ecu thinking 1 injector, because you would
Be piggybacking just injectors.
On both TBI's the internal fuel pressure regulator needs to be removed,
The bigger 4500 uses a external regulator which is better . For LapTop
Tunning
I do not know if Holley make dual TPI for the 1100 to be piggybacked like other
S-1 & S-2's . Holley web catalogue not easy to navigate search.

@ActionYobbo The way you where wanting to use the 1100 is doable
Just not sold pre made bolt on parts .
Custom & thinking out side box.
Let's just talk distributors
2 4 cylinder cap distributors
Dual distributor Drive.
One to fire 4 cylinders Driver side
One for the Passenger side
Phased in way to fire cylinders
correct order on each side .
& 2 coils one per side / each distributor.

or use One V8 distributor
Making 2 custom 4 lobe cam's
Stack on top of each other phased to fire
Each side correct ,
Like a dual point , but separate Cam's .
2 pick ups
One coil,
Set Both ECU's to 4 cylinder but in Reality 8 cylinders. Each ECU thinks
Its a 4 cylinder ..
even doing this way with 2 independent ECU's to be close to Balance on each side of engine You would have to deal with
2 TPS
2 coolant temps
2 O2 's
2 maps
2 IAC .. maybe you see the thinking.

On one engine combo I working on
I was able to use a regular distributor ECU thinking it was a Hyper spark Distributor. "Timing Control"
Just with a regular distributor & crank trigger

 

The last time I looked, there was no "Sniper2" version of the 1100. Is there now? I'd imagine there is close to zero interest in piggybacking 1100s, as most would go for the 2300 if they wanted two barrels.
If not, the ECU is contained within the unit itself. The 1100 also has an internal fuel pressure regulator. Which is why I believe you need to treat as two separate systems. I know the Sniper 2 is now externally regulated, as well as having the ECU as a separate box. This adds to the cost.
As far as using a laptop for tuning, I'd imagine you'd need to do that, although the "Wizard" should allow you to get a base tune to get it running. But that's about all the 3.5" handheld is good for. I only use mine as a display for EFI functions on a temporary basis. I use a laptop to dial in the tune.
Now it's opinion time. Just an opinion, and I am not an expert by any stretch on EFI systems. But I have learned a lot in the last couple years I've been dinkin' with on Ol' Furd.
I think you would be better off both from a tuning, as well as a financial standpoint, to run two throttle bodies from a single controller. Only one would need the IAC, and everything else would be able to operate with single sensor inputs.
I don't know how you would do that however, with the 1100, since it is internally controlling its injector, IAC, fuel pump operation and pressure, temp inputs etc.
The 1100, at least in my case, had a few "quirks."
• It would flood easily once warm, so a specific starting routine had to be learned.
• Most times, the idle would drop and sometimes stall running up to a stop. Maybe automatic trans cars didn't see this happen, but roll up to a stop, clutch it, and the rpm would drop momentarily to the point of stalling. Sometimes it would stumble and recover, most times stall unless I was "johnny on the spot" covering the throttle. It took quite a bit of fiddling in the software to make that livable. Could not get it all the way out.
• It did get good fuel mileage out on the road. In town, not so much. But then it's still not great in town with the Terminator system either.

 

Yes I see the problem with the trigger wire giving 8 signals instead of 4