Dual down draft Carb selection for 2056 Options

[technicalninja]

I'm looking at the Empi dual down draft carb kits and had a quick question regarding differences in the carbs themselves.

It looks like they have HPMX or Dual D carbs available.

Which one would you choose?

Should I lean towards real Webers or Dellotos?

The intention here is to use the kit in its stock form initially and later change to port fuel injection using the carbs as throttle bodies much like MB911 is doing with his EFI conversion.

http://www.914world.com/bbs2/index.php?showtopic=363246

Being able to remove everything in the bores is critical for me. No fixed boosters or venturis is a requirement.

I'm planning on starting with an 8.5-9.0 compression 2056 with a webcam #86.
I am planning on having the final engine as a 96mm bore/78mm stroke, but this will be in the future.
I believe I should start with 44 mm carbs instead of 40.

Suggestions, tips, and opinions would be greatly appreciated.

[technicalninja]

36mm Venturi readily available for Weber 40IDF via multiple sources

Don’t forget 44s also have more area at the butterfly that will cause problems at transition since flow slows as a function of area and as a result 44s just have less vacuum signal at the transition ports.

Yes, I am aware of the issues regarding using a performance carburetor with too large a butterfly. Basic throttle tip in usually requires a progressive linkage to make it more tractable at low-speed operation.

I've also had experience regarding the opposite.
The Cobra replica (on my website) that I wrenched on had a mild performance 460ci engine that the previous shop speced out a 600cfm Holley for it. This is way too small for this displacement. A proper street carb should be 800 cfm and a serious race carb would be over 1000 cfm.
But, the 70 year old customer told me he NEVER ran it above 3K.
For his driving style the 600 cfm carb worked great.
What a waste...

It was VERY responsive down low and had 600+ ftlbs of torque in a 2300lb car.
It's the most violent car I've ever driven. At any speed below 70 in what every gear you want you could turn it sideways with throttle input alone.
Dangerous for the un-initiated...

I expect I will have this changed over to aftermarket FI fairly quickly as I have to use a Microsquirt to control the COP system (or waste spark if I wanted to be lazy).
I will have to spend money on ignition stuff anyway (like an appropriate distributor), so I'll go the full Monty and do the Microsquirt. This will require cam/crank sensors, map sensor and a TPS if I want ignition only.
At this point adding port injectors is child's play.

What would your suggestion for throttle size be regarding 4 ITBs, using port injectors, on a 10/1 compression ratio/300 degree cam. 2270 with a redline of 7K?

I hit your thread regarding type4 oil pump shenanigans...
You, Sir are also a foundation of this website.
Thank you so much for freely sharing your findings.
Saved me lots of "spin up" time regarding oil pumps.

[moto914]

With the ITB setup being the second goal, maybe use eBay clone webers. They cost less than getting a real Weber or Dellorto rebuilt. Maybe they can work as donors for the throttle bodies.
Bought one once just to get a (was running when parked 914) started.
Both real Weber & Dellorto carbs are artworks as carburetors.
Good luck moving forward.