Custom EFI 390 Tri power... <hr style="color: rgb(255, 255, 255); background-color: rgb(255, 255, 255);" size="1">I am looking for some input on a custom efi set-up I am building for my FE powered 65 falcon sedan. Basically I curious what people think is the best route to modify my manifold to accept the throttle bodies I have picked for this project. Background info: Manifold is an Edelbrock 3 x 2 dual plane which should be used with some type of old stromberg carbs - cool but not for me on this build. Throttle bodies are from the Honda CBR1000rr bikes. Each throttle body twin has 2 44mm throats and I will be running 3 sets of them. I picked these because of the butterfly size, simplicity, looks and because they are cheap!! (I am pretty sure 6 x 45mm butterfly is more than I actually need) Engine management will be from Megasquirt Fuel Rails will be located at the ports on the manifold same as most do it. Now onto the actual question: You will see in the pics that there are 2 challenges: 1. The center to center dimension of the throttle body throats is about 1.25" wider than the manifolds inlet holes 2. The diameter of the throats is about .25" bigger the the manifold inlet holes. One more detail - the throttle bodies and not bolted on. The are held in position with a sleeve. So the manifold or adapter needs to have 2 pipe sections sticking up to allow the throttle bodies to mount - not a big deal just want to throw that out there. I have proposed 4 possible ways I could make this work. Option A. Weld on more aluminum material to each side of carb riser and re machine inlet holes to match throttle body bores. Option B. Make a plate adapter with a funneled diagonal connection - many ours with the dremel! I am not crazy about the increase in restriction as the "funnel shape" is introduced to the air path. not sure if this will cause more turbulence of not? Option C. Put the manifold on a mill and machine new holes in the right place for the throttle body that reach the tops of the plenum cavities. These holes will require tube sleeves to enclose areas of the carb riser that will be cut right through. Will take care of the tube to throttle body mounting issue also. Not sure if this will cut away too much of the riser and actually stick past the edge of the plenum. will need to radius and blend the bottom of the tubes on the plenum side. Will have to do some filling with weld at the top of the riser too. Option D. Bore out manifold inlet holes to the right diameter. Make a mounting plate that still bolts to the risers and has a fabbed tube section that will fix the center to center issue as well as the throttle body mounting issue. The drawing is not really to scale - they would have to stick up less for hood clearance but you get the idea. I am leaning towards option D. I have access to a bridgeport mill so the machining is not that big of a deal. Just want to do it as right as possible. Clearly this is not just a "bolt on" application but I think it will be unique and bad ass.
Personally I like option B or D the best. I think those options would best maintain air speed through the throttle bodies. Options A and C look like they could lead to sharp edges that cause flow issues. One question though, are you planing on using a mass air flow sensor or a manifold air pressure sensor, and how / where are they going to be located?
I would also go with B or D, similar to the drawing in the lower left of your post. That way it can be a "bolt-on", in case you go in a different direction later. I wouldn't worry about any funnel effect, as your tightest restriction will be the internal manifold runners anyway. Here is a Lynx manifold to adapt Weber two barrels side drafts to a modified Falcon six head. Notice how it shifts the air flow to line up the carbs to the ports. Later, Kinky6
i have always had it in my mind if it would be possible to remote the injectors and run hard lines with nozzles on the end, just to get away from all the wires and plastic injectors.
Not that it is going to make a lot of difference in the whole scheme of things but you left out option E. Get a single plane manifold. I am certainly not the world's reknowned expert on TPI but if I recall they work better with an open plenum for your air intake than with a devided plenum. As for mateing the throttle bodies I would most likely try and build a spacer as opposed to a slingshot then taper it to the bores in the manifold like they do with a standard 4bbl adapter.
You're making this way more complicated than it needs to be. Find three junk carb cores of your choice that fit the intake and use them for throttle bodies. You can gut them and even remove the clusters and venturies for more airflow. Keep the throttleshafts and butterflies functional. You can put a TPS on a carb, on the linkage, or I've even seen is hid on the accelerator pedal. The MAP sensor is on the megasquirt board, just run a vacuum line to it. You don't need a complex IAC setup, you can set the idle speed with the idle speed screw on the side of the carb.
I like what Dzus said, but if it were me, I'd sell or trade the 3 X 2 intake for a 2 X 4 intake. Would be easier to adapt the throttle bodies to the plenums that way. Of course this is just my opinion. Personally, I have always wanted to take a Weber style intake and weld up riser tubes that bolt to the intake and pass over one another to create a cross-ram intake for the FE. Then plumb the injector rails underneath the cross tubes so that they are somewhat hidden. I bought a set of N.O.S. throttle bodies off of flea-bay and I figured I would also use the Megasquirt system to control it. Using this style of intake My throttle bodies It would look something like this. But the injector rails would be underneath the tubes, hopefully mostly hidden.
Thanks for all the input. I had considered using a 4 weber manifold....The main deterrent is cost and availability. The Fe series of motors is expensive for aftermarket parts and I could wait around forever looking for the optimum parts to come up at a good price. Actually the best option for a ITB set-up would be to use one of the obscure "adapter manifolds" like the Algon. It adapts the fe heads to a cleveland intake. Would be very easy to fab itb runners. Perfect solution just impossible to find for a reasonable price. I eventually decided on the tri-power set-up for a few reasons. 1. It seemed like it may be more forgiving than an itb set-up as far as design, tuning and execution. 2. I have not seen another one on a FE ford motor - or any ford for that matter - and it is the logical evolution for a motor that had performance models with the tri-power carb set-up. 3. As for using these throttle bodies over others that would fit easier or carb bodies - They have the basic look and shape of the weber ida which I like. Just add velocity stacks and they will look "right". I am not worried about the machining / fabricating needed to adapt - just want to choose the best option.
If that's what you are looking for you don't even need the entire carburetor. Use just the carb throttle bodies, and fab you velocity stacks to bolt straight to them. The main point is that they line straight up with the intake ports. Any jog in the path is less than optimum.
Ok - after a lot of measuring and thought the only really viable route is "B". This is really the only way to make a clean transition and it also does not require welding on the manifold that could possibly cause some warping. I will retain the 3 bolt Stromberg mounting studs to attach. I think that will work fine. As much as I would have liked to go route c it just won't work with the dimensions. I have bought 3 aluminum billets to cut up - they are 1.5" x 3" x 6". I have laid out the basic hole locations as well as the mounting stud positions. Once it all works and fits I will try and make the adapters look a little nicer and not so "block-ish"
I'm not near my original Ford Tripower manifold but they used the standard Holley Carbs with the larger bases. You might consider one of those manifolds. Just measure the base of a 450-500 CFM holley 2V to get measurements. I've got the same Edelbrock tripower for 3 Stromberg WW's or Rochester 4 bolt base carbs. as your's in the original post You can usually get one of the 1962-63 ford Tripowers for around $300-500. Movin/on
making some progress on the adapters. Still have quite a bit of hand "die-grindering" to open the holes drilled through the adapter connecting the throats to manifold inlets. I ordered my velocity stacks as well.
Updated pic - with all 3 throttle bodies in place and the velocity stacks in position. Still need to weld in the injector bungs and finish the custom air cleaner. pierre
It's great to see this coming together. Once you get it working and tuned it would be nice to do some radius and contour work on the exterior of the adapters to make it flow visually as well A/F wise. Mike
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