MSefi.com read only forum (Jan.15,2018)

I've been searching this forum and the internet for two days trying to find information to no avail. I'm thinking of picking up a Megasquirt kit for my 51 Ford for my wife but am trying to figure out some things first. I'm looking to hide 4 injectors inside the float bowls of two stock carbs and by the calculations in the manual I need 15lb/hr. So I'm looking for 2 injectors that can fit horizontally in a 2X2X4 bowl (maybe off a bike?) any one have any ideas? Also anyone have any good links about Thorttle position sensors? I would like to contain it in the float bow also is possible.

Hers a picture form another forum I visit of someone building a similar set up:
http://www.jalopyjournal.com/forum/atta ... 1199040155

Thanks,
Matt

What you're doing amounts to twin throttle body injection. I'm not sure I see a benefit to using two side-by side injectors in the same throttle body.

Lots of info on injectors here in the Megamanual:
http://www.megamanual.com/v22manual/minj.htm

You could probably squeeze two injectors into 2x2x4", but it would be easier to just put one in there and probably equally as effective.

The TPS needs to be attached to the throttle shaft or to some sort of linkage that attaches to the shaft. I don't know if you'll be able to put that sensor into your float bowl... unless the throttle shaft happens to pass through it.

BUT... a TPS is not required. You can build a system without it. That might be the way to go for this application.

As an afterthought...

Who ever said a TPS had to be under the hood? You could fit something to the throttle linkage inside the car. The only thing it is used for it to tell the ECU when there's a rapid change in position (you want to accelerate NOW) or when load exceeds a certain percentage and you want to go into "open loop" or "performance" mode rather than "closed loop" or "economy" mode.

Tangent: I used to work in an experimental aircraft instrumentation shop, you name it, we had to find a way to measure it. To measure a pedal position, we'd normally use something called a "string pot". I'm sure you could find one, though it might be expensive. It's simply a precision potentiometer (just like a TPS) that is pre-wound with a spring-loaded cable that self-returns, sort of like a tape measure. Mount that somewhere under the dash and string it to your accelerator pedal... there's your "stealth TPS". Of course, if you happen to have some sort of a pivot point on your accelerator linkage inside the car, you could fit a standard TPS to it just as well.

why couldn't you place the injector/s under the air cleaner in the thoat of the carb?

The problem I see with putting it in the float chamber is that not only the injector has to fit, but the fuel supply plumbing as well.

If you have the money you could buy one (or more) of these:

http://www.retrotekspeed.com/products/b ... -quad.html

I have been told they will sell you the TB assy by itself but have not confirmed that myself.

I am curious to see the picture you tried to post or link to but I couldnt get it to work.

Hmm. That picture doesnt tell much. It doesnt help that I dont know anything about stormbergs. Unless the injector(s) are stuck out the other side there does not look like there is enough room plus you cant see the fuel inlet or rail. Its a tight fit on that giant holley double pumper thing. Another thing to remember is the bigger the injectors the more rare and expensive they get.

Ithink I'm going to mount them in under the carb and cut out the bottom of the bowl so they extend up into it like this guy



Thanks,
Matt

What did those bottom sections look like before the mods for the injectors? Any idea what the to of the bowl area looks like for the fuel connection? It looks like the top of the bowl may come off.

Those are completely home fabbed units, heres the whole series
http://www.jalopyjournal.com/forum/show ... +injection

The top does come off heres and inside shot:


The stock bototm units look fairly similar but about an inch shorter. I will be fabbing those up from scratch like he did but using an actual holley AA1 carb body for the throttle body to keep things looking old.

Matt