I will start by saying that I have not completed this project yet!

Take a look at the throttle bodies from a 1000cc GSXR. The bore is 40mm which is roughly the same as the venturi insert on a 45 weber. The throttle body has the boss for the injector built into the body. The bores are slightly closer together than the barrels of a side draft weber. (thus requiring a custom intake manifold) There is a throttle position sensor attached to the throttle bodies. They are relatively cheap on e-bay (at least here in the States, I bought a set up for $65ish, shipped). It looks like making an intake manifold will not be too hard. (as your father was going to weld the bungs for the injectors into your current manifold he can probably do this type of work, too) I am actually fabricating one for an SR type engine. I think that there are examples on the picture page of some one doing this so search around a bit and it may give you an idea.

As an example view this handy photo;
http://datsun1200.com/modules/myalbum/photo.php?lid=14254

Still havent got those jet figures for you mate, will do though.

Pressurized fuel will flow through the rail, which is delivered to the injectors. The pressure will pop the rail of the injectors if you don't bolt it down.

The regulator doesn't have to be adjustable. It will simply maintain a constant pressure of about 3 bar in the rail. It does however have a pressure input, which will rise the pressure when you add boost, or lower it when vacuum occurs. I run an unadjustable 2 liter Mazda one on mine, which I got of a manifold I have, and it works perfectly for my application. I only used it because it looked better(read newer) than the Toyota one

Other than that the fuel pressure has nothing to do with the size of the engine, the amount of fuel delivered is controlled mainly by the management system, and the pressure only plays a small role where sane NA or light turbo applications are concerned. However you still need good control over the pressure to keep it constant, otherwise it will be very difficult to set the management. It's only when you start going to insane boost levels that you really need an adjustable regulator, where you start relying on the fuel pressure to inject enough fuel.

No need for a throttle position sensor, at least not if you use a Dicktator, it uses a map sensor to determine manifold pressure/vacuum, and according to that works out how much juice to spray. I took a hacksaw and removed any evidence of a TPS from my throttle body, and my car has been running just fine like that. The webber idea could work, as they would just be a means of controlling airflow. Just make sure you plug all holes properly, so you don't end up with air leaking through the old fuel passages.

Quote:
What will this be for? is this to bolt the rail to the manifold so that it is tight and not a loose bunch of stuff?

Thanks for your reply kulula. To be honest, when I saw you logged in onto the site I was hoping you would reply.
Is the 4AGE one ajustable? Must it not be a ajustable one to bring the preasure down for the 1200cc engine?

Oh and the plan is to go turbo later.

First of a big ...

Then, I have a set of injectors that came from a 1st generation 4AGE, they flow 182cc's, which you can have. I don't know how this compares to the VW ones, but they should be close anyway, and you'll have some capacity for when the turbo bug bites...

Then you'll also need to have a fuel rail made up, this can be as simple as a piece of solid aluminium that is hollowed out, and has places machined into it for the back of the injectors to fit into. On that you'll need a fuel pressure regulator, I have one, also from a 4AGE, which you can have. Just remember that you'll nee to have at least 2 bosses in the mani and the rail to bolt the lot down.

For the plenum You simply take a piece of 100mm round aluminium tube, weld an end onto it, and a flange for the throttle onto the other side. This in turn could be welded onto the intake manifold or if you flatten it on one side, simply bolted down. In theory, this is if you plan to go turbo later on, it would be ok to have a plenum made up of square tubing, as the turbulence created will work better for that type of application.

Then from either GW or Volkspares you can get a fuel pump for as little as R399. You can simply use the original pickup from the tank for a start, but you'll have to run high pressure fuel lines to the motor for this application. The original fuel line and one vent on top of the tank can be used for the return. If you plan on going turbo one day, you will might need to install a slightly bigger pickup once you do so.

4 chambers is actually the ideal. Gives more airflow and obviously more power.But, cost too much.I am thinking of a cheap way and with stuff I already have.

I have heard (don't know how true) that using weber sidedrafts or Dellortos, you remove all their interior parts, put injectors on the intake manifold and a throttle position sensor on the throttle shaft and then you have 4 throttle body fuel injection.

I wonder what the difference is from having a plenum chamber with a single throtlle body, compared to having 4 throttle bodies (in a sidedraft weber style) - that is one for each intake port.

How much control of air velocity do you lose with a plenum chamber and only a single throttle body...

Hi all

I am busy doing some research.
Ok, I have a spare GX intake manifold.Looks perfect to create fuel injection intake manifold of. I can drill the injector holes into it and let a engineering shop turn injector bosses on a lathe. My father-in-law can then weld it on for me as required.I can also let him make a box to bolt on the carb side of the intake and put a throttle body on it.
Now the questions:
1. What injectors? I am thinking VW 1.4i
because they are cheap here and the cc
is close enough.
2. What throttle body.Maybe also VW 1.4i?
3. What about the electric fuel pump.Can I
just put it in the engine bay pulling fuel
from the fuel tank? Or do I need special fuel lines from the fuel tank.
4. What about the distributor's vacuum
advance? Currently it already has the Pertronix ignitor in it.

Any info appreciated.

Thanks.