EFI conversion on a Gen-1

[RempageR1]

Hi!

It`s been a while so I thought it was time for an update. I`ve done a lot of work in the mean time and decided not to just move the injectors closer to the intake manifold, but to use two sets of injectors. The second set I got from a CBR 600 PC41.

The injectors close to the cylinder head will be used for more precise fuel delivery whilst the injectors that are inside the throttle bodies will be used when more power is required. An injector has a duty cycle, which is the time the injector is open during a full 720 degree revolution. 100% percent duty cycle therefore means open all the time. I want to use a duty cycle of 15% to start with so the injector will only be injecting fuel when the intake valve is open. Since I now run sequential, I know exactly when the valve is open. With that, you can setup the Speeduino to be done with injecting fuel at a certain time to ensure it`s all delivered before the valve closes.

If more fuel is needed that can be delivered within 15% duty cycle, the second set of injectors is added so all eight injectors fire. This is all done automatically by speeduino, you only need to know the exact flow rate for the injectors. To do that, I connected each of the injectors to the fuel line and had it spray into a coke bottle as shown below:



View attachment InjectorFlow.mov

I used a kitchen scale to measure the weight of the bottle (minus injector and wiring) and then turned the injector on for 30 seconds. The difference for the small injectors was 78 grams (with 1 gram deviation between them). The big ones (I already had) do 132 grams (also with 1 gram deviation between them). So the small ones` flow rate is 156 grams per minute, the big ones 264. Next step is to convert that to cc/mins and configure Tunerstudio.

I also worked on creating new manifolds, will provide an update about that shortly .

 

[Radioguylogs]

It's a treat to watch your ingenious and detailed engineering efforts.

 

[Fire-medic]

If 1 ml=0.68 gram gasoline then 156 grams/ .68 g = 229.41 ml as 1ml =1cc.

Then 229 ml = 60 seconds of fuel delivery for the smaller F.I.

264 grams / .68 grams = 388.24 ml

388 ml = 60 seconds of fuel delivery for the larger F.I.

 

[RempageR1]

If 1 ml=0.68 gram gasoline then 156 grams/ .68 g = 229.41 ml as 1ml =1cc.

Then 229 ml = 60 seconds of fuel delivery for the smaller F.I.

264 grams / .68 grams = 388.24 ml

388 ml = 60 seconds of fuel delivery for the larger F.I.

Thank you, I will use values close to those. In the Netherlands, we use fuel which has around 5% ethanol so I have account for that as well. Ethanol is heavier so my flow rates are slightly lower. It doesn't mattter that much however, the ratio between the two injectors is what mostly matters.

On to the manifolds then . I spent a lot of time trying to figure out the best way to fit the smaller injectors. Since the cylinders are quite close to each other, it was a very tight squeeze to get them in. Also since the front cylinders are 5 cm or so to the right, the injectors would ideally be placed like this:




The challenge with that is to fit a fuel rail. Since the injectors are so close to each other the only option would be to fit fuel line directly. But that would mean the fuel line for the left one would go around the manifold on the right looking horrible.

After a _lot_ of different test prints I decided to go for a setup where the injectors face eachother and both are tilted up 15 degrees from horizontal.

Some pictures:





To drill the holes correctly, I 3d printed a 'holding tool' where the aluminium block fits into. This has a 15% angle so you can drill straight down with a column drill:



This drilled a hole of 10.4 mm which I expanded to 10.6 with a reamer tool.

So well on my way with this round of updates, will keep you informed on the progess

 

[Jack Hammer]

Would diesel commonrail tubes be out of the picture? After all, it would not be very practical to have a fuel delivery system that requires one to take off the intake manifolds in order to be removed. What is your fuel delivery pressure?

 

[RempageR1]

There is about 7mm space between the two injectors so a T-shape connector is the only thing that fits. You should see it as a subassembly like the Vboost manifolds . Fuel pressure is about 60 PSI.

 

[Jack Hammer]

A Tee connector with that space would be very difficult to install without hurting the o-rings. You were thinking of prying it on with least possible shoulder? How do you secure it in place, how do you secure no leak situation? How do you connect between the two Tees? How do you import fuel, how do you control the pressure?

 

[RempageR1]

A Tee connector with that space would be very difficult to install without hurting the o-rings. You were thinking of prying it on with least possible shoulder? How do you secure it in place, how do you secure no leak situation? How do you connect between the two Tees? How do you import fuel, how do you control the pressure?

That`s a lot of questions in 1 post .

You first install both injectors into the aluminium t-connector, then add the manifolds and across the manifolds there will be two aluminum plates securing the two manifolds together. That will be the same style as you can see in previous posts.

The mainifolds will reach all the way up to the aluminum t-connector as you can see here:

It all goes together pretty smooth. I already did a leak test and it works just fine that way. Fuel pressure is controlled by a regulator, you can find the details in this thread.