Fuel injection retrofit

[kzz1king]

Draw through turbo systems use a plenum and a single carb all the time. The main difference would be I believe the turbo mixes air and fuel better to prevent dropout. The one I built for an inline 4 900 Kawiworked pretty well. I think the V4 would be tougher to plumb the exhaust to but you would have more height to drain the oil back into the crankcase from the turbo

[gpineau]

The velocity stacks on my 98 magna are about 3 .5 inches long and are flared on the end.  On my 87 magna the stacks are only about an inch an a half long. It is not fared on the end and  Is just slightly larger that the mouth of the carb.

The runners that are pictured are just under 3 inches and do not have a flare.

So what are the velocity stacks for? The purpose is to accelerate the air and  force as much air as possible into the cylinder before the valve closes.  I dont think it will matter if that air is from a plenum or open atmosphere.  When the valve opens it is going to rush down the runner where it will mix with the droplets from the injector.
But I can see where the size of the plenum will have a dampening effect on sudden changes in the throttle.

But I dont think it is that critical. I have seen designs where the throttle body, injector and runner was one piece and just a couple inches long.

I have also see designs with very large plenums and long runners like my idea. I will try for the smallest that is feasible to work with.  In the photos the last one is for a Suzuki GSRX

I plan to mount the injectors on a 45 degree angle on the side of the runner. An alternative would be to place the inside the mouth of the runners inside of the plenum.

[connie_rider]

Good images and your making a good point that the plenum can be bigger than I thought.
 My understanding is you plan to inject into the plenum?
Looking at your images;
#1 (4) Injectors are at the base of the runners, just above the valves.
#2 (4) Throttle bodies and Injectors are at the base of the runners, just above the valves.
#3 Unknown. (Throttle body could have an injector, but I suspect it has 4 injectors)
#4 (Suzuki) (4) Throttle bodies and Injectors are at the base of the runners, just above the valves.

Velocity stacks are used to increase air velocity/volume before the carbs.

Not trying to shoot your idea's down. Injecting into the plenum will probably be fine.
Just throwing out thoughts.. (& I'm probably over thinking).
If you use 2 injectors, I think I would place them both at the center of your plenum. {with #1 aiming towards the front runners, and #2 aiming towards rear runners}.

Ride safe, Ted

[gpineau]

Its been a terrible day for working on this project. Didnt get time until late this afternoon.
Was up late last night.
I pull into the garage and close the garage door and go into the house. Just as I step into the house I hear a loud noise behind me. I turn around and see nothing unusual. Later my wife tells me the garage door wont open. So after investigating I see one of the torsion springs has snapped and not enough lift to help the garage door opener. So what was going to be an easy 10 minute fix turned into a 4 hour series of bad luck mishaps.

I clamped the broken spring together at the break and then welded it back together. Rewound the spring and did a test. Looked like it was going to work until the door got half way up then it sagged to one side and froze into position.

Turns out when the spring broke the lift cables came off the spools and wrapped themselves around the shaft and kinked in several places. It was bound up tight, half open and tilted on an angle. Couldn't get access to the pulleys because of the door was partly open so I unbolted the top two panels and used the opener to pull them out of the way.

But as Murphy dictates both panels came loose from the railing and now I have two panels dangling from the opener rail bobbing side to side in the middle of the garage.

Oh well I thought I would deal with that later and resolved not to use the opener for assistance. So I managed to get the door straight and level on the floor again, I restrung the cables, and rewound the torsion springs and locked them into place.

Now it is time to reunite the two dangling panels with the rest of the door. I managed with the help of Fiona and two ladders to lift the two panels back onto the rails and straight and level. But I did not want to use the opener because it was too fast and jerky. So I put a rope hoist on the upper panel and tied the other end to a hook in the back wall of the garage. The plan was for Fiona to work the hoist and slowly feed me the panels while I kept them straight and on the rails. All was going so well until the panels reached the downward bend in the railing.

Then the full weigh of the panels pulled the knot out of the rope that secured the hoist to the back wall. The panels came crashing down off the rails completely. One side in the garage and the other outside.

Two more hours and I get the panels back inside the garage and on the rails again. Bolted everything together, gave up and went to bed.

What's the they used to say on hee haw. If it wern't for bad luck........

Then I take my car that my kid wrecked last month to the body shop to get an estimate for the insurance......they said it will probably be totaled.  So I had just a couple hours to myself in the garage this evening. 

[gpineau]

Just washed up and uploaded some photos of the plenum I made today.
I am not going to upload photos here because the site cant handle high res photos. I will post links to them at the end of this post.
I  got a piece of 3 in pipe to use as the plenum. It was easy to work with and did not take up that much room.  Drilled the holes for the runners and I surprised myself and didnt mess it up.
Will mount the throttle body to the top of it. Put the temperature sensor inside and the  vacuum sensor wherever there is room.   I also want to put a fuel presser regulator somewhere near here but as it is shaping up there is just enough room for a filter on top of the throttle body unless I mount it on the side.

I am pleased with he way things are fitting together.  I ordered the fuel injector bungs and throttle body so I am at a stand still until they arrive. I will use the time to study the relationships between temperature, rpm, load...etc

photos are here.
https://fuelinjectorproject.shutterfly.com/pictures/28#28

[gPink]

No pics of the garage door fiasco? 

[gpineau]

My wife took a couple of photos but not impressive. just me standing on a ladder throwing things.. I would rather not relive the moment

[gpineau]

I was just thinking about how cool it would be to put plexiglass ends on plenum and mount the injectors in such a way you could see the spray of fuel and watch it being sucked into the cylinder.  Not only interesting but educational and could lead to clues to tuning the injector timing......Cool? not cool?

[gPink]

How would you seal it to stand the heat and fuel solvents?

[connie_rider]

Wouldn't be cheap, and a leak would ruin your day.
But, if you use (reinforced) glass (cut exactly right), a machinist could thread the plenum ends, and make caps (similar to a flashlight), with O'rings doing the sealing.

Ride safe, Ted

[gpineau]

 It' not to be permanent. I just want a look inside during development.  I plan to use a 3 inch pipe cap when I am done playing. For now I will just use RTV or bathtub calk.

Connie_rider,  My plan all along was to put the throttle body top side center. There is more room there and I can easily come up with a filter that will fit there.

[gpineau]

An after thought.

Instead of messing with the placements of the injectors to play with the injector timing. ....I can buy another vacuum sensor and attach it to  the cylinder I am interested. By hooking one channel of a scope to the vacuum sensor and the other channel to the injector pulse I can measure the injector time and pulse width to the nanosecond.

This also solves my injector timing problem. 

Before I was going to use the coil firing to tell which set of two cylinders were at TDC . But since the two cylinders share the coil you didn't know which one of the pair was on a power stroke  and which one was on exhaust. 

But with the vacuum sensor hooked up to one of the cylinders I know exactly which one is on the intake and using the firing order I can calculate which cylinder will be next to be on the intake stroke. And knowing the rpm I will know exactly when to pulse the next injector. That sure simplifies things.  Why didn't I think of this before? 

Now it sounds simple. Did I overlook something?

[connie_rider]

Where do you plan to install the vacuum sensor?
If in the #1 runner, there will be some difference there, but the entire manifold will be under vacuum during a intake stroke of any of the cylinders.

Are you still planning to use 2 injectors?
If yes, it doesn't matter.
  (If both front cylinders are at TDC, and you fire the injector, the air/fuel will go only to the one that is on an intake stroke).

Ride safe, Ted

[gpineau]

There is a vacuum port on the side of each cylinder right next to the intake valve. It is normally used for synchronizing the carbs but it would be useful to determine which cylinder is on the intake stroke.

You are right while one cylinder of the pair is on the power stroke the other would be on the intake and would use the fuel from the injector. I want to believe that sharing an injector between cylinders would be enough. But on the magna the pairs are about 5.5 inches apart. Putting the injector between them would put the injector about 6 inches from the intake valve. Its worth thinking about. 

On a Connie the distance between cylinder 1 and 4 would make sharing an injector very difficult to pull off.  But if there is an injector per cylinder the Connie will be a lot easier to work with than a V4 manga.

I am inclined to put an injector on each cylinder, as close to the intake valve as I can get it.  I think this will be less problematic. 

I am still awaiting the arrival of the throttle body and the injector bungs. (not sure I will be using the bungs) . There is so much to do . Connectors, harness, prototype circuit boards. It a lot to keep in your head.  I want to rush it but I know this is going to take forever.

[connie_rider]

{I think}

There is a vacuum port on the side of each cylinder right next to the intake valve. It is normally used for synchronizing the carbs but it would be useful to determine which cylinder is on the intake stroke.
Those ports are located before the valves, and will have vacuum when another cylinder is on intake.
   {because you have a manifold instead of individual carbs or throttle bodies}.

You are right while one cylinder of the pair is on the power stroke the other would be on the intake and would use the fuel from the injector. I want to believe that sharing an injector between cylinders would be enough. But on the magna the pairs are about 5.5 inches apart. Putting the injector between them would put the injector about 6 inches from the intake valve. Its worth thinking about. 
This is what I was worried about around post #34-37. It might be overcome by injecting the fuel a little e bit earlier.
But, you have an intake stroke every 180* of rotation, so {based on BDF's 85% note) part of your fuel charge will probably go to another cylinder. 
NOTE: because the injectors fire so quickly, spraying/fogging the fuel into your plenum may disperse the fuel just fine..

On a Connie the distance between cylinder 1 and 4 would make sharing an injector very difficult to pull off.  But if there is an injector per cylinder the Connie will be a lot easier to work with than a V4 manga.
If you pair injectors as you were planning, 1/2 and 3/4 would be paired.

I am inclined to put an injector on each cylinder, as close to the intake valve as I can get it.  I think this will be less problematic.
Agreed..

I am still awaiting the arrival of the throttle body and the injector bungs. (not sure I will be using the bungs) . There is so much to do . Connectors, harness, prototype circuit boards. It a lot to keep in your head.  I want to rush it but I know this is going to take forever.
Agreed.

Ride safe, Ted

[connie_rider]

{I think}

There is a vacuum port on the side of each cylinder right next to the intake valve. It is normally used for synchronizing the carbs but it would be useful to determine which cylinder is on the intake stroke.
Those ports are located before the valves, and will have vacuum when another cylinder is on intake.
   {because you have a manifold instead of individual carbs or throttle bodies}.

You are right while one cylinder of the pair is on the power stroke the other would be on the intake and would use the fuel from the injector. I want to believe that sharing an injector between cylinders would be enough. But on the magna the pairs are about 5.5 inches apart. Putting the injector between them would put the injector about 6 inches from the intake valve. Its worth thinking about. 
This is what I was worried about around post #34-37. It might be overcome by injecting the fuel a little e bit earlier.
But, you have an intake stroke every 180* of rotation, so {based on BDF's 85% note) part of your fuel charge will probably go to another cylinder. 
NOTE: because the injectors fire so quickly, spraying/fogging the fuel into your plenum may disperse the fuel just fine..

On a Connie the distance between cylinder 1 and 4 would make sharing an injector very difficult to pull off.  But if there is an injector per cylinder the Connie will be a lot easier to work with than a V4 manga.
If you pair injectors as you were planning, 1/2 and 3/4 would be paired.

I am inclined to put an injector on each cylinder, as close to the intake valve as I can get it.  I think this will be less problematic.
Agreed..

I am still awaiting the arrival of the throttle body and the injector bungs. (not sure I will be using the bungs) . There is so much to do . Connectors, harness, prototype circuit boards. It a lot to keep in your head.  I want to rush it but I know this is going to take forever.
Agreed.

Ride safe, Ted

[gpineau]

Posted it twice. Were you trying to make a point?  lol

Re: The vacuum sensor on the intake port. it is a sensor and will read the amount of vacuum at that port which will be different than the vacuum of the plenum, (at least for a short time) at the instant the valve opens. I could use the difference between the two sensors to determine which cyl is on the intake  stroke. It's worth a try. 

Using the coil signal only tells me that two cylinders are at the top of the stroke but does not tell me which one will be starting the intake stroke. Short of putting a sensor on the cam I can't think of another way to determine which cylinder is on the intake stroke.. Even the signals from the sensor on the crankshaft can't differentiate between the two cylinders and fires both spark-plugs cause it does not matter firing a cylinder on the exhaust stroke.

I could use just a  couple of injectors and spraying directly into the plenum between the cylinder ports and tune it to work just fine. In fact some of the earlier systems did not time the injectors at all but just fire them all at the same time and got decent results. And that is probably enough for proof of concept on a motorcycle. Maybe its not important to time the injectors to the intake stroke  but I think it will give me more opportunities for adjustments and tuning if I have one injector per cylinder.

(Im on a budget so this is going to take a while)
I ordered the injector driver transistors and they shipped yesterday.  Will be here in a week. got some blank prototyping  bread-boards yesterday. Fuel regulator is on the way.
Eventually I will need the temperature sensor(s) and the oxy sensor, but not necessary for playing with the design. 

The throttle body should arrive today it comes with the position sensor attached.  So I will have something to play with this weekend.

The more I read, the more I learn just how much I don't know....

Baby steps...
Gerry

[gpineau]

oh my. I forgot I had bid on a throttle body last week.  Never thought I would  get a brand new 2017 Honda CRV throttle body for $10 but I was the only bidder. I have a lesser quality one that I paid a lot more for arriving today.

I am replacing at least one of the runner tubes with an acrylic pipe so I can see what is going on when the injector fires. 

Sitting around waiting for the postman makes me crazy. He will probably come as I am leaving for work.

[connie_rider]

My oops. I keep forgetting that your paired cylinders would be on the same up/down stroke.
If you stay with the 2 injector plan, the pick up coil for each pair, will be your best signal.
If you go to the 4 injector plan, (because the engine is a V) maybe you could use the differing time between pick up coils to determine #1?
ie; I keep thinking the engine fires at 180* increments. But with your V, it is different...
        What is your firing order?
     If 1,2,4,3, Maybe the degrees/time from 3 to 1 is distinctive?

Good deal on the throttle body. Do you know what size it is?
If not, what is the engine size and RPM range of a CRV?

Ride safe, Ted

[gpineau]

 the firing order is 1432
The CRV is 2.4 L

Darn, no throttle body yet.  its 2 days late.
The throttle body I am waiting for is off a 1.5L Hyundai