Injector placement in 2V head.

[Kaptain Ketchup]

My megasquirt conversion is leaving the ground and I am looking at how to install the injectors on a turbo engine (4 injectors, one in each runner, batch fired). I don't have enough room to put the injectors in the back the ATP manifold and have decided to put the injectors right in the head iteslf.

Any help/advise on the following would be great:

-Preferred injector angle/placement (have the thin bosch style injectors) with relation to intake runner.
-What should I point the injector at? (base of valve guide, back of valve, etc.)
-Would the heat from the head be too much for the injector body?
-Is it possible to put the injectors too close to the valve that would hurt performance?

I have a spare 750 head that I plan on using for as a test bed to find proper placement then only drilling the 1000 head once. I am going to weld the bungs in and remove the bung material protruding in to the runners.

A rough pic of where I plan on putting the injectors. I am going to put them as far "in" (away from where the carb boots would be) as I can without getting in to the spring pockets. I may trim the one cooling fin off the back of the oil feed line to get room to weld the bungs in.

Good idea? Bad idea?

[humhead]

Are you sure you're going to be able to mount the injectors you use correctly?
Try to duplicate the exact mounting position, angle & depth of the throttle body
the injectors originally came from. If you're using aftermarket injectors, see if the manufacturer has any recommendations. Pics of the manifold & throttle body you're using would help us help you.

Terry

[Kaptain Ketchup]

Humhead,

No, I'm not 100% sure quite yet. I just don't have room on the rear of the manifold to put the injectors and there is a bunch of room between the manifold and the head.



Throttle body, compressor side, and one of the four injectors I am using.



Manifold is to the left of the calipers.

[humhead]

Looks like you're using an old style draw through system & replacing the carb with a throttle body. What brand & type injectors are you using? do you know the exact dimensions of the hole they're designed to fit into?
Do you have the tools necessary to precisely drill four holes with the right dimensions in the head?

Terry

[ArttuH]

Well, I think that it's not a bad idea to fit the injectors in the head. Except amount of work needed. Heat is another question but I guess that it won't be a problem. Many car engines have injectors in the head and although your engine is air cooled I think that the head doesn't run significantly hotter compared to water cooled one.

In theory the injector should point at back of the valve. Distance to the valve should be long enough to allow spray pattern to spread over the whole port area. But my opinion is that also less ideal placement works just fine in most cases. I think that difference is biggest at low rpm and when the engine is cold. Otherwise difference is most likely very small.

Are you sure that there isn't any change to mount the injectors to the manifold? I'm asking just because this head modification sounds quite difficult and risky to me. How about mounting the injectors on top or bottom of the manifold and pointing them at the intake ports?

[Kaptain Ketchup]

Terry, Yeah I am replacing my carb with a throttle body on a draw through system. I'm using 28 lb/hr bosch injectors (Bosch # 0 280 155 931). I plan on using bungs similar to these.

http://www.cprracing.com/injbung1.jpg

The head will be drilled to fit these (I'll have exact dimensions when I decide which ones to use) and I'll weld them in place and grind out what sticks out in to the runner.

Drilling the head will be the tricky part but I plan on using a two-axis table on a bridgeport mill. I will need two mirrored sets of holes (1 and 4 will be the same but mirrored and 2 and 3 mirrored as well). If my goal is to hit the backside of the valve then each set may (depending on runner design) have a different angle with respect to the runner and they will both be set at different o'clock positions around the port. IE: The middle set (runners 2 and 3) will have the same installed angle, say 45°, from the runner yet they will be mirrored around the runner (#2 will be at 11:00 and #3 will be at 1:00). Then I have to do the same procedure for the outer runners 1 and 4. Runners 1 and 4 may be set at 10:00 and 2:00 to get them to point at the back of the valve with the outer runners on a GS head being a bit longer.

This is why I need to use the 750 head as a template to get my numbers. I don't imagine the final head will be hard to do once I get the bridgeport set up using the 750 head.

ArttuH,

I can't just put the injectors in to the manifold. If I tried from below pointing in to the intake runner and I'd run in to the wrap around pipe on 3 and 4. To have them installed on the rear pointing right in to the runner I hit the turbo on 2 and 3. I can't find a spot that would work for all four injectors on the manifold. I guess it is risky... I may have to find another spare 4 cylinder 2V head to make sure I have things right.

[humhead]

Sounds like you've got it worked out. The fuel rail is gonna look interesting!

Terry

[Kaptain Ketchup]

It won't be a rail so much as a distribution block and some flex line running to each injector. I can run the return and pressure regulator off the block, away from any inductive heat sources.

I really need to get out of an apartment and in to my own house so I can get some shop area... Makes it hard to finish a project when I can only get back to my parents' house every few weeks.

I need shop space in Ottawa!! (I am currently looking for a house, just living in an apartment renting out a room to save some money)

[KoolKat]

Interesting project!
I remember the first gpz1100's (B1) had the injectors mounted in the head,but from that model on,they had them throttle body mounted.You may be able to find out with a search if there was a genuine reason for the move.I was hearing that the B1's were washing bores,but that may be crap and also may have had nothing to do with the injector position.
What about building some 'spacers' that bolt to the head,like the original rubber manifolds,and mount the injectors in them,then mount your manifold to the 'spacers'.They could be made quite thin in there width,not taking up much room?
You mentioned batch firing,so my thoughts are that exact injector position may not be as critical,as if they were fired sequentialy.
I am interested in your MS conversion,as I'd like to try it on both my bikes and cars,and my car is a heavily modified turbo set up.

[Busafied]

I know on our turbo busas, there are a few variations.
The fuel injection is setup with them under the blades of the t/b's (factory), and the secondaries are in the plenum directly above each t/b (pointing into each t/b).

IMHO-
Find a TB setup from a 600 f4i or similar, take the tb's apart, and adapt them for your bike.
I recall another member here doing just that a yr or 2 ago now..

GL-
Ron

[Flatline_Racing]

Find a set of GPZ1100 throttle bodies and use them.



or you could go with something similar to this turbo setup:

[drhach]

You're a brave man. Try to make sure the the spray pattern is hitting the head of the valve. this will help to atomize the fuel.

[Flo]

is there any more info on that blue Turbo GS?

[Flatline_Racing]

is there any more info on that blue Turbo GS?

I had to go back through my emails to '05 to find this information:

Mitsubishi TD04 Turbo from a 9-5 Aero
Saab VDO Pump For oil return
GS750 oil pump gears
Stock charging system
4 wire 02 sensor
350cc/min injectors form a Saab 903 Viggen

I am not the owner of this bike, but had email contact with him when i started planning to put a turbo/efi on my1000.

[Nerobro]

wow, that's one seriously ugly turbo rig.

I'm not sure I'd mount them to the head. For temprature reasons. By mounting the injectors off the head you can expect your o-rings to last forever. On the head they will cook.