The thinking, exploring, reading, and slow comprehension of how big and expensive this project is continues. Lately I’ve been thinking about injector manifolds and throttle bodies. I’ve also continued to think about longer intake runners.
Looking at where to put injectors into the engine for direct port injection, I could remove one of the two spark plugs and use the open spark plug hole to inject. However, there’s probably a reason that Honda put two spark plugs in the engines. I don’t think it would be wise for me to mess with that.
I could potentially drill into the intake header on the engine and install the fuel injector there. However, I’m very leery of drilling into the engine. I want to be able to reverse whatever I do if I screw it up.
To be on the safe side, I think I will get a couple of aluminum blocks, bore out the middle of them for airflow, and then drill and tap in holes for the injectors. One thing I still don’t know about is if I need to have the injectors angled in a certain way or not. Can they jut out at 90 degrees or do they need to be turned toward the valves? Would it be better to have the injectors staring straight down the barrel of the intakes and have the air curve around to the side?
One person on the IPCRC suggested I switch from dual throttle bodies to a single throttle body. Evidently many car engines ran on single throttle bodies. However, several websites suggest (to me anyway) that it’s better to go with multiple throttle bodies because the rider will have more control and better response. I think I will try to stick with two throttle bodies. If possible, I’d like to reuse the ones in my carb. Just have to figure out how to hack off all the extra bits of the carb I’m not using…
Intake runner length continues to kick around in the back of my mind. A few conversations on the IPCRC got me thinking about it. It seems like it could be a nice little power boost if I could actually figure out the correct runner lengths. Perhaps I will setup the bike so I can change in and out different lengths of tube. Once I get FI timing and whatnot down, then I can play with tube length.
A few good articles people have sent me:
Intake Manifold Tech: Runner Size Calculations
V-Max Fuel Injector Kit (including scary costing figures)
Engine Basics: Detonation and Pre-Ignition
A few other thoughts…
The Suzuki GSX1300R has nice fuel injector-equipped throttle bodies. The Honda CBR600 also has fuel injected throttle bodies. So does the CBR1000. I wonder if perhaps I can find one of the proper diameter to drop onto my engine. There certainly are enough sets of them for sale on EBay. What sport bike, street bike, or cruiser has fuel injection, only two cylinders, and has in the range of 1000cc worth of displacement?
uh hello! my V-Strom 1000 is fuel injected, you could use the throttle bodies from one of those too.
Brilliant! I forgot the V-Strom was fuel injected AND a two-banger. All I’m seeing on E-Bay is V-Strom 650 throttle body assemblies. Looks like V-Strom 1000s don’t wreck and get parted out that often. The 1000 would be better than the 650 as I assume it’s designed for larger displacements. Mind letting me borrow your throttle body for a few days? 🙂
And it appears that there aren’t any fuel pumps on EBay for the ‘strom… That would be quite convenient to have a fuel pump from the V-Strom although it appears to be an internal tank pump. I wonder if it needs to be immersed in gasoline to keep it cool or if it could run externally with a hose hooked up to the intake. The PC800 has an external fuel pump that is gravity-fed from the tank.
Honda VTR1000 SP-2 for example
or new ones Honda Varadero
Or Aprilia RSV Mille
Or the new ones Honda Shadow
There are alot of them actually
I’ve been looking through the microfiche for a lot of bikes. So far none has stood out as THE solution. I was hoping that the new Honda Shadow with FI would do the job but the way the injectors and throttle bodies are setup, it wouldn’t be worth it. I’ll look into the Aprila and Varadero to see if they might work. 🙂