K75 injectors.

[mjydrafter]

Thread update:

I found a set of the green Bosch 415's at the local u-pull lot late last fall.  I finally got around to cleaning them up and trying them out this weekend.  I give them 2 big thumbs up.  the bike runs really well with them.  I will have to track the mileage for a bit, but so far so good.

In regards to the white ones I was trying earlier (in the foreground of the pic below).  I believe they might still work, as my fuel pump went out just after I tried them last summer.  I believe that my fuel pump may not have been 100% when I tried them.

The green ones (I believe they are the ones from earlier in the thread from Ebay), seem to work really well.

My name is mjydrafter and I may have an injector collecting problem

[Westone]

Hmm. I looked at the fleabay ones. Those are 17 pound injectors. Seems like it would richen the mixture significantly.

Agreed, yet that 17lb rating is at 43.5lbs of pressure. The K Bike system runs at 36lbs if my Clymer's is accurate. I'm wondering how much that may affect the flow rate. More questions here than certainties with these injectors. One thing that is certain is that my bike is running much better with the fleabay injectors. And in a few hundred miles I will be able to compare mileage against the stock injectors as well. I was getting 43 mpg with the originals.

ETA: On Stan Weiss' home page there is an online calculator to convert injector flow rate between different fuel pressures. Enter the rated flow rate of the injector, the pressure it was rated at, and the new fuel pressure, and it supplies the flow rate at the new pressure.

According to it, a 17lb injector rated at 43.5lbs pressure will flow 15.465lbs, or 162.5cc, at 36lbs pressure. That is just barely closer to 14lbs than it is to 17lbs.

The flow rate is calculated in pounds flowed per hour, or CCs per minute, at the given pressure. Fuel weighs 6lbs per gallon. So in theory the difference in flow rate between the stock injectors and the ones I installed today is just a hair over 1/4 gallon per hour, when the new ones are run at 36lbs pressure.

Correct me if I am wrong, but I think the difference between theory and reality is the flow rates are calculated at 100% duty cycle of the injector, and in application they are sized to operate at somewhat less than that. Which would make the actual increase in fuel flowed somewhat less as well.

[Westone]

The only downside I can see is that the Ford injectors don't have the slit cut at the top for the spring clips that hold the K75 injectors to the fuel rail, these are not really needed as the fuel rail is bolted down clamping the injectors in between the intakes and the fuel rail. 

So it would seem, however in my case I failed to install the clips on the new injectors, and found that the clips are necessary to keep the top of the injector snug up into the opening in the fuel rail to remain sealed. The opening in the rail is not straight walled, it expands outward from the rail. The clip keeps the injector and O-ring snug up in the opening. On the cylinder head end of the injector, the opening is straight, and the injector and its O-ring can move up or down in the opening and remain sealed. This design would allow for variations in manufacturing and dimensional changes with heating and cooling cycles in the engine block.

[caseyvr6]

Realizing this post is old, wondering if the OP still runs the 415 injectors. The 415's are substantially higher across the board than the OE 210's and I'm considering installing them as an upgrade.