question about DSM 450cc bluetop injectors
 

I have a set of bluetop dsm's installed on my car, they are fed by a dual-feed fuel rail that i don't know any information about. I paid 30 bucks for the rail and i know it came off a miata, and i also know the guy i bought it from probably knows more about miatas and injectors than anyone else i know.

The key issue is that i seriously doubt that he used this fuel rail along with bluetop dsm injectors, and the rail is not machined to the exact fitment specs of a stock fuel rail. So the result is that the rail, when bolted down, doesn't go down as close to the head as the stock rail, leaving the injectors room to move around. they are not quite snug i would say, but they don't move up and down, just around if you turn them. I don't think they are actually moving around while I'm driving.

So along with this issue, the injectors themselves are not as long as stock miata injectors. The physical characteristics of the injector are pretty much the same except the pintle cap on a stock injector is about twice as long as the one on the dsm. This means that the injector doesn't protrude down into the head as far as the stock one would, and i'm wondering if it is affecting the spray pattern. Almost as if the pattern was hitting the sidewall of the opening in the head, causing the fuel to actually drip down into the cylinder rather than being a mist.

I don't know if shaving the fuel rail down will help any in order to get the rail closer to the head. Does anyone have any experience using these injectors? Wishin I would've gotten RX-7 injectors now...

thanks, Alex

maybe try putting your fuel rail on without the spacers or maybe shorter spacers.