Any info on 5hole vs 7 hole injectors on 12v?

kawi600

kawi600

got Coal for Christmas
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Jun 9, 2008
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I did some searching and I could swear there was some threads on this I cant find anything that has what Im looking for.
Trying to get some experience on dyno or seat of pants dyno, with both nozzles in VCO or SAC dont matter so long as theyre comparable flow.
At what point does boost penetration become an issue on the 7 hole injector?
This play / tow truck doesnt see more than 50psi.
Im leaning towards a a 7x.012 VCO 148*, maybe with a smaller delivery valve initially to see what the smoke is like. I tend to run lower timing for low end power. Low smoke is a factor for me, I dont want to be 'that guy' that ruins the sport for everyone in the area.
 
Im hoping theres something to the claims of better atomization and low end power.
 
There has been a few threads started on this subject. It hasn't been talked about in over a year at least though. There are a few vendors on here that can get you a good/clean 5x0.XX injector for your setup. Smokem (Weston), CTDyounggun (Seth), to name a few.
 
My 7x14's were very dirty. I put part of the blame on my pump with full cuts. In my opinion a nice set of 5 hole sticks are hard to beat
 
Does seem a little odd that the 6 and 7 hole injectors are so popular with vp trucks but not so much with the 12v crowd. That being said the 5 hole injectors seem to do the job just fine.
 
zfaylor said:
Does seem a little odd that the 6 and 7 hole injectors are so popular with vp trucks but not so much with the 12v crowd.
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That has everything to do with availability, later engines with a centered injector location would have stricter emission regulations, hence more orifices of a smaller size. The flip side of the coin is the injection systems on later engines also produce more pressure, this is needed to create fuel penetration with smaller orifices.
 
Smokem said:
That has everything to do with availability, later engines with a centered injector location would have stricter emission regulations, hence more orifices of a smaller size. The flip side of the coin is the injection systems on later engines also produce more pressure, this is needed to create fuel penetration with smaller orifices.
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I would say this pretty much answers the OPs question then. In other words p7100s lack the injection pressure necessary to take advantage of and/or need more holes?
 
I had a really nice set of 7x.015 SAC injectors that Chris at E.D had built for me a few years ago. Made decent bottom end power, but since then I suggest to customers to run 5-hole injectors. Hands down the 5-holes still run better and we've had better luck with them.
 
zfaylor said:
I would say this pretty much answers the OPs question then. In other words p7100s lack the injection pressure necessary to take advantage of and/or need more holes?
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The 7-hole nozzles are from a John Deere application, most likely to reduce low speed smoke that was common with the 4-hole nozzles they replaced.
 
good info guys, guess I stick with a 5 hole nozzle probably 5x014.
Ive had decent luck with westons suggestion of running low timing along with 155* spray cone. Its got good power and the smoke is low compared to what it was.
How much timing can you throw at a marine injector before its out of the bowl? Not sure how much the DV affects the trailing edge of the injection event.
 
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