injectors-6 hole vs. 5

[92strokersmoker]

Im looking to change it up again and wondering whats the low down on the 6 hole style. I know the IC trucks came stock with 6x.009 and I got 5x.012. I was thinking about trying a 6x.012 or .013. Do the 6s just spray a wider area or cause less smoke? Im just trying to get a better understanding.

[ahale2772]

check out the injector breakdown thread, its got lots of good info.

you need to note the style of tip as well as the size, a sac nozzle may be less efficient than a VOC, even if they are both 6holers of the same size

usually the spary angle is a function of what year of the truck....noIC is 145*, i believe IC is 155*

hence even if you get an efficient injector with the wrong spray angle you wont be very happy with results

[Richie O]

check out the injector breakdown thread, its got lots of good info.

you need to note the style of tip as well as the size, a sac nozzle may be less efficient than a VOC, even if they are both 6holers of the same size

usually the spary angle is a function of what year of the truck....noIC is 145*, i believe IC is 155*

hence even if you get an efficient injector with the wrong spray angle you wont be very happy with results

You have it backwards. 155 non cooled, 145 cooled.

[cougar]

This is something I've wondered about myself. Never found a good answer to it either.
So let me throw this thought out there and see what you think.

Compare a 6 hole and a 5 hole injector with equal cross sectional area and all other factors being the same;
6 hole I would think would give you better atomization at lower throttle because of smaller holes, but might become a restriction at high flow WOT.
5 hole may not give as good atomization at lower throttle, but the bigger holes may have less restriction at high flow WOT and atomization improves.

[ahale2772]

You have it backwards. 155 non cooled, 145 cooled.

gotcha, thanks Richie... and oh yeah no cooled has 7mm tips and cooled has 9mm (DOHH).. mix them up all the time too

also interesting to not that some 6holers have 3 small holes and 3 larger holes

[Richie O]

You have it backwards. 155 non cooled, 145 cooled.

gotcha, thanks Richie... and oh yeah no cooled has 7mm tips and cooled has 9mm (DOHH).. mix them up all the time too

also interesting to not that some 6holers have 3 small holes and 3 larger holes

You mean the non intercooled trucks have 9mm and intercooled trucks have 7mm right?

[oldestof11]

Lexdysic are we?

[PToombs]

Lexdysic?

I thought that was the special grease you used on electrical stuff?

[oldestof11]

No pete. It is what your boyfriend uses.

[Douglas]

This is something I've wondered about myself. Never found a good answer to it either.
So let me throw this thought out there and see what you think.

Compare a 6 hole and a 5 hole injector with equal cross sectional area and all other factors being the same;
6 hole I would think would give you better atomization at lower throttle because of smaller holes, but might become a restriction at high flow WOT.
5 hole may not give as good atomization at lower throttle, but the bigger holes may have less restriction at high flow WOT and atomization improves.

Time to get out the Fluids text again... W/O getting out the book to determine exactly ,the more holes for a given area the lower the flow will be at a given pressure...and since the pump is going to try to dleiver a particular volume, more holes will up the pressure which seems to lead to a better spray/atomization.

What I need it two trucks, one for power, the other for mileage. The FE one would just get a 4BT...maximum efficiency happens at power levels well above cruise requirements. Sooo IC'd injectors and a tight, efficient turbo *WITH* intercooler lay the foundation for good mileage...
cheers,
Douglas

[ahale2772]

you mean the non intercooled trucks have 9mm and intercooled trucks have 7mm right?

I was just joking that time ...honest, Pete allready put me in my place on that one a while back

[Richie O]

you mean the non intercooled trucks have 9mm and intercooled trucks have 7mm right?

I was just joking that time ...honest, Pete allready put me in my place on that one a while back

I thought so, but wanted to make sure. It easy for wrong info to get spread around. I am as dumb as a box of rocks, but when I do learn something I hope its right, because I never can replace wrong info for correct info.

[PToombs]

No pete. It is what your boyfriend uses.

Dreamer.

[cougar]

This is something I've wondered about myself. Never found a good answer to it either.
So let me throw this thought out there and see what you think.

Compare a 6 hole and a 5 hole injector with equal cross sectional area and all other factors being the same;
6 hole I would think would give you better atomization at lower throttle because of smaller holes, but might become a restriction at high flow WOT.
5 hole may not give as good atomization at lower throttle, but the bigger holes may have less restriction at high flow WOT and atomization improves.

Time to get out the Fluids text again... W/O getting out the book to determine exactly ,the more holes for a given area the lower the flow will be at a given pressure...and since the pump is going to try to deliver a particular volume, more holes will up the pressure which seems to lead to a better spray/atomization.
cheers,
Douglas

Consider the non-constant parameters. Our injectors have a pop pressure of 245 bar. That is not an absolute delivery pressure, but a minimum. The pump regulates volume, not pressure. So does the pump output pressure increase with RPM? If the pressure is not regulated, it has to. So at what pressure through a given hole diameter does atomization become more efficient?

[Smokem1]

http://www.competitiondiesel.com/forums ... p?t=109421