View Full Version : High Output Injector Question
Steelkilt
05-13-2009, 22:04
I am about to replace injectors and wondering whether it would make sense to use high output injectors. currently in the process of installing turbo master, heath chip, a 4" exhaust, and guages. (after the vacuum pump failed.) i do some towing, up to 7500 pounds. but truck is mostly used as a family hauler. it has the 14 bolt 10.5" diff and 4.10 gear. just wondering what additional advantages or disadvantages there might be to the high output injectors as opposed to stock output. in terms of power, fuel economy, driveability, wear.
arveetek
05-14-2009, 08:17
I would take the time to read this thread:
http://www.thedieselpageforums.com/tdpforum/showthread.php?t=26767
It goes in-depth explaining the differences between injectors. Summary: go with stock injectors if you have a stock injection pump.
Casey
Check this article out. It's all about the question you asked. http://www.thedieselpage.com/members/features/65fuelinjectionc.htm
Steelkilt
05-14-2009, 11:11
Thank you. I had ordered the standard injectors and wanted to make sure before installing this weekend. it still has the original injectio pump on it. probably right to go with the standard injectors, at least until i'm ready to change the pump, and start spending more at the pump. would probalby get more benefit from an intercooler.
This question has been around probably since the discovery of the marine DB-2 & marine injectors. In order to put this thing to bed once and for all we need someone with dyno access to do some comparison runs. Same truck, same dyno, same day - a series of runs with stock injectors and a series with marine injectors. I know that is a lot of work but at least we would have hard data. Anybody up to the challenge? How about it JK?
DmaxMaverick
05-14-2009, 17:48
This question has been around probably since the discovery of the marine DB-2 & marine injectors. In order to put this thing to bed once and for all we need someone with dyno access to do some comparison runs. Same truck, same dyno, same day - a series of runs with stock injectors and a series with marine injectors. I know that is a lot of work but at least we would have hard data. Anybody up to the challenge? How about it JK?
You are right. But, it isn't that simple. There are too many definitions involved, and not-so-reputable vendors selling injectors of the same name. If only brand names and common vendor products were available, it might be practical. However, as long as Ebay and the like is around, it isn't going to answer the question. It still won't prevent the tall claims made by some vendors.
You are right. But, it isn't that simple. There are too many definitions involved, and not-so-reputable vendors selling injectors of the same name. If only brand names and common vendor products were available, it might be practical. However, as long as Ebay and the like is around, it isn't going to answer the question. It still won't prevent the tall claims made by some vendors.
This is so true. 40 more h.p. with injectors is a pretty tall claim. As far as I know there is no hard data to back up these claims. However if Bosch marine injectors (for example) had the ability to give 5 more H.P. and would change my torque curve to give me max torq at a higher rpm I would buy them. Right now it's just a crap shot.
Changing the injectors can change the injection pressure, the duration of the injection event and/or the spray pattern. It CANNOT change the amount of fuel injected. Only the injection pump can do that. So, unless your injectors are bad or a poor match for the application, changing them (alone) will not add a single horse power.
TMSAISTI!
In April's article on 6.5 injectors Jason figures the fuel rate doesn't change but the fuel flow does. After this statement the author writes I wish there was data to back this up. It seems some people think there is an advantage to marine injectors. I would like to know for sure. We all have our opinions - for me the jury is still out.
...the fuel rate doesn't change but the fuel flow does...
I don't understand what this statement means.
The injection pump is a positive displacement pump. If it schedules 60mm3 of fuel, that fuel either has to go out the injector, bypass back due to internal pump leakage, or blow a hole in the injection line. Either way, there's another 60mm3 right behind it. If you completely remove the injector, the 60mm3 will driibble out the end of the line under zero pressure. If you block the end of the line (pump inefficiencies excluded) that 60 mm3 will find or create a leak to get out of.
If you put a high pop injector you'll get a (potentially) better spray pattern (good)and a slightly longer injection event (not so good). If you put a high flow injector you'll get a sorter injection event and maybe a less atomized spray (same fuel going through a bigger hole.) The high pop might possibly increase efficiency by better atomization, but the high flow injector doesn't have anything to offer unless you're already over flowing the existing injector.
TMSAISTI!
More Power
05-16-2009, 14:36
In April's article on 6.5 injectors Jason figures the fuel rate doesn't change but the fuel flow does. After this statement the author writes I wish there was data to back this up. It seems some people think there is an advantage to marine injectors. I would like to know for sure. We all have our opinions - for me the jury is still out.
Dave, you are exactly right!
Believe me, if I were selling "marine" or "performance" injectors, I'd also proudly display all manner of hp/tq graphs that anyone could reproduce on a chassis dyno that clearly show an advantage for non-stock injectors over new stock injectors.
I know of NO vendor who is doing that. I'd like to know why....
By the way, the day that article you referenced hit the Page, I received an email from a longtime friend and automotive writer. He said a friend of his recently bought a set of Bosch "marine" nozzles off eBay. As it turned out, the nozzles he bought were made by Bosch, but they were factory stock on-road nozzles - not marine, as referenced by the stock/marine ID numbers listed in the article. The seller was misrepresenting his product on eBay. Buyer beware...
Jim
If you put a high pop injector you'll get a (potentially) better spray pattern (good)and a slightly longer injection event (not so good).
TMSAISTI!
Yes you will get a better spray pattern and I believe if you are putting the same amount of fuel thru the same size hole at a higher pressure you have changed the fuel flow. I'm thinking there may be some value in marine injectors. I would just like to know for sure.
By the way, the day that article you referenced hit the Page, I received an email from a longtime friend and automotive writer. He said a friend of his recently bought a set of Bosch "marine" nozzles off eBay. As it turned out, the nozzles he bought were made by Bosch, but they were factory stock on-road nozzles - not marine, as referenced by the stock/marine ID numbers listed in the article. The seller was misrepresenting his product on eBay. Buyer beware...
Jim
That's one of the things I appreciate about this page - the opportunity to get an education. From the articles as well as the members. They say the older you get the smarter you get but the part they don't tell you is how old you have to be before that finally happens. 55 and still learning.
..if you are putting the same amount of fuel thru the same size hole at a higher pressure you have changed the fuel flow...
Can't happen that way. The pressure is higher because the needle is obstructing the oriface (due to increased spring pressure.) So, for practical purposes, the hole is smaller. Regardless, the total fuel flowed cannot exceed the pump output. The flow rate may change, hence the duration of the injection event, but flow (volume) cannot change unless the pump changes.
I upped the pop press on my wife's 95 stock inj to 2200 psi. when i replaced the nozzles.
That is 39000 km ago.Engine runs as happy as can be,346000 km on orig engine.Over 200 k on the IP.
Cold starts are quiker, no glows needed for restart after sitting for up to 1/2 hr when warm.the Milage is very good at 23.6 mls/gal.
If there is a shorter injection duration cycle in theory,who will notice a millionth of a sec in real life?. I certainly dont.But IMO the improved atomization is noticable as the engine has more snap than my freshly rebuild 98 with stock press nozzles(inj were still good)
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