Understanding Marine Injectors

[North Maine]

Ok I did search, but it really has never been REALLY clarified, so I'm asking.

Marine injectors/HO Injectors/High Pop Injectors whatever you want to call then every vendor claims will boost power, and the general rule is that they will only boost power if you can supply more fuel, such as with a chip/ECM reflash. This however, does not make sense to me. The way I understand it, lets the say the IP is pumping 60mm^3 of fuel per stroke, wouldnt ALL of that fuel get sprayed thru the injector, regardless of marine nature or HO nature? I don't see how an injector can put more fuel into the engine, which is what makes power. Can someone educate me on this? (I feel dumb now.)

 

[RCpullerdude]

Main idea of a marine injector is atomization from higher pop pressure, not injecting more fuel. I think there may be some nozzle swapping involved too for different spray cone and atomization.

 

[North Maine]

yes the nozzles are different and the pop pressure is slightly higher... but I dont see that making 40 extra horses

 

[RCpullerdude]

I think the point has been made over and over, that's over worn out stockers. In reality, I doubt there'd be much of a gain, brand new stock and brand new marine.

 

[JMJNet]

I am also interested in this question.

My question is "does it worth the extra dollar?" in some cases, it is only about $20 to $30 dollar extra at the bay "good" supplier. However, it is very substantial price difference on the one from Heath or Kennedy.

 

[Goldsburg]

It is my understanding that in addition to what's been said already, the orifice size and pintle are slightly larger.

The purpose of this would be to reduce peak injection line pressures from additional fuel delivery of the marine pumps. Lower peak injection line pressures (already in the neighborhood of 11,000psi) will help reduce wear and fatigue on the pump drive systems turning the marine pump which, in the majority of 6.5 diesels, is the (cam) timing chain.

Furthermore, the larger orifice and pintle would provide for less mechanical capacitance in the injection line itself. The mechanical capacitance (think of a rubber hose swelling under pressure) would also ultimately limit the amount of fuel (delivery) reaching the injector or cylinder. The pump would not be "working so hard" to pump fuel through the nozzle. Some minute additional delivery in-cylinder would result.

Well... what about the cracking pressure being higher? The answer there is that it is just a "cracking" pressure, the pressure at which the nozzle will open. Remember the injection line pressure I mentioned earlier? This was much higher than the cracking pressure of the nozzle. Yes, the higher cracking pressure will result in better atomization because the nozzle is starting its injection cycle at a higher pressure, but because of the larger pintle and orifice the injection cycle is slightly shorter.

It is because of the slightly shorter injection cycle and minutely increased delivery that I believe that vendors can claim higher horsepower. Is 40HP increase in power accurate? IMHO maybe, but only if you are replacing worn out nozzles to start with...

Regards,

 

[Goldsburg]

I think the point has been made over and over, that's over worn out stockers. In reality, I doubt there'd be much of a gain, brand new stock and brand new marine.

IMHO, there wouldn't be much of a difference unless you are running "marine-like" delivery rates on your 6.5TD fuel system.

Regards,

 

[matuva]

IMHO, there wouldn't be much of a difference unless you are running "marine-like" delivery rates on your 6.5TD fuel system.

Regards,

X2. Unless you have a reflash wich allows more fuel flow, there's no use for "marine" injectors on your truck.--- but even so---

I have a GL4 reflash with stock brand new BOSCH, and I can't see noticeable difference compared to a V.2 reflash with BOSCH marine injectors---

my .02

 

[North Maine]

I think the point has been made over and over, that's over worn out stockers. In reality, I doubt there'd be much of a gain, brand new stock and brand new marine.

I disagree that point has been made over and over, I wouldn't think Heath would say his HO injectors put out 40 extra hp, but then decline to state thats compared to worn out stock not his reg. injectors, otherwise, he would sell both STOCK and HO as +40 HP injectors. Nope, don't think so. HO does mean something.

 

[RCpullerdude]

I'm sorry, but if you search on the old site, it has been covered over and over, and now it's been covered here at least once.

 

[North Maine]

So in your opinion Heath is misleading people buy having HO and Stock injectors? (along with all other vendors)

 

[RCpullerdude]

Honestly, to a point, yes. I imagine they have a small gain over stock, but like Golds mentioned, a real gain would be noticed with a marine pump built for them. IMHO, if you have everything else, for the few extra bucks when changing injectors anyways, why not?

 

[North Maine]

Agreed... though with the Heath units its more like a mortgage payment! haha I have Marines waiting for install, hopefully this weekend. The stock ones are at 220, so I'm hoping for a boost

 

[JMJNet]

I think the 40HP is what everybody is saying about marine injector, not just Heath.

North Maine, would you update us on your truck after your installation of the marine inj.

Have fun.

 

[sshewins]

Not sure if this has been covered either, but lets not forget that while the upgrades may have a different spray pattern and higher pop pressures, it still only sprays into the pre cup. Now if you were to start altering the port sizes, using a N/A cup or even one from a 6.2, I would have to think that we could then see additional increases. IIRC, the page did some research on the pre cups. I'm too cheap to subscribe, so I can't say for sure.

 

[chrisk1500]

GL4 and HO injectors were roughly half a second faster in the 1/4 mile vs stock injectors and 2.0 tuning....

How much of that .5 second was due to programming only is questionable....but I bought the HO stuff for a reason....

 

[Shlep]

I noticed a difference over 2200 rpm with the 40hp injectors, with a much smoother accel with less lag. Looking into the reflash next, to help pull the 5th wheel.

 

[SCREAMINXL]

I wonder what makes Heath's Injectors "H.O."? Different tips, pop pressure or both? I had Diesel Pro put together a set of marine injectors for my brothers 94 when I rebuilt the engine and he told me I was wasting my money installing them instead of stockers, fine by me since it was by bros money! I would like to send Diesel Pro a Heath H.O. Injector to find out what it is. Inquiring minds would like to know!

 

[Turbine Doc]

H/o injectors as has been described to me have stiffer spring hold inj closed longer so psi goes up for better atomization/burn, some also claim to have bigger injector tip as well as stiffer spring to allow for more flow with increased pressurization, which sort of defies basic physics law that for given orifice if psi goes up volume comes down, and vice versa if you enlarge the orifice size, but maybe some vendors have hit on combination of both that do improve both psi & gph.

Supposedly h/o I have in my truck from Kennedy do this tips & springs, my experience was little gain when I did h/o injectors only, I did not see great gains until I reflashed, IMO unless you have a program that actually asks for max fuel a IP can deliver you are wasting your coins, 99% of 6.5ers with the original injectors with 100+K on them will realize same net gains with fresh set of stock injectors and stock programming and some but not as much even with reprogramming, my burb with stock inj is pretty spry with stock injectors and reflash.

Now add in a reflash or chip whole different story, but IMO h/o injectors would be the last addition to add after exhaust/DP-gauges-remote FSD-T/M or fooling-h/o water pump & fan clutch-FTB-h/o lift-ATT

 

[JiFaire]

A number of people (incl. Bill and Todd at HeathDiesel) have told me that HO injectors are a good performance addition.

- better pattern and atomization... especially at higher RPM. If the orfice is unchanged and the big difference is the pop release pressure, a given volume of fuel can be squirted in a shorter burst.

- with HO injectors and stock programming, that is about the best benefit you should see; Todd told me that with HO injectors alone, you would notice very little difference in HP, but mileage and drivability may improve.

- add higher fuel rates, and you can get the same volume of fuel expended in a much shorter duration. Again, at higher RPM, you should notice the biggest difference, as the fuel volume is up, and yet the injection event remains crisp.

That's my take on it, anyway; I don't know enough about the mechanics of the event to build a better explanation, but a friend of mine put in a chip first, then HO injectors, and noticed a pretty big gain each time (first with the chip, then with the injectors). Unless it's the Hawthorne Effect; you pay more attention to something and it seems to improve.

Who knows?

When I went to buy my new injectors, Bill asked if I was still pulling my big heavy trailer in the Rockies... I said yes, and he changed his mind and recommended that I get the normal Bosch injectors. He said that with my tune and with that weight, I would risk overheating and high EGTs with Marine injectors.

I figure if Bill intentionally made less money off me, there must be something to the story.