Moose Misters and carbon buildup

[rembrant88]

I know a lot of repeated Moose questions are asked here, if I missed something in search and someone has asked this question please let me know.

Now that Mel's products have had a lot of testing time for those of you who have them on your trucks, I was wondering if anyone has had any problem with buildup in the prechambers. I remember reading something years ago about the injector angle testing international did to prevent just that. I don't know how true that is, for all I know it was another emissions stunt. Mel I imagine has put a ton of miles on his motors so maybe he will post. I don't think buildup would occur the same way because of the finer mist, even if that mist was burnt more in the prechamber than with other injectors the fuel would have a cleaner burn. So I actually see fewer carbon deposits with moose misters. Some of the other injectors though I see leaving fuel deposits. Is my logic incorrect? Any opinions or experience?

 

[hesutton]

I've not pulled my heads and had a look at the precups to tell you for certain. But I can tell you that my DPS injectors were "dirty runners" for sure. They leaked, they popped ealier than they should, had zero atomization and crappy off center **** stream (not even a cone of fuel). That made for rough/smokey idle, harder starts, and lots of smoke when decelerating. That inefficency certainly made for more carbon in the precup.

The Moose injectors had a nice atomized, massive (center of the nozzle) cone of fuel on the pop tester. None of them leaked either. I don't have rough idle, or smoke on decel. My experience with them seems to suggest they produce more efficient consumption of fuel..... which in theory would lead to less carbonization on the cups. Plus, in the crew cab's 6.9, I run that truck hard when pulling the camper. EGT's are up as is boost and water temp. That should burn out carbon in the cup better than to the daily driving I do in the F250.

When the time comes (I hope years and years latter on the 6.9) to pull the heads, I'll let you know what I find. I'm more likely to know about the 7.3 in the F250 sooner as I will repower it with a DT466 in the future.

Heath

 

[rembrant88]

Thanks for the response. That's what I thought on the DPS injectors. I hear they can be tuned and don't produce the inconsistencies but even then I see the concept of that un-anodized fuel posing a problem.

 

[icanfixall]

I'm wondering where you heard of this carbon problem... I have been around a few years and have never seen any posting nor have I read anything anywhere with this issue. I believe the precups changed a bit from the early 6.9 but not sure what if any changes were made. Supposedly the 7.3 precups we want to use have the "88" cast into them. Other than that the only thing I have ever read here about carbon buildup is from using waste motor oil for fuel. Can't really add much more than that..

 

[Darrin Tosh]

Just gonna guess here, on the Moose carbon Problem,. Mel (of Moose Product Fame) ran straight WMO on his IDI Bronco Daily Driver for years, with just some stock injectors, I believe he had some precup buildup because of the burning the WMO. I guess it would be possible for this information to be reconfigured over the years to say that Moose Injectors have a carbon build up problem.

Again, Just speculating,..

 

[rembrant88]

If I come across that article I'll post it and see what you think. I think it was out of diesel power mag but I can't remember for sure. I came across it searching one day. It mentioned pre-production testing, had nothing to do with anything being anti moose products.

Lol, I think you are too used to some of the somewhat dishonest criticism of moose products floating around. I am in no way a purveyor of such things or a disciple of those who I think to be too critical, though I am aware of some who are. My question is simply a product of my own curiosity and does not stem from any source other than that. My personal opinion, as stated already, is that the moose misters would be a cleaner burning injector on the subject of buildup, but I don't pretend to be an expert on any injectors, mainly because I'm not an expert on the subject but also because I've not had personal experience with any of the aftermarket products. I am also not an expert on carbon buildup although I have seen examples of it, mostly because of poorly timed engines or engines that were running way too much fuel without a turbo. It is because of my lack of experience that I ask the question, not because I want to be critical.

 

[icanfixall]

Rembrant88.. Thats an exlant way of explaining what you were trying to figure out. No harm done either asking questions. Like has been posted about carbon possible buildup. I think it was Mel that wrote about it after he had run wmo for a good long time. ?Even he was surprised at what he found. I'm no expert with wmo or any carbon buildup issues in these idi engines. I really don't feel we will have any issues running number 1 or 2 diesel. Maybe its a problem with waste motor oil burning as a fuel. We have plenty of members doing this all the time. Some claim to be running 80 to 100% oil as a fuel. Myself, I don't feel like I will ever run motor oil as a fuel be it clean or not. I'm very happy with the diesel I get at the stations in my Moose pump. Maybe someday I will try it but no time soon...

 

[Hydro-idi]

I had one of my precups gum up with rock hard carbon a month after I installed those junk reman injectors from mylex. I knew the engine was only running on 7 cylinders and smoking something awful. When I pulled the bad injector, I looked down in the hole to find that it was completely blocked off. So I used a small chisel to break up the carbon and blew it out from the glow plug hole with an air compressor.

 

[rembrant88]

I can understand the speculation. I have seen a few examples of unfair criticism directed towards Mel. I still like his ideas and hopefully will be able to afford some injectors pretty quick. I don't know if they will be best suited for my supercharger, but why not? I haven't read about the wmo problem Mel had that I know of but maybe that was it. Seems running wvo or wmo or liquified bat guano or whatever almost always causes a problem eventually. I made the mistake of mentioning alternative fuels to the guy who rebuilds my engines and he went off . Apparently he gets gummed up engines coming into his shop once in a while....

 

[racer30]

I didn't find any carbon build up in the last IDIT engine I disasembled, But I did find large black gunky goo stuck on the back of the intake valves almost enuff to block the flow of air in 7 and 8 along with black goo in the intake manifold runners. I am pretty sure it was from the crankcase breather system putting alot of oil fog into the manifold and hardening onto the back of the intake valves. Yummy....There has to be a better way to vent that stuff....

 

[Hydro-idi]

I didn't find any carbon build up in the last IDIT engine I disasembled, But I did find large black gunky goo stuck on the back of the intake valves almost enuff to block the flow of air in 7 and 8 along with black goo in the intake manifold runners. I am pretty sure it was from the crankcase breather system putting alot of oil fog into the manifold and hardening onto the back of the intake valves. Yummy....There has to be a better way to vent that stuff....

Good point and observation. I haven't even thought of that being a possibility of happening with our engines.

 

[hesutton]

I didn't find any carbon build up in the last IDIT engine I disasembled, But I did find large black gunky goo stuck on the back of the intake valves almost enuff to block the flow of air in 7 and 8 along with black goo in the intake manifold runners.

I had the same finding on my 6.9 after pulling the heads for the rebuild. I can't blame the CDR in my case though. The vavle guides were the issue. All were worn past spec and the oil that leaked past coaked on the intakes. Fixed with new Precision Engine Parts valve guides and I'm also running a road draft tube and removed the CDR. Not really over concerns about oil vapor coaking on the intakes, but oil vapor condensing in my intake, intercooler tubes and the intercooler itself.

Heath

 

[Hydro-idi]

I had the same finding on my 6.9 after pulling the heads for the rebuild. I can't blame the CDR in my case though. The vavle guides were the issue. All were worn past spec and the oil that leaked past coaked on the intakes. Fixed with new Precision Engine Parts valve guides and I'm also running a road draft tube and removed the CDR. Not really over concerns about oil vapor coaking on the intakes, but oil vapor condensing in my intake, intercooler tubes and the intercooler itself.

Heath

This is also a good point and probably what is going on with my rig. I get a nice puff of gray smoke on initial startup when the engine is hot. I am guessing that oil is leaking past the guides and going into the chamber. My valve stem seals are probably toast too. I'm starting to get annoyed with this intermittant ticking my engine has had for a while. Probably a combination of worn lifters and heads that are in need of a rebuild in my case.

 

[rembrant88]

Good point on the the CDR. I plan to remove mine and run the draft tube like Heath.

Outward opening poppet nozzles were tested first with a 30-degree angle toward the swirl chamber wall and a smaller hole spraying 10 percent of the fuel toward the glow plug. Performance with this design was satisfactory, but hydrocarbon emissions were high and coking of the small 0.009-inch orifice proved to be a problem. As a result, inward opening pintle nozzles were developed to fit in the space confines of the 0.67-inch orifice nozzles. Performance, emissions, and durability all proved to be excellent with the new design-and nozzle coking was kept at a minimum.

Read more: http://www.dieselpowermag.com/tech/...onal_diesel_engine/viewall.html#ixzz2LNg02Z2V

My memory is better than I thought. Well, sort of. I'm now reminded it is about coking of the orifice and not the precup itself. Still asks the question though, if the angle of the injector and pintle design is important to prevent coking of the orifice than why? Is this to do simply with improperly burnt fuel or some other factor? And if the orifice was getting deposits does that leave potential for an overall buildup problem. I have to ask these questions in considering whether to use DPS injectors. Now it very well could be that it has more to do with how that fuel is burned and not how it goes in. In that case installing a forced air system would prevent carbon buildup by burning whatever fuel exists without regard to what injector or angle is applied in the equation, a variable that was not incorporated into original testing of the motor. So as an example for my supercharged 6.9 idi, with boost throughout the entire rpm range, there will be a clean burning of the fuel if the injection pump is adjusted to where there is no smoke and this visual sign is enough to conclude the fuel is being burned properly, leaving no reason to surmise the existence of a coking problem.

I don't know how good the source is for the DPM article but the idea sounds reasonable enough to me regardless. Maybe I ask too many questions? Am I looking to critically here?

 

[Agnem]

Interesting article. I think I've read that somewhere before, but completely forgot about the mention of the outward opening poppet nozzle design. I have NEVER seen an outward opening poppet nozzle equipped injector in our IDI's. All are inward pintle type. As for the coking, yeah you figured that out. But I will mention that pre-cup coking occurs when running heavy fuel like WMO. I've seen it, and I know Subway saw it at the 2011 IDI Weekend. You know you have it when you pull the injector and your amazed that there is black steel in the hole where the injector used to be. It's the fuel and not any injector design that causes that problem.