Two new Product Reviews

[More Power]

Please note: All feature articles, product reviews and tech pages appearing here in The Diesel Page are formatted to appear correctly on your computer monitor when using an 800 x 600 screen resolution and with the web browser window maximized.

Mega Fuel Filter Kit
for the Duramax 6600
By Mittie M. Dragosljvich

http://www.thedieselpage.com/reviews/megafilter.htm

Product Review: General Motors' 6.6L Duramax turbocharged diesel engine was introduced in the 2001 model year 2500HD/3500 pickup trucks and chassis cabs. Along with the new engine came the Bosch high-pressure common-rail fuel injection system. Fuel pressures as high as 23,000-psi demand much from the high-pressure pump and solenoid-controlled fuel injectors, and the less than stellar quality and cleanliness of the available diesel fuel here in the US may present some durability and longevity challenges for these components. Supplemental fuel filtration may be required.

Uni Foam
Racing Air Filters
With applications for the 6.5L & Duramax 6600
By Jim Bigley

http://www.thedieselpage.com/reviews/unifoam.htm

Product Review: Today's performance air filters must excel at two vitally important and yet polar opposite functions. First, they must allow the engine to breathe without unnecessarily restricting airflow. Second, today's performance air filter is also judged by its dirt capturing ability. Truck owners in the know demand an air filter that allows an engine to perform up to its full potential yet stops virtually 100% of all harmful dust and other airborne contaminants. Creating the perfect blend of unrestricted airflow and maximum dirt stopping ability is the goal of today's performance air filter manufacturers.

[ 09-14-2003, 05:07 PM: Message edited by: More Power ]

[sonofagun]

Thanks Jim.

Bob

[tysmith]

As always, great job!

Ty

[SoCalDMAX]

Awesome job guys!

Thanks! :cool:

Regards, Steve

[More Power]

Yes, Mittie did a really fine job. Excellent research, excellent writing and excellent photography.

Thanks again Mittie!!

MP

[mdrag]

Thanks for all the support and encouragement. This project was more demanding than I initially expected :eek: and evolved into a tremendous positive learning experience for me.

Working with quality individuals like George, Jim, and John was an added benefit that made it that much better. http://forum.thedieselpage.com/ubb/icons/icon14.gif http://forum.thedieselpage.com/ubb/icons/icon14.gif

[k1xv]

A great job of presenting the information in an objective and balanced way.

Refreshing change from the forum discussions on this topic, that in time dissolved into arguments, ultimately shedding more heat than light.

[Tractorhauler]

Jim,
That was great!
I was speaking to my Dealerships top diesel man in service today and we were visiting about fuel filtration and he made the comment, "I don't know why they did not put a lift pump on this Dmax"
I thought he hit the nail right on the head regarding the problem with air in the line.

Would the lift pump take care of the problem with the megafilter and air in the line?

Regards,

Mark

[More Power]

Tractor,

I'm hoping mdrag will weigh in on this, but yes, I think a lift pump could reduce the gases coming out of solution in the diesel fuel.

I've heard there's a lift pump kit in the works from one of the vendors.

Does the Bosch pump need a lift pump when using additional fuel filtration? I doubt it.... I seem to remember a phrase that went something like "it'll suck a golfball through a gardenhose", or something along those lines.

MP

[Kennedy]

After tons of debate, etc. I have come to the conclusion that we are bringing the fuel to it's vapor point, and what we are seeing assimilates the early stages of vapor lock. The combination of reduced pressure (suction) and heat are the key factors. Placing the fuel under pressure has positively eliminated ANY gasses from collecting in my filter head...

More here:
http://www.kennedydiesel.com/docs/Duramx_Mage_filter_FAQ/duramax_Mega_Filter_FAQ.htm



Does the Bosch pump need a lift pump when using additional fuel filtration? I doubt it.... I seem to remember a phrase that went something like "it'll suck a golfball through a gardenhose", or something along those lines.

MP After having a customer drive in with a DORMANT Holley red pump and promptly wrecking my 30"hg gauge measuring the suction head at an IDLE, I'm a believer in the suction capabilities of this pump! UNFORTUNATELY, ability does not necessarily equate to longevity, and I'm pretty certain that keeping a clean, "air" free fuel supply, we are promoting a long, healthy pump life...

[ 09-18-2003, 07:18 PM: Message edited by: kennedy ]

[mdrag]

The BALDWIN TSB 94-6R (http://baldwinfilter.com/engineer/pdf/94-6r.pdf) provides a credible explanation of diesel air-vapor issues occurring in suction side fuel filter installations. From this, I know that more air-vapor is released from diesel fuel when the temperature is increased and/or the pressure is reduced.

That leaves us with a few obvious choices to reduce the amount of air-vapor that is formed in the Dmax fuel system:

1) Ensure that there are no suction side leaks.
2) Reduce the fuel temperature.
3) Minimize the magnitude of pressure reduction occuring in the filtering system.
4) Increase the filter media pore size - but then the goal of improved filtration will fall short.

By using the clear hose test outlined by the Helm's manual, forum members have demonstrated that air-vapor release occurs when the diesel fuel passes through the FICM (due to increased fuel temperature). By adding supplemental filtration, pressure reduction becomes MORE of an issue...For example, I've measured a 0.5" to 1.00" hg increase in the stationary vacuum reading after installing the MEGA (the change varies with the fuel level in the tank).

Since the fuel is used to cool the FICM and a fuel cooler is already incorporated in the system, there probably is little more that can be done easily or cheaply to reduce the fuel temp. That leaves us with #3 , and the addition of a fuel lift pump will likely be the answer....

Or install pre OEM...I've given the pre/post no-air/air challenge more thought the last few days. Why are pre OEM installs NOT trapping air-vapor? Kennedy (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=3;t=006731) posted a basic drawing of his understanding of the relative pressures in the fuel system (cut and pasted from his post):

Here's a simple "laymen's" drawing of where the pressure drops are in the system. The under score (_) indicates the lowest pressure drop, the dash (-) is the middle, and the "bunab" (~) as I call it is the closest to atmosphere.

Post OE:

TANK~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~P---S___PUMP

Pre OE:

TANK~~~P-------------------------------------------------S_______PUMP

http://forum.thedieselpage.com/ubb/icons/icon3.gif By installing the supplemental filter pre OEM, it will be subject to less of a pressure reduction and MAY BE just below the threshold where air-vapor release becomes an issue. The OEM Racor then becomes the subject of the increased suction pressure, and for whatever reason (filter design, larger media pore size etc.) the OEM Racor does NOT seem to entrap or accumulate air-vapor. Please remember that this is MY unproven explanation based on a number of assumptions.

Since I plan to keep my post OEM supplemental filtration install intact, and a source of 'low entrained air' diesel fuel has yet to be identified - I'm favoring a fuel lift pump install even though I have not experienced any drivability issues.

[SoMnDMAX]

...."it'll suck a golfball through a gardenhose", or something along those lines.

MP [/QB]I know a girl like that...

smile.gif :cool: smile.gif

:D

[NWDmax]

I knew SOmebody would drop to the gutter on that analogy! :D :eek: tongue.gif

[a bear]

Excellant write ups. Thanks guys for taking the time to put this together. :D I just installed the Unifilter today. This filter is very well made with an excellant sealing gasket. When I removed the K&N I did notice a very thin coating of fine dust on the intake tube. I didn't have this the first time it was serviced. It's possible it lost a little efficiency with the servicing. Don't know, but I did follow the servicing instructions to a tee. I did clean the tube well so the next couple servicings should tell the tale on the UNI. I have a good feeling about it. smile.gif