Microns

['956Wheel]

There has been a lot of air filter talk lately, more boost means we gotta let her breathe. Many members have been asking about micron ratings on filters, a micron is one millionth of a meter, thats 39" divided into one million parts. 39 divided by 1,000,000=. 000039. That would make a micron about 4/100,000", if a filters rating is 5 microns, (I found one) , that would be . 00004 X 5 = . 0002". Two tenths of a thousanth! Seems to be real good filtration, this is a polyester filter with a removable foam pre-filter with a 500 CFM rating. Check my math... its late for me!



Is 500 CFM enough? I need more cfm's as the minder is pulling down to "change filter" with a new (stock) one installed.



Mike

 

[bigkid59]

Hey Mike!

I am looking at an Engine Data Sheet from Cummins for a CPL 0987 engine. This is a 1990 certified engine that was used in some fire truck applications at that time.

This engine was rated at 230 HP @ 2500 RPM and 483 foot pounds of torque @1600 RPM.

At this rating the engine intake air flow was 535 CFM at 2500 RPM and 340 CFM @1600 RPM. The exhaust flow was 1531 CFM @ 2500 Rpm and 940 CFM @ 1600 RPM.

While these figures do not correspond exactly to your situation, they should help get an idea of the flow needed.

Hope this information is of use!



I misquoted the torque spec on this engine. The 483 foot pound figure is what the engine is producing at 2500 RPM. The maximum torque is 605 foot pounds at 1600 RPM.

 

[LSMITH]

600 CFM will be plenty up to about 35 PSI@2600 RPM. The exhuast CFM is a ton higher because of the expansion ratios.

 

['956Wheel]

Have any members used the filter minder on their BHAF? Does it stay in a upper position?



Any micron ratings found on the BHAF? How about CFM ratings?



Bigkid, on that engine you mention in your post, does the data say anything about the air filter used?



Mike

 

[tmarti96]

BHAF flow rate

I have BHAF filter and read somewhere it has a flow rate of over 900 CFM! I don't doubt it.

 

[bigkid59]

Mike

The Engine Data Sheet that I quoted the flow info from does not concern itself with any air filter. This sheet gives the specifics of engine performance based on performance as delivered to the manufacturer of the equipment, be it a truck, construction equipment or whatever. The selection of an air filter is left up to the equipment manufacturer since they must determine what fits and works with their particular installation.



The Data Sheet does specify that the engine specifications are based on 10in water intake restriction and 2" Hg exhaust restriction. These numbers guide the equipment manufacturer in selecting intake and exhaust components to maintain the rated output.



The need for charge air cooling, an aftercooler in our case, is shown by the turbo compressor outlet temperature shown on this spec sheet. It is a whopping 304 degrees at maximum horsepower!

 

[Big White Beast]

Got a filter minder on my BHAF

I installed it on a 4" piece of ABS pipe (¾" hole) then clamped the turbo hose to the pipe and the pipe to the filter (Used a double pipe clamp with rubber gasket, the type for clay pipes). Works great. Never moved the minder at all and I've been to some really dusty job sights. I checked the minder prior to using it. Sucked it down and it stayed there over night. Sounds like it's working to me.



I cleaned filter the other day using a 4" rubber ABS pipe cap. Cut a hole in it for the air compressor hose and let her rip. Blew all sorts of dust out. Not enough pressure to hurt it just get the dust off. Thinking of a small foam pre filter. We'll see.





Garrett