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Pre-Air Intake Cap Modifications - More air to the engine ?

LouWon

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Since my engine is the 6.2L I was trying to figure out how to get more air in the intake.
I have seen some you tube videos where the guy modified the inside of the air filter housing and intake where the pre-air cap sits
I also read that CFM in is about 360

Keep in mind that my days of running the Humvee with water over the hood are over, mostly city/highway and trail riding

I had a spare cap so I removed the mesh inside the pre-air cap, I felt that the mesh might cause a restriction
I also have on order a 4 inch diameter silicone collar that is 3 inch tall, to raise the cap from the hood

I should have all of the parts tomorrow and will be road testing this weekend
Has anyone else tried this

IMG_2101.JPGIMG_2102.JPG
 

ken

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I think Donaldson makes a 90deg ram air snorkel head. That would shove air in somewhat.
 

LouWon

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I think Donaldson makes a 90deg ram air snorkel head. That would shove air in somewhat.
I had seen them but mostly on imports, I did not know the manufacturer. Thank you


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juanprado

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I would be very Leary of removing the mesh and being able to ingest large debris. Yes, I know the air filter should catch it but the idea of stuff going into the can does not appeal to me.

There is one way to get more air down the pipe. There is at least 3 different makes of prefilter oe for the military on the hmmwv. The donaldson one I think is just an oil bath separator but not a fan. I know 2 have a rotating fan blade to help remove debris away from the air flow so they do not get ingested and the rotating fan helps force more air down at speed. I have the sy-klone and very happy with it. Pics on my thread Juan's M998 and gimpyrob had some for sale a while back. Might want to pm him.

http://www.sy-klone.com/series9000.html
 

gimpyrobb

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The only ones I have left are for big trucks(deuce-5ton). Try "Postman515" he had a few last we talked.
 

LouWon

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your HMMWV won't start when you have a bird nest in the intake. I pulled one out of a windshield frame.
That’s a good one. Mine is always parked in the garage, I should be fine. Thank you


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papakb

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I used a 5" section of an old snorkle tube to get the mushroom up and out of the hood well. I can't really tell if it made a difference or not. I think an even bigger restriction is the openings in the exhaust headers and I've never seen a solution for them.
 

LouWon

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I did order a silicone collar to raise it a bit.
I took it out for a spin today, seems peppy enough on take off and in the city for a 6.2L.
Once I hit the highway on my next road trip, maybe then I will see more of a difference
It's been fairly constant at about 14MPG, so I cant complain

If I ever take the engine out I will look at the headers, to be continued...
 

LouWon

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It won't matter how much air you push into the intake, if the air filter oly allows a certain CFM to pass through it.
You have a point. I think it’s only 360cfm


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LouWon

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You have a point. I think it’s only 360cfm


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I know that the OEM is very heavy in material. Since I probably don’t need such an heavy duty filter. I wonder if there is a lighter weight one available


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dhaumann69166

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I know that the OEM is very heavy in material. Since I probably don’t need such an heavy duty filter. I wonder if there is a lighter weight one available


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Check agricultural filter such as tractors and skid steers and things like that. They use the same style filter and it wouldn’t surprise me if you can find one the right size to fit. Cheaper filters will flow more air but more dirt also. Don’t know if it matters on the HMMWV but on my Scouts I have to run cheap oil filters because the new high end ones have to fine of micron filtration and restrict oil flow to much on older vehicles.
 

LouWon

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Thank you, I will take one the spares that I have to NAPA and see if they can match it with a less severe duty filter.
 

98G

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Thank you, I will take one the spares that I have to NAPA and see if they can match it with a less severe duty filter.

I am continually amazed at what people consider an "upgrade".

Trading filtering efficency for potentially more airflow will almost certainly not flow enough more air to make any perceptible difference. It will, however, most likely flow enough more dirt and grit to make a measurable difference in service life.

If the goal is to flow more air, I'd suggest a filter that still filters as finely, but has more surface area to flow more air. This way you won't be sacrificing service life...

I further doubt that the intake air restriction is the limiting factor on the performance of the 6.2. I doubt that there's much improvement to be made here, even if you removed the filter entirely...

Edit to add -

This isn't a high performance, high rpm gasoline engine turning 6500rpm and moving copious amounts of air, where a tiny improvement in airflow yields 20hp at the crank and a noticeable bump in fuel economy.

It is a low rpm diesel.engine, running high compression. It has a really low tolerance for grit in the charge air. The grit will kill it faster than the grit would kill the above.mentioned gas engine.

And while 360cfm sounds tiny when viewed in the context of the high air flow gasoline engine using 1200 or more CFM, consider that 550cfm is adequate for a 14 liter Cummins.
 
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