Went to the Overland Expo today !

[Lmtv772]

Suprman imagine it like this: turn a bottle of water upside down and the water will come out at a certain rate. Now give that bottle a twist and create a vortex. The water will come out 4 times faster than before. I think the design of the intake is to do the same thing with airflow. But what do I know.

 

[Suprman]

But if you move the box straight down and just extend the intake tube you are not changing the dynamics of the intake.

 

[Lmtv772]

True. You would though if you'd replace the thing with a box or a k&n filter

 

[98G]

But if you move the box straight down and just extend the intake tube you are not changing the dynamics of the intake.

Sure you are. Tubes of different lengths will have different resistance to flow.

Is is a significant difference? Probably not....

 

[coachgeo]

For reference if anyone has pdf(s) or pic(s) that shows the OEM FMTV air cleaner setup from engine on back it would be very informative to readers if you could post this here in this thread. Much thanx in advance to anyone who puts those up.

 

[scottreb]

What I dont understand is why it requires a special high tech air box. No other CAT engine has this, or do they? Plenty of CATs in off road application with traditional set ups. I dont doubt it has some benefit but these are not crazy high performance engines that require a ton of air.

 

[Lmtv772]

What I dont understand is why it requires a special high tech air box. No other CAT engine has this, or do they? Plenty of CATs in off road application with traditional set ups. I dont doubt it has some benefit but these are not crazy high performance engines that require a ton of air.

I've seen very intricate air box designs on different MV be it a HEMTT or a PLS . I am sure every bit of performance gain helps.

 

[coachgeo]

For reference if anyone has pdf(s) or pic(s) that shows the OEM FMTV air cleaner setup from engine on back it would be very informative to readers if you could post this here in this thread. Much thanx in advance to anyone who puts those up.

Partially answering my own post. Not that the PDF's for parts manual show much but put them below. Hard to picture it on truck via the parts manual. Pics if anyone can post them would still be helpful. Will be adding a few below as come across them

http://www.steelsoldiers.com/attachment.php?attachmentid=625423&stc=1


1) Turbo back.........................2) Deeper in......................3) Scavenge attachment to exhaust?

Seems to be nothing too complex in the set up as appears in the manual. Probably much more to it than meets the eye. Are the vortex air spinning fins inside the air filter thus not shown in the manual? If so; interesting that a 1970's Era Kubota air filter has fins in the filter too. Physics don't change I guess.

Update- added some Vortex/spinning info in post further below

 

[Lmtv772]

...

 

[coachgeo]

This PDF shows where some of the spin may come from. It also seems to claim this set up is in the FMTV

http://india.donaldson.com/en/aircraft/support/datalibrary/066268.pdf
View attachment 066268.pdf

 

[coachgeo]

Apparently another Donaldson version... obviously not to military spec... but made for the 3116 CAT as used on the GM Topkick truck is

Model number 15625106
Element number 15619013

see http://www.michelecaroli.com/info.asp?oempartnumber=15625106&donaldson=G110119 for more info/applications. Does not look like a vortex type but maybe it is too. Not recommending a swap to this or any other. Just info to help others base their own decisions on.

 

[coachgeo]

More info is peaking out. The exhaust port into the air cleaner..... as brought up briefly in another thread is a scavenge line. It apparently is part of the FMTV's complete Air filter system... maybe a form of Pre filter as seen in below PDF. Again just info for folk to make their own decisions based on. Least it maybe??? opens doors to possible retrofits that might nearly meet standards to what is on there now. Call Donaldson themselves? There in MO if I remember right.
View attachment 065851.pdf

 

[1951M1078]

Could not find a better photo of the intake. Its just behind the air side wing .

 

[coachgeo]

Could not find a better photo of the intake. Its just behind the air side wing . ....[/img} [/QUOTE]Here is two screen grabs from youtube. First shows the air cleaner they used with camper box that has a pass thru to cab and spare tire mounted elsewhere. So its completely different Air Cleaner unit than FMTV. Maybe still a Donaldson unit though?[ATTACH=CONFIG]625549._xfImport[/ATTACH]

Next image is air cleaner they used with smaller box. Similar size to FMTV hard box. Air Cleaner appears to use same as FMTV. Snorkel might be flipped toward center of cab? There is a Faux lip on box nearly hiding it. Lip on air cleaner side is a good 2 foot wide. Spare Tire is in same location as FMTV on opposite side. Same lip but only above and below tire. Lip might be there for Aerodynamics (oxymoron) and to guide limbs? Probably just as illusion to make box look bigger and cleaning up the lines. Box/cab is unfinished in this Grab. AKA roof rack not yet installed and a few other things.
[ATTACH=CONFIG]625548._xfImport[/ATTACH]

 

[scottreb]

Interesting that its just a lip. They really didnt gain anything. Thats one of the biggest reason the LMTV family gets no love from the overland community. You loose a couple feet of box with the air cleaner. Cant afford to loose living space on a relatively short frame. You could just build around the air box, remove tire and use that for box. Lopsided but better use of space.

 

[scottreb]

If you look at this video it has no false walls/lips. Box is square and air box is modified. https://www.youtube.com/watch?v=z0fP9A1Heg4 About 1:20 in perfect shot of airbox area.

 

[Suprman]

Not like you can get a capable diesel truck anywhere else for anywheres near as cheap as LMTVs are though.

 

[scottreb]

Thats the problem Suprman. Its the perfect American base vehicle really. Everyone argues they want mechanical engines, it has. COE, it is. Factory 4x4 it does. International parts availability, its pretty close.
Theres one in my neck of the woods at a shop in town. Ill have to go look at it more. I really like everything about them but that gigantic airbox!

 

[scottreb]

Plus with the gear change options that helps even more!

 

[coachgeo]

If you look at this video it has no false walls/lips. Box is square and air box is modified......[video]. at About 1:20 in perfect shot of airbox area.

Scott in the screen grabs posted earlier there is two different trucks with VERY different camper boxes. Sorry didn't explain well. One of them is like the video you posted.. It is a large box with no wings. It also has a crawl thru to the cab. Not sure how they tilt the cab though. As you pointed out it uses a completely different air cleaner system.

The other one (with the wings) is a shorter box and appears to be based on the same or similar box as what the military uses and has what appears to be the same FMTV Air Cleaner setup. It is from a much older video. I'm assuming they no longer use that model camper box.

The larger box with relocated spare tire may also help with weight distribution. the FMTV looks front heavy with the spare where it is. This is ONLY an observation though. No clue what the real front to back weight distribution is.