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TX-FMC

Posted 2016-08-02 12:14 PM (#3736)
Subject: FMC Factory Ram Air Induction

(66.68.174.212)

My FMC has two factory "ram air" induction ports, one on each side - an RV with factory ram air induction, a very cool 1970's muscle car style option (cool air induction can increase horsepower around 15 to 20%). I have only seen a few with this configuration. Does anybody know how many came with this option and what unit number span came with them? I recall speaking with somebody who said twenty or so were produced with ram air. I figure FMC was experimenting during the production run. My air cleaner has one port and had a flexible tube running to one of the ram air ports. What was the other used for or was it a dual intake "two into one" intake tube? Thanks.

dkarnath

Posted 2016-08-02 2:43 PM (#3739 - in reply to #3736)
Subject: Re: FMC Factory Ram Air Induction

Location: Medford, OR
(69.9.147.138)

You need to post pics (start an album) for everyone to see what it is you are describing. Otherwise, we don't believe you.....

hemi354az

Posted 2016-08-02 2:57 PM (#3741 - in reply to #3736)
Subject: RE: FMC Factory Ram Air Induction

Location: Scottsdale, Aridzona
(24.251.160.88)

Hey TEX,
Are you talking about what is shown in Figure 11-3 ( http://www.fmcmotorcoach.com/files/Parts_manual/11_Fuel_System.pdf ) ?
Don't think that Donaldson will get you 15-20% more horsepower . . . and there isn't much "ram air" at the back end of a 29 foot box.
Coach #548 and up had a SINGLE driver side air inlet. Sure you got two inlets ? Love to see the "plumbing" on your set up. Picture(s) please ?
Ram ON ! Lou #120

Edited by hemi354az 2016-08-02 3:01 PM

Duramaxer

Posted 2016-08-02 3:23 PM (#3744 - in reply to #3736)
Subject: Re: FMC Factory Ram Air Induction

Location: Oslo Norway
(84.213.61.97)

If you looked this up in the parts manual over at Fmcmotorcoach.com you would find that coaches 548 to 600 came with the one "scoop, cold air intake".

If you have a FMC 2900R Motorcoach with a factory option actual Ram Air System I guess you are one really lucky man.
And if you have just coach with dual cold air intakes, where one might be added after the coach left the factory that is nice to, even without the Ram Air part of the story.

Kjetil
"FMC Muclecoach" #477

BigRabbitMan

Posted 2016-08-02 7:27 PM (#3746 - in reply to #3736)
Subject: Re: FMC Factory Ram Air Induction

Location: Cottage Grove, OR
(75.139.213.151)

I "heard" that the outside air scoop was discontinued because in a heavy rain situation water got into the filter housing and caused the paper filter material to collapse and plug the intake.

hemi354az

Posted 2016-08-02 11:35 PM (#3747 - in reply to #3736)
Subject: RE: FMC Factory Ram Air Induction

Location: Scottsdale, Aridzona
(24.251.160.88)

Hey TEX,
That isn't much of a Welcome we gave you. Let's start again.

WELCOME to the cornfused World of the FMC 2900R Motorhome and Bus/Transit.
If you don't already have Owner's, Parts, Service Manuals . . . our good friend in Norway Kjetil #477 (appearing here as Duramaxer) maintains a WEBSITE all about the FMC which is always available to anyone for FREE at - http://www.fmcmotorcoach.com/index.html

Most of us use it to answer all kinds of questions we have about the FMC, and of course we assume EVERY FMC Owner has also read every page. Alas, that is often not the case, and "answers" that are readily available there are asked by new owners. Often a new owner will ask something that has already been asked and answered, but the new owner hasn't used the SEARCH feature to get an answer. We might send you to the answer indirectly . . . telling you to look in the Parts Book at some page or figure . . . to get you using the resources that Kjetil has made for us, and all the stuff already here on this Website, and the "other" FMC Website -
https://groups.yahoo.com/neo/groups/FMCMotorCoach/info - which you must join to see Photos and lists and everything. It is now a PITA to "navigate" since Yahoo "improved" it about a year or more ago. Both websites do not have all the same info, and if you can't get what you need here , or at Kjetils Website, then try the Yahoo FMC site. We all have no preference really and FMC "stuff" is all over the Nets.

Please fill in more info about yourself and your FMC (#605 ?) in the Coach DB (data base) and Member Roster, and we all love PICTURES of FMCs ! Please share some Photos of yours in the Albums, and tell us how you came about your FMC and what City you keep it, and any other interesting thing about you, your family, and your FMC. Again . . . WELCOME !
Lou #120

byegorge

Posted 2016-08-03 12:34 AM (#3748 - in reply to #3736)
Subject: Re: FMC Factory Ram Air Induction

Location: Olympia, Washington
(73.42.182.228)

Did someone slip you some 'nice' pills Lou?

Nice on Lou.

TX-FMC

Posted 2016-08-03 2:15 AM (#3749 - in reply to #3736)
Subject: Re: FMC Factory Ram Air Induction

(66.68.174.212)

Hi all. Yes, I will post some pics. Hemi you are correct, it is shown on page 11-7. Duramaxer, yes the manual does say they are on coaches 548 to 600, but having quite a few rare musclecars over the years and documenting them, what is publicized doesn't always correspond to what the assembly line does, and vice versa. Hemi is again correct - this is coach #605. So the manual is approximate but close. What I have learned from car makers of that era - they used what they had available until they ran out of it (so it would be interesting to hear if 601, 602, 603, and 604 have them, I would think they do. If not there are reasons why, such as special order, part availability, etc.). But, what the diagram does show is a cold air induction system that is no different in its concept as was used on musclecars of the era - "cold" outside air via a scoop, traveling into the air cleaner, through the filter and into the carb. As far as the 15 - 20% stat, that is what the car manufacturers of the day claimed for a cold air induction system, esoteric but every little helps and the cool factor is over the top. There are two scoops, one on each side. The scoops are on the sides underneath the "FMC" logo plate, not on the back of the coach. (It is where on some coaches had a "ski storage compartment" ). As far as "much air down the side of a 29 foot box", heck yes, what happens when you put your hand out the window on the interstate, lotsa wind blowin' by. I will take pictures, but the line drawing is accurate, even the special aluminum air cleaner. (I had wondered if Holman Moody made these, but found no markings on it though so it must have been made in house by FMC). And it is connected to the driver side scoop. The passenger side scoop is identical to the driver side, but there was no tube on it after 30 or so years. It is a very original coach, with all manuals and most paperwork - even the original FMC logo plastic zipper folder to hold the warranty and registration documents. It is a unique coach. I will take some pictures. It was sold in Houston and has never left Texas. I am the third owner. (And we really really like our FMC). Thanks for the intro Hemi, and yes, thanks to Duramaxer for his website, it is very helpful.

Edited by TX-FMC 2016-08-03 2:17 AM

Duramaxer

Posted 2016-08-03 2:50 AM (#3750 - in reply to #3736)
Subject: Re: FMC Factory Ram Air Induction

Location: Oslo Norway
(84.213.61.97)

Welcome to FMC ownership and to this forum Tex.

Sorry for the "flaming". I'm so slow on writing english that was I still typing while Lou made his first comment. should have deleted my post. I'm 9 years in to it and has still not finished restoring #477, that's how slow I am.

And Lou; thank you for the "correction" and the good example.

Kjetil
#477

Duramaxer

Posted 2016-08-03 4:24 AM (#3751 - in reply to #3750)
Subject: Re: FMC Factory Ram Air Induction

Location: Oslo Norway
(84.213.61.97)

Tex
I have been collecting pictures of FMC's for some years.This is what I can confirm regarding what coach have what COLD AIR intakes, based on my knowledge of serial number and what can be confirmed from pictures. I state only what can be seen on pictures, for quite a few coaches I do not have pictures of both sides. Also I am currently not viewing the latest update of my catalog, but I hope you might find it interesting anyway.

#589 - "First" coach with cold air intake, Passenger side confirmed
#571 - No intake drivers side
#589 - Drivers side confirmed
#604 - Dual
#609 - Passenger side confirmed
#611 - Passenger side confirmed
#617 - Dual
#619 - No intake passenger side
#621 - Drivers side only
#632 - Passenger side confirmed
#634 - Drivers side only
#638 - Drivers side only
#640 - Drivers side only
#644 - Dual
#645 - Passenger side confirmed
#648 - Last coach with cold air intake, Drivers side only

I have since long believed the FMC's might have bee given serial numbers in a different order than they left the" production line", I have reasons for that, but that is a discussion I have avoided for years and that I'm saving for a later time. Than one we can pick up when I'm sitting by one of the fjords in my FMC sipping Jack and have the time to improve my documentation. So yes I think you are right about the documentation available is approximate on the serial numbers affected.
I think you are wrong about the external air intakes being "Ram Air System", but that might be just as much a discussion on what would qualify as such system. Then we might also be into the difference in what is marketing and what is engineering. But I have my opinion what a Ram Air System is and I can't se that single or dual air intakes on the sides of the coach qualifies.
I think also that I have a quite complete collection of the FMC Motorcoach marketing from back then and I can't remember to have seen anything on such a system and certainly I have not seen it described as a "Factory Option".

Looking forward to seeing pictures and learning more about your coach.

Kjetil
#477

TX-FMC

Posted 2016-08-03 9:51 PM (#3759 - in reply to #3751)
Subject: Re: FMC Factory Ram Air Induction

(66.68.174.212)

Duramaxer, “Tex” here - you have brought up many interesting points. Thanks for the coach numbers with cold air induction. Most every coach is unique in its own respect due to one variation or another. I don't imply it was an “option” but consider it to be an experimental running change. FMC may not have specifically called it “ram air induction” but it would be safe to say it is a “cold air induction” system (and that is what “ram air” is). As most every FMC owner knows, it gets very hot in the back engine compartment. My opinion would be that FMC received feedback about this and the cold air induction was one of their attempts at alleviating part of the problem caused by high heat conditions – poor performance. There was no promotion of such a thing but there sure should have been, consider “ ..the only RV on the market with ram air induction.. ” that would have been a great selling perk. These scoops quietly came on the production line and just as quietly disappeared.

A “ram air induction system” consists of a scoop or scoops, channeling cool air into the air cleaner and thus into the carburetor. It sure looks like that is the case on page 11-7. Consider an example of other ram air systems of the period:

Basically the same, cool air through a scoop into the air cleaner then into the carburetor. Again, I think it was just something FMC experimented with (and I am very glad somebody at FMC had the fortitude to make it happen – it sure looks cool). As far as “working”, yes I think it does what it was designed to do; but was the benefit it provided worth the extra cost? Now that is more likely the reason it was discontinued shortly down the production line.

(I am only speculating and merely basing my opinions on what I have learned about car manufacturers during the same era).

Thanks for all you do Duramaxer!

byegorge

Posted 2016-08-03 5:34 AM (#3752 - in reply to #3736)
Subject: Re: FMC Factory Ram Air Induction

Location: Olympia, Washington
(73.42.182.228)

Is there any confirmation of the ram air or cold air intake actually working? You would think if it worked they would have continued using it.

BigRabbitMan

Posted 2016-08-03 6:44 PM (#3756 - in reply to #3752)
Subject: Re: FMC Factory Ram Air Induction

Location: Cottage Grove, OR
(75.139.213.151)

byegorge - 2016-08-03 3:34 AM Is there any confirmation of the ram air or cold air intake actually working? You would think if it worked they would have continued using it.

I believe it worked in that it took in cold air, but apparently, it also took in rain water and so it was discontinued. That was explained to me by Jim Black of RVS when I was positioning the Hummer air filter that I used when I still ran the 440. it could have been positioned to take in cold air from the driver side air louvers, but due to that consideration, I moved it inboard enough to avoid possible rain water ingestion. Rain water will cause paper air filters to collapse and block or bypass air. It still took in cool air per the intake air temp reading provided by the Edelbrock MPI fuel injection system I used at the time.

Ram air/cold air intakes have periodically come up for discussion in other RV forums when the rain water problem has surfaced. There is usually a modification explained that eliminates the problem, but it is a real problem if not dealt with in the design process.

5Dollar

Posted 2016-08-03 8:56 PM (#3758 - in reply to #3756)
Subject: Re: FMC Factory Ram Air Induction

Location: Bethune, SC
(165.166.72.232)

Stephan,

I installed a Banks kit on a Sports Coach with a P30/454 chassis. It had an opening in the intake hose that let water scape from the hose. It is a large hole at the apex of an elbow just after the water entered the intake scoop. Worked well.

I have two coaches with the dual snorkel system. I will check to see what design features are included to control water.

Henry

hemi354az

Posted 2016-08-03 11:53 PM (#3760 - in reply to #3758)
Subject: Re: FMC Factory Ram Air Induction

Location: Scottsdale, Aridzona
(24.251.160.88)

Oh, now everyone is an Aerodramticist. The wonderful ability to "know" where and in what direction something that can't be seen is going.

Please, please, please, someone tape 5 inch pieces of knitting yarn every 6 inch in a grid all over the last half (bathroom window back) top corner to bottom, including the side engine bay grill and all across the back to the center line, and then have a couple friends in a car take pictures of which way those tufts are "flowing" at 65 MPH. Be advised that those tufts will change direction if the car is close to the side of the FMC.

Some key words - laminar flow, turbulent flow, attached flow, separated flow, reversed flow . . . damn flow.

Fly ON ! Lou #120

Edited by hemi354az 2016-08-03 11:55 PM

TX-FMC

Posted 2016-08-04 8:52 AM (#3762 - in reply to #3760)
Subject: Re: FMC Factory Ram Air Induction

(66.68.174.212)

The correct testing would be a aerodynamic wind tunnel smoke test. This has been done by NASA on 18 wheelers. Not an exact match to an FMC but there is little doubt that flow will be similar. There is enough wind speed effect near the rear side to qualify as "ram air," but more importantly "cool" air induction (which is the primary reason for the induction system). You can watch the video wind tunnel test at the following link, the side flow is shown briefly around the 1:45 mark and more definitive at the 2:28 mark:

https://youtu.be/uE_0VUL6B08

Edited by TX-FMC 2016-08-04 9:00 AM

hemi354az

Posted 2016-08-04 12:12 PM (#3763 - in reply to #3762)
Subject: Re: FMC Factory Ram Air Induction

Location: Scottsdale, Aridzona
(24.251.160.88)

"correct testing" ?
Video clearly shows (briefly) the turbulent smoke flow about less that half way down the trailer, in this "Promotional Video".
That test is NOT at 65 MPH as the guy can't stand there holding a 10-15 foot long pipe. His hair isn't even messy (next time the hired a bald guy).
Differences between a aero pointed cab tractor with a 40 or 50 foot trailer and a bluff bodied 29 foot box with wheel wells and open grills at the end (FMC) are considerable.
You rent the NASA Full scale Wind Tunnel for your FMC RAM AIR INLET TEST, and I'll buy a roll of yarn and a roll of painters tape, and we can compare test results.
Test ON ! Lou #120

Fun Video - https://www.youtube.com/watch?v=6s-fWpA0Fxo
Note how often TUFTS are used by NASA . . .

Now once you think you have it all fingered out . . . please see - https://www.youtube.com/watch?v=QKCK4lJLQHU

I put some pictures of TUFTS to visualize actual airflow in the Photo Albums titled Tuft Airflow.
If someone thinks this is not a "FMC subject" tell me and I will remove this Photo Album.
YOU are encouraged to add you photos of the airflow in, around, over, under a FMC as visualized by ANY METHOD !

byegorge

Posted 2016-08-04 11:17 PM (#3767 - in reply to #3763)
Subject: Re: FMC Factory Ram Air Induction

Location: Olympia, Washington
(73.42.182.228)

So Lou how does the front air dam option affect your tufts?

tuft on

hemi354az

Posted 2016-08-04 11:50 PM (#3768 - in reply to #3767)
Subject: Re: FMC Factory Ram Air Induction

Location: Scottsdale, Aridzona
(24.251.160.88)

Duh . . . what is the Part Number and what Figure does a "front air dam option" appear in the FMC Parts Book ?

Off hand, I think that something below the front bumper on a FMC wouldn't have any effect at all to the air flow at the last foot of a FMC about 4-5 feet off the ground, but that is really just a SWAG (Scientific Wild Ass Guess). (Scientific ? Yea, long time ago I got a couple Engineering Degrees)
Ask TEX . . . he is the Aerodramatics by Similarity Wind Tunnel expert.
Air Damn ON ! Lou #120

Edited by hemi354az 2016-08-04 11:55 PM

TX-FMC

Posted 2016-08-05 12:24 AM (#3769 - in reply to #3763)
Subject: Re: FMC Factory Ram Air Induction

(66.68.174.212)

Hemi, I tested it – and don't try this at home! I drove the FMC at 65 mph (downhill) and the wheel wells created such a turbulent vortex so massive that tornadic vortices formed on each side that sucked out so much of the oxygen in the air flow going into the ducts it stopped the internal combustion in the engine. Not only that, air molecules on the side of the FMC bounced so wildly the electron friction between the atoms created such a volatile condition that the sun's reflection off my shiny Alcoas ignited an air burst that produced flames trailing off my FMC down both sides which made the outside temperature actually hotter than inside the engine compartment! (Now I really know why they stopped production of this extremely rare feature!).

hemi354az

Posted 2016-08-05 12:51 AM (#3770 - in reply to #3769)
Subject: Re: FMC Factory Ram Air Induction

Location: Scottsdale, Aridzona
(24.251.160.88)

WoW ! Thanks for the TEST REPORT. I never considered that turbulent flow could separate the oxygen molecules from the nitrogen. You may be on to some type of new and improved OXYGEN GENERATOR. Have you told NASA yet ? Got any pictures of the BURNED PAINT ?
Laugh ON ! Lou #120

ricogomez

Posted 2016-08-03 8:41 AM (#3753 - in reply to #3736)
Subject: RE: FMC Factory Ram Air Induction

Location: Houston, Texas
(96.85.4.38)

Hello TX-FMC, welcome to the Family Club, let us know if we can help you,
we know very little and still learning, we are from Houston Texas and we had
our FMC for around 4 years now.

My Bro in law, they have # 638 here in Houston, Tx.

Rico & Carmen
397

andy1canada

Posted 2016-08-03 8:47 AM (#3754 - in reply to #3736)
Subject: Re: FMC Factory Ram Air Induction

Location: Victoria, BC. Canada
(50.92.248.189)

Ditto on the "Welcome".

RU- Tex, or, do you have a regular name? Appears you've been branded...

Terry
#846

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