how far back can I put the toilet in my MCI

[Oregonconversion]

I want to put my toilet as far back as I can. What is the farthest back I can possiblly put my toilet in my 8?

[viento1]

Not sure if I quite get what you mean... From a plumbing perspective? RV toilets work best directly above the tank... Yes $#!% flows downhill but 15' of pipe and 3 or 4 elbows and 2 ounces of water... yeash.  You can buy a fancy macerator toilet and mount it on the trailer hitch if you like...

[Oregonconversion]

yes that's what I mean. I just want a large living space and a small everything else.

[NJT5047]

Assuming you plan to place your blackwater tank in the rear bay, you can install the pottie about anywhere that is over the rear bay....anywhere that doesn't interfere with steel.
You can go sideways for 3 or 4 feet.  Any further and you'll probably want a macerator pot.
A macerator pot can be installed about anywhere. 
A straight drop for an RV pot is ideal, but mine is 3' off center and has been problem free. 
With an RV style pottie, you don't want to get into the drive axle area. 
If you want the pot on the curb-side, get a tank with the inlet as near the pot as possible.  If you want it on the street-side...same.  Put the inlet on the street side.  It doesn't matter. 
Always install your dumps on the streetside.  You may want a curbside drop, but most CG will have streetside dump stations.
If you want the pottie in the OEM location, you'll have to find some way to locate blackwater tank in the curbside engine room.  Or, use a macerator and pump it forward.
A macerator uses a garden hose for connections.  They'll pump uphill or whatever.  They are a little noisy...but it can be located anywhere.
JR

[Oregonconversion]

Thanks for that reply. Sounds like I need to do some research on macerator pumps. Does this mean I can have my toilet in the original location as the original MCI bathroom and keep the black water in the rear bay? I don't care about noise.

[NJT5047]

Yep.  Check with marine suppliers.   A macerator pot uses a garden hose to move stuff from the pot to the holding tank.   If you'll add one more pump at the blackwatet discharge, you will be able to use a garden hose instead of the usual large 4" RV hose for a dump hose. Just don't mix the hoses up!  May God help you if any of these components fail while in use! 
If you buy a macerator, be sure that your spousal component understands exactly what can be placed into the pot.  That will be your largest issue. 
If it hasn't been eaten first, it don't get into the pot.   
JR

[Tom Y]

Oregon, I saw an new air operated toilet in a coach. But they also put in a 24v compressor for backup. The toilet was mounted behind the drive axle.    Tom Y

[Sean]

We have one of those air-operated toilets, a Microphor LF-210.  Pricey, but works great, and we were able to put the potty where we wanted it, 15' or so from the black tank.  The other advantage of this system is that the waste pipe from the commode is 1.5" rather than the customary 3", which may make for an easier installation in some coaches.

FWIW, we also evaluated the Vacu-Flush system, electric marine toilets, and macerating toilets (which is an entirely different animal from the separate macerator pumps).  In our case, we already needed a supply of compressed air on board, as we are using the air suspension for campground leveling, and our entry door is air operated.  We have a Hitachi oil-type electric air compressor on board to keep the air up at all times.  (An added bonus -- we can always drive away at a moment's notice, no need to wait for the coach to air up.  And an extra quick-connect on the compressor lets us air up the scooter tires, inflate the hot tub or the boat, etc.)

Be advised that the Microphor uses two quarts per flush, far more than gravity-drop RV toilets.  I think the Vacu-Flush is a quart or so, and macerator types fall somewhere in between.

HTH,

-Sean
http://ourodyssey.blogspot.com

[Oregonconversion]

Thanks Sean, I am looking into the 1 and 2 quart microphor toilets.

The air assisted look very nice. How much did your setup cost not including the compressor?

What is the advantage to using this type of a system vs a macerator system?


Can RV toilet paper be used with either system?

[Sean]

Thanks Sean, I am looking into the 1 and 2 quart microphor toilets.

The air assisted look very nice. How much did your setup cost not including the compressor?

I have to confess that I don't remember.  This was a good five years ago now.  Most of the cost was the toilet itself, which I seem to recall was very spendy.  It is, though, a nice porcelain fixture, well finished, and looks very much like a high-end household model.  Also, it accepts household toilet seats, so you have many low-cost but nice looking options at Home Depot (do NOT get the optional seat from Microphor -- it's a cheapo plastic item for ~3x what it would cost in a home center).  The only other components you need are an air pressure regulator and a water pressure regulator.  Everything else is standard PVC plumbing and air lines.

The air pressure regulator can be had for ~30 or so from Grainger and others.  Get the type with the integral gauge; you'll need to set the pressure fairly close to 60psi.  For the water pressure, we used a miniature "irrigation" regulator from Watts, with a screw-type adjuster.  Again about ~$25-$30.  This is the only way to regulate how much water gets used per flush.  Before we installed the regulator, we were using way too much water.  I bought mine from the water filter guys at an Escapade rally, and probably over-spent for it.  Get yours from an industrial supply.  I think ours is 3/4".

As I wrote, we needed the compressor anyway.  We're on our fourth one.  The first one, a Senco nailer model, just did not generate the CFM to keep our system up, and was running too much.  We then went through two oil-less pancake models (replaced under warranty once, and repaired a second time) before determining that our duty was just too much for these occasional-use homeowner oil-less models.  Since we put the nice oiled one in, no further problems (but I do have to change the oil about annually).

What is the advantage to using this type of a system vs a macerator system?

Macerators need their impellers and/or their blades replaced periodically.  Yuck.  But, they use less water.

Can RV toilet paper be used with either system?

This question often leads to religious debates.  I have my own opinion, based on experience:

No need to use expensive RV toilet paper with any of these systems.  We use Quilted Northern with no problems; the Costco stuff is also great, but we can't fit 36 rolls of TP on board.  If you are worried about the TP, take a couple squares of whatever you'd like to use, and put them in a jar half full of water.  Wait five minutes or so, and then shake the jar vigourously,  If the squares don't break up at all, you might consider a different brand.

That said, a macerator will likely have more problems with TP (or any other stuff - see below) than either the air or vacuum systems.

Speaking of "other stuff" -- make sure NOTHING other than human waste and TP gets in there -- no matter what system you have, even a gravity-drop RV model.  I know whereof I speak -- I once had to disassemble and replace a Valterra full-way gate valve on a black tank because one of those supposedly flushable baby-wipe thingies jammed into the slot, causing a leak.

This means, and pardon the disgusting graphic images everyone, that you will need to have something like a foot-pedal garbage can (what we use) or other semi-sealed container in the potty area for anyone aboard with, umm, "feminine needs."  Some folks go so far as to mandate the TP goes in there as well, Mexican-style, but we are not of that school and, as I said, have had no problems with either the air-flush toilet, or the macerator pump that we occasionally use to dump (when the dump is farther away, or uphill, than our gravity dump system can reach).

-Sean
http://ourodyssey.blogspot.com

[Oregonconversion]

I called microphor and those toilets are about $2000.00 without the compressor!!!

I did find some good info for anyone looking to get one of these fancy air toilets though.....

They sell "slightly damaged" models for 50% off.


Looks like I will be using a macerator system. Can I use it with any RV toilet? Or does the toilet itself have to be special.

[NJT5047]

Macerator potties have the macerator pump built into the pottie outlet.  So yes, they are 'special'. They are a unit and the pump will grind whatever goes into the pot at the pot.  Then it pumps the waste product thru a 3/4" or 1" hose to the black holding tank.   This allows rather flexible mounting location.   They'll even pump uphill.   A water supply (1/2") and a small drain line is all you need....and 12Vdc to run the pump.   
Macerator pots may be about as expensive as an air operated unit.  They are common in marine applications, but not RVs. 
A different style of "Macerator" is used on the outlet of blackwater tanks.  That unit attaches to the blackwater RV style outlet and grinds the contents of the blackwater tank sufficiently so that it will pump thru a garden hose.   
You don't need both pumps...unless you wish to drain your blackwater tank with a garden hose.   
The standard 3" RV drain hose will work OK with any type of pottie you install. 
Macerators work well, but when need service, they're nasty as H to repair.   Still, a macerator will allow you to locate your pot where you wish. 
JR

[Sean]

I called microphor and those toilets are about $2000.00 without the compressor!!!

I was surprised to read this, since what sticks in my mind is that we paid maybe $1,100 for ours.  As I said, spendy.  That was five years ago, though, and they may have gone up.  Also, Microphor probably quoted you their suggested "list" price -- the dealers actually pay quite a bit less, and I believe discounts are widespread.

Looks like I will be using a macerator system. Can I use it with any RV toilet? Or does the toilet itself have to be special.

I don't think you will find macerating toilets to be any cheaper.  One manufacturer is -- you guessed it -- Microphor.  When we looked into this problem six years ago, we found that all three possible solutions -- air-operated, vacuum-operated, and macerating -- were about the same cost, overall.  We went with air because we already had the air on board, and we did not want to add yet another system.

There are two "cheap" ways to do this.  One is to use a standard RV toilet, and locate it someplace where the angle to the tank will let it work.  My rule of thumb is no more than 90° or so of total bend.  So you could probably get away with two 45's, or one 90 and a side-entry into a tall tank.  If you have a "horizontal" section in the pipe, make sure it slopes at least an inch for every two feet, and bear in mind that you will need to use more water per flush with this method, and may have to snake out the pipe occasionally.

The other method is to use a manual-pump marine toilet ("head").  These are meant to be flushed with seawater, and there is no provision made to prevent the head from back-contaminating the water supply.  So, to be safe, you should install a separate tank to supply flush water to the head.  This tank can, itself, be filled from your fresh water system through a valve and some type of backflow prevention, preferably an air gap of at least 1/2" above the flood rim or overflow.

Manual marine heads are more expensive than RV toilets, but cheaper than the other solutions presented by a wide margin.

HTH,

-Sean
http://ourodyssey.blogspot.com

[Len Silva]

There is a third option and that is to use a pressure assist household toilet.  http://www.flushmate.com/
You can get them as low a 1 GPF.

[NewbeeMC9]

The original MCI bus toilet was as far back as you can go  

Maybe put the old one back and just run a macerator over to the other side

sorry couldn't resist.


anyhoo,  if you wanted to keep it simple, the ball valve type are kinda low, so you could raise it by building a pedestal and put it over a wheel and then run the two 45's like Sean said, then put the black tank in the back side of the rear bay.


or you could put the black tank over behind the engine air filter and put the potty over it, or move the air filter to the other side of the bus.


Simpler is better when dealing with $hi-$hi no matter how fancy the toilet.  Less TO go wrong means less CAN go wrong.

and I doubt you'll get a bunch a busnut rallying to help you fix it   that help will remain a keyboard away

do it your way