mastacox

Well I'll make sure and take some pictures of the finalized installed system. I'm thinking about making it so that the compressor will be mounted somewhere in the undercarriage or under the hood, and then a hose will go to the back where I can either plug in the tank if I want it, or just plug in a hose to air up the tires.

Conveniently, the air intake for the compressor is already threaded with 1/4"-18 NPT threads, so it would be easy to make a sort of a "breather" to make sure the air intake doesn't suck in any nasty stuff (mud, water).

We'll see how it works

AH64ID

Well all I can find for the MV-1050 is max flow rate, at 2.54 CFM. If you compare that to amp draw its comperable to the 400C,H Viair. Thou I would imagine the Viair holds higher CFM ratings thru the psi rating?? So using the average CFM for the ViAir at that psi range, 1.97CFM, which would fill all 4 tires from 15-50 in 5.7 minutes... my guess is you wont see that with the MV-1050... but it will be interesting to see what you do get...

4Hummer

Nicely Done... Like the Idea of the switch....

mastacox

So I did a little more testing a week or so ago and wasn't really sure the single compressor would keep up would keep up with me. Here at altitude in Los Alamos it was having a heck of a time getting up to 105 PSI (never actually hit it). I was wondering why, and here's what I came up with-

Max pressure on the compressor is stated at 120psi. I'm assuming this is at sea level where ambient air pressure is 14.7psi. Since this is a single-cylinder compressor, that would mean it's compression ratio is about 8.16:1.

Why is this important? Well, at 7000 ft (where I live), the ambient air pressure is about 11.34psi. I think you see where I'm going with this- the max pressure this compressor is <theoretically> capable of generating at this altitude is 92.5psi Ug, PITA. Turns out there seems to be a bit of a discrepency because I'm able to get to about 100 psi in the tank, but it won't go higher.

So, what to do? Well, through a stroke of genius and some luck, I was able to get myself a FREE (albiet non-working due to head issues) MV-50 (Checker's version of the MF-1050) from a friend. Paired Frankenstein-style with my non-working MV-50 (electrical issues) I will be able to get myself another compressor to use with my system. So, I'll have dual compressors which will definitely alleviate any flow issues I might have had before.

As for the pressure issues, I changed my order at the last minute to just the pressure switch minus the relay for a slight monetary savings, and will build my own relay box to handle the dual compressors. Paired with a 3-way switch (ON-OFF-AUTO) I plan to only use the AUTO feature under 6000 ft. If I use the AUTO feature abover that altitude, it's possible the compressors will not turn off, since they might never hit the necessary 105psi necessary to turn off the pressure switch.

For wiring, I plan to have it set up such that the compressors can only be activated when the ignition is in accessory or on mode, through a tap into the cigarette lighter's wire. Each compressor will have a separate relay and 30 amp fuse in a block under the hood, tied driectly to the battery. It could be that I will have to upgrade my alternator in the near future due to the 60amp max draw from the comprssors (which I planned to do anyway in preparation for other accessories), but for now I will install a voltage gauge and only use them in short runs. I was also throwing around the idea of getting a 4-way switch and using a possible OFF-Single-Dual-Auto configuration, or perhaps two switches, one being Single-Dual option, and the other being an Off-On-Auto configuration, where I can turn one compressor on by itself if I want. I'll have to poke around at Radio Shack and see if anything suits my fancy. Should be one fancy custom switch box one way or another .

It will also be interesting trying to fit both compressors in my undercarriage, but I'm convinced I can make it work. Round two of pics will hopefully be coming up shortly, stay tuned for details.

mastacox

More pics!

The Three Amigos. No surprise that they all look exactly the same. The two on the right will be cannibalized to make one that works




And the pressure switch... I also decided to get a check valve to put after the compressors before the tank, to assure when they are all hooked up the system will hold air, since it's possible the compressors will have slow leaks that would drain any pressure in the tank. Basically air will be able to flow out of the compressors into the tank/tires, but not the other way around.



Now I have to think up a nice schematic to show what my idea is for wiring these guys up

deserttoy84

I just bought one of those at costco today for 50 bucks. I tried it out real quick and it works great. THe only thing is i was thinking about mounting it under the hood where my intake resonator box is, i want to knwo i can run a longer hose off the compressor?? I also want to change the fitting on the end, the one that ocmes with it does really work for me.

garrett1478

brian have you ever looked into replacing the filter it comes with with a less restrictive one? if you ever find out what size/threading the intake hole is please post it...

mastacox

The intake hole is actually 1/4-18 NPT, or very close to it. A little chase of the threads with a tap and you're got a prime spot to attach a custom compressor breather. This is what I plan to do, since the compressors will be mounted kinda low down. It seems strange to me that they made the intake hole 1/4-18 NPT and the output some wired non-standard thread, but such is life. I plan to remove the pressure gauges on the compressors also, and then tap and plug the holes they are in.

I wouldn't worry about the stock intake being restrictive on these things, but I would worry that they don't filter very well. I'm thinking I'm going to tee the two compressors' intakes together, and then route the breather up into the engine bay with some sort of filter on the end, like a valve cover breather or something.

I'm also thinking I will try and seal the compressors' bodies better with some RTV, to help avoid dirt contamination on the inside... My old one got pretty damn full of sand from a couple trips to the dunes.

mastacox

By putting a standard fitting on the compressor, you should be able to go with a longer hose. All you need to do is drill and tap the output hole to 1/4-18 NPT, and then use a 1/4-18 NPT nipple in conjunction with an air-hose coupling. I used an elbow on mine, but it isn't really necessary unless space becomes an issue (which it may).

I'm using a 25 foot hose and it works fine. You have to keep in mind that when airing up tires using a longer hose makes the "observed volume" of the compressor larger than if you were using a shorter hose. While 25ft probably doesn't make a big difference, a hundred foot large diameter hose might. In the end, the volume of the hose is small compared to the volume of the tire.

91_4x4runner

I'm doing a similar setup only using a York Compressor instead. Are those pumps very loud? Pictures of how theyre mounted/set up?

mastacox

The compressors are pretty quiet, when properly maintained. My old one was getting pretty loud when it got sand in the crank case, but I have since cleaned that out.

I don't have pics of them mounted and set up yet because I haven't done it. Stay tuned

91_4x4runner

Haha, sand in the crank case. How'd you go about doing that one?

garrett1478

yeah, i noticed that its very close, but whenever i try to thread a 1/4 NPT connection it doesnt thread correctly. what do you mean by "chase the threads"?

mastacox

It just means run a 1/4-18 NPT tap through the hole, to make sure the threads are the right size... If the connection didn't thread correctly it could be that it isn't going to work, and it might be necessary instead to go up to a 3/8 NPT connection. I'll have to look into it more.

mastacox

An ugly layout of what the system will look like, I'm going to make a more advanced wiring diagram a while later...

deserttoy84

are one of the bolts on the "top end" of the compressor like drill out and look funky? it seems liek they put the bolts in then like drilled outthe hole so u couldnt loosen it up ever. im def gonna use the filter it comes with whenever i use it because I will always use it in the desert.

CyMoN

looks cool but how much did you spend so far?
also in the write up it says having the pumps in the engine well make them trip faster due to the higher heat level.
I was going to mount mine in the engine well now I think I am going to make a bracket and mount it in the rear pass storage box space

mastacox

As my very first post shows, I have only spent $144 thus far, and it hasn't changed since I got the two other compressors for free. Add $50 if you plan on using two compressors and all of the stuff I have gotten (and subtract 10 because Costco has the compressors for $10 cheaper than I got mine for). I'm basically looking at $184 for all of the stuff I have if bought brand new, and perhaps another $20-30 in wiring, tubing, switches, relays, and miscellaneous. So basically just over $200 for a dual-compressor on-board air system with a 7-gallon tank and automatic pressure control system.

As for the compressors getting hot in the engine bay, I don't plan to mount them in the engine bay, but instead down on the frame rail either by the t-case or above the front skid plate. There just isn't an room in my engine bay since I have the 4-wheel ABS and an auxiliary fuse block next to it.

mastacox

Hmm, mine are just regular socket head cap screws that I can undo with an allen wrench... If I were you I would take them out and see if you can replace them with new ones from Ace or something...

CyMoN

I missed the part about getting the other two for free nice score.