Belt Driven Air Compressor a.k.a. Unlimited On-Board Air

Unbelievable Ben, great work and write-up.....

 

Thanks!

 

sub'd may do this at some point.

 

guessing co2?

 

First off, nice write up and I love the mod but I do have an important question:

You talk about the belt you used being "tight" and you'll prob get a longer one next time. When you say tight tho have you left enough room for play during accel and decel so as to not wear out all the pulley bearings due to extra stress from an over-tight belt. I know about the tensioner pulley (I'm not a complete novice to the mechanic world) but I'd be concerned about gettin a belt at the right length so the tensioner still has the correct amount of play.

Any thoughts?

 

nope, belt driven compressors, just a little larger than the one the OP used. a good belt driven compressor can fill a tire faster than CO2 due to the regulator on a CO2 tank only being able to flow a limited CFM. still faster than a standard portable air compressor, but it won't keep up with a large belt driven.

 

I could still pull the tensioner pulley back a couple inches when I first put it on. I did expect the belt to stretch just a little bit too but only a very small amount. I've put almost 8,000 miles on it since the install and haven't had a single problem. That includes a 2000 mile road trip with the longest stretch of driving being 14 hours.

The biggest reason I would go with a slightly longer belt is that in order to get mine on, I had to physically pull the tensioner back while putting on the belt. Whereas with the stock belt and configuration, you can pull the pulley back and slide a screwdriver in to hold the pulley in place while you put the belt on/off.

Due to the spring loaded pulley, I don't know that it would really matter if the belt was a couple inches longer or not as the spring sets the tension amount.

 

Great! Thanks for the full answer and driving stats. Even though you did have to kinda "force" it on it sounds the there's still plenty of play

 

Nah, there was nothing forceful about it. It was just a PITA to manuver both of my arms in there at the same time. Had the truck been on a lift, ramps, or a couple jack stands where I could have straightened one of my arms, it would have been much easier.

 

Ya I gotch, done a few jobs like that myself... The lack of room is the problem, not the belt length

 

Alright I've been drooling over this one for way too long- I'm gonna jump into this one- my viair compressor is only 33% duty.. Luckily I already have a tank/ OBA setup on my rig now just to switch the compressors out

I'll have lots of questions for ya
But first
Any way you can take some more pics of the compressor & how it's mounted to the engine?

Thanks for the inspiration here!

 

Go for it! It works great!

Your timing is perfect. I'll actually be disassembling everything in there this weekend to service it all. So, it should be a great opportunity to get some pictures. Is there any picture in particular that you're looking for? Like the brackets bolted up without the compressor in place?

When I built the main bracket out of 1" angle, I goofed and didn't cut out a spot for the grease gun to get to the zerk fitting on the compressor housing. So, I'm gonna have to pull it all out to add some grease to it. I also plan to open it all up to check out the inside of the compressor as well to see how it handled the extended use and heat in moab and numerous other day/weekend trips.

Are you planning to convert the compressor to run on grease or are you going to use an automated tool oiler w/ coelescing (sp?) filter to recirculate/reuse the oil?

 

Sweet!

where do you live? Wish I could come over & look at everything. I'm in SoCal

Yes PLEASE blow up this thread with photos bracket on without compressor, bracket next to ruler so I can get an idea of the dimensions..
A couple different angles on where exactly its mounted on the block..
Pics of how to pull the compressor apart & convert to grease..
I've found a couple write ups on this process & think I can do it but having a ton of extra pics always helps!

My dad has a similar setup on his jeep, but he actually has some circulating tube thing that connects to the crank case & circulates the engine oil through it! No Idea how to do that here though.

Also
Really hoping the second gen engines haven't changed in the '13 model I have.

 

I live near Denver, CO.

I'll get some pics of the brackets and how it's all oriented in there and with some measurements. The bracket you make for your compressor may be slightly different due to the size of the compressor and the orientation/location of the mounting lobes. So, it'll all be custom made to fit.

If you have a 6 cylinder, it's the 1GR-FE engine and that is the identical engine you'll find in 2005-Current tacos. So it's going to be the same.

Regarding pics of converting the compressor to run on grease. I followed the instructions and pictures in the link that I posted to JP Magazine. It was actually very simple to do. In fact, that was the easiest part of the whole process. The compressor itself is very simple and only has a few moving parts inside it.

I've seen a couple different setups using oil to lube the compressor. One guy used an automatic chain oiler like you would find on a motorcycle and it's vacuume operated. He just had to make sure he popped the hood and hooked up the vacuum line to make it work. If he left it on all the time, it would just flood the compressor with oil while it wasn't running. The other setup just used an automated pneumatic tool oiler. Then on the output, they put a filter inline to remove the oil particles from the air.

 

Here's the belt diagram for the engine. You can see where the compressor goes here and the new belt path (in red). It goes on the bottom of the passenger side of the engine. Just below the power steering pump.

 

Couple of questions for ya sir!

How did you make sure the clutch wheel was aligned with the rest of the pulleys? I'm having a hard time finding a reference point to measure from.. Maybe a laser level?

Does the zerc fitting need a vent? I imagine if its sealed up in there after the conversion it'll build pressure and stress parts that weren't meant to be... Or does it release pressure by leaking a bit into the pistons?

Do you know the torque settings to bolt into the motor block?

Did you find your compressor model by trial & error? Or did you find a way to search one by dimensions? I'm having a hard time with that, as they're listed by vehicle model..

The plan here is to find the perfect compressor dimension- wise and buy a new one, do a perfect install and never ever touch my on board air system ever again. And my truck is only 8 months old so I'm not putting anything from a junk yard near this baby it's gotta be perfect.

Thanks!

 

PM'd

 

Photo Dump...as promised...

Hope these help. I'll throw a couple more up of the inside of the compressor once I open it up. Probably going to be a couple weeks on that little project.

Here's a shot of the general location of the compressor. This is the passenger side of the engine.


This is a shot of the bracket/spacer between the air compressor and the power steering pump, above. The primary purpose of this bracket is to keep the compressor pulley from being pulled up into the power steering pump pulley. There is just enough room between the two to slide in the factory belt should I need to and bypass the compressor.


This shot shows the two small brackets that attach front corner of the compressor to the engine block.


Closer shot of the top bracket from the above photo. The bolt on the engine was already there.


Closer shot of the bottom bracket from the above photo.


Here is a shot of the main compressor bracket. The bracket supports the compressor from the bottom and it attached to the engine via the bottom bolt of the motor mount.


General measurements for the main bracket. (Please excuse the booger weldz! I learned to weld on this project.) Note the 4 elongated compressor mounting holes. This is what allows for the front to back spacing adjustment so that the pulley lines up with the other pulleys. I used a couple flat washers to shim the front of the compressor up a hair so that the pulley was exactly inline with the others.





General measurements of the power steering pump bracket/spacer. Note that the bracket has a slight diagonal shape to it and one of the prongs broke off at some point. Not sure when this happened as I found it this way as I took it off. I'll probably redo this bracket and the other two smaller brackets as I was in a hurry when I made them.



Of the two small engine side brackets, here is the top one with general measurements.




...and here is the bottom one on engine side. Note, there is no significance to the notch in it. Just a piece of scrap re-used for this bracket.

 

I've got the same question about how picked your compressor as Spencer, I don't mind using junk yard parts so much as I've got an older, dirtier truck but I need to know what I'm lookin for before I go buyin a bunch till I find one that fits.. Obviously.

 

I picked my compressor and then found a way to make it fit, haha! I had to trim a bit of metal and move tranny coolant lines to make the room for it.

All Sanden 5 or 7 model series compressors are relatively the same size and even look the same. The only difference is the mounting tabs/ears that are on the compressor body and the depth of the pulley. Another note is that the heads of all these sanden compressors are interchangeable within the model series. (The head is the end where the in/out air ports are.)

What I did was spend time at http://www.polarbearinc.com/applications.htm and I went through a lot of the common vehicles that I have seen or expected to see in a salvage yard and noted whether or not they had a SD5 or SD7 sanden compressor. I made a list of all the vehicles which had them. Then I went and googled the vehicles to find out what type of serpentine belt/pulley configuration they used. By doing this, I was able to find a compressor that already had the right pulley on it. This meant just one less thing to modify.

That's how I ended up with the '94 Dakota w/ the V8 engine. I found a yard that had this vehicle and I went straight to it. Fortunately, it still had the A/C compressor so I just backed off the bolt holding on the air lines to discharge the system, cut the hoses and unbolted it. I was in and out of the yard in about 20 minutes.