Outer Limits 4x4 Board

how can i turn the air conditioning compresser on my GQ in to just an air compresser. an pics please

there are a few threads in the nissan mk bible i hav found and some pics on dr frankinstines in there too

Hi nissan_onroids,
Assuming you have the Sanden SD5xx single ended swash plate compressor, it's reasonably easy.

1) Pull the compressor head off (back plate)
2) Find the oil return hole that pumps oil back from the suction side hose to the crank case
3) Drill and tap it out (can't remember what size I used, it was M6 or M8 I think)
4) Apply loctite to a blind stud and block the hole off
5) Reassemble with head and torque to proper specifications
6) Drill and tap the oil fill hole (on top of the unit) to say 1/4" NPT and insert a sintered bronze breather (also 1/4" NPT).
7) Fill the crankcase with a mixture (80/20) of Lithium Moly grease and heavy (60W) compressor oil.
8) Refit to vehicle.
9) Make up hoses to suit (I run my suction side through a 1/2" fuel filter which gets it's air from between the pre-filter and main filter).
10) Make sure you have a working safety valve (125psi depending on the tank) and pressure control switch on the tank / discharge lines. These compressors are capable of 500psi+ and commonly operate around the 300psi range.

do you need a tank to do this or its not necessary?

I have a spare aircon from a GQ and was looking at selling the aircon kit or making it into a air compressor

Before I answer that last question - I should have added that it:

- Is neccessary to fit an air/oil/water seperator on the discharge line between the pump and the tank. These compressors are not completely leak proof between the crankcase and the piston bores, and some leakage is inevitable.

- Also a "Load Genie" or pressure relief valve is highly recommended as it stops pressure backing up against the check valves / pistons in the compressor. These delivery line relief valves also provide much better sealing capabilities than the compressor itself, which means cycle times are greatly reduced to keep your tank topped up.

The reasons to use a tank include:
- Provides a resovoir of air to operate things such as air horns, air lockers (regulator is *required* to run either of these - lockers require a fairly tight band of pressure in which to operate - too little and the dog clutch may not engage fully, too much and the seals may blow out).

- Provides an accumulation point for dissolved water / oil to seperate out (water and oil that may not have been collected by your oil/water seperator). So it won't enter your equipment or tyres or air beds or whatever it is you are using the compressor for.

- Regardless of whether you are using a tank or not, you should still fit a safety valve to the discharge line (or tank if you are using one) and pressure switch for the compressor clutch; and of course the air/oil/water seperator-filter to get rid of any rubbish in the line.

Hi spannercrab,

Will a Sanden TRS105 be a suitable compressor? I have one in good condition. I noticed there is a O-ringed bolt on the front - perhaps this is a place to add the lube as you mentioned?

thanks

hey spannercrab

thanks for the info much appreciated will eventually give this a go.

No worries morkz - good luck! It's certainly a handy piece of equipment to have on board.

Grazza - no the Sanden TRS105 is a monodirectional scroll type compressor which essentially means that you cannot effectively do the conversion as the scroll itself needs to be lubricated. Vane pumps also will not work (for long).

You need to use a single ended piston pump. Double ended pumps are not suitable either (such as Denso, some Sandens, Zexel etc.). as their suction / discharge and crank case (or swashplate case) cannot effectively be isolated.

You can roughly see the piston bores cast into the pump housing when looking at compressors.

The only pump I've had experience with (and the one Endless Air sell) is the Sanden SD505 which I know is suitable.

Thanks for that.

Some info on the Sanden's:

http://www.sanden-europe.com/QuickPlace ... enDocument

I wonder if the 7-piston types are better than the 5-piston, and if the higher capacity is worth looking for. Any preference between the wobble-plate and swash plate designs?

I got this info off the web about a Mitsubishi FX105V compressor:
(OEM #AKA201A201 AKA201A205 - USA)

"The check valve that needs to be removed to allow operation as an expander."

It pretty much boils down to what you can fit in the engine bay, and on price.

Previously I was using a sumped & modified Unicla vertical 2 piston pump - which was quite a bit faster than the current Sanden SD505 (around 50% I guess, unfortunately I never took any specific measurements), it was a very nice pump and much better suited to compressing air than are the rotary swash plate designs.

And again, unfortunately, this vertical compressor is too big for the Patrol engine bay, hence the swap to the SD505, the 7x pumps should fit as they are only 4mm larger in diameter.

From Sanden's specs sheet: Seven (7) Cylinders for reduced operating pulsations and improved noise and performance - so I don't think the 7-piston designs have any higher capacity than the 5-cyl models. Sitting next to a TD42, I can handle a few "operating pulsations"!

Re: swash vs. wobble - theoretically there is no difference, as long as the lubricant is making contact with the lubricated surfaces - some pumps use crank case designs where this is not an option. It's easier to try it and see if it blows up than to pull it apart and find out for sure (imho).

Can you tell me where you got the Unicla pump from?
I dont have a space or mounting problem.
Thanks.

thanx for that spannercrab

Picked mine up from Salisbury Wrecking - they had quite a few of them there at the time (a few years back) I think they were marked with 3B in paint marker (as in vehicle model descriptor) - I've never actually seen one fitted to a vehicle so not 100% sure what they're out of.

Apparently there are also some York type ones floating around also (Fairlanes etc?) which are much the same.

If you do end up going that way you will need to modify the oil return path - the oil line is located behind the clutch, same deal - just drill and tap the return hole, add a breather & fill with oil.

The front crank seal needs to be replaced also with a standard FLAR seal (easily obtainable from most bearing suppliers - I think I got mine from A&B Seals).

As these are a sumped design, and use a reciprocating crankshaft in the true sense of the word you can use heavy weight oil rather than the grease / oil combination.


Or, of course, I have the whole kit (Unicla, pipe barb fittings, pressure switch, pressure guage, check valve, backside idler, brackets & mounts) sitting on my bench wasting space - was going to chuck it on eBay when I had a chance ...

thanks again.

With your earlier mods to the Sanden, does this mean that from then on you dont need to worry about oil again? i.e. filling the crankcase is enough.

I am going to find an SD5xxx but I would be interested in your setup - perhaps put a reference to the eBay auction in the For Sale section here.

No probs.

I think that as will all compressors the oil does need to be checked on a fairly regular basis, as there is some leaking past the pistons themselves into the discharge pipe - but it's certainly not a daily chore.

My SD505 has been running for 18 months on the original fill of LiMo/Oil mix and still shows no signs of running low. Of course it's hard to put an exact usage figure on it as only turns on when the tank is running low or when inflating tyres etc. But it gets it's fair share of work!

morkz wrote:hey spannercrab

thanks for the info much appreciated will eventually give this a go.

did you end up rigging this up morkz? did you do it on the GU?

What vehicle does a Sanden SD505 come out of as I am looking for one for a air system.

Before anyone asks, I need either the SD505 or the SD5H09 due to the fact that they are only about 160 mm in length.

Cheers

morkz wrote:do you need a tank to do this or its not necessary?

I have a spare aircon from a GQ and was looking at selling the aircon kit or making it into a air compressor

I don't have an air tank on mine, straight to the regulator, which controls the clutch. Water/oil separator before the Regulator in my set up.

I didn't do any of the above, that spannercrab mentioned. But because the bearings in mine are almost shot (lots of mud, and open pipes do that). The downsides to not fitting the tank, and going the way i have, is that the hose gets very very hot lol.

It will blow the fitting off the regulator if they are not big enough, or your clamps are crap.

its done a years worth of work, and my mates all use it after I've re-inflated my 37s from 10 pounds. It sounds like a tin full of ball bearings in milo tin, but its yet to give up. I do chuck some oil in it, from time to time..

I've been running this type of set up for about 6 years on all my cars (40, disco, nissan), and i am yet to see one give up. The air con pump on the nissan is very very robust, and will take lots and lots of abuse
They are cheap to get hold of as well, most guys are throwing them in the bin.

My junk looks like this, and its up to you if you follow it. For me, it works/working.







The filter and oil goes on this hose



straight pipe



ohh and if you want to use the factory wiring and button on the dash, you will need to cut and join all the wires off the air con, otherwise, it wont work





Pics are an idea of what you need to do. It would be easy to add a tank, etc etc into this set up.