Engine mounted, belt driven air compressors? Has it been done?

[Toxic_Avenger]

I'm in the market for an air compressor, been looking at the usual suspects that people recommend, but more and more it seems that the 12V power supply is the limitation of getting to good air flow (CFM or LPM) value. An engine driven compressor looks appealing, able to offer double the LPM flow for similar price.

I've notice Endless Air make a belt driven compressor unit for mounting to the engine, and have suitable mounting kits for the range rover / disco V8. Similar in make and size to an AC compressor, it seems like a good way to get some great flow for fast tyre inflation, air tools etc.

Has anyone doe this on a defender? At a stretch a Puma?
Has anyone modded / re-purposed an AC compressor to work as an onboard air compressor?

[LR V8]

Some Perenties have them, but its mounting brackets would be designed around the Isuzu engine.

Pete

[jboot51]

I'm in the process of getting a bracket laser cut for my 300 tdi defender.
It will retain the original a/c compressor with a second modified sanden sd7 as the air compressor.
Seems like it will work using the exiting a/c tensioner with a longer belt.
The back plate on my existing a/c compressor will have to changed to allow the a/c hoses to attach to the rear of the pump instead of the side.


$ wise it's probably not worth it as the mods to the a/c pump + regas will be about $310 alone.


Boss make a 12v 3.5 cfm compressor for ~$305


12 Volt Air Compressor PX07 Bare | Boss Air Suspension Shop

[Blknight.aus]

I'm.quietly.certain that there's some fool on this forum who made an air compressor out of a York reciprocating ac compressor a starter motor from a petrol series and some other miscellaneous junk. Then went and used it in support of a cape York trip.

You want to try and get a old school reciprocating piston compressor if you can as they survive nor having lube in the gas a little better than the other types.

[weeds]

Some Perenties have them, but its mounting brackets would be designed around the Isuzu engine.

Pete

If it's the twin piston jobbies I doubt they would have survived this long.........they were pieces of crap to say the least and removed from all the 6x6 I came across, we had bins full of them

[bee utey]

I've been using York twin piston a/c compressors as air compressors (shed and vehicle mounted) for the last 30 years or so. For compressor duty you have to remove the head and look for the oil gallery that connects the low pressure side to the front bearing behind the crank seal. Plug this gallery with a small grub screw and it won't spit much oil at all. Basically you just fill the sump of the compressor with around 25mm of oil, there used to be a drawing somewhere on how to make a dip stick out of a piece of wire and insert it into the filler plug on each side.

Another compressor that came recommended was a twin piston Diesel Kiki model although they are quite rare, being used in the 70's, same deal with the oil gallery. I've never looked at a Sanden Rotary compressor for air duty but it can't be too hard as that is the one used by the Endless Air people I believe.

Be warned though that you need a relief valve and/or a pressure switch as these compressors happily pump up to 300psi if you forget.

[Toxic_Avenger]

So I made up some cardboard mock ups of ARB compressors, the CKMA12 (single pump) and the CKMTA12 (twin pump) using the dimension in their catalogue.

If I go 12V, then I can fit the CKMA12 in the channel down behind the passenger seat in my puma 90. Going the twin pump CKMTA12, it will fit either on the sloped section behind the passenger seat (at the expense of fore/aft seat adjustment) or very nicely on the top of the wheel arch. Nice and convenient for cable routing too.

I'm yet to scope out available real estate in the Puma engine bay for a belt driven unit. Still chasing info on dimensions and suitable pumps though.
I think going this route would be preferential but more costly with much more dicking around to make it work. It would be a long term solution though.

The thing I'm seeing is that a lot of compressors rate their flow rates at no load, while what we all really need to know is how they flow at higher pressures (for example getting the tyre up to road pressure from say, 18psi).

[BadCo.]

Some good talk of compressor brands in this tgread
12 volt air compressor for general use

[BadCo.]

If it's the twin piston jobbies I doubt they would have survived this long.........they were pieces of crap to say the least and removed from all the 6x6 I came across, we had bins full of them

Is this the one you are bagging?

Isuzu Perentie 4×4

I hope not, because it would be awesome to have one in my Personnel Carrier!

[Toxic_Avenger]

Some good talk of compressor brands in this tgread
12 volt air compressor for general use

I've been reading a lot both online and on this forum (including that tgread), so far I have been unable to find flow rates of the Dr Air compressor under load. Would be interested to see some figures to make a true comparison.

I've mocked up the mounting position for a 12v ARB item, so next step is to gather data on the alternatives - engine mounted air on board, endless air, and other 12v options- Dr Air pro flow, and perhaps some other common alternatives. Hopefully that's where the forum can offer some assistance.

Going blindly on one 'shootout' review by a 4wd magazine without knowing alternative performance information is not really my thing. I like informed, educated comparisons.