Thread: Endless air on TDI

Hi,
I went to the wreckers today and found an a/c compressor that looked easy enough to fit next to my air con. one. Its a bit smaller so I pulled it apart to see how it works.
I found that its a vane compressor, five vanes with two compression cambers.
(will try and remember to take some pics).

Do you think it will work okay as an air compressor?
It would need oil circulating for sure.

This is probably a stupid question.

Can you get an alternator, like those used on 4BD1s, that has the vacuum pump on the back and turn it into an air pump?

Simon

Originally Posted by abaddonxi

This is probably a stupid question.

Can you get an alternator, like those used on 4BD1s, that has the vacuum pump on the back and turn it into an air pump?

Simon

I don't really know but a single stage vacuum pump really only pumps about 10-13psi absolute, so what would happen if you tried to increase the output pressure ?
Also I'm guessing the volume wouldn't be great either

Originally Posted by Cobra

Hi Diff

I've had this system on my '95 Disco 300 TDI for the last five years and it works really well. It's way faster than other compressors.

The air compressor is run by replacing the aircon belt idler pulley with a custom made pulley which has both serpentine and V drive.

The tyre compressor then has its own tensionong system.

Cobra

I'm very surprised this works, unless it different to how I imagine from the description.

The problem I see is that the drive has to come from the belt that drives the aircon compressor and is transferred to the air compressor drive belt via the idler pulley. Now it is the flat, not multi-vee, side of the aircon drive belt that runs on the idler pulley. Also the wrap angle on the idler pulley is quite small. So I believe the aircon drive belt would slip on the idler pulley and not transfer sufficient torque to drive the air compressor.

Below are some pics I found somewhere, showing an air compressor mounted alongside the aircon compressor.

Originally Posted by Bush65

I'm very surprised this works, unless it different to how I imagine from the description.

The problem I see is that the drive has to come from the belt that drives the aircon compressor and is transferred to the air compressor drive belt via the idler pulley. Now it is the flat, not multi-vee, side of the aircon drive belt that runs on the idler pulley. Also the wrap angle on the idler pulley is quite small. So I believe the aircon drive belt would slip on the idler pulley and not transfer sufficient torque to drive the air compressor.

Below are some pics I found somewhere, showing an air compressor mounted alongside the aircon compressor.

This set up significantly reduces the amount of belt that is in contact with the A/C. I guess it works?

this page has other info you might find useful:
York Compressor for On-Board Air

Originally Posted by slug_burner

This set up significantly reduces the amount of belt that is in contact with the A/C. I guess it works?

Yes it does.

I have no idea how it performs - those were just some pics I found in a post somewhere.

I saved them when I had a 300Tdi in my rangie - now replaced with a bigger rubber band.

I would look at modifying that arrangement to improve the belt wrap if I was to fit an air compressor to a 300Tdi.

Originally Posted by EchiDna

this page has other info you might find useful:
York Compressor for On-Board Air

Yorks are the pic of the compressors for onboard air IMHO. But I think it would be a challenge to mount one on a 300Tdi.