Thread: Under Bonnet ARB Compressor

Originally Posted by mrapocalypse

I thought the ARB battery cradle might be good for the ARB Compressor. For tyres not diff locks sadly.

Are they OK in the heat from the engine?

I don't think that under the bonnet is a good place for a compressor, and especially not near the exhaust manifold/s, exhaust down-pipe, or turbo.
When you run a compressor, it gets hot, and so does the air that has been compressed. This heat has to be disposed of by the compressor (which is why it has cooling fins).
Under the bonnet, the intake air for the compressor is already going to be heated (and hence somewhat expanded).
So then the compressor is trying to compress warm air that has been expanded prior to entering it.
AND the compressor has to dispose of extra heat after compressing the warm air.
AND the compressor has to transfer heat to already hot surroundings!
Inefficient and hard on the compressor.
AndrewMilne

Don't do it.
Everything AndrewMilne said is true. I have a TJM big red 2 under the bonnet and it dose not work as well as my portable unit in the box (which is also the TJM big red) after the engine has heated up.
Once the heat builds up in the engine bay I go to inflate the tyres and after a minute or two it would cut out. I took it back to TJM and they informed me that it was tripping due to the heat. The unit works well when cold but only has the issue after a run in the car. The one I carry in the box in the back of the car has never had this issue.
Regards
BKH

Thanks guys.

Glad I asked.

Ian.

I have an ARB compressor mounted in the engine bay and this is used to run both Air Lockers and as a compressor for pumping tyres.

I have never had an issue with this unit. If I wish to inflate tyres, the bonnet is up and any hot air has an escape route. The unit is high up and therefore has access to air being drawn in from the outside via the open bonnet. Whilst using the unit to engage lockers, it only runs for a few seconds each time. I do not have it connected to an external air tank, using only the air stored in the units own tank.

Just commenting on my experience, others here, have different experiences.

Regards

XDrive

Originally Posted by XDrive

I have an ARB compressor mounted in the engine bay and this is used to run both Air Lockers and as a compressor for pumping tyres.

I have never had an issue with this unit. If I wish to inflate tyres, the bonnet is up and any hot air has an escape route. The unit is high up and therefore has access to air being drawn in from the outside via the open bonnet. Whilst using the unit to engage lockers, it only runs for a few seconds each time. I do not have it connected to an external air tank, using only the air stored in the units own tank.

Just commenting on my experience, others here, have different experiences.

Regards

XDrive

x2 Yep same experience here , Oh i have just replaced the compressor as i had the large old style compressor that blew up yes blew the cyclinder off the compressor motor still worked fine ,
Make your own mind up or follow the crowd
2xfor
2xAgainst

Originally Posted by rangieman

x2 Yep same experience here , Oh i have just replaced the compressor as i had the large old style compressor that blew up yes blew the cyclinder off the compressor motor still worked fine ,
Make your own mind up or follow the crowd
2xfor
2xAgainst

So if i follow your advice is that making my own mind up or following the crowd?

It's an expensive experiment. Which is why I suppose one asks advice.

So performance is affected but it's not bad for the compressor?

And I take the point about bonnet being open during operation which would take most f the heat away. So Maybe..... ???.

As an alternative, my arb compressor is behind the driver-side headlight as there is enough of a gap to have it there.

A careful analysis of the available data would seem to suggest that :

• Putting it under the bonnet is a great idea, because "I've done that".
• The head will come off the compressor though.