Tube & Fin Condenser on Roof?

[Davo in Australia]

Yeah, I saw that! And plenty of people from up north are driving down to Perth or back up after the holidays, so a really bad time to be travelling.

Those specs you list are sort of what I'm looking at . . . well, not so extreme, but I want to get this system so that it can handle an extreme day and just loaf during the rest of the year.

[ice-n-tropics]

Guy with a sunburn right arm walks into a bar and says: "I'm buying drinks for whoever can guess location and description of my occupation?
hotrodac

[ice-n-tropics]

Guy was a AUSSY (RH steering) truck driver between Onslow and Perth during record setting temps.
hotrodac

[Davo in Australia]

Ha ha, imagine what he would've looked like if he'd had a flat tyre!

[ice-n-tropics]

Davo,
Today a diesel 2.5L Defender 110 sold at Barrett Jackson auction for $60,000.
If you need more compressor capacity, there is a little known SD7H15 development called "enhanced". It was developed to replace 210cc compressors on giant Komatsu and CAT mining trucks and validated at the Anaconda mine in Arizona (and #14 suction hose was used). Class 8 trucks (with sleeper) quickly adopted the SD7 Enhanced for claimed 15% + capacity increase (before system suction hose upgrades). The downside is increased compressor noise, therefore, it is used mainly on diesel applications.
1) The suction and discharge flapper valves were allowed to open wider which increased volumetric efficiency. Also, the discharge valve was made from thinner material of Sandvic flapper valve steel to open with less force/lower pressure drop and prevent fatigue failure.
2) The discharge valve is shotblasted which minimizes the oil stiction for valve flutter reduction.
3) The re-expansion volume remaining at TDC is reduced using wings shaped suction valve for better adiabatic, isentropic and volumetric efficiencies.
4) Selective component measurements and parts matching is used for all SD7s to reduce TDC clearance and "wiredrawing" due to re-expansion.
hotrodac

[Davo in Australia]

Thanks for that. Landies in America have always gone for silly prices.

Hopefully I won't need another compressor but thanks for the tip. I have to start on this job soon and I'll really have to remember to post an update.

We had a week of rain recently, and I had a couple of long drives to do. The aircon was freezing! Then it warmed up again and the aircon went back to being unimpressive. So something is going on. I'll figure it out eventually.

[ice-n-tropics]

We would record suction and discharge gage readings and louver temps vs. ambient temps and vehicle speeds.
hotrodac

[tbirdtbird]

Davo, your opening post managed to attract the attention of none other than Ice himself.
I have followed all this nicely, but
"KF Head with 1 1/16" threaded #12 horizontal suction port. not HF ???"

Kindly inform us what KF and HF signify

[ice-n-tropics]

T bird,
Outback sunshine may have heat stroked Davo, thus "HF" misprint.
KF is a compressor cylinder head made in Japan and used in the USA with "KF'' cast in 1/2" letters below the oversize 1 1/16 (#12) threaded suction port.
If you need one, try Tim for the part #.
hotrodac

[Davo in Australia]

Hi guys. A thousand apologies for leaving this for so long, but this job took a huge amount of time, and during a big move between towns as well, so I've been flat out. I couldn't leave this without an update though.

I had to build an ally chequerplate box for the condenser, drier, and relays, all in a carport during the wet season. Not fun!

But it all worked out. Moving the condenser onto the roof has completed fixed the engine cooling, and the aircon is superb . . . though there's a confession about that. Being self-taught, of course I know nothing, and this time when I was charging the system I just couldn't get the vent temps down. I'll spare you the details, but I finally worked out why you have the engine running fast when you do this! Yes, all this time I was running an undercharged system because I'd charged at idle. This time around, with the revs up, I realised that's what makes the suction pressure go down. I know, I know, (hangs head in shame, lol), it seems obvious now. So I got to pressures of around 25/220 psi at 35c ambient, vent temps at around 9c, and the compressor cycling at idle the way it should.

I've been running it for a couple of months like this and it appears I've built a monster system that can handle just about anything. It pulls down in about five minutes on a hot Kimberley day, and gets too cold on the highway at 35c.

A big thanks again for your interest and help. And I learned something again, too, to say the least!