If the radiators are sized, well within their limits for correct operation of the vehicles, why is it neccessary to have such a larger radiator when a/c is fitted?
Not only does the AC dump heat in front of the radiator (in the hottest of possible weather), it also adds 15% extra work to be done(if you drive with the windows up anyway)....but lots of cars use the same part AC or no.
The vanagon radiator is over-sized regardless of A/C. Same radiator was fitted for A/C or non-A/C equipped vanagons.
Budget and packaging not withstanding, one can never have too much thermostatically controlled cooling. (or be too thin or too rich).
I can't speak as to the Vanagon, but a Rabbit TD'd with AC on when working hard is pushing it cooling wise on the stock system.
Hence the relatively giant radiators on real hard-work vehicles like 745 mentioned, and the availability of "tropical climate" clutch fans
on many vehicles that use such, and various thermostat temperatures.
A truly go anywhere anytime cooling system will by nature be overkill for 90% of people 90% of the time.
That 10% bugs me personally and I operate with an eye toward it.
When you get the Vanagon cooling and sorted out, put an oil temp gauge in it for more fun and worry/expense.
Some funny stuff it there

I do have an oil temp sensor and gauge but I'm not paying attention to it cause I need to swap the + - wires to get a proper reading. It has a 180 F switch on the cooling system though and I have heard the aux fan come on a time or two.
I'm much closer to the my goal but your right, it's that last 10% that's bugging me. This van/project is a concept that is supposed to bring endless joy and minimal sorrow at the drop of a hat, under extreme conditions. My patience is (or lack of) is allowing compromise creep in. On the other hand, spending every weekend "working on the van" is getting old, especially for my sweetheart.
There is after all, another life (I think).
Finish the air cleaner build, and mess with the timing light and timing - one, two days max, done.
Funny, I had to cut and reverse the wires on my VDO trans temp gauge because it's wired backward from the VDO oil temp gauge I got the connector from.
I subsequently repined the connector so my colors were back to right.
Make a pump-bracket mark, light time, rotate your pump in 1mm increments till you find the spot you like, then check time again will cut some hassle time.
Keep at it, if it was easy everyone would do it.

I found a stout engine oil cooler to be of benefit on a hard working TD, and pleasant overkill on a NA motor.
Easier said than done on a Vanagon I guess, but it's a thought.
I'm much closer to the my goal but your right, it's that last 10% that's bugging me. This van/project is a concept that is supposed to bring endless joy and minimal sorrow at the drop of a hat, under extreme conditions. My patience is (or lack of) is allowing compromise creep in. On the other hand, spending every weekend "working on the van" is getting old, especially for my sweetheart.
There is after all, another life (I think).
Finish the air cleaner build, and mess with the timing light and timing - one, two days max, done.
I can feel your frustration\pain - as I've been there many times with diff. projects (putting a steel roof on my multi angled roof house by myself - 2wks straight turned into 4 wks

)
But seems that you are just about there & it is a new year!! A bit more finetuning and you'll have a super rig to drive in.
I do have a good oil cooler and remote filter mounted. Fan turns on at 180 F. I've heard it several times.
Good idea on the timing marks before I move it. Right now it starts easy - almost too easy. I'm hoping to quiet the intake with something I will fab up today. I think a lot of the noise in the cab can be attributed to it, but that's way off topic. Messing with the IP timing may reduce my EGT's a bit as Mark and several others have pointed out.
Thanks all - Happy New Year
Speaking of your intake, where is the filter located? I tried the best I could to isolate mine from engine heat. I built a lexan shield over the filter so that it would take more of the cold air rather than the engine air. That could be part of your issue is pulling hot air once the thing warms up.
Speaking of your intake, where is the filter located? I tried the best I could to isolate mine from engine heat. I built a lexan shield over the filter so that it would take more of the cold air rather than the engine air. That could be part of your issue is pulling hot air once the thing warms up.
The intake used to be a K&N filter (don't like them personally) located at the end of some ABS fittings and stuffed into the driver's side pillar (the inside corner of the van where outside air is supposedly directed into the bay at speed ( now that sounds funny). I may block that off so the engine heat doesn't get to it as you suggest. It will also limit the air from cooling the bay though.
Right now I have a huge round filter but I'm thinking of starting over with a rectangular one from the local FLAPS and building a metal housing for it. Trying to reduce noise is the goal here and I doubt the round one is going to help that much.