T4 Air Conditioning Modernization

[raygreenwood]

..... it took me a minute.....but that was a giggle! Ray

[MGVWfan]

I'M BACK!

Sorry for the absence...work and other stuff has taken me offline for the past 4-5 months. I've finally got some time to catch up with the fun stuff!

Yep, that's the compressor. I've had it in the car now for 6 months, it's performed flawlessly. I used POE 100 oil ("retrofit" oil) since that's what I had in the York before, and the system was saturated with it. I drained the Toyota ND 10PA15 compressor, and refilled it with POE oil, and it's worked just fine. I will need to replace the original lines sometime, I leak about 14 oz (one can) every 6 months, not acceptable, but it was a good way to test the feasability of the ND compressor in this system.

Observations...

Ray's modified centerlink is still working 100% great, no slop, it's now got about 15K miles on it. Those KYB 3/4 ton Ford van shocks (5406 I think) are too stiff for the rear of my car, even with original-type tall sidewall tires. I'll be going back to the 1/2 ton shocks next year. The OE-style NOS KYB slip-in struts are working well, when I load the front end (like on a trip), the thing handles very well. No uncontrolled motion in front.

It's had two round trips of about 500 miles total, one of 600 miles total, and two of 550 miles total all over Texas, including lots of hills. No problem, power in reserve, even with those small-dish 1.8L pistons. D-Jet is still working great, had to re-tighten one injector line after a trip (I check the whole fuel system over about once a month, and a clamp just decided to loosen up on a trip for some reason with no warning), all seasons, from 96 deg F outside to 45 deg F. I've gone through two thermostats to date, kinda strange. The Eber still works, though I had to replace the original hot air blower with a motor from a bus, my motor finally siezed up, the bearings are toast. With my recent bonus check, I can paint it sometime in early 2007 (keeping it original, L96M Marathon Silver/Blue Metallic). It's been giving me 20 mpg (US) in stop-and-go driving, 25-27 on the road (27 at lower speeds on flat terrain, 25 in the hills of East Texas at 70 mph). The trans shifts firmly, though I have noticed an interesting little flare between 2 and 3 when upshifting at very light throttle openings. It's not noticeable unless you look for it. I suspect the AT's oil pump is just a little worn, so at very low engine rpm's it just puts out enough to operate the Direct/Reverse clutch slowly, and the clutch doesn't engage before the brake band releases fully. It shifts like a dream on the road.

[MGVWfan]

Well...after losing two computers to lightning, a Shuttle mission, some Scouting adventures, and other good stuff, I've found my way back to the land of the 412. I'm running Linux now (got tired of the other OS and its bugs and virii ), so things should be OK in PC land for me now.

The Nomad (my '73 412 with 1.8L Mahle jugs and pistons, moderate CR, etc.) has about 15K more miles on it than last time I posted, and no major issues. I finally got a good Wahler tstat in it from Bus Depot, and it's lasted 6 months now. It impresses everyone who rides in it with the excellent ride quality and comfort, certainly not what most expect from an ACVW.

The A/C in the Nomad is working great. I have pictures now, and I'll post them when I get the floppy drive in this new PC working with Linux...

Even with R-134a and the original hoses and condenser, I'm getting acceptable duct temps (50 at worst) except in the hottest stop-and-go driving, where the original condenser's small area becomes a limiting factor. The real problem with running VPC port-installed AC in a T4 in traffic is the low charge rate of the stock 55A alternator. I have to put a charger on the battery weekly to keep it from discharging enough to prevent starting. There appears to not be a bolt-on or "frankenstein" alternator option for the T4's combination of mounting , cooling, and pulley size, but I saw an Audi 5000 in the yard a month ago, with a cooling duct on it...hmmm.

[ubercrap]

Good to have you back, again. I guess there isn't much to discuss when everything is running great?

[raygreenwood]

Yes...there is a solution to the alternator. I will be putting one on mine when I get to it. Bear in mind, that the original alternator blows cooling air from back to fron. In other words it vents into the engine compartment. I have been told that most of the other Bosch and Motorolas with their own fans....also pull air from back to front.. .
Others have aleady done this. You will have to do some minor adaptor wiring at the voltage regulator if you use a Motorola. But the alt. chassis is very close in size. Do some careful selection of pulleys...and then you will need a spacer on the mounting bracket. You should be able to get a 75 amp alternator with a single wire internal regulator without much problem.
From that point...cool air into the alternator from the back should be little problem as it is ahead of the muffler.
The spacering is so the pully can line up right. May be some adjustments to the fit behind teh original sheet metal but all of this is doable.
I will be adding the twin battery option and putting the AC and the huge draw lights I haveon the second battery. Ray

[MGVWfan]

Uber...yeah, I'm happy with no VW woes, just trying to get a factory AC unit in a 76 Duster that had heater only

Ray...So what cars have the Motorola alternator in question?

The problem that's getting me is finding one that fits in the space allowed, and has mounting ears with spacing and clocking that's "shimmable", and draws air in only from the rear...that and the pulley, as you noted. The one thing we have in our favor is that the old N-frame Bosch alternators on our T4's had a lower max speed than most anything later, due to slip ring linear velocity limitations (the larger the slip ring, the faster the slip ring goes past the brushes, and the more the wear and forces on the slip ring), and to a certain extent the max bearing speeds. Anything from the mid 80's on will probably have a higher max shaft speed, so we can get by with a smaller pulley without overspeeding the alternator on a max-throttle upshift. But I've not found an alternator with 180 degree mount clocking and closed sides (no vents on the sides, only on the rear...

[raygreenwood]

A lot of the golfs, jettas and a few saabs had Motorola alternators whose mounting ear spacing (in "clock" spacing)...should work. But...the problem is that they will not mount up to the bracket due to length. This is where the spacers come in. The spacer bushings will go on the mounting bracket where the allen wrench locking bolt is...AND on the main pivot bolt. It pushes the whole altrenator backwards toward the front of the car. Once you mock it up with spacers....you will then need to see which pulley will line up and then....if another adjustment to the spacers will need to be done.
There are a whole slew of pulley types that fit. Only a couple will work. Bear in mind that with the two spacers...you will need two new longer bolts.
It is a bit of work...but not real ugly. Just some careful measuring, a couple afternoons of mocking up and reinstalling...then get-er-done. I will see if I can get you some part #'s. It also helps to look in the brown Haynes manual from the rabbit/jetta/sirroco (pre-90). It has excellent photos of all the bosch and motorola parts. Ray

[MGVWfan]

Danke schoen herr Doktor! I'll see what's up next time I'm in the car breaker's yard.

BTW, I have a Mitsubishi alternator off a Ford Taurus on my '67 MGB in place of the Lucas dynamo (pitiful thing that), and I fitted a ND alternator to my '67 English Ford Anglia in place of the Lucas dynamo (done while in college)...this is the toughest retrofit case I've seen due to the tight clearances and the cooling system.