e3/e12/e28/e23 A/C stats Show & Tell

[e12euro]

Might be useful for present and prospective classic BMW sedan buyers to have this info. Could be a good "sticky" thread. I will start things off. (Look for underhood red decal for factory A/C refrig. capacity)

1976 e12 530i refrig. capacity 2.64 lbs, mods: Sanden SD 508 compressor, Vintage Air 12in x 20in parallel flow condenser, R134a TX valve, R134a gas, performance: Good

1984 e28 528e refrig. capacity 2.82 lbs, R12 gas, performance:Excellent

[wkohler]

I don't understand how you can have good performance in the E12 when the air volume is non existent for the AC. A fan is blowing but there is virtually nothing coming out of the vents.

[e12euro]

My e12 is working well. The car has the original evap core and blower box. Yes, it pushes out less air volume than an e28, but that's only one part of an a/c system. It's a smaller blower box than the e28 unit, which does overhang the transmission tunnel, but I get 38F cold air from the vents so overall it isn't bad.

Must say my e12 is the best one I have come across on a/c. But have made some mods. It has 20% more capacity than a stock car (2.2 lb refrig.)

As you can read here Mike W. from First Fives spent a holiday in Vegas and his 528i worked quite well.

e12 528i a/c

[Kenny Blankenship]

I think the evaluation is correct, acknowledging the E28 is better than the E12. Though I have not experienced an early E12 HVAC, my understanding is the early E12 (75 and 76) system is not as good as the later (77+) cars. Even so, the later cars are "marginal" enough that the color of the car makes a big difference. My beige car had adequate AC, but I wonder how it would perform in a black car.

[Mike W.]

I think the evaluation is correct, acknowledging the E28 is better than the E12. Though I have not experienced an early E12 HVAC, my understanding is the early E12 (75 and 76) system is not as good as the later (77+) cars. Even so, the later cars are "marginal" enough that the color of the car makes a big difference. My beige car had adequate AC, but I wonder how it would perform in a black car.

I agree there is a difference between early and late. I'd actually put it at 530/528 which had a different condenser. But ours worked well, steaming thru the desert in Nevada/Utah I had 42F air coming out of the vents in 110F brilliant sunshine. Temp was a setting and the compressor was cycling so it wasn't even at it's max capacity. Blower was at 2, which like E28s is actually 3 but not max. The only problem with it was it took a while to come down to temp. But once down it would hold it comfortable. That was in a cashmere car which is not black, but certainly not white.

E3, pretty poor. I even rebuilt it with a later swashplate compressor which while it smoothed out the awful vibration didn't really improve the performance much.

E28 worked quite well really. Not that I haven't seen any better, but it would blow cold air quickly.

All 3 are with R12.

[OcCoupe]

E9: the driver's right arm and the passengers left arm are frostbitten while the drivers left arm and the passengers right arm have 3rd degree burns from the sun.

The brain trust of BMW engineers felt two small vents coming out of the lower center console were adequate to cool a car that has the greenhouse of the Crystal Cathedral...

[e12euro]

I went to the Vintage Air condenser, which only cost 120 bucks. I know Robert Bondi put a 14 x 20 in Vintage Air condenser in his 1977, and living out in Texas he said the car works quite well.


I also have the dashboard pod with directional vents, I trimmed my dash with material, got a very good window tint. Put in a thick headlining when I retrimmed the interior. The condenser has a new style slimline condenser fan and I replaced all the refrig. lines. All these changes didn't cost much in parts and now I get a lot of water collecting under the car which shows the evap core is getting cold. My car is Fjord Metallic Blue.

I agree with Mike W. the early to late e12 difference is in the condenser, early to late evap / blower box is about same size, just looks different cos they integrated the HVAC controls.

I know my e12 is also better on a/c than any stock e23 I have been in.

What does the refrig capacity label say on a late e12 or e23?

[Kenny Blankenship]

I know my e12 is also better on a/c than any stock e23 I have been in.

Apples to apples (both running R12), an E23 air conditioner should be better than an E12. The air circulation is much better.

Getting an E23 air conditioner to run properly is a different matter...

[Brad D.]

I think e28 AC is marginal at best when ambient temps approach or exceed 100F. This is even worse when R134a is run with no condenser mods. I replaced my condenser with a parallel flow unit and have run both R134a as well as HC based refrigerants, with the edge in performance going to the HC based stuff. In traffic with outside temps over 100, it can maintain vent temps in the low 40s and mid 30s while moving. However, if I have a car full of people, it just feels hot. Window tint helps significantly as the greenhouse of the e28 is rather large.

[e12euro]

I know my e12 is also better on a/c than any stock e23 I have been in.

Apples to apples (both running R12), an E23 air conditioner should be better than an E12. The air circulation is much better.

Getting an E23 air conditioner to run properly is a different matter...

True, a stock standard brand new 1980 528i versus 1980 733i on r12, the e23 is going to be better. Plus, the e23 has a rear cabin outlet.

Must say though, that back when my e28 was newish on r12, it did well even at 100F and higher.

Only e3 with a/c I was ever in was 20 years ago. An a/c tech guy with a rusty, oil leaking Bronze Euro 3.0 L (long wheelbase). Car was in very bad shape, but was surprised how good the a/c was. Must have been the only good thing on the car. I was surprised given how poor e3s are on a/c reputation. It was a high 90s day and the car was cool inside. Looked like the usual factory Behr system.

[Mike W.]

I know my e12 is also better on a/c than any stock e23 I have been in.

Apples to apples (both running R12), an E23 air conditioner should be better than an E12. The air circulation is much better.

Getting an E23 air conditioner to run properly is a different matter...

True, a stock standard brand new 1980 528i versus 1980 733i on r12, the e23 is going to be better. Plus, the e23 has a rear cabin outlet.

Must say though, that back when my e28 was newish on r12, it did well even at 100F and higher.

Only e3 with a/c I was ever in was 20 years ago. An a/c tech guy with a rusty, oil leaking Bronze Euro 3.0 L (long wheelbase). Car was in very bad shape, but was surprised how good the a/c was. Must have been the only good thing on the car. I was surprised given how poor e3s are on a/c reputation. It was a high 90s day and the car was cool inside. Looked like the usual factory Behr system.

The hood does make all the difference in the world on E12s, without it you get no air.

Back to Bavs, I had an early one but I'm not sure they changed. It had very small cages compared to an E12 and didn't blow much air at all. Along with a tiny condenser fan without a shroud. That car was advanced in some ways, but A/C wasn't one of them. It worked well enough I would have hated to be without it, but that's about all.

[e12euro]

I know my e12 is also better on a/c than any stock e23 I have been in.

Apples to apples (both running R12), an E23 air conditioner should be better than an E12. The air circulation is much better.

Getting an E23 air conditioner to run properly is a different matter...

True, a stock standard brand new 1980 528i versus 1980 733i on r12, the e23 is going to be better. Plus, the e23 has a rear cabin outlet.

Must say though, that back when my e28 was newish on r12, it did well even at 100F and higher.

Only e3 with a/c I was ever in was 20 years ago. An a/c tech guy with a rusty, oil leaking Bronze Euro 3.0 L (long wheelbase). Car was in very bad shape, but was surprised how good the a/c was. Must have been the only good thing on the car. I was surprised given how poor e3s are on a/c reputation. It was a high 90s day and the car was cool inside. Looked like the usual factory Behr system.

The hood does make all the difference in the world on E12s, without it you get no air.

Back to Bavs, I had an early one but I'm not sure they changed. It had very small cages compared to an E12 and didn't blow much air at all. Along with a tiny condenser fan without a shroud. That car was advanced in some ways, but A/C wasn't one of them. It worked well enough I would have hated to be without it, but that's about all.

When you say hood, do you mean the dashboard pod that has directional vents? BTW changed my car's interior from vinyl to cloth, that helped too, and comfier. I trimmed the dash vent pod too.

Have heard 1982-84 e28s have bigger condensers than 1985-88 cars, and cool much better.

Maybe earlier pre climate control 733is might be better (i.e. less problematic) with their manual a/c?

I was in a 1976 e3 3.0L. I also don't know if they made a/c changes through the e3's life. However, Road & Track did a 1973 e3/e9 survey of around 112 cars. Many complaints on a/c being weak. Same magazine did a 530i survey in 1979, over 300 cars in the survey and a higher % with a/c than in e3 days. In the e12 survey there was no complaint about a/c. Average e12 surveyed was older and had more miles than the cars in the e3 survey, so a/c must have been better.

[Mike W.]

When you say hood, do you mean the dashboard pod that has directional vents?

Yes.

Have heard 1982-84 e28s have bigger condensers than 1985-88 cars.

Yes, but... Early cars had copper aluminum condenser and 85+ used all aluminum. IMO all aluminum is better for heat transfer.

[e12euro]

I noticed this article on the Bavaria's luxury counterpart the 3.0S. In this November 1973 test they said the car didn't miss a beat when they performance tested it in a 100F test session.

Motor Trend page 4

[wkohler]

They said the air conditioning was on, not necessarily that it was working.

[Mike W.]

E3 A/C was a joke. They had substantially smaller blowers than E's 12 and 28 and until 75 had a vile York compressor that vibrated like crazy, had rubber mounts that failed and those in turn led to it getting out of alignment and tossing the belt. At 100F it was better by far than having the windows down, but it wasn't cool and comfortable. Bavs were fine cars in many ways but HVAC wasn't one of them. Not to mention they wanted to die at idle with the A/C on with those evil Zenith carbs.

[e12euro]

E3 A/C was a joke. They had substantially smaller blowers than E's 12 and 28 and until 75 had a vile York compressor that vibrated like crazy, had rubber mounts that failed and those in turn led to it getting out of alignment and tossing the belt. At 100F it was better by far than having the windows down, but it wasn't cool and comfortable. Bavs were fine cars in many ways but HVAC wasn't one of them. Not to mention they wanted to die at idle with the A/C on with those evil Zenith carbs.

Might have helped on the final 1975 & '76 3.0Sis cos they shared the 530i's injection motor (concerning stalling). Anyone here ever own a 3.0Si?

[CSBM5]

E3 A/C was a joke. They had substantially smaller blowers than E's 12 and 28 and until 75 had a vile York compressor that vibrated like crazy, had rubber mounts that failed and those in turn led to it getting out of alignment and tossing the belt. At 100F it was better by far than having the windows down, but it wasn't cool and comfortable. Bavs were fine cars in many ways but HVAC wasn't one of them. Not to mention they wanted to die at idle with the A/C on with those evil Zenith carbs.

Having lived with one for 14 years, I know too well how worthless the "A/C" in an E3 can be. I did change the compressor to a rotary one of some type at the same time I had to replace the evaporator. Pulling "that box" out of the dash was so much fun, you know, the one they build the car around. Of course I guess it was a piece of cake compared to a modern car.

Re idling...try dealing with 95+F temps with triple webers and then turning on the A/C. I played with setting the idle speed higher in the summer, and I also used an MSD Ping Control attached to an MSD6A to advance timing (i.e. I set static timing advanced a bit and then used the PC to retard it for most situations until I needed it).

Ah, the good ole days...

[Mike W.]

E3 A/C was a joke. They had substantially smaller blowers than E's 12 and 28 and until 75 had a vile York compressor that vibrated like crazy, had rubber mounts that failed and those in turn led to it getting out of alignment and tossing the belt. At 100F it was better by far than having the windows down, but it wasn't cool and comfortable. Bavs were fine cars in many ways but HVAC wasn't one of them. Not to mention they wanted to die at idle with the A/C on with those evil Zenith carbs.

Having lived with one for 14 years, I know too well how worthless the "A/C" in an E3 can be. I did change the compressor to a rotary one of some type at the same time I had to replace the evaporator. Pulling "that box" out of the dash was so much fun, you know, the one they build the car around. Of course I guess it was a piece of cake compared to a modern car.

Re idling...try dealing with 95+F temps with triple webers and then turning on the A/C. I played with setting the idle speed higher in the summer, and I also used an MSD Ping Control attached to an MSD6A to advance timing (i.e. I set static timing advanced a bit and then used the PC to retard it for most situations until I needed it).

Ah, the good ole days...

Yeah, I ended up putting a later swashplate compressor on mine, an E21 condensor fan and repurposing a throttle positioner meant for smog to keep it idling. But still, while I kept it from stalling, not much cooling. By the time I was done about the only original parts were the evaporator and condensor. It was smooth and quiet, but that was all.

[0257]

Gentlemen, I know we’re an e28 forum, but I’m posting on this thread because it was immensely helpful, and partly addresses an issue I’m currently facing with my newly acquired (and otherwise nearly showroom) ‘81 528i as I revive its A/C system. I am interested in knowing if anyone has (1) successfully installed an e28 evaporator in an e12 528i, (2) had an e12 528i evaporator re-cored to greater capacity (as per HackMechanic’s e9) or (3) found a higher output blower motor that is a direct fit into the e12 528i.

Also interested in knowing the largest parllel flow condensor anyone has installed in an e12 528i and any installation hacks of note.

In the absence of concrete answers, I’d appreciate a push in the direction of a shop that specializes in these kinds of mods. I’m in southwest FL (thus the need to make every improvement possible), but don’t really expect to find this resource near me.

Thanks in advance for any further insights.