E28 Evaporator core vs. E12

[Robert Bondi]

Still slowly collecting parts for this project....

I acquired an E28 blower box from a 528e and took pictures of it next to the E12/earlyE24 blower box.
The units are essentially the same from the outside, so the main difference, as discussed, is really just the
different fittings for interfacing with the rest of the AC system.

https://www.flickr.com/photos/robertbon ... 0297675328

BTW, as far as AC systems, a guy over on the E28 board has started a company selling AC conversion kits basically targeting R134a conversions and all the components in the engine bay. I bought a Sanden compressor
and their bracket for the M30 engine. The just added an E30 kit.....they indicated that an E12 kit is also in the works.

https://www.acsolutions.co/

Robert

[tlake]

Thanks for the heads up Robert

[0257]

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.

Ken

[528i-1981]

Hi Ken -

Welcome. The 14x20 Vintage Air condenser (03261-VUC) fit for me using short-drop 90-degree fittings for the hoses. The mounting takes a little engineering but isn't that difficult. The factory top mounting tabs work. In my install, I used SPAL 30130011 mounting brackets which are long and extend past the bottom edge of the condenser, providing a place to secure the assembly to the sheet metal. I would be surprised if you could fit anything bigger in there.

Cheers,
Eric

[0257]

Thanks, Eric. i’ll explore that item, sounds about the right size. Attachment tips a welcome bonus.

[Robert Bondi]

FWIW, I found my 2006 posts talking about some of these parts. I don't recall if Eric had referenced the same stuff for his work, but we both used that same parallel flow condensor. The SPAL elec fan P/N looks different, but that also means they both work as options. I'll look for my photos from this project as well....far enough back I think it's an actual stack of photgraphs that I need to digitize.

Vintage Air Condensor
https://www.firstfives.org/wb/msgs/8728.html

SPAL aux fan replacement
https://www.firstfives.org/wb/msgs/19468.html

Ken: You might also consider the duct work as a possible part of the inefficiency of the E12 AC/ventilation system. I have the central part of the duct work very visible now in my restoration car without AC (different thread)....unless there are other parts missing, it really seems like some of the passages for air or more of guidance than direct, dedicated duct work.

I'll work on getting more pictures...my new E28 evap core next to the E12 evap core might be useful....

[HB528i]

Be sure your Spal fan has curved blades or it will sound like an F-16.

[528i-1981]

I used a Spal 30102030 with curved blades. It's quieter than the OEM fan but by no means silent. The Spal p/n referenced above is for the mounting brackets.

[Mike W.]

The key to noise or the lack of it is to keep the factory's 2 speed operation. I don't even recall being able to hear the factory 528i fan running on low speed with the A/C on. High speed yeah, that sounds like a plane getting ready to take off, but low speed is all that's required for the A/C.

[0257]

Thanks for all these tips. I am still researching but while doing so have got all the old parts out of the engine bay. I think I’m going to keep the factory condensor fan. It moves enough air on “high” to lift my tii off the runway, I think. And one less wiring chore. And the 60s-era resistor is kind of irresistible. Seems to work fine, but I wonder if there’s a post on rehabbing the factory fans back to newish condition….

[0257]

I note too that my factory condensor is approx 17x21 inches. So I’m not sure why I shouldn’t be able to fit something nearly those dimensions in the opening?

Btw, was pleased to find my first-ever BMW vehicle mouse-house smack in the middle of it.

[0257]

Hoping it’s ok to ask this question on this string: what receiver/drier are folks using? The OEM part seems unavailable. The revised system will probably carry a little more R12 than the original, what with the larger condensor. Looks like the system typically wants about 45-6 oz of R12. Spec for drier is .54 dm3 (decimeters cubed), absorbency 5-8 grams. I reckon we’ll be close enough to stock that we can stay with that spec.

Thoughts? The usual vendors (AZ, FCP, CarID, Pelican, etc etc) don’t have it. Don’t see any NOS on eBay, either.

Thanks.

[Mike W.]

I think dryers are pretty generic, if retaining the old flare type fittings, that's more what you have to look for. They're common on all sorts of refrigeration equipment, just not modern auto A/C which uses O rings. When I rebuilt the A/C on my Bavaria long ago I used a dryer I found at a flea market, it had the right fittings although I forget how it mounted.

And at the moment Rockauto appears to have an original type in stock, Four Seasons brand.

https://www.rockauto.com/en/catalog/bmw ... lator,6972

[0257]

Well, looky there! Thanks, Mike. I rarely use RockAuto, and my friend Mike Self chides me for it. Had forgot to look there.

Now that I have the evap box out I’m scheming on next steps. Looks like it shares the lower half (which means it will accept same fan) as e28s. Everybody seems to acknowledge that e28s move a lot more air, and assuming my spare half-box is an e28 I can confirm the fan is 1/4” larger in diameter with all the other pertinent dimensions being the same. Have not pulled Evelyn’s box apart yet to confirm, but pretty confident.

Btw, seems my iphone foto files are too large to upload here. Can anyone tell me the best way to get a typical iphone/ipad image to the right size? Or maybe what else I’m not doing right?

[Mike W.]

Btw, seems my iphone foto files are too large to upload here. Can anyone tell me the best way to get a typical iphone/ipad image to the right size? Or maybe what else I’m not doing right?

You can't upload directly here. Pictures have to be hosted elsewhere. https://imgur.com/ seems to be the best/easiest, no registration or anything and free. Upload, right click on the uploaded image to get the image address, not the page address, then paste it between the img brackets. Never done it on a phone, but after once or twice on a PC it's really quick and easy.