converting oval to square ports on heater boxes..(have you?)

[airkooledchris]

I think the subject pretty well sums it up, could you just swap the pipes on oval port boxes to some from a set of square port boxes?

Im looking into the available options to convert to the coveted 72-74 exhaust system and have a spare set of square port heater boxes (off of an aircooled Vanagon) that I could theoretically swap the ends onto a pair of 72-74 boxes.

I *think* the passenger side heater box is the same on my 79 as the 72-74 setup, so id only have to do this once on the drivers side box (or track down the proper 79 only federal box)

any reason that wouldn't work?

[SGKent]

my understanding is that the heads ae different in mounting the exhaust - no step cut in on the 79 heads. You both need the 79 heads and 79 HE's.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Randy in Maine]

The way the "fan air" gets into a 79 heater box is different than the way a 80-83 Vanagons does it...

http://www.thesamba.com/vw/forum/viewtopic.php?t=280397&highlight=heater

[busdaddy]

I think he intends to use the Vanagon HE as the donor for the square flanges which he proposes to weld onto a 72-74 HE.

I can't see why it wouldn't work, I'd want to do the welding while bolted to a core engine so everything lined up nice though.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[airkooledchris]

thanks for the replies. yes, id just be using the Vanagon HE for the square port flanges.

I do have a spare square port head I could bolt it to during welding to be sure it lined up on that end, but no full mockup with case and fan housing.
id have to hope that the stub pipes cut to exact equal lengths will line up close enough or tweak it where it connects to the fan once bolted together.

[CessnaJon]

I have an 2.0 AC Vanagon engine in my 1973. You will need r and l heater boxes from a 1979 bay to have heat with square ports.
_________________
1973 Westy (shared birthday)
1990 Westy Multivan
2015 Passat TDI 6sp
2015 Sportwagon TDI 6sp
LR-JET, Gulfstream 159

[Wildthings]

As Busdaddy suggests you would need to have it bolted up to a core engine to get all the angles right. I think you would need some kind of insert inside the pipes as well so that the internal alignment was perfect, otherwise the flow characteristics could end up being poor.

You might look into using the Vanagon heater boxes and then adding some kind of centrifugal fan to push the air through them.

[tristessa]

It might be easier to re-skin the Vanagon heater box with the casing off a '72-'74 Bus one .. if the structure of the internal finning makes it possible. Not sure, I've never looked at the Vanagon boxes that closely.

[mattcuddy]

Lots of answers, but I think maybe you need to clarify your question a bit.

So, you want to take 72-74 boxes, cut off the oval ports that mount to the heads, and weld on square port ones from a 79 or air cooled vanagon?

Why? The 79 heater boxes you already have are essentially just what is described above. Square ports where they mount to the heads, and trapezoidal where they mount to the muffler/crossover pipe.

[airkooledchris]

thanks for the replies thus far.

My initial question is weather I can just switch the oval ports of a 72-74 heater box to square, by using donors from the Vanagon boxes.

answer - yes, but it'll be tricky to make sure it all matches up exactly right where there aren't any gaps.

[Amskeptic]

[Wildthings]

The Bay heater system primarily gets its air from the "square" connections on the bottom of the fan shroud. The aux fan adds a little bit of flow at idle and that is about it. If you went with the Vanagon heater boxes you would want to redo the inside of your fan shroud to make it the same as a Vanagon fan shroud. Not a big deal if you know someone who can do the welding for you.

[airkooledchris]

thanks for the replies guys, very very good information.

I do have an aircooled Vanagon fan housing, but that would probably bring even more odd connection issues into the mix.

I think realistically for someone with a 79 CA setup currently wanting to go the 72-74 heater box setup - get the proper 79 Federal heater box for the drivers side. Since the passenger side is already setup like the 72-74, it's certainly going to be a cleaner final install when it's all said and done Vs the amount of hacking of parts to modify the more commonly available 72-74 or 80-82 federal heaterbox.


I wouldn't have pushed so much to try and find a workable solution if I didn't have all these other bits in the garage just waiting for a project.