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airkooledchris Samba Member
Joined: January 25, 2005 Posts: 2711
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Posted: Wed Mar 30, 2011 2:35 pm Post subject: converting oval to square ports on heater boxes..(have you?) |
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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? |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Wed Mar 30, 2011 3:24 pm Post subject: |
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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 |
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Randy in Maine Samba Member
Joined: August 03, 2003 Posts: 34890 Location: The Beach
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busdaddy Samba Member
Joined: February 12, 2004 Posts: 51145 Location: Surrey B.C. Canada, but thinking of Ukraine
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Posted: Wed Mar 30, 2011 4:29 pm Post subject: |
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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! |
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airkooledchris Samba Member
Joined: January 25, 2005 Posts: 2711
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Posted: Wed Mar 30, 2011 5:04 pm Post subject: |
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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. |
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CessnaJon Samba Member
Joined: August 15, 2008 Posts: 677 Location: Senoia,GA
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Posted: Thu Mar 31, 2011 4:00 am Post subject: |
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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 |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50348
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Posted: Thu Mar 31, 2011 10:07 am Post subject: |
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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. |
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tristessa Samba Member
Joined: April 07, 2004 Posts: 3992 Location: Portland, OR
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Posted: Thu Mar 31, 2011 11:26 am Post subject: |
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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. |
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mattcuddy Samba Member
Joined: October 22, 2003 Posts: 2036 Location: Philly, PA
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Posted: Thu Mar 31, 2011 1:03 pm Post subject: |
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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. |
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airkooledchris Samba Member
Joined: January 25, 2005 Posts: 2711
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Posted: Fri Apr 01, 2011 3:36 pm Post subject: |
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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.
Quote: |
You might look into using the Vanagon heater boxes and then adding some kind of centrifugal fan to push the air through them |
Good point wildthings. It looks like it would actually be really easy to do - BUT, im not sure how the fan housing on the baywindow connects to the heater boxes and what it does.
You can easily tell where the boxes on both the bay and the vanagon connect to the fan to push the air through it, but the bay's have that square connection that apparently connects to the cooling fan housing and im not clear on what it does...
The Vanagon heater box has one port to push air through - simple enough. What does the fan housing channel do on the bay window box? |
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Amskeptic Samba Member
Joined: October 18, 2002 Posts: 8568 Location: All Across The Country
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Posted: Fri Apr 01, 2011 3:58 pm Post subject: |
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airkooledchris wrote: |
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.
Quote: |
You might look into using the Vanagon heater boxes and then adding some kind of centrifugal fan to push the air through them |
Good point wildthings. It looks like it would actually be really easy to do - BUT, im not sure how the fan housing on the baywindow connects to the heater boxes and what it does.
You can easily tell where the boxes on both the bay and the vanagon connect to the fan to push the air through it, but the bay's have that square connection that apparently connects to the cooling fan housing and im not clear on what it does...
The Vanagon heater box has one port to push air through - simple enough. What does the fan housing channel do on the bay window box? |
That is the primary air supply for the heater. The fresh air blower is secondary. It wins at idle however, so you need the aluminum flaps on the engine fan housing to prevent "backwash". The blower fan also has flaps to prevent the primary air from a rapid engine fan from blasting hot air *out* of the exchangers up the fresh air hoses to the fresh air blower's intake at highway speed. This can (been there, done that) overheat the engine on a hot day.
Colin _________________ www.itinerant-air-cooled.com |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50348
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Posted: Fri Apr 01, 2011 3:58 pm Post subject: |
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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. |
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airkooledchris Samba Member
Joined: January 25, 2005 Posts: 2711
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Posted: Fri Apr 01, 2011 4:09 pm Post subject: |
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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. |
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