Happy First Sunday of the Oktberfest Gentlemen! PROST, from Munich!

Curious about this almost comical "instruction on our ventilation controls..."MAX DEFROST, upper levels left, lower lever right"...I was thinking, how is this correct, when the upper lever left turns the blower onto the windshield OFF?!

So I found this thread...

http://www.914world.com/bbs2/lofiversion/i...php?t75480.html

and then I went out and tested to see how much warm air from the back is actually blowing out of the vents at the windshield. Virtually NONE was coming out at all.

So...before I go seeking the possible reason, I'm curious about others' results for this same test. What is the best / normal (stock) result here? The hoses in the compartment were OK. I haven't checked those under the car or the dash yet.

How much more effective would a stronger blower be? Power / spec suggestions?

Thanks guys, and have a great Sunday!

Mike in Munich

The black levers control fresh air, the red levers control warm air ( GERMAN logic!). The engine fan and fan in the engine compartment should blow air through the heat/defrost ducts. Sometimes shifting down a gear to increase engine rpm will increase the defrosting rate.

Enjoy Oktoberfest, wish I could be there! My grandfather was from Munchen and I've always wanted to visit Bavaria.

I have found the best defrost comes from all three levers to the right. That turns on the fresh air fan mixing cool outside air with warm air from the heat exchangers if the red heat lever on the floor is up. Not the best for a warm cabin but great for defrost

This only seems logical, which makes me wonder about the "max defrost" instruction / tip. But getting back to my question, how much air comes out of your defrost vents when only the rear motor is blowing and the car is at idle or not even running?

M.i.M.

In my experience you should be able to noticeably feel air coming out. That's about it. At its best it's not going to blow you away like the max fan setting on a modern car. I actually took my blower out after futzing with it and trying to optimize the volume of air it would put out. It clutters the engine bay and I get enough heat/defrost from the engine fan.

Having said THAT...the teener has been relegated to outside the garage to make room for my wife's car. I drove all winter last year, but it's going to be a different story with the car starting outside and exposed to the elements in the winter mornings...

Sounds like I need to check the tubes. The air isn't getting into the cabin the way it should. So, my HEAT should be really BLOWING onto my feet, instead of "drifting" (light blowing) into the cabin?

Yes, check for blockages and make sure all the tubes are set up properly. The blower is only going to do so much. The real test is the engine fan. When you brake with the engine you should really noticeably feel more air come out if you hold your hand over the vent -- that's the "real" test to see if everything is set up properly or if perhaps you have a blockage somewhere.

Yeah, check your hoses.

I've got a completely stock setup, with the engine bay blower fan on the drivers side. Without the fan, I get plenty of hot airflow when the RPM's are up and the levers are in the "defrost" position. With the aux fan engaged, I get decent airflow at idle, but nothing like when the engine revs.

I've been caught in quite a few downpours. While it gets very uncomfortable in the cabin, the stock system does a good job of keeping the windshield clear of fog.

My 70 had a 73 2.0L engine in it with no heater blower, just the engine fan. In the cool fall / early winter months I had plenty of heat to stay toasty warm, as long as I was moving, but come to a stop light you could feel the cabin start to cool down. As for defrosting the window I would just move all the levers to the right and use a mix of out side air with the warm air of the cabin and it seemed to work well that way.

When I had my 2.0 SSI's, late october I had bitchin heat, in fact on a cool day I had enough blasting out to keep it comfortable with the top off.
Not modern car blasting heat, but for a aircooled excellent heat, 100X better than any other aircooled I've owned.

I bet you have a mouse nest up your tubes.

http://www.volksbolts.com/faq/cooling.htm

Maybe more info than you want..... but click the link and scroll down to TIV.

Plus the fan housing has small openings on the bottom. the air from the openings goes into the HE. There are little "gravity" flap doors that keep hot air from coming back into the cooling fan during idle. So if your flaps are stuck closed..... If you have removed a HE you can pinch them closed upon re-installation. They must be checked before the HE is too snug and tightly installed.

Click to view attachment

I've always kept my blower/heat exchanger system in "top notch" shape.. AND always kept a cotton towel behind the passenger seat to "Defrost" my windshield...

I perfected my rainy-weather glass clearing techniques during Rugby season in high school with my Beetle filled with muddy/sweaty/half-drunk team members... "wipe your window and pass the towel...."

"Defrost" is literally the only capability of the VW/Porsche system.. melt ice...

but Hot-Wet air will not dehumidify the interior and get rid of fogging.. you need AC and the dry-hot air it produces for that.

I run the heat with the top off fairly often and it actually blows harder and hotter with the top off because you have removed the restriction (the top) and when moving the cabin becomes a low pressure area causing much greater airflow through the heating system than both blowers provide on their own.


I have also driven through a cold and snow-less winter and found the heat and defrost capability to be adequate at low speeds and toasty at highway speeds.

Thanks for the info!

So how does one access the tubes in the longitudinals?

I'm thinking a shop vac...stick the vacuum cleaner's hose up through there from the back?

Other suggestions?

Thanks again,

M.i.M.

A functioning heating system should be able to warp a vinyl record.

That is how I did it. Behind the speaker pod is where it comes out in the cabin. So you could run the vacuum cleaner hose from the back, then the front. It needs to be a flexible hose. You have a slight bend from the rear and a 90* from the front.

With both off, maybe a leaf blower to blow it all out.

You could also buy a cheap borescope (e.g., Amazon, $25) and do a sort of heater tube "colonoscopy" to see if there's anything in there.

Look at your plumbing on this though, including those little flaps on the fan shroud that blow the air into the HE's as Malcolm pointed out. Do you feel ANY air when you hold your hand over the defroster vent during a healthy downshift?

Thanks!

quote]
Look at your plumbing on this though, including those little flaps on the fan shroud that blow the air into the HE's as Malcolm pointed out. Do you feel ANY air when you hold your hand over the defroster vent during a healthy downshift?
[/quote]

New info! At high revs, air does come out apparently pretty well on the DS defrost, warm only and now front blower, but the DS had essentially no air coming out of the windshield vent, so I'll be checking that side first and foremost.

Thanks for your time and help.

At Red rocks we were having a discussion about heat in our subaru conversions. Somebody came over & said my buddy went & bought 12volt hair dryers from camping world. Wired them to a relay & switch. Piped them direct where the tubes fed them from the engine bay. That sounds a little nuts but man I'm going to try it

This was suggested to me as well, in my case for a six w/o heat exchangers. Way too many things ahead of it on the chore list, however...

I have both exchangers hooked up, and the splitter on the alx fan. All the duck work tightly fitted. On the coldest day in Michigan, it will produce to much heat!

40 years ago, I would were a heavy coat, hat, and gloves. Keep my ice scraper close, to remove the frost from the inside of the windshield. A little JC Witney 12v heater, would just blow the cold air round. This was due to a rusted out system from road salt.

On a long trip every hour or so, I would stop and warm up at a small dinner, or donut shop.

Glad those days are over.

Yes. That is what I did when I got my 1.7 and I sucked up insulation from a mouse nest.

When your heater system is working, it will not blow air with force but it will move very hot air once the engine is warmed up. My electric fan on the engine has never worked and I still get plenty of hot air in the winter. Enough that I usually crack the window to mix in some fresh air.