When the fan is heater fan is on I don't get the feeling ang warm air is getting pushed into the cabin- is this common.

I'm thinking that plugging the HE tubes would keep more hot air moving forward. Anyone else have an idea ?

My fan doesn't work but I still get tons of heat into the cabin. Tons.

Do the fans work? Absolutely! The do what they were designed to do and that is supply heat to the cabin when the car is idling. If you have no heat you might have problems with your system. Loose and rusted tin on the pipes, worn out ducting and hoses or the hoses behind the speakers are crushed

Is this at idle only? The problem may be missing or stuck flaps at the engine fan housing. They are there to prevent air from the fan from blowing into the engine fan housing at low speeds. This would be the path of least resistance

If all heater components are operating correctly the heat will curl your hair! The real problem is regulating the amount of heat while driving, as the blower motor is either on or off, and no in between settings are available.

True, the blower only has one speed but the flow through the heater control flaps is adjusted via the heater lever. For me I can regulate the amount of heat flowing into the cabin that way - works well in my case. Beats the hell out of the '74 Beetle we had when I was a kid...

As above, tons of heat in both of my cars. Even with the top off, it blows enough hot air that I stay warm even if it's chilly outside.

It definitely warms up. Hoses are new and clamped, no crushing behind the speakers; flapper valves are good and open all the way when red lever is pulled back.fan flappers are in place. Too.

To really get decent heat I have to roll the driver side window down 2 - 4 inches; then I feel the hot air being pulled through.

I'm wondering if the tubing him the longs is bad.

Something is off. Once I'm on the road, I'm turning the heat down. Even in cold weather, max heat becomes an oven.

I've never seen a bad heater tubes, even in rusted out cars but shining a light from the engine side or an inspection camera might be usefull. I did shove a flexible vacum hose through my longs and sucked up a bunch of mouse nests.

Is it possible that your car is running rich? I noticed a BIG difference between when my car was running lean (hot) and when it was running rich (cool).

Are the tubes going into the HE capped, or is your blower still attached ? I will make a try at inspecting the tube in the longs-never can tell...

Blower is still attached. Front fan doesn't work either. I will get to it one day.

Jim, try removing the aux fan hoses and covering the j tubes with some 2" rubber pipe caps found in the plumbing department of your fav hardware store. Rather than lowering a window try adjusting the heat/fresh air slider on the dash for a mix of fresh and outside air. Mixed right the heat will still be plenty warm.

I move the levers so the heat comes out under the dash and use the fresh air fan for the defrosters. Works great for our California climate. It's been years since the six conversion, but my heater fan did make a big difference at any speed.

Thanks,
Will try that...seems like it would keep air from moving back toward the eengine bay. I have the caps-

Gonna hookup my shop vac to the system too.

FWIW, in answer to the OP, I think that maybe the problem is common. Until a month ago when I swapped engines and HE I had a similar experience. Drove all through a fairly harsh winter with a heater and blower motor that SORT OF worked, but I was always in the "this heating system is fairly pathetic" camp even when others, like Curt and mepstein, were telling me it would fry me when working properly. I was skeptical. I tried sealing up my connections and tubes, I used a leaf blower to try to clear out anything that might be stuck in the tubes, and I repeatedly removed the speaker grilles to inspect the hoses. Didn't make too much difference, and during the winter I was constantly putting my hand below the dash trying to figure out whether anything was actually coming out of the outlets.

Last month I put the new engine in with SSI HE's. Once I got the heater tubes/flappers connected, I couldn't believe how much heat came out even when I didn't have a blower fan connected. So now I'm a believer. I don't even really know what changed. My old HE's were pretty rusty. Because of this thread I am going to check to see if I had flappers on the fan outlets on my old 1.7. I wasn't even sure what those were for when I saw them on my new 2.0. That might be the difference in my case.

Only other thing I can ask or suggest: have you actually inspected your flapper boxes to see if they are opening by removing them and seeing if the flapper moves properly? I did have one where the bolt in the center broke through the flapper material. I had to put some washers on it so it would work. Otherwise it was stuck in the closed position no matter how much I pulled the heater handle.

My 74 1.8 has the heat on the passenger side blocked from the engine compartment fan. The cap has a 914 part number on it.

They make a duel outlet nozzle for the fan that will blow to both sides which I hear was for severe cold climates. I also hear when using the duel set up you can cook your self !

Good information. Yes, I have SS heat exchangers. I'm definitely going to inspect the flapper valve. Years ago I had that center bolt break too. I'll see if my repair still works.

Thanks for all the suggestions.

I live in that climate. Mine will dry your eyes.

Andy

Jim,

If you get a chance to read a 356 manual you will see that opening a window to create the Venturi is actually how you operate the heat in these cars...

It may also be in an old vw beetle manual.

My blower fan in the engine bay works great, it for when you are idling..
When you start driving or raise the rpms, the fan over powers the blower motor.

But...and it's a big but....you need to open the window because the whole system cannot overcome the close pressurized cabin....so when you open the window it all works.

I agree with that; I have a question for you: Can you feel air being pushed through by the heater fan at idle or with the engine off !

Yes, but it's slow....but enough to make defrost work.
Typically when I need it, it's for defrost that I turn it on, and I move all the magic levers to direct all the air to defrost.

See if you can find someone to allow you to read a 356 owners manual, it's a fun read...

Jim - just one or two more comments (from me anyway). Yes, I could feel air coming out with the blower on at idle or engine off, but it was not a particularly impressive. I did just confirm that my old engine does NOT have the flaps on the fan outputs. So Mark's (Bartlett 914) comment (post #4) about those was probably relevant in my case.

OK- things are getting better. First, the heater blower was wired in reverse, when I reversed the + and -, the fan blew air instead of sucking air. I can feel a slight flow under the dash. Ran the car with window open 2 inches; started with 72 ambient temp and got it up to 89 after a nine mile drive- things are a lot better.