Heater Blower Motor, How to remove it for replacement Options

[sburns1967]

I have a 1973 914/4 2.0 which is is partially disassembled.

It came with two hot air blowers:

Single Port - Working Motor
Dual Port - Dead Motor

In 1973 there was apparently a switch between the dual outlet blower to a single outlet with a Y pipe.

I was thinking I would like to use the dual outlet one so I thought I would swap in the working motor.

Two questions:

1) Does the dual outlet unit provide better heat flow through the heat exchangers than the single outlet with a Y connector? Any pointers to pictures of each type mounted/hoses?

2) How to remove the motor:

Removed the 6 screws on the motor flange
Removed the nut/washer from the cage fan

After doing so I can get zero movement from the motor from the housing. Even prying between the flange and the housing nothing moves.

Does anyone know if there is some kind of adhesive between the motor flange and the housing? If so do I apply a little heat maybe?

Thanks in advance
Scott

[chmillman]

I have a 1973 914/4 2.0 which is is partially disassembled.


In 1973 there was apparently a switch between the dual outlet blower to a single outlet with a Y pipe.

Actually the "Y" pipe was just an accessory added by some dealers using VW parts. It was not stock from the factory. When they switched to a single outlet blower, they just used one hose on the driver's side. The passenger side had no hose going to it and was capped off. Some people have restored the two hose system using either found old Y junctions or 3D printed new ones.

[Olympic 914]

If you have good heat exchangers, there will be enough heat coming into the cabin with the single outlet blower.

I added the Y pipe and hose to the passenger side, but rarely pulled the lever far enough to activate the blower. ( it only comes on at about 3/4 to full on the lever) didn't really like the looks and additional clutter of the hose going to the passenger side. So i removed it and capped that side. As it came originally.

I get plenty of heat as it is.

[wonkipop]

in terms of what the factory did with the blowers.
as noted above. single hose blower for 73/74 to drivers side heat exchanger.
single hose blower for 75 up to late nov/early dec 74 production date.
y junction adaptor to single outlet blower with twin hoses starts after that to end of production dec 75.

all of the blowers are parts bin components from the VW 411/412.

the early (70-72) twin hose blowers are from the 411 2 and 4 door sedans.
the 73-74-early 75 single hose blower fans are from the 411/412 variants (squarebacks) but without the squareback y adaptor. then later after nov/dec 74 using the y adaptor from the squareback.

when installed in the 914 the later twin hose set up used some stand off clips to keep the right hand hose clear of restricting the air flow to the cooling fan. i think this is an important detail. i have seen a few 73/74 cars that have had twin hose set ups installed by owners that lack the positioning clips and the hose restricts that gap that the cooling fan draws through. this was not an issue with the VW sedans/variant as the cooling fan drew air through a rubber boot and dedicated air duct in the bodywork.

as to why the 914s got only a single hose fan for a couple of years i would speculate that possibly it was felt beneficial to bias the fan forced air flow to the drivers side to assist with windscreen demisting in the small cabin of the 914 and ensure the driver side portion of the windscreen demisted faster. then later decided this was unnecessary.
its possible that the later style heat exchangers in the 75 models might have delivered more heat to the cabin than the earlier heat exchangers and the biassed fan boost was less critical for deep winter demisting. the exhaust system in that last year of production was itself a thicker guage pipe inside the heat exchanger acting as a kind of thermal reactor to deal with unburnt hydrocarbons as they exited the combustion chamber. it was designed to retain heat in the first section of exhaust pipe to burn those hydrocarbons and so probably generated greater heat inside the exchanger.

i am sure there would have been a rational reason they reverted back to a twin hose.
maybe what i put foward above.

in any case i have never found the single hose version in my 74 inadequate.
but l live in australia. hardly a severe winter climate. (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/beerchug.gif)

[dtmehall]

I have always found that the heat from a single hose in my 73 was sufficient, even here in the great white north!

[sburns1967]

Thanks for the info and detailed review of the two setups/history.

I may just go with the splitter kit from Auto Atlanta to split off my working single port blower and drive both heat exchangers.

With my wife using the heated seats in her cars, even when it is 35C in the summer, I can use all the heat I can get.

Scott