Here's pix I took last night of the ACS, classic german enginutty!

2nd

3rd

4th

and don't forget that one of those holes - i can't recall if it's the bellows bracket or the pulley - is a *through hole* into the case.

if you remove those parts and don't replace the mounting bolts, you'll have a lovely oil leak...

thanks for posting this root... it really helps to see what I'm missing:

yea, my engine has the pulley for the thermostat, but no thermostat, and I;ve never seen those flappers before, they just flat weren't on either 914 I've had

Rich, the bolts are there I think, there's no leak.

it looks to me like I need to get the whole thing... but I may "rig" something on the 3-4 side first, until I can pull the engine and the tin to install all of this... correct me if I am wrong, but it looks like the 1-2 side would just not warm as fast(may cause a little extra wear) BUT if the 3-4 side doesn't have the flapper the air never gets to those cylinders... causing it to warm up faster, but get hotter than normal!

any idea WHY someone in Houston would have taken this stuff off?! from what I understand he was a porsche guy and knew these cars well... I bought the car from a friend who bought it from him... my friend never drove it(duh) and only owned it a few days...

QUOTE (ArtechnikA @ Apr 27 2005, 06:07 AM)

and don't forget that one of those holes - i can't recall if it's the bellows bracket or the pulley - is a *thourgh hole* into the case. if you remove those parts and don't replace the mounting bolts, you'll have a lovely oil leak...

I think it is the pulley hole.

Ask me how I know.

Paul

QUOTE

if you remove those parts and don't replace the mounting bolts, you'll have a lovely oil leak..

I think Ury's right - pulley hole open = oil...

QUOTE (root @ Apr 27 2005, 09:29 AM)

QUOTE if you remove those parts and don't replace the mounting bolts, you'll have a lovely oil leak.. I think Ury's right - pulley hole open = oil...

probably why the pulley is there and nothing else...

Somebody PM me when this thread plays out and I'll put it in the Classics forum.

Nice work.

Is it really magnesium?
I just thought it was just cast aluminum.

Paul

An old Porsche mechanic told me that it was Mg, (he's actually older than me)!
Does anybody know for sure?

QUOTE (root @ Apr 27 2005, 10:14 AM)

An old Porsche mechanic told me that it was Mg, (he's actually older than me)! Does anybody know for sure?

does it light on fire? are you unable to put it put with water?

if so- its magnesium...

it acts and feels like a magnesium alloy; certainly it's weak and brittle enough.

aluminum will burn too, in the right circumstances - check out Thermite...

I have a question..... in the photos the lower right had side (bottom passenger side) there is a port for air to exit the housing. On my 72 1.7 it seems to be joining the heating system. What's going on??? Why would cooling air be diverted from the engine to be sent to the passenger compartment. And more importantly, if I block it off will the engine run cooler??

QUOTE (tat2dphreak @ Apr 27 2005, 09:22 AM)

any idea WHY someone in Houston would have taken this stuff off?! from what I understand he was a porsche guy and knew these cars well...

Never underestimate the capacity for a DAPO to do things that leave you pondering just how much of a DA the PO actually was

QUOTE (Borderline @ Apr 27 2005, 09:28 AM)

I have a question..... in the photos the lower right had side (bottom passenger side) there is a port for air to exit the housing.  On my 72 1.7 it seems to be joining the heating system.  What's going on???  Why would cooling air be diverted from the engine to be sent to the passenger compartment.  And more importantly, if I block it off will the engine run cooler??

There are outlets for heater connections on both sides. Engine air is always being pushed through the heat exchangers, but it only reaches the passenger compartment when the heater control lever is pulled up. Otherwise it gets dumped out the flapper boxes under the car. Unless you have an auxiliary heater fan, that's the only way heated air gets to you.

Jake Raby sez blocking the outlets makes cooling worse. Apparently he tested this while working on his DTM. My wild guess as to why: All the auxiliary air take-offs from the plenum come from the 3&4 side (pass. on 914): alternator, oil cooler, and heat exchangers (see the j-shaped outlet on the left by the alternator bracket, and the hole just above it for the alt. air) The diverter tins, air plenum and cooling system volumes are tuned for this airflow. If you block off the outlets, you increase the pressure inside that half of the system past what is was designed for, the air mass stagnates and doesn't move through the heads/cylinders the way it's supposed to.

Again, this is all happening on the 3&4 side, which already cools worse than the 1&2 side. So messing with these makes the temp differential side-to-side even more pronounced.

one more thing... why are the thermostats NLA?! it *LOOKS* similar to a beetle stat, can they be interchanged?

QUOTE (tat2dphreak @ Apr 27 2005, 06:22 AM)

any idea WHY someone in Houston would have taken this stuff off?!

'Cuz ever'body knows them flaps just gits in the way! We alluz pull 'em--an' if the motor runs so hot without the flaps, it must'a bin runnin' even hotter with 'em!!

--DD

QUOTE (tat2dphreak @ Apr 27 2005, 07:22 AM)

any idea WHY someone in Houston would have taken this stuff off?! from what I understand he was a porsche guy and knew these cars well...

The purpose of the flaps is to help the engine warm up and to maintain proper temperature. They are built so that if the thermostat cable breaks they will go to the wide open position so that you don't overheat the engine.

I think this is what has lead some folks to think that it is ok to remove these flaps. They can't imagine a situation where an air-cooled engine could be running too cool. I live at 7,000 feet so cool mornings are a reality for me, but more important - I think the engineers at VW/Porsche actually had a clue when they designed this stuff. It may be a crude way of maintaining engine temps compared to today's water cooled/electronic beasts, but it does the job at some level. I ALWAYS make sure the flaps are in place and that the system is working properly.

I recall previous threads that the engine case is aluminum and the trans case is magnesium...

Seems like someone one this forum should have the material info on these components.
I've been staring at the 'flappers', the only thing that bothers me is why the right one is never fully closed. Does anybody know for sure?

QUOTE (root @ Apr 27 2005, 11:14 AM)

An old Porsche mechanic told me that it was Mg, (he's actually older than me)! Does anybody know for sure?

Yes. I know for sure.


After the engine fire that totalled Betty's 74, The Arlington Texas fire marshall's report stated that the fire started due to a gasoline leak, and was accellerated due to the manufacturers use of magnesium in the engine fan shroud.

Thanks Clay, I guess that solves the engine shroud material question, Magnesium it is!

Now somebody tell me why the right side cooling flapper is always 1/2 open and I'll let
this topic rest....

QUOTE (bowlsby @ Apr 27 2005, 03:04 PM)

I recall previous threads that the engine case is aluminum and the trans case is magnesium...

that is true - but we're talking about the air cooling housing,,,

QUOTE (root @ Apr 27 2005, 05:37 PM)

Now somebody tell me why the right side cooling flapper is always 1/2 open and I'll let this topic rest....

It never closes completely because you always need SOME air moving over the oil cooler.

Ernie, I think you could be correct about the oil cooler needing some air always.
In other words...... if anything goes wrong with the system (and it does) the oil cooler has the continuous partially open flap as a safety.

One last question here, I have an old bellows with a pin hole in it, has anybody repaired one of these?

It's brass right? ('nother material question)Seems as though a good high temp silver solder would work.

I took an old ;eaking bellows to work. Cleaned it in an ultrasonic cleaner and found that it's made of copper.......Going to try an silver solder it next week sometime.

Great job on the pics..

Let me clear up a few small pieces:

The drivers side flap when closed opens the passenger side flap. This cuts off air to the drivers side cylinders (to warm them up) and lets the air on the passenger side go OVER the oil cooler instead of through it. The passenger side also tries to block some of the air for those cylinders (warming that side up also)

Now. You can remove the drivers side flap and rod that runs across. But you MUST leave the oil cooler flap in place and permanantly flowing air over the cooler. I do this by placing the flap UNDER the two guides in the engine tin piece that is placed over the oil cooler. This ensures me that the flap will NOT move under any circumstances.

Recommendation: leave them in. It is up to you whether or not you use them. Just make sure they will go back to their default position (open).

Surprised somebody hasnt come up with a different method for controlling the flaps.

B

Here's my idea for a manual control cooling!

COLD POSITION - "UP"

WARM POSITION - "DOWN"

Be careful. If you forget.... bad day. The engine will burn up in a few miles depending on how cold it is that day.

Clean engine setup. Nice ventilator tubing. Do you work in the medical industry? Interesting use.
I wonder if it is metric


B

Thanks for the warning!

If I blow the 1.7 then I guess I'll just have to build that 'Massive 4' sooner than I thought.

The clear tubing isn't metric but the I.D.'s run tight. It's reinforced high vacuum tubing $$.

I work in Materials Research lot's of Exotic High Vacuum Equipment around.

Awesome pics root. Thanks. This thread is going to the Classics Forum.

Yes, I know for sure. I watched Betty's 914 while it burned. The fan shroud lit off and it looked just like the magnesium flare we made in high school chemistry class. It took 2 huge CO2 fire extinguishers and 1/2 of a big pumper fire truck's onboard water supply to put the damn thing out.


It is DEFINITELY Magnesium.