Aircooled VW South Africa

Anytime Slak, we got BPW, henred, rockwell, swift, Jost etc. 0824165606 or 0219454923. Thanks for the Info Ron&Gill, currently have 2 pipes that I made that goes to the two carbs's ramtubes, will see how it goes on the first race then make mods as needed. Have a heat gauge that I want to fit on the heads together with the oil temp gauge just to make sure its all nice and cool

Hi Ron,
Just to clarify a few things with the three different Type 3 set ups.
When you speech of cooling, in your notch, you have a good system. The air is forced over the car and crashes down into the air vent behind the back screen.
Hence good cooling. Your carb air intake comes from the same vent, which is effectively pressurized, hence good carb air pressure.

Now we talk about the other two step sisters, The Fastback and Squareback (variant)
The vents are on the side, the vents are also sitting at a narrower section as the rest of the body. These vents are effectively set to push away water, so the fan has to suck the air around the fins. This also still works as the fan is not bad, and will cool the engine at low speed.
BUT, when speeding up, the air passes over the vent, creating a low pressure area, the fan now has to overcome the fins, as well as the low pressure area over the fins, this results in a vacuum in the air cooling channels of the body, to which not only your Fan is connected, but also your carb, or carbs (if Twin)
So now your engine runs rich, or starves under load, resulting in over heating and engine damage.
That is why when you ask a Notch driver, he tells you the Type 3 engine is the best, and if you ask a Fastback or Variant driver, and he will say its the biggest under the sun.
That is why I fitted a type 4 into my Fastback, which has a bigger fan, which can overcome this problem, with carbs drawing from the engine bay.
This is why HR has overheating problems on his Fastback.

Me, myselvers and eye, think the cooling on a standard type 1 should be excellent, as the air is rammed into the air intake of the fan, due to the engine being inverted.
Would only have 90Deg, bends fitted to the carb rams to face forward, to take advantage of the force of the air entering the grill.

OMO
Herman

retrovan wrote:Hi Ron,
Just to clarify a few things with the three different Type 3 set ups.
When you speech of cooling, in your notch, you have a good system. The air is forced over the car and crashes down into the air vent behind the back screen.
Hence good cooling. Your carb air intake comes from the same vent, which is effectively pressurized, hence good carb air pressure.

Now we talk about the other two step sisters, The Fastback and Squareback (variant)
The vents are on the side, the vents are also sitting at a narrower section as the rest of the body. These vents are effectively set to push away water, so the fan has to suck the air around the fins. This also still works as the fan is not bad, and will cool the engine at low speed.
BUT, when speeding up, the air passes over the vent, creating a low pressure area, the fan now has to overcome the fins, as well as the low pressure area over the fins, this results in a vacuum in the air cooling channels of the body, to which not only your Fan is connected, but also your carb, or carbs (if Twin)
So now your engine runs rich, or starves under load, resulting in over heating and engine damage.
That is why when you ask a Notch driver, he tells you the Type 3 engine is the best, and if you ask a Fastback or Variant driver, and he will say its the biggest under the sun.
That is why I fitted a type 4 into my Fastback, which has a bigger fan, which can overcome this problem, with carbs drawing from the engine bay.
This is why HR has overheating problems on his Fastback.

Me, myselvers and eye, think the cooling on a standard type 1 should be excellent, as the air is rammed into the air intake of the fan, due to the engine being inverted.
Would only have 90Deg, bends fitted to the carb rams to face forward, to take advantage of the force of the air entering the grill.

OMO
Herman

I believe the area at the base of the Notch rear window is also a low pressure area, but the reason I say it would be a good choice of cooling system is that the fan would be pointing forward in the Gol, and the intake is through the grill, can't get much more high pressure area than that... The air is not being rammed into the T1 tin, quite the opposite, the fan intake is facing towards the rear.

Makes sense if I look at it to change it later to the fan that faces forward to the Gol, luckily the exhaust silencer is not in the engine compartment like in a beetle, so that in itself will prob help the Gol compared to a Beetle? Must say you guys (retrovan and Ron&gill) do know your stuff around VW aircooled Appreciate the advice!

The fan at the back is not such a bad idea. Think about it this way... on the golf, the fresh air vent is at the back of the bonnet. How much air is forced in there when you are driving at 60km/h.... so you will have the same effect if there is a bonnet vent like on a golf on the rear of the bonnet or under the front window

I see there is a bonnet vent on it already. Maybe just direct airflow to the fan from it.

No, the fresh air vents are in communication with the water trap behind the black rubber strip you see, and it is fresh air for the cabin only. It does not provide air into the engine compartment.

Anyway, on about the rear window of the notch, if you imagine the air stream flowing over the car, you'll see the stream following the exact profile of the body and the "notch" versus the flow over the body in general is a longer flow path hence the velocity of the air must be higher and we all know the higher the velocity, the lower the pressure which is of course the principle of "lift". Therefore VW put the vents in a low pressure area. I wager the pressure on the intake on a fasty and a square is probably higher at speed than on a notch. It would be an interesting experiment to run, actually. All you need is a rubber tube and a barometer...

Hear what you say, Ron, and I respect that, my thinking is that the Grill of the Gol is bigger then the air loss past the engine, therefore creating a pressure cell within the bonnet/engine area, therefore not an issue where the air hole is.

On the Notch, I do think that as the air is compressed when forced over the roof, the high pressure will assist the air down to the vent, up to approx. the max. speed of the Notch.
Had the car had a Higher top speed, I think the low pressure cell would be more dominant, and occupy the full area of the vent, then the pressure will drop. Till then the VW guys designed the body shape to suit the airflow. You must remember the Notch was the original Type 3 design, the other two where afterthoughts. Also know the Notch was designed in a air tunnel, never heard the same for the other two. Would be interesting to find tests to proof or disproof any of this...

Any body want to Google for it ????

Herman

So am I understanding correctly that this cooling should be sufficiant for this cars design but that there is better options if it has overheating prob? What would the normal operating temp be for the oil? Putting a guage in now want to mark the safe zone. Got the car back from tuning and glad I took it. Was running very lean and pump jets wasnt working correctly. Feeling 10 x better and much more drivable now

Stand under correction, but the Type 1 runs at approx. 103 to 107 C. That is oil temp. And the type 4 can run approx. 5 deg. C hotter.

Herman

Ok perfect will make a mark at 110 degrees so I know to check it out if the temp goes over that. Thanks Herman
Car of to body shop hopefully have enough time to get it done by friday.