Oil bath filter controls

[subheatadey]

Hi, i have the OG oil bath filter but it does not cold start thermostat to operate the air flow, been my first VW I don't really know what i need has anyone any pictures and advice of how/ where i get hold of the controls bits (it's always the little bits) or is it something i can manufacture myself? Also how does the flap with the weight operate, is it just operating on air speed/suction?

 

[RichardAlexander]

From the back of the fan shroud there is a lever mech that is operated by the thermostat, this in then pulls. On the cable, bit like a brake on a bike, that changes the flap posistion on the filter. The purpose of the flap is it draw warm air In from the bay. When it's cold then as the engine warms up it starts to draw from out side cooler air. The help prevent carb icing

The flap with the weight into help control the air flow as the engine sucks more air it pulls on the flap with the weight and allows more air in for acceleration

They are rarer than rocking horse poo so one day I will attempt to make my own, but as I don't use mine as a daily and never when it's freezing cold I have just set it to draw the outside air for now


I think that's right

 

[cyberdyne systems]

Try getting a slightly later vacuum operated one

 

[BrotherNumberOne]

From the back of the fan shroud there is a lever mech that is operated by the thermostat, this in then pulls. On the cable, bit like a brake on a bike, that changes the flap posistion on the filter. The purpose of the flap is it draw warm air In from the bay. When it's cold then as the engine warms up it starts to draw from out side cooler air. The help prevent carb icing

The flap with the weight into help control the air flow as the engine sucks more air it pulls on the flap with the weight and allows more air in for acceleration

They are rarer than rocking horse poo so one day I will attempt to make my own, but as I don't use mine as a daily and never when it's freezing cold I have just set it to draw the outside air for now


I think that's right

I think the one in the pic is the later type. The bit that's missing is the thermostat(waxstat possibly?) and spring on the side. It's controls a flap in the filter inlet and starts with the flap closed so the engine draws warm air from around the cylinders to speed up the warm up process. As it heats up, the thermostat opens the flap and cold air from the engine bay is drawn in instead. Unless of course the stupid thing breaks like mine did last year in which case the flap stays closed and the engine gets really hot. I guess that's why this one's been removed. VW swapped to the vacuum controlled one later.

 

[cyberdyne systems]

There is a later type still with vacuum. I believe the one above was one year only replacing the cable operated type.

 

[BrotherNumberOne]

There is a later type still with vacuum. I believe the one above was one year only replacing the cable operated type.

ah, I see. My one was out of a '71 and the OP has a '71, so I guess that was the year. I wonder if VW dropped it because of the potential for overheats?

 

[cyberdyne systems]

There is a later type still with vacuum. I believe the one above was one year only replacing the cable operated type.

ah, I see. My one was out of a '71 and the OP has a '71, so I guess that was the year. I wonder if VW dropped it because of the potential for overheats?

I'm not sure why you think it would over heat? It's only to allow warm air in to help with cold running, and would default to the open position.

 

[BrotherNumberOne]

There is a later type still with vacuum. I believe the one above was one year only replacing the cable operated type.

ah, I see. My one was out of a '71 and the OP has a '71, so I guess that was the year. I wonder if VW dropped it because of the potential for overheats?

I'm not sure why you think it would over heat? It's only to allow warm air in to help with cold running, and would default to the open position.

well mine defaulted to the closed position and the engine was drawing almost all it's air from round the barrels and heads. It's a positive feedback system, the hot air from round the heads is drawn into the engine making it run hotter which in turn makes the air round the heads hotter. A bit like running an engine without tinware and seals.

 

[subheatadey]

Are these cold start thermostats for that filter obtainable?

 

[chad]

I got mine from VWH - it's a 'Classic Part' that they need to order from Germany

 

[Trikky2]

Are these cold start thermostats for that filter obtainable?

I haven't seen any new ones for sale.

It's a case of finding a working one second hand or you might get really lucky and find NOS.

It's likely that if you do find a second hand one it will be attached to an entire filter though.