The boy racer in me has always ripped these off at the earliest convenience, so I have very little understanding of how they work - but I've decided now I'm a bit more grown up I'm going to put it back on.

So I dug the filter out at the weekend, trying to figure out where it all goes. There's a pipe to the right which I think it the oil breather hose. On the left theres a lever that opens/closes a flap, what does this connect to? Also on the bottom of the left hand side is another pipe that looks like it should go somewhere - where does this go?

:oops: :oops: :oops: :oops:

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I think you are correct, the nozzle on the rhs is a breather that would connect to the oil filler neck, the nozzle on the lhs I think will be for warm air. on later cars this was by a large pipe connecting to the exhaust on the front (same size pipe as the heating for the car 'clean air') On some earlier and 1200 engines it was connected via a smaller diameter pipe to the casing of the heat exchanger at the back of the engine round behind the fan housing.
The little lever that operates the flap as far as I am aware does not connect to anything, I have seen them with a counter weight on them, I believe the flap opens up at higher throttle as the pressure differential increases across it, over comming the weight keeping it closed and allowing full volume flow.

Not a diffinitive answer but hope it helps.
Pete.

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Cheers Pete! :beer: The little lever does have a weight on it on the back.

The pipe on the left looks about the same size as a breather hose, I've found some photos that show it going down through the tinware at the bottom - what does it connect to at the bottom?

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Dose this help ?  0307vwt_04z+1964_Volkswagen_Beetle+Engine.jpg You have insufficient rights to see the content.

Yep, that looks like my filter - but I don't have a hole in my tinware for that left side pipe.

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Robb, have a look at the tinware behind the fan housing, I've seen that pipe routed round behind the coil, think it conects to a nozzle on the heat exchanger around the location of the control flap.
Search for images of beetle heat exchangers, there are a couple of variations. I'd post a picture but my Ipad does not seem to facilitate for this.

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How about this one  3564060578_bba6a74b66.jpg You have insufficient rights to see the content.

That will do nicely.
This setup draws warm air from the heat exchanger, the other setup from around the exhaust Scilencer.
The warm air helps with fuel vapourising at low air flow making for a smoother idle / slow running. at high air flows every thing keeps mixed & moving along better so the warm air is no longer benificial, it actualy becomes counter productive.
As the flap opens i'm pretty sure from memory it simutaniously colses of the warm air, scince hot air is less dense than cold air and the engine is demanding more air at this time.

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Quite right, in addition, the flap can be locked in the cold air only position (by clicking the loop in the lever over the seam on the air filter) for summer running.

Mike

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OK, so now I need to know where it connects to the heat exchanger as I don't seem to have any spare holes there...

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Found this on theSamba, I don't have this piece...  pre-heat.jpg You have insufficient rights to see the content.

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That looks to be on the front of the engine and the pipe passes through the tin work that you dont have a hole for. Or is it the wrong air filter for your engine or is the wrong tin wear fitted ??????? That part may fit on to the rear but you will need a hole in the rear to bas the preheat pipe through.

Andy W

Since I've added a dog house oil cooler, I don't think sending the pipe around the back is going to be an option. Cutting a hole in the tinware seems much easier, or just blocking off the pre-heat hole on the air filter. There's really no telling whats original on the engine and whats not any more, it's long past that point.

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From a practical point of view its only of any real significance if you intended to run the car through the winter months, other wise its only down to how accurate you want to keep the apperance of the engine. With your very mild vintage speed theme Robb, i'm gussing your not going to loose a lot of sleep over this.

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The vintage speed stuff is all off now, but true - I'm not going to lose sleep if it's not original. I'd like it to be more reliable for the next owner though... :beer:

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It dose help with the iceing up problem if you can get the pipe in then i would.

Andy W

It also makes a small but non-the-less significant improvement to the the mpg. This system was originally fitted to the pre-clean air 34BHP engines, they had the smaller air filter with a take off to the left and the small diameter pipe which ran round to the front of the engine through the tin ware and on to a take off on the top of the left hand heat exchanger.

The diameter, location and number of preheater tubes varied through the 60s until finally for the '68 model year, all engines ( I think) got the large diameter pipe (same as the heater pipes) coming off the right hand side of the air filter and locating on to a hot air scoop at the rear of the engine taking pre-heated air from the right hand pair of cylinders.

So there are several systems you could opt for if you're not concerned about originality, it might just be a case of seeing what set up you can get all the necessary tinware, pipes and air filter for?

What year is the car? it maybe worth fitting the set up that is rigth for the model year, even if the engine isn't stock...

Mike

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:rofl:

Childish...

:rofl:

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It's a 65.

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