rad tricks for pre heat tube cleaning

[70's Looker]

i wanna hear what has worked for all you folks who have ever wanted to drive a vw in the cold, without stalling!!

let the fun begin!

[silas]

find a new/used one that isnt clogged with carbon build-up....fo serious!

or if you're dead set on unclogging the one you have....soak it for days with penetrating fluid (pb blaster, liquid wrench...carefull when used with heat), lots of heat (we're talking cherry red), sharp knocks with a hammer, coat hanger on a drill, compressed air, rinse, repeat, and then rinse it and repeat it again...and again...and again.

you can also scribe the preheat tube where it bends (often that is the area that is most clogged and most difficult to un-clog) and the cut off the "legs" and clean it out using the methods above...then weld it back together.

[BUSDADDY]

18" of clutch cable with the end fuzzed up usually works for me, put it in a drill and wear thick leather gloves while you probe.
If it's really a mess drill a hole at each bend and attack it straight on or use a 12" drill bit (cheap at Princess auto, KMS, etc..).
Or there's the burn it out with oxygen method, works if it's mostly carbon with little rust and really exciting too!

[Chris]

fuel injection upgrade.

[Hansk]

To those who have done this , did you find any improvement in cold drivability?
I did this a few times in the past and found it did not help much.
Getting warm air to the air cleaner made the most difference for me.

[BUSDADDY]

It makes a little difference in the cold weather, the main purpose is smooth idle and throttle response anytime of the year, keeps the gas from condensing out of the mixture before it gets to the ports.
You're right though, aircleaner preheat is the best bang for the buck this time of year.

[beetlemandan]

the best results i've had ( and i've ran a superbeetle in -36c, yikes!) is warm air to the airbox. the best airbox for that is the palstic one with the paper airfilter (73+), and you need to run the small vaccume line on the side of the intake manifold just below the carb flange to the airbox, then to the heat-flap-deal, then make sure you got the tube that sucks air off the #2 cyl.

as for the exhaust x-over, use a stock muffler, not a header, and if you have to run a header, try to angle the holes so that the exhaust wants to go through the pipe. ( like on the #2 side, drill the hole towards the head, and on #4, away from the head).

as for cleaning out the x-over pipe after its been clogged. HEAT, LOTS OF HEAT. i find tiger torches do a wonderfull job. after its cooled down, i take a ball peen hammer and then proceed to start peening the pipe. the heat burns converts all the oil and soot to carbon, which is very brittle, so if you whack it with a hammer, in theory, it should fall out. start at the ends and work your way to the middle. ther should be lots falling out. just hold one end with your one hand and swing with the other. if you put it in a vise you will bend it.

after no-more comes out, try blowing some compressed air through it, then bang some more, then more air.



fun history note: for a while the factory ran the intake manifold inside the exhaust x-over, and while it worked very well, within months all were warrantied due to the fact that intake manifold rotted out inside the x-over. Can you say vaccuum leak?

[silas]

18" of clutch cable with the end fuzzed up usually works for me, put it in a drill and wear thick leather gloves while you probe.
If it's really a mess drill a hole at each bend and attack it straight on or use a 12" drill bit...

right on!!! i've used those methods too & i completely forgot about them!

It makes a little difference in the cold weather, the main purpose is smooth idle and throttle response anytime of the year, keeps the gas from condensing out of the mixture before it gets to the ports.

exactly...plus it also helps to de-ice the manifold and a little heat will help the atomized fuel reach the chamber in it's ready to vapourize state!

i found it helped, especially in the cold weather, especially with an icy manifold/carb.

[70's Looker]

cool thanks everyone! tonite shawn,ron and I went at it and got it all cleaned out, man there was a ton in it, we used the freyed cable routine, took forever but a great feeling once the drill fell right through, will it help alot? i dunno im sure it would do something vw was very good at keeping a good thing going, when i had the bus bastard would stall out on me look at the carb and it was frozen up good! so well see!

 

[CHEECH]

GREAT SUCCESS