Clearing VW Heat Risers - COMPLETE GUIDE

This is the complete and definitive guide to clearing clogged Air Cooled VW Heat Risers!
4 Methods are shown in detail
1) Boring with a cable
2) Blasting with media
3) Burning with Oxy Fuel
4) Drilling and Welding
Follow this video to 100% CLEAR your Heat Risers!
To contact Hiltz Machine Works for quotes or about your project, you can follow us here:
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[@stephengates7215]

I'm glad I'm not the only one that doesn't put the 'How to keep you VW alive' on a pedestal! It may have it's place but it's not the book people make it out to be IMO. Great video, personally I used some net curtain wire on a drill and it worked a treat. Keep up the good work😊

[@MaineMachinist]

Thank you for the encouragement! That’s a good idea about the wire. I can he harsh against that book, but it’s only because of how high it’s elevated by some people. There’s no question it’s helped a lot of people, and it’s entertaining, but as you know, it doesn’t always have good information. Thanks again for watching!

[@reddmann2216]

I used small diameter pvc pipe to encircle cable about 6-8" long to guide cable my hand don't touch cable while spinning... Even garden hose works,,,, my saying notice how the fingers never leave the hand! I have many years as a sawyer and value safety ....hearing protection I didn't think about in the early years but a continuous drone can be worse than loud bangs...

[@MaineMachinist]

Excellent idea and much safer!

[@iinerd]

Just watched your video from Milan, italy! Thank you so much for the complete explanation of this 'very common beetles issue'!!! All the best for the new year!

[@MaineMachinist]

I'm so happy to hear this! I love Europe so much. I had the wonderful privilege of living in Europe for a short time, and I miss it each and every day. I was over the Adriadic Sea in northern Serbia 2009-2010.

[@thomasfeeney7306]

Thanks from England for the very descriptive video. More importantly, the warning about wearing gloves with the wire in the drill.

[@MaineMachinist]

Thank you. I hope it helped!

[@yoshinoyajones8924]

I feel lucky to be alive!!! I used gloves!

[@MaineMachinist]

@@yoshinoyajones8924 lol.....

[@samsonbeshah5648]

Thank you for the great work I have got huge lesson I will be touching next v w problem

[@MaineMachinist]

Thanks for watching!

[@chicagomike6666]

great video! I actually have used a Harbor Freight Bauer power drain "snake"...it fits perfectly and is extremely powerful---it cleared mine in minutes!!

[@MaineMachinist]

The next time I go to HF I’m going to take a look at that tool! Thank you for the comment!

[@MrTodo6969]

Thank you awesome video

[@MaineMachinist]

Thanks for watching! I appreciate it!

[@cindyk5750]

Hope you didnt mind, but I shared this on my shop page for customer's benefit.

[@MaineMachinist]

Share away! I appreciate it! Hope it helps someone!

[@MaineMachinist]

I'm going to be putting up a lot of Air Cooled videos, so subscribe if you're interested!

[@notyodaddy1499]

My dual port has no heat risers and always runs awesome 👌🏽

[@MaineMachinist]

What are you running for carburetion?

[@sandyman099]

Have you shot the intake with an infrared temperature gauge after cleaning to see what it reads? I just did a makeshift heat riser on my headers but I think I'm going to have to go a bit further. I drilled out the tube with a 1/2" bit and ran a 3/8" copper tube through it. I sealed bot ends with high temp silicone to try and trap the heat under the manifold. I wrapped both ends of the tube around a header pipe and wrapped it all with fiberglass header wrap. I was hoping I would get enough convection heating to get the intake hot but it's holding around 116F degrees. Plan B is to drill into the header and use the exhaust ends from a scavenger kit. I can face one end towards the engine and the other away to get the flow but I would rather not have to go that far with it.

[@MaineMachinist]

Next time I run my buggy I will take my infrared thermometer and check the temperature on mine. I like all of the ideas you mention here and please keep us updated as to how it plays out.

[@spemann1974]

Thanks for the great video-- I just finished doing this for my engine last month and used method #1. Question: How "open" do you think the pipe needs to be? I broke through with an ~1/4" cable, and could blow air through, but do I need to ream it out much more? The carbon was super hard to get through ( actually took many days of frustrating attempts). I also had an aftermarket exhaust that I had to open up the riser flanges myself, but I wasn't sure how big to drill...thanks!

[@MaineMachinist]

My recommendation is to finish it with a sand blaster if you have access to one. Unless you have really good air flow through the pipe, I would keep working on it.

[@MaineMachinist]

and thanks for watching!

[@MaineMachinist]

Another thing - if you fabricate custom risers, its important that one side of the riser system is longer than the other to create the vacuum drag through the heat riser pipe. Most of the aftermarket exhausts don't contain riser connections, and the ones that do often just have simple flanges. That isn't really good enough. The pipe I show from inside the stock muffler shows how one side on the original muffler has a long pipe inside, and the other side has just a flange. The air movement past the long pipe creates vacuum that sucks the air from the flange side and draws the heated air through. I hope that makes sense. I will make a video showing a way to fabricate custom heat riser flanges on a collector style buggy or Baja exhaust.

[@TEDodd]

Around 3:30 mark you showed the flow backwards. The tube in/near the tail pipe creates low pressure that draw out of the heat riser tube. Same way the low pressure in the carb pulls fuel through the jets into the air stream.

[@MaineMachinist]

You caught the mistake lol... hopefully the bigger picture still stands!

[@TEDodd]

@@MaineMachinist yeah the point was made. Just jumped out at me, probably because I just swapped to a new "muffler" because the old one didn't have the heat riser tube in the right place (no venturi, no flow through the riser)

[@MaineMachinist]

When I went back and checked the video I sat here and went “hmm... why the heck did I do that” hahaha

[@OkFixer]

3:40 this is no joke....the correct muffler and tail pipes must be used and book measurement of tail pipe placement. Or aftermarket stuff with the left tail pipe about 3/4 of an inch from the inside tube.....use a flashlight and look inside the muffler. Measure with a tape or dowel. Bernoulli’s law you know, low pressure in the pipe will cause the exhaust to flow right to left. You can feel it on start up of a cold engine. The preheat pipe will get warm....almost hot in about a minute. Aftermarket exhausts and headers is the reason all these pipes are coked up.

[@MaineMachinist]

People don't think about the fact that there is a science to the factory muffler and heat riser designs

[@OkFixer]

@@MaineMachinist 👍👍

[@TEDodd]

I've seen a few aftermarket "mufflers" that don't have the pipe to the tailpipe to properly create flow through the risers. I just replace one like that. From the tail pipe you can't even see the tube from the heat riser flange.

[@OkFixer]

@@TEDodd yeah.....I’ve seen as well.....they are for dual carb, 3 liter engines that last 5,000 miles. 🤪🤪🤪

[@richardmarkham8369]

Interesting! How easy is it to remove the manifold? Do you have to reomve the entire motor to do it?

[@MaineMachinist]

You can do it in the car

[@cqpate]

my 72 bug was running good until it just stalled and died on country road after new brakes, muffler, shocks, carb, ball joints, ect restoring. it finally cranked up and got home. a hole was in the left intake riser with air so hot it burned plastic off electronic dist wire. new risers waiting.

[@MaineMachinist]

It will certainly make a difference! I hope it all worked out!

[@billleitz9150]

I take gunk carb cleaner plug one side and fill and let sit overnight cleans it right out . [Method 5 ]

[@MaineMachinist]

As long as it cleans out, its good!

[@jerryrobison3786]

That's what I did! I let it soak over night and it was clear the next morning.

[@MaineMachinist]

@@jerryrobison3786 I have since tried this on another one that I had and I couldn't get it to clear with the soak method. It was so clogged though that it had carbon essentially all the way to the holes. Worth giving a shot before trying the harder methods thought!

[@mainlandrenovations]

Just use a cut toilet snake on a drill, keep the end sharp

[@vintage76vipergreenBeetle]

👍

[@michaelnelson9140]

Well I think I got lucky. I poured a couple ounces of ethanol in one side of the heat riser and let it soak. Later, I tipped it to the dry side down, and some black fuel came out. So it isn’t completely plugged! Scratching my head as to how to completely clean it without having to drill a hole? If I could get some kind of wire through, maybe I could attach something to scrape it clean. Any thoughts?

[@MaineMachinist]

Using an old throttle cable as a boring wire as I did in the video works, but it can quickly grab you so just be very careful.

[@manningcustom]

I have dual carbs. Do I need a heat riser?

[@MaineMachinist]

No. Heat risers are only for center mount carburetors, so you’re good!

[@michaelknight2897]

Could you use a 1/4 drain cleaning cable?

[@MaineMachinist]

Try it but be extremely careful

[@rjgarciasr]

The side (I've seen it referred to as an exit pipe) that's connected to the front of the muffler (side facing the engine) is the low pressure side? if so then the small hole gasket is installed on the opposite side? My exit pipe doesn't protrude into the muffler more than an inch. it's nowhere as long as the one you removed from a muffler. if it doesn't protrude into the pee shooter how is vacuum created to pull hot exhaust from the other side?

[@MaineMachinist]

Do you have a German made muffler or is it an aftermarket Chinese one?

[@rjgarciasr]

@@MaineMachinist Surprise it's a USA Walker, but discontinued. I think the Germans have also farmed off these mufflers to other countries. Even if it says German OEM it may not be so. PC in Cali claims to have them, I'm calling today to inquire.

[@richardmarkham8369]

Just done this on mine. They were blocked nearly all the way... Took a good few hours to get a 6mm steel wire rope through. So now I have a 6mm wide hole through all the carbon in the tubes. What next to get it all clear? Just keep at it with the end of the steel cable opened up a bit? Are there any chemicals that might soften it up?

[@MaineMachinist]

I’ve tested just about every chemical out there from solvents to brake cleaner and even carburetor cleaner. Soaked them overnight in each liquid and I couldn’t get anything to break up that carbon

[@MaineMachinist]

One thing you could try is fraying the end of the wire so it operates like a brush through the 6mm hole and continue to work at it

[@richardmarkham8369]

@@MaineMachinist Yes, I just kept at it! I also put a borescope camera down to see how much I had cleared!

[@MaineMachinist]

@@richardmarkham8369 good to hear! I hope it makes a big difference!

[@richardmarkham8369]

@@MaineMachinist I hope it stops my bug dying at junctions when I let off the gas. Only does it after its run for a while.

[@cointelpro25]

Ha came here AFTER I just did method 4. But I have a sandblaster. The same one you have. Oops.

[@67VWForever]

I had a 1641cc, it ran fine without them I ran my car with dual carbs and single carb and my bug ran better and haled ass they were mad for cold Environment . no hesitation what so ever ran it for 3 years like that...

[@MaineMachinist]

Dual carbs don’t require it, because the manifolds are short and directly over the heads.VW installed these from the factory in Africa and Australia. They’re not only for cold environments.

[@bestofthebest3821]

heat risers are needed in carburated bugs cause the gas was squirted from the carburator ..if it doesnt get heat it wont turn into vapor inside the intake runners...in mexican new fuel injected bugs there are fuel injectors at each cilinder SPRAYING gas so theres no need for vaporizng the gas, so mexican fuel injected bugs have no heat risers

[@MaineMachinist]

That is absolutely correct. The Bosch German fuel injected Beetles from 1975 on also didn't need a heat riser.

[@bluebug66]

I have cleaned a single port intake out with the drill and cable method. Buy a new manifold and save yourself a lot of trouble. They are not that expensive and will last a long time if you use a good quality stock muffler with proper heat riser connections.

[@TLH442]

Fuel injected throttle bodies than throw all of that stuff away.

[@MaineMachinist]

Long term I think those TB systems will be impossible to service

[@7CAJONEZ]

As long as you have the manifold off, here is the best way to clean it: buy a new one. You will never get the original i.d. and it will clog again. Or wrap the manifold below the carb with 12 volt heat tape. And you dont want to heat the carb, only the manifold.

[@MaineMachinist]

I’ve collected and stored some of these OEM German ones after cleaning them up. You’re right that it might be easier just to get new, but with the lousy parts quality we’re seeing, even that can be a gamble.

[@Wiencourager]

Camera tip: a polarizing filter on the lens would have eliminated reflections and made it easy to see into the blasting cabinet.

[@MaineMachinist]

Good call. I’ll look into that. Thank you