Exhaust to front heater box seals

72_square · Post by **72_square** » 14th June 2005 - 2:00pm

I know this was covered in a recent copy of the type three club newletter, but I can't find my copy! Can someone run over the options again for sealing between the exhaust and the front small heater boxes (the ones with the damn big nuts!)

Stuart Sepple · Post by **Stuart Sepple** » 14th June 2005 - 4:21pm

1) Heat resistant graphite-based packing( boiler plumbing?)

2) Copper thermostat tubing - about eighth inch diameter

3) Furnace thermocouple lead which is a thin copper tube with insulated wire inside

4) An eighth inch slice of 42mm dia (quarter inch bore?) copper piping.

I need to do this too v soon so perhaps we should keep in touch

Stu

Post by **Editor** » 19th June 2005 - 5:59pm

4) from Stuart should be more like 1and5/8" bore, but it's a metric standard size of copper pipe apparently - need to be an industrial plumber to use it and have some scrap I guess.

Latest suggestion, and probably the easiest really, is to cut down a couple of manifold gaskets - same requirement - just need a circle of diam about the same as the heater box hole. the inside hole is correct for the bore already! Thanks to G. Tunks (I think) for that one.

Matthew · Post by **Matthew** » 21st June 2005 - 9:31pm

I went to an exhaust wholesaler and went through their catalogue until I found gasket of roughly the right size. It was one of those card & metal sandwiches. I unwound the excess material until it was the right size. I think it is still sealing well. It was at least 5mm thick before it went in.

Matt.

72_square · Post by **72_square** » 22nd June 2005 - 8:24am

OK, I tried option 4, here's what I did:

Struggled to get the exhaust off
Went to plumbase and brought a 42mm straight pipe connector for about £8.
The connector is slightly oversized, about 44mm. I cut two 3.5mm slices of each end, carefully filed them flat and smooth. I then cut a section out of the ring and re-soldered it to make the right diameter.
I put the exhaust back together (complete with swearing!) and used a tiny bit of Holts exhaust lub and sealer.
I went and brought a 46mm spanner (£12 from Cromwell tools) and tightened the nuts up as much as possible.

Sat back and fired it up and promptly watched it leak far worse than before. Talk about lots of effort for negative gain!!!!!!!!!!!!

I can only think that either the copper washers are too thin and have bent/folded over. Or else 3.5mm was not thick enough.

I have now happily plastered the entire joint in the holts paste! rather messy, but I couldn't face taking the damn thing off again.

Sounds like Matt has the right idea

Post by **Editor** » 22nd June 2005 - 11:34pm

That's a shame to spend so much time and effort and have it fail again.

Having seen the simplicity of using just the normal manifold gasket, I have to wonder why that could go wrong. George T found it worked. If the thread in the heat exchanger is not clean I suppose it may not wind tight.
VW said to put graphite paste on those threads, but do you think most exhaust fitters would bother!

It's probably worth dry fitting those boxes without the gasket inside to ensure they tighten completely, then dismantle and put the gasket in when fitting it. Most gaskets would probably seal OK in that case.

72_square · Post by **72_square** » 23rd June 2005 - 8:14am

Dave

I was fed up and stressed out with it yesterday (could you tell?). Now I've calmed down, I realise it will have to come off again. I think I'll take the whole lot off this time, pre heat boxes included. I can then dry fit the big nuts into them and check for fit. I did use a bit of copper grease first time around.

I'm going to the car parts shop to find a modern gasket that will fit, like Matt did.

The reason for the clinical precision is that I have a new toy - an oxygen sensor welded into the tailpipe. Trouble is with these exhaust leaks it's pulling in external oxygen and making my engine look lean when its probably running rich. i want the exhaust fully airtight to get true readings.

It got so bad yesterday I was on the verge of buying a duel quiet pack exhaust...............

Matthew · Post by **Matthew** » 27th June 2005 - 7:27pm

Craig,

I've written up what I did on my website. Its all very "work in progress" so take it with a pinch of salt. There's a photo of the gasket I used, which may help. http://vw1600e.org.uk/exhaust/.

Cheers,

Matt.

Stuart Sepple · Post by **Stuart Sepple** » 26th July 2005 - 6:45pm

However, before fabricating Gaskets check whats around - I just got some originals from TD3 last week

Post by **Editor** » 26th July 2005 - 10:30pm

I found similar gaskets are used on some aero-engines, though our size is in the caralogue, it doesn't seem to be stocked. I've got a company named Whitby and Chandler in Sheffield who can apparently make these up in smallish batches. Something to follow up if they are going to be a resonable price.

What were the ones T3D sold priced at, Stuart?
Dave.

72_square · Post by **72_square** » 27th July 2005 - 8:57am

I found a guy on ebay who sells metal type gaskets for small motorbikes. He keeps a good range of sizes. This was his email:
stone28@btinternet.com. Just do a search under gaskets in the motorbike section. Think it was for a susuki or similar.

I was on the point of ordering some from him (about £2 each), but I've ended up ordering an 'up and over' coated exhaust from the states.........

gracie · Post by **gracie** » 19th April 2013 - 12:19am

a long time on from the last post on this item I find myself reinstating the stock exhaust and pre heaters etc. Can anyone steer me to more detail on the shape and size of the gasket I need to source to set things up correctly?

Many thanks

Graham

72_square · Post by **72_square** » 19th April 2013 - 7:46am

I went back to a stock exhaust in the end. The up and over custom exhaust was just too noisy for me. I learnt that my past problems were due to the threads in the exhausts being a bit rusted up. They looked fine, but rust was stopping the big nut from seating properly. I used a demel tool with a mini wire brush and cleaned all the threads out. That with a bit of copper grease allowed the nuts to tighten right up with ease. Back to your original question, I cannot remember what i used as a washer! I *think* I stuck with the wire gause type motorbike gaskets that I had brought.

gracie · Post by **gracie** » 19th April 2013 - 4:36pm

Many thanks Craig!

Post by **purplepeter** » 19th April 2013 - 6:59pm

Someone suggested a while ago that Motorbike exhausts often use Copper crush rings.
A trip to my friendly local motorbike shop this afternoon has resulted in a bag of 10 being ordered-they're slightly thicker than the originals, but hopefully that'll mean better sealing? They are, like the originals proper crush rings, not just flat washers.
Graham, either pm your postal address & I'll stick a pair in the post, or if you prefer to source your own The dimensions of the originals are 42mm External Diameter, 36.5 mm Internal Diameter, 3mm Height
I'm expecting them in a weeks time, so it'll be 10 days before they get to You. No idea of cost, but I'm happy to offer them as a gift to You & also to Rob Camber, who I know is looking for a pair

I'll look into the asbestos rings for the silencer/main exchanger joint, When I've located my spares that were on the desk until My other half "tidied" !... I suspect Dave Hall might have a stash of those, but you'll have to ask Him!

Post by **Editor** » 23rd April 2013 - 12:01am

The heat exchanger joints and small-bore 'asbestos' rings are the same as (normal) Beetle tail-pipe fitting kits - just try to get the ones with the proper clamps not the thin strips (well, they probably work, but they don't look the part!). I don't think I have a stash of them - may have a couple, but I tend to re-use the metal parts a few times.

PaulDickinson · Post by **PaulDickinson** » 26th April 2013 - 8:29pm

Editor wrote:The heat exchanger joints and small-bore 'asbestos' rings are the same as (normal) Beetle tail-pipe fitting kits - just try to get the ones with the proper clamps not the thin strips (well, they probably work, but they don't look the part!). I don't think I have a stash of them - may have a couple, but I tend to re-use the metal parts a few times.

There seems to lots of wierd and wonderfull ideas about these sealing rings but it is quite simple really.I just ordered some copper washers of the correct size or thereabouts from a nuts and bolt supplier and fitted them, perfect and no fuss.

Post by **Editor** » 3rd May 2013 - 1:44am

Wow - I'd forgotten what wonderful fixes we came up with in 2005 (see the dates on most of this thread).

Anyway, the proper copper crush rings are 36 x 42 x 3mm for the small heat exchangers to stock exhaust joint and are still available - maybe purplepeter has them now. I wouldn't be surprised if plain coper washers fit fine, though, as Paul reckons - the surfaces are usually pretty flat, and it's not going to poison anyone anyway.

If anyone is after the crush washers, I found my stash from my USA trip last year when looking for something else just this evening! I'll bring 10 of them to Stanford Hall.

I got them from this couple:- http://www.bandbaircraftsupplies.com/homepage ; look for AN900-22 - don't know what the post from Kansas would be but it shouldn't break the bank, and at 65cents each, you're doing well anyway!

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Re: Exhaust to front heater box seals

Re: Exhaust to front heater box seals

Re: Exhaust to front heater box seals

Re: Exhaust to front heater box seals

Re: Exhaust to front heater box seals

Re: Exhaust to front heater box seals

Re: Exhaust to front heater box seals