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LJay Samba Member
Joined: August 05, 2007 Posts: 584 Location: Arbroath,Scotland
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johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
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Posted: Sat Apr 07, 2012 8:01 pm Post subject: |
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I recently bought one of these very rare '54-'55 intakes. It was known to be rusted inside and was unusable, but I just wanted one for my "Intake Museum" and on the out side this one was very nice, and looked original. I knew I would never use it on an engine.
Some discussion was started in another thread about intakes.
http://www.thesamba.com/vw/forum/viewtopic.php?t=503628
Some excellent documentation posted there, verifying these different split and oval intakes. Consensus was that these intakes were used '54-'55 timeframe and are very , very rare. They obviously suffered a design defect and very often rusted out inside the enclosure, allowing pressurized exhaust gas from the heatriser to leak into the intake runner. Invariably, once this breach was of any size at all, the VW it was in probably didn't run at all.
Going through all of my intakes, I suddenly realized I already had one of these (you know you are parts hoarder when.....). I bought it from another enthusiast for relatively little money, as it had been damaged in shipping and there was evidence of a poor restoration. I concluded that it probably was unrestorable and jsut stashed it away.
But this recent thread on these peaked my interest and I started to examine it a bit. First I noticed a small hole under the enclosure, through which I could see another hole in the intake runner tubing. Figuring it probably wasn't usable anyway, I cut a small opening in the bottom and discovered a rather substantial rust perforation in the intake runner.
I stared, and poked, and shone lights at all different angles on this thing, and slowly started to see a challenge to restore it and make it usable. Both heat riser legs had been bent toward the intake runner in the package it was in. The left side one showed a substantial crack in its midsection, the right one just bent back about 2" from its original position.
I cut the cracked section out on the left heat riser and discovered that the previous "restorer" had fit a thick spring in the heat riser, and welded around it. It was ground down, and a layer of body filler spread over it before it was painted.
For the intake runner perforation, I cut from another scrap 36hp intake runner a section the length of the opening I cut in the enclosure and about 1/3 the circumference of the tubing (sorry, no pic). I mixed JB Weld epoxy and brushed it on the rusted intake runner inside the enclosure, applied a thick coating on the backside of the donor tubing section, and using magnets, placed it over the rusted opening. I brushed more JB Weld on the donor metal covering the overlap areas.
I figured it was worth a try. I decided that after it set that if it passed a 10 psi compressed air test after the epoxy had set, that I would go ahead trying to restore it. The next day I tested it, and it passed the test (keep in mind that 90% of the time, the intake runner is running with a vacuum inside.)
First order of business was to try to straighten the right side heat riser that at least looked intact. I bolted the intake to my fixture, and pulled on the heat riser, outward. It bent outward, but then I saw some paint pop off near the enclosure as the tubing started to buckle; I had feared that. I had the riser leg within 3/4" of where it needed to be.
So I ground off as much of the paint as I could, and using some vice grips and an awl as a drift pin, gently cinched the heat riser end into position on the fixture and bolted it down.
Then I heated the heat riser with a propane torch, moving the flame from one end to the other. This tubing is VERY thin, even when not rusty. It heats to red almost instantly. I let the metal cool completely, and then took the screws out of the heat riser flange. I expected the end to move at least a little bit, as it was under pretty intense stress bolted down, but to my amazement, it didn't move an bit. The flange stayed perfectly positioned, and in flush contact with my fixture plate.
_________________ John Henry
'57 Deluxe
'56 Single Cab |
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johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
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Posted: Sat Apr 07, 2012 8:40 pm Post subject: |
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So on to the left side heat riser repair. About a 1" section needed to be replaced. I cut a section out of a scrap heat riser from an old K manifold. This tubing is VERY thin. I'd guess less than 0.5mm (I'll mic it later and post below). I use 2mm wall tubing for my repro K manifolds and jacketed K repairs, but face welding a tube 4-5 times thicker to another one is very, very hard. So it made sense to use same thickness tubing. After a grind and fit, grind and fit, grind and fit, ... I got a repair section just right. Here I use some small rare earth magnets to position the donor piece, my intake fixture holds the intake and the heat riser just right.
A few tacks from the MIG welder gets things started.
It is a multi step process, of tacking, knocking down the welds with the grinding disc, then flat filing the tubing. Here the welds are knocked down with the grinder.
Here we have a rust hole on the backside of the right side heat riser, filled with body filler!!
The body filler is chipped out and the hole is filled with the MIG and ground. Farther to the right in the pic below was a tear in the tubing that occurred when the heat riser was bent back into position. It is welded up.
Below, the repaired section is ground and has had a first pass with the flat file. You can see some low spots that after this pic, I filled with MIC and ground again.
Below you see the final repair. This is about 2 hours worth of work, and my hands and wrist ache. But this is a paint ready (well, after media blasting) all-metal repair that will be undetectable when done.
I intend to finish this intake, paint and bake it, and put it up for sale. And these pics and detail will be a record of how it was repaired. That being said, this intake is still very fragile. It would not take much pressure at all on these heat risers at all to buckle and crack them. While I expect that this intake will be fully functional, I will highly recommend to whoever buys it, that the heat riser be blocked off on the right side to keep gases from circulating through it. This will increase it's useful life. And to be sure, I know that the intake runner is probably paper thin in other areas inside the enclosure, but hopefully this intake will be installed in a well restored oval that is driven sparingly.
I can honestly say that I have NEVER seen one of these intakes in a running, drivable oval. They are much rarer than even the earlier jacked K 25hp intakes. It has been a lot of fun restoring this one knowing it will be a real conversation piece in someone's oval one day. _________________ John Henry
'57 Deluxe
'56 Single Cab |
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Grant Reiling Samba Slow-Change Artist
Joined: November 28, 2003 Posts: 491 Location: behind the wheel
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Posted: Sun Apr 08, 2012 2:25 am Post subject: |
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LJay wrote: |
Absolute cracking thread John,really one of the best ive ever read-thanks! |
NICE work, Maistro! carry on.+Happy Easter..(Now that's Truly "Rising from the dead ) |
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johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
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Posted: Sun Apr 08, 2012 6:57 pm Post subject: |
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Repaired the cut away section on the enclosure tonight. Fitting a new piece of metal and using the little magnets to position it (and then dropping it down in the enclosure!)
MIG welded in the patch
Knocked down the welds with the edge of a carbide disc.
Ground down the welds with an 80 grit small disc
.. then went over it again with a brown ScotchBrite pad.
Pressure tested the intake runner again at 10psi
So I decided as an extra measure against intake leaks, I would flood the intake runner with gas tank sealer.
Then I dumped it out, flipped the intake over and flooded the enclosure via the heat riser tubes.
Now to media blast and paint...... _________________ John Henry
'57 Deluxe
'56 Single Cab |
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runsplit Samba Member
Joined: September 18, 2005 Posts: 118 Location: REUNION ISLAND
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Posted: Sun Apr 08, 2012 11:21 pm Post subject: |
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Nice and great work. Thanks to share |
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johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
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Posted: Wed Apr 11, 2012 7:21 pm Post subject: |
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Finished the '54-'55 intake.
Media blasted and ready for paint:
Painted and baked:
_________________ John Henry
'57 Deluxe
'56 Single Cab |
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ZwitterND Samba Member
Joined: September 08, 2005 Posts: 1451 Location: Fargo, ND
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Posted: Wed Apr 11, 2012 8:50 pm Post subject: |
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Great work John! _________________ Bill |
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sunroof Samba Member
Joined: October 06, 2006 Posts: 1774 Location: Winnipeg
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Posted: Thu Apr 12, 2012 9:08 am Post subject: |
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Gas tank sealer! That is my Idea of the Day!
Don |
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johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
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Posted: Thu Apr 12, 2012 9:50 am Post subject: |
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sunroof wrote: |
Gas tank sealer! That is my Idea of the Day!
Don |
Thanks, I literally thought of it in the moment, and actually had a can of it on the shelf. I think it will work very well for this, although in hindsight I would have applied it after I painted and baked it.
I dipped two pieces of scrapped heatriser in the can when I flooded the intake as "control" pieces. I wanted to see how long it held up, and ended up test "baking" one of them at 350F to be sure it could stand up to the heat. It did very well. It just got tacky when hot, but cooled again and did not blister or lift. I carefully controlled the temp when baking this intake, the paint requires at least 300F so I kept it at 325-350F. Normally on an all metal intake, I would run it up near 500F. _________________ John Henry
'57 Deluxe
'56 Single Cab
Last edited by johnshenry on Mon May 14, 2012 10:19 am; edited 2 times in total |
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sunroof Samba Member
Joined: October 06, 2006 Posts: 1774 Location: Winnipeg
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Posted: Mon Apr 16, 2012 9:35 am Post subject: |
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How did you pour the excess back into the can without making a huge mess?
Don |
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johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
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Posted: Mon Apr 16, 2012 9:42 am Post subject: |
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sunroof wrote: |
How did you pour the excess back into the can without making a huge mess?
Don |
It actually wasn't that bad. For the heat riser, I just slowly upended it and let it run out. Hung it up from one end and let it drip for a few hours. _________________ John Henry
'57 Deluxe
'56 Single Cab |
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8287111 Samba Member
Joined: January 02, 2010 Posts: 141 Location: Finland
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Posted: Mon Apr 16, 2012 11:45 am Post subject: |
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Great work,but why you stil use this odd color for intakes? |
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johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
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Posted: Mon Apr 16, 2012 12:07 pm Post subject: |
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8287111 wrote: |
Great work,but why you stil use this odd color for intakes? |
Closest I can come to original color in a heat resistant paint that truly won't discolor.
_________________ John Henry
'57 Deluxe
'56 Single Cab |
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johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
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Posted: Tue Apr 24, 2012 6:51 pm Post subject: |
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johnshenry wrote: |
beetlekey wrote: |
52HoffmanSplit wrote: |
This is so John's version of porn... Manfold Porn..... Can I get this perfect bound on glossy paper and sent to my house in a brown wrapper? |
John,
will you porn me up that 24 hp manifold?
Marcus |
That is a real tough one Marcus. I have maybe 4-5 of those and there is no real usable solution there. The problem is that the heat riser is not round where it runs along the intake runner (tubing) and into the jacket. It is deformed as it is bead rolled along its length. Eric Jones and I were working on a plan to have some if it rolled, but that project has stalled. Even if you could reproduce the heatriser profile, you could not just ream the jacket out with a reamer as a round bore is not what is needed.
I suppose if you could get a replacement riser made, you could very delicately pic out the old steel from the jacket and maybe clean/shape it a bit with a dremel tool before putting the new heat riser leg in. The single biggest effort in restoring these JKs is extracting the old heat riser tubing from the jacket. I use several homemade tools and chisels, and literally pic bits of metal out one at a time with long nose pliers.
Perhaps one day I'll take a crack at it. That intake (Marcus's) is probably almost as rare as the JKs!! |
Ok, I'm back on this and pretty excited about it. I found a source for metric spec 18mm OD x 1mm wall seamless tubing. Dead on for the original stuff.
The piece above at the top is an original 18mm leg with some compromised/thinning of the walls.
I stumbled upon a cool way to make the press dies and will post pics and details when I do.
Here is one of my candidates:
Although I will probably do this one last as the pressed part that is needed is longer (about 9.5"). I have a couple of the "701 style" ones that are missing right legs also. I'll do those first, the bends will be easier too.
Here's something cool I did last night. This pic shows the cross section of an original 18mm pressed section (bottom), and a "701/701E" 20mm section above. It has 2 mm thick walls and some major carbon build up.
Notice how the the 18mm one is uber-clean? (Ok, I shot media in the blasting cabinet through it after I did the trick below). It had a fair amount of carbon in it to. Somewhere in this thread there is a pic of me doing the "solid rocket booster" trick on a clogged riser section; heating the carbon to red with an oxy-acet torch, then cutting the acetylene and blasting it with oxygen.
I went to do this last night but found my acetylene tank was empty. So just for kicks I tried it with a propane torch and compressed air... and worked great! Ok, not quite as smoke-spectacular, but the compressed air from the blow gun at maybe 40psi, get the stuff glowing and red hot chunks of it flew out of the other end like a roman candle (and one bounced back at me and burned the crap out of my finger). I think this would prob work with any heat riser that had even a bit of a clear passage, and you might even be able to clamp/rig something to hold you blow gun at one end and just set it outside and let it burn. Or do it at night on the 4th of July. Sorry, no pics this time...!! _________________ John Henry
'57 Deluxe
'56 Single Cab |
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Blue Baron VW Aficionado
Joined: June 16, 2006 Posts: 24130 Location: Southeast USA
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Posted: Wed Apr 25, 2012 9:32 am Post subject: |
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johnshenry wrote: |
While I expect that this intake will be fully functional, I will highly recommend to whoever buys it, that the heat riser be blocked off on the right side to keep gases from circulating through it. This will increase it's useful life. And to be sure, I know that the intake runner is probably paper thin in other areas inside the enclosure, but hopefully this intake will be installed in a well restored oval that is driven sparingly.
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Manifold icing is a huge problem on these cars, even in warm weather. Try touching the manifold below the carb after it's been running 30 seconds and you'll see what I mean. This is why there's a heat riser. I can't imagine someone putting a nonfunctional heat riser on their "well restored" car just to drive on and off the trailer.
That having been said, that's some really fine work on saving these old parts. _________________ We are striving for perfection, to make our cars run forever, if possible.
Heinz Nordhoff |
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johnshenry Samba Member
Joined: September 21, 2001 Posts: 9364 Location: Northwood, NH USA
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Posted: Wed Apr 25, 2012 9:53 am Post subject: |
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Blue Baron wrote: |
johnshenry wrote: |
While I expect that this intake will be fully functional, I will highly recommend to whoever buys it, that the heat riser be blocked off on the right side to keep gases from circulating through it. This will increase it's useful life. And to be sure, I know that the intake runner is probably paper thin in other areas inside the enclosure, but hopefully this intake will be installed in a well restored oval that is driven sparingly.
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Manifold icing is a huge problem on these cars, even in warm weather. Try touching the manifold below the carb after it's been running 30 seconds and you'll see what I mean. This is why there's a heat riser. I can't imagine someone putting a nonfunctional heat riser on their "well restored" car just to drive on and off the trailer.
That having been said, that's some really fine work on saving these old parts. |
That's not been my experience. I put probably 3000 miles on my '50 with a blocked riser manifold and never had any icing issues. I drove the car in all kinds of weather, humid to dry, hot to cold. Occasionally I saw a little bit of condensation on the carb riser, that is it.
Moreover, a functional heat riser is only marginally effective at warming the riser section, never mind the carb. After a 1.5 hour highway run in my '57, I used an infrared thermometer and took readings at the hot elbow of the heatriser and got about 250F, where the heat riser met the jacket 160F and on the jacket I got about 130F. The cylinder tins were at 140, the fan shroud about 115. Granted, it was a pretty warm day.
I'll contend that the heat accumulation inside the engine compartment is more effective at preventing icing of the carb than the heat riser.
HOWEVER, I do agree that in some very specific conditions, cool weather and high humidity, carb and carb riser icing will occur, and that is the reason why VW persisted with the jacket and riser approach. It is well know that the VWs were designed to operate in any condition and the heat riser design was already implemented since the first design. _________________ John Henry
'57 Deluxe
'56 Single Cab |
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sunroof Samba Member
Joined: October 06, 2006 Posts: 1774 Location: Winnipeg
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Posted: Wed Apr 25, 2012 10:22 am Post subject: |
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I have had problems in the past with the idle circuit freezing up in cold weather. The worst is around 0 celcius with rain or sleet, it requires constant attention to keep the car idling in traffic. Something that seems to work is to warm the engine up by driving for a few Km and shutting it off for a few minutes. When you start it back up the problem usually goes away. I spent a couple of winters driving my '59 here in Winterpeg where it will be below -30 C for weeks at a time. It works OK until you have a passenger who will insist on breathing which will frost up the windows solid. Fortunately few people are interested in riding in a '59 beetle when it's 40 below.
Don |
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ZwitterND Samba Member
Joined: September 08, 2005 Posts: 1451 Location: Fargo, ND
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Posted: Wed Apr 25, 2012 10:37 am Post subject: |
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I remember driving my zwitter one late fall in 1974, typical cold damp New England evening. Engine started sputtering and losiing power. When I got home the intake was frosted over on the outside, I pulled off the carb and the manifold was almost plugged with ice, save around the edges where it had started to melt. I always thought thats why they put those paper preheat tubes to air filters on later models. because the heat risers were not efficient enough? _________________ Bill |
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Shadd Samba Member
Joined: January 18, 2007 Posts: 883 Location: Lancaster, Ohio
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Posted: Wed Apr 25, 2012 12:13 pm Post subject: |
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We got tons of info about carb icing in aviation. It is really amazing that it does not have to be freezing to get carb ice.
I wonder if anyone has come up with an thermostatically controlled electric carb heat for a VW? Exhaust heat works good but with these rare old manifolds, electric may be a better option. |
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