How to stop huffing noxious fumes?(heat exchangers)

[Clatter]

OK,
I'll be the guy to say it.
There is a pretty serious issue with our beloved busses.

The heat exchangers sit underneath the valve covers.
Inevitably, oil leaks down and into the heat exchangers.
It accumulates there, being burned into a toxic oil sludge over time.
Every time the motor is run, the sludge is heated up, off-gassing into the passenger compartment.

Whee!
No need to smoke any weed in a VW bus to get high,
This is like huffing solvent, only it's burned oil instead!
Different kinds of oil over the years, no less!

Now, I'm not the health-nut orgo type to be sure,
but,
this is bugging me.

Cutting open a heater box is actually quite easy;
Drill a couple spot-welds, and pry it open.

Look at the burned oil sludge, clogging up the exchanger fins, and, more importantly, soaking into the asbestos(?) mat that insulates the shells.

To make this useful...
Obviously, the idea here is to get all of the oil out of there, and, forevermore keep the oil out.
(be religious about fresh/correct valve cover gaskets - easy enough)

The foil layer can be cleaned, or new made out of similar thin sheet.

The woven material, is, however, another issue.
The likelihood of either burning the oil out, or soaking in a tank or such, is likely to yield imperfect results, and just give us another set of chemicals to be huffing...

Who out there knows of something similar that can be used?
Someone suggested using exhaust header wrap.
it certainly would stand the heat.
Comes in thin strips, though. working it into shape would be difficult.
Wonder what kinds of fumes it gives off?
Anybody know?

Someone else mentioned 'fiberglass wrap'.
What is that?

Someone out there know of a silver bullet for this?
Certainly there has to be some aerospace, or HVAC solution for high-temp insulative sheet suitable for an indoor air environment...

Just leaving it out is feasible, you would lose some heating capability, and the things would likely be rattly.
Plus the heat would burn the paint off.

Anybody out there know a good solution?
You just might save us all from cancer!
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Bus Motor Build

What’s That Noise?!?

[Tcash]

Maybe this stuff would work?
Turbo heat shield
Thermo tech

Paint the tins with a ceramic coating.

Happy T-Day

[Clatter]

Thanks for the tip.

This one looks good, too.

http://www.amazon.com/Temperature-Header-Exhaust-A...merReviews

Looks like 1/8" thick or less,
And 2000F at a minimum.
The stuff would need to be rated for direct contact with an exhaust manifold.

Having the constant airflow, with space, between the heat-sink fins should help keep it from burning off.

Otherwise, imagine the whole stink/smoke-out session you could make for yourself....!
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Bus Motor Build

What’s That Noise?!?

[Wildthings]

You can make high temperature silicone dams or JB Weld dams were the pipes enter and exit the shells to divert the oil. Since the silicone is on the shell and not the pipes it doesn't get super hot and will last for a while. Best just to stop the leaks though.

[Clatter]

Before we had some pics of the heaters disassembled, and what we discovered was inside.
They had been tanked clean, and a plan was formulated.
Here's what happened with them:

First, a blasting was in order to get them really clean clean between...

This is a proper glass-bead cabinet at my local Santa Cruz Metal Polishing.
Looking closely, the leftover baked-on grime is obvious.

Two hours(!) later, they look mostly clean.
This is a Big/Badass Blaster, mind you, not just a HF cheapie...

After the first blasting session, the remaining tiny bits of burned oil are chased out of cracks/crevices with a sharpened tiny screwdriver.
Then, it's blasted again, to remove the residue under the chased-out bits.

EGR port welded up.

Flanges detailed.
It irks me when the blobs of welding slag protrude into the airflow at the flange.

After porting a few sets of heads, any airflow impedance starts getting looked at.
Yeah, likely a waste of time. (look what happens when we get to the muffler! )
A stone in a die-grinder cleans the welds up.

After.

Super high-performance blueprinted raging power perfection!

Rusty garbage outer skins.

Weld, grind, cuss, weld again, grind, cuss, repeat.

Helps to have a motor upside-down on the stand to mock these up.
There is a LOT of tweaking and hammer/dolly work to get everything tight.

Even sanded down like this, they look super crappy,
But,
They have no pin-holes and are finished on both sides, smooth enough to work, at least.

The halves get assembled bare to check the fits.
And to make-up patch pieces for areas that are too gone to just plug-weld...

Some of this blobby birdshit welding looks like total crap,
But it's in a location where I'm just not going to deal with grinding it.
Plus, they're heater boxes fer chrissakes!

Bodywork, fit, weld, grind, repeat...

Finally, the big moment is upon us,
The insulation from Thermal Zero is trimmed up and installed, and the 'final' assembly if the boxes is completed.

All fit up, and ready to be tightened down...

Now, this is all bare metal.
The motor is slated to be test-run in the coming days/weeks, and the bare metal will allow any stink/fumes from the insulation to be identified.
If this stuff runs-in on the stand without stinking, I'll be coating the tins and heaters inside there.
Then we will run it again to see of the coating stink burns off like it's supposed to.
So we'll keep y'all posted....
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Bus Motor Build

What’s That Noise?!?

[Brian]

niceee.
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[Wildthings]

While you are at it you should weld all the way around where the pipes both enter and leave the boxes. These areas are already thin and will rust through in a few years if you don't thicken the metal a bit at this point in time. You should be able to wrap the pipes in some copper sheet and then do the welding with the pipes in place to support the undersides of the molten welds. This will lessen the level of cursing a bit.

[eche_bus]

Impressive work

[1967250s]

I'm thinking that the only reason the wrap is inside the heater box is to protect the heads and tubes from heat, and that an external heat shield might be better. Either exhaust wrap or an additional sheetmetal like the T1's use; you know those L-shaped tins that attach to the lower tin?
Nice work, BTW. Where were the spot welds located? I'm thinking of doing the same thing.
Also, am I wrong or are the aluminum pieces cast right on the pipes?
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'72 Elm Green Deluxe

[jtauxe]

[Clatter]

[Steve22]

Nicely done, too bad you didn't pull some patterns for the shells while you had them apart...
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'65 Karmann Ghia 'vert
'73 Super Beetle
'59 Beetle ragtop
'73 Sunroof Transporter

[1967250s]

[Clatter]

[Clatter]

[Clatter]

[Clatter]

Here's a pic of the heat-shield heat-shields...
We will call it 'sheathing'...

The shiny 'sheathing' is non-magnetic, guessing it's aluminum.
It's .014" thick. Approx 29 ga.

This stuff goes between the heat sink and insulation.
Cleaning it up almost destroys it.

I might just try and find some of this sheet, and make new.
_________________
Bus Motor Build

What’s That Noise?!?

[Clatter]

Just to follow up... Found some more pics...

Here's what the inside of the lower tin looked like.
My repairs look a lot better where they can be ground..

There was this metal 'shielding' (sheathing?) between the heat-sink and insulation.
Presumably to keep the insulation from burning off?
Likely to keep it out from between the fins of the sink, too..
I'm going to try using the shields on the top to keep it out of the fins.
But,
On the bottom, gravity will keep it out of the fins,
and,
The new insulation is rated to 2000F,
So it should all work, right?
We'll test it!

Here's the shield in place; Upper side of box.

The insulation got trimmed better later....

Also, got to surface the, er, surface, that the manifold uses to attach to the head.
Some say to use a file. Yeah, right. Don't make me insert some more eye-rolls...
Here's how they do it, when it's done correctly; an automotive 'milling machine' used for 'surfacing', a.k.a 'milling' heads.
While we have a motorcycle head mounted up here, hanging an exhaust manifold is done in a similar manner.

The manifold is very carefully aligned, to take only the minimum required to make the surfaces true and flat.
This manifold had surface corrosion and bad/deep pitting,
And you will notice that Jim at Carr Parts in Santa Cruz <--Shameless Plug--took only the very minimal amount required to clean up.
Those dark spots are the very, very bottom of former craters in the surface.
This is perfection, folks; Those remaining pits show only very slightly.
You do not want to take any more off of here than is absolutely needed.
Some irregularity between the two 'arms' of the manifold was corrected, too.
Beautiful...

NOW, we might take a file and smooth out the finish of these mounting faces.
And de-burr the edges...

Otherwise, using a file would have been futile, and an exercise in vandalism, possibly, even.
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Bus Motor Build

What’s That Noise?!?

[raygreenwood]

If you really want to stop noxious, fumes from burning oil on the heat exchangers....simply stop the oil leaks. I havecnit had a leaking valve cover in about 30 years.

But your work on restoring the heat exchangers is excellent! Ray

[SGKent]

looks great. One tip I learned from our welder. In places where the metal was eaten up, and there were complex contours, instead of fabricating a piece of metal to fill the area, he cut lengths of appropriate diameter welding wire and bent it to follow the contour. He then tacked the ends and placed another wire along side it with a small gap. He then filled in between the gaps which partially melted the wires into one mass. When it was ground down with my dremel one and painted one would not know it was patched.

The exhausts look very clean. Make sure your head ports are equally clean but not shiny, and if your machine shop knows what they are doing have them swirl polish the backs of the valves. It will be the cheapest extra horsepower you will ever get.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin