Webasto woes again

[Jim Eh.]

Ditto on the 120v circulating heater. That is all we use in our beaten and abused shop shunt truck that lives outside. It will be outside tonight and ...

"A bitterly cold Arctic air mass is moving into southern Manitoba. Northerly winds of 20 to 30 km/h will combine with the extremely cold temperatures to produce dangerous wind chill values near -50 across southern Manitoba." (Thats -58F to you southerners.) It does complain a bit when we wake it up in the mornings.

It's sooo cold we even had to put a winter jacket on today.... 

BTW, around here the refineries (still called that but just tank farms now.) switch to #1 diesel as the temperature drops. It would be a good thing for you to fill up with #1 if you are expected to go into sun zero temperature areas. And/or carry a couple of containers of 911 (or equivalent diesel fuel conditioner)

BTW ... "everytime we go above sea level..."? You sig says you are from Texas, not New Orleans? 

[David Anderson]

BTW ... "everytime we go above sea level..."? You sig says you are from Texas, not New Orleans? 

A bit of a sarcastic exaggeration but only about 3000 feet from reality.  It is still smoking some after two days of hard use.  I can still fill air blowing around the unit. It seems to be leaking air between the burner head in the water jacket. I tighten the bolts very tight but I am afraid to do anymore with fear of breaking off the tabs. At least it is working better than it has for years. When I get home I’m going to do some serious sealing attempt.  I now believe that this is the problem.

[buswarrior]

The burner/water jacket seal won't do anything for the air/fuel mix, by that point you're on the exhaust side?

A fuel pressure tester can be readily made using an old nozzle. Drill it out, a shirt pipe extension to a suitable fuel pressure gauge. Check your books for the pressure range required. drilled, threaded, soldered together, whatever you prefer.

Easy to screw it into the nozzle port, and engage the unit to measure fuel pressure. Part of annual preventive maintenance, measure the fuel pressure and record, while swapping in a fresh nozzle.

Which Webasto unit do you have? A .035 nozzle is a healthy size, with only 1.5 inch exhaust. How often does it cycle on and off? Going down a little in nozzle size might smooth things out, stop smoking, burn a little longer, cycle a little less, depending...

happy coaching!
buswarrior

[David Anderson]

It is a DB2010

40000 btu

[Geoff]

It should be a DBW2010, 45,000 BTUs.

And the cover O ring might be missing or broken.  Here is one I found:

http://www.suremarineservice.com/Heat/DBW2010-Figure-2/50412244.html

[RichardEntrekin]

"The burner/water jacket seal won't do anything for the air/fuel mix, by that point you're on the exhaust side?"

I see it a little differently. The combustion chamber is pressurized by the impeller on the motor shaft. There are three areas where air can exhaust from the combustion chamber. One, around the penetration grommets. Two, around the seal the Webasto makes with Aquahot unit and water jacket, and three the exhaust pipe. If you take the Webasto and the swirler out, and you stare at it a little while, you could see the air flows in one direction through the swirler/combustion chamber all the way to the end, and then reverses direction to get to the exhaust hole. If the leak is at the grommet or seal, the air will take the path of least resistance, reducing flow to the combustion zone.

My personal experience has been that the slightest leak at either the grommets or the seal between the Webasto and the combustion chamber will make it smoke like a tug boat. I have a 2 1/2 exhaust pipe.

I had good luck sealing up the grommets with High Temp RTV. As they get older, they lose their pliability.

[chessie4905]

"Warning! Cancer and reproductive harm". I'd be afraid to buy it, let alone handle it.lol

[buswarrior]

Interesting.

the test benches I've seen, the burner head alone mounts to the open bench and just blasts into a tin catchment box assembled across from it, connected to a decent exhaust to outside.

But then, it isn't being forced through the jacket on the bench...

I'd certainly want no leaks between the burner head and the water jacket/burn chamber to control soot in the hosting compartment.

The next sizes up have much larger exhaust pipes.

Based on the variety of configurations I've seen in seated coaches, and the smaller ones used for pre-heating truck engines, and the wide differences in the amount/velocity of the exhaust "blow", I'd love to know how close or how far any certain model is to deteriorating conditions/smoking tolerant?

Top secret proprietary info, air flow rates etc, no doubt.

But then we'd know whether dropping a nozzle size would make all our problems go away for a nominal loss in "heating"

We need a retired Webasto engineer to catch the busnut bug?

happy coaching!
buswarrior

[Oonrahnjay]

  "Warning! Cancer and reproductive harm". I'd be afraid to buy it, let alone handle it.lol 

      But only in California.

[David Anderson]

It should be a DBW2010, 45,000 BTUs.

And the cover O ring might be missing or broken.  Here is one I found:

http://www.suremarineservice.com/Heat/DBW2010-Figure-2/50412244.html

Thanks Geoff, you have the numbers correct. 

I don’t recall seeing an o  ring😳 but it definitely shows it in the parts illustration.  I will check when I get back to Texas in 2 weeks

[Brian Diehl]

Interesting.

the test benches I've seen, the burner head alone mounts to the open bench and just blasts into a tin catchment box assembled across from it, connected to a decent exhaust to outside.

But then, it isn't being forced through the jacket on the bench...

I'd certainly want no leaks between the burner head and the water jacket/burn chamber to control soot in the hosting compartment.

The next sizes up have much larger exhaust pipes.

Based on the variety of configurations I've seen in seated coaches, and the smaller ones used for pre-heating truck engines, and the wide differences in the amount/velocity of the exhaust "blow", I'd love to know how close or how far any certain model is to deteriorating conditions/smoking tolerant?

Top secret proprietary info, air flow rates etc, no doubt.

But then we'd know whether dropping a nozzle size would make all our problems go away for a nominal loss in "heating"

We need a retired Webasto engineer to catch the busnut bug?

happy coaching!
buswarrior

I've done a bunch of looking around and can not find a smaller nozzle.  Is there a smaller nozzle available or is .35 the only option we have now?

[sledhead]

from what I could find the .35 is the smallest and when I could not find one I used a .40 and so far have had no problems . but did order 2 x .35
nozzles . the 1st one ( danfoss ) is the .35
WPX-886-41A - Danfoss
delavan 40-60w

dave

[buswarrior]

There is another nozzle supplier whose name escapes me at the moment, starts with "S"?

I've seen their chart with sizes dropping down past .25, but whether that's with the same standard base, I don't know.

More investigation...

Happy coaching!
Buswarrior

[Fredward]

Not to sidetrack too much but why would we want to go “smaller” ? I like my DBW2010 when it puts out 40,000 BTU.
Fred

[David Anderson]

I never posted back on this because I wanted to do some more usage before declaring a  victory.  We did finish the trip from Albuquerque/Taos and used the furnace extensively for the remainder of the trip.  It worked very well and no smoke or sooting issues.  Since I'm waiting for my turbo charger to be rebuilt (another post) I was finally able to open the burner head today and check inside the chamber.  It was clean and looked good.  Therefore, it was the leakage from the grommets causing my issues. 

Also, my swirler tube was out of round, so I called Sure Marine and asked the tech if he thought I should replace it.  He recommended to beat it back to round, so I found a cylinder (the screw cap off my acetylene tank) and I carefully hammered it into the tube and made it round again.  He also said make sure the welded seam faces down in the burner assembly.  I buttoned everything up, ran for 30 minutes, no leaks and the system runs great.   

Thank you Richard,  I truly believe I have this issue solved. 
David