Maybee Jan isnt telling us something. Maybee he got it to run on woodgas so good it ran too high rpm and got valve float
Could be, if my theory is correct, Iâve been riding on 3 cylinders for a while in the woods without noticing it.
Hmm. I think JanA. Has expressed a real concern with this engines valve adjusting type.
I remember my own Saab V-4 being surprised it had no locking nut on the adjuster screw. Just threads interference resistance. I also was sceptical on Chevy/Gmâs doing the same on their rocker arm stud/nuts. The only advantage to theses styles, the ability to do engine hot running adjustments. Yeah. Oil spitting, flinging and all.
JanA you will have to remove the adjuster screw and distort damage the threads a bit to get the resistance back. Or change out the rocker and ajuster for a better one.
The only way to be sure, yes.
S.U.
Jan, i got spare rockers if needed,
If I see correctly, it is a suction valve that has stuck during operation, this is a fact, otherwise the push rod would not have popped out. As you state that this is not caused by tar or soot, well, a possible cause could be a slightly bent valve stem, which happened during the event when the push rods bent.
Yes, Iâve thought about it, but donât know what the valve stem looks like if it sticks out so much that it can bend.
I set the valves and ran the engine, it ticked a bit at first but then it ran smoothly and fine, will look at the valve again when I get time.
Checked the valve today, it was completely loose, the adjustment had gone all the way up, just that the push rod had not come loose.
Put another bridge there which worked.
Cleaned the Illet today, isnât it strange that it is built up so differently in the core tube, a nozzle is hardly visible.
Jan, is it possible that you have a clogged up nozzle, and no air going through it or very little?
Yes, it is possible, but I tried with a steel wire and there were holes.
Do you think the long nozzles can cause the wood to hang?
Jonas H called and talked about Niklas having big problems with hanging, but I doubt that the nozzles are the cause?
Nozzles are seldom the cause of hanging, about a decimeter over nozzles pyrolyzis are going on.
Mostly troubles are from a âfunnelâ slope, as if the hopper are much wider than the hearth, when chunks going down, they also pushes inwards, just as a valve bridge.
This is a problem us woodgassers will have to battle forever
Saw cut round wood (dowels) helps, but isânt a working solution, maybe to use at special occasions, lot of stationary work?
Sometimes a more âpointyâ funnel makes it worse, (wedge effect) and a more shallow funnel allows for a better flow.
This is my train of thoughts, I would think that firetube diameter would have an impact too, the narrower the firetube is the easier it would be to get bridging and if a narrow firetube is used plus throw in pretty long nozzles into the equation as well, would not those also in a way be a part of the bridging? Especially if they are high up close to the hopper funnel.
I am not saying it is a problem on Janâs iller, just thinking out loud trying to figure out if I am thinking correctly as I am learning.
EDIT: long nozzles high up towards the funnel I see can have other problems too as tar bypass routes and small wood that could bypass the nozzles. That would be better with a âroofâ over the nozzles i.e. the funnel having a smaller hole but that would make the bridging problem worse.
Iâd appreciate feedback on this
A mixture of charcoal and wood is good in this instance too. The char bits âlubricateâ the wood chunks.
Thatâs my belief too.
The downsides with a shallower funnel are debrie buildup and chunks left and gluing to it after shutdown. Still better than bridging while youâre driving.
Bridging is probably the most annoying factor we have to deal with in a gasifier, especially if you use different shapes and sizes of fuel like I do. The best solution is, of course, a gasifier made with the same diameter from top to bottom, but since they are mostly made wider at the top and narrower at the bottom, it is necessary to ensure that the fuel collapses inwards⊠Now I add air near the wall of the funnel, which allows charring and pyrolysis of wood in a wide area a few cm above the narrowing of the hot zone, âŠ
Iâm still loving that machine Jan.
Why?
Went all last winter, and now it happened again, what am I doing wrong? Is the unit too large, can the tar go between the nozzles and through the restriction?
The short answer is yes; even on a well designed system, it still can pass through tars.
Many specific details unsaid about this event. Wood dryness? Ambient conditions? State of the gasifiers hearth internals?
But one; the most dangerous, you have said:
âWent (well) all last winter (under nearly daily use) . . . (but now after sitting used for months) it is happening again (passing though tars)â.
âWhat I am doing wrong?â
Maybe rushing the getting up to full internal operating conditions.
Maybe you were too nice, and over-cleaned the internals.
Maybe you bobbled, not smoothly the control times, and control sequences.
I almost always do all of these on my wood stoves in the first few days getting my smooth operations rhythms back remembered in the Fall.
Sooting up my door windows glass. Embarrassing.
That first pancake, or waffle, or fritter is a toss-out. A treat for the dogs.
Look at those using nearly daily, year around: WayneK, Tone, J.O. . . . smooth operations. Only ever problem with usage erosions of their metals.
Smooth operations maintained. Not set aside; half forgotten.
Be patience with yourself Jan Axelsson. You have the most important personal tool. Persistence.
Regards
Steve Unruh