Author Topic: Chang-chai and ST head, deal? Or no deal?  (Read 494 times)

dkmc

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #15 on: November 07, 2021, 11:55:17 PM »

Another curious observation while inspecting the ST head....

Wire lugs on the output terminals with no wires crimped to them.
Are they from the factory? Could it be this generator was never used?
The jumper 'buss bar' that connects the output for 120-240 or just 120 was on the F2R terminal, not connected to anything else. Why I have no idea. I could not figure out how to remove the brushes, but checked and observed continuity between the slip rings and brush terminals. Maybe it needs to be flashed? I need to determine which wire is the + on the rectifier. It started right up from 50F today on the first spin up.


guest18

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #16 on: November 08, 2021, 01:03:23 AM »

dkmc

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #17 on: November 08, 2021, 02:13:01 AM »

+ to the slip ring closest to the windings..........got it.
Thanks.

This wiring diagram should work.

https://www.utterpower.com/wp-content/uploads/2010/07/Figure1.gif

veggie

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #18 on: November 08, 2021, 06:38:31 PM »

The spare brushes that came with my ST-5 are exactly 1 Inch long.

- 6/1 GM90 Listeroid - Delco 33si Alternator
- Changfa R175 - Lease/Neville Alternator
- JiangDong R165 Air cooled - 2 kw

mobile_bob

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #19 on: November 08, 2021, 07:28:43 PM »
that seems odd to have uncrimped eyelet connectors still in place, that would make one believe that it may never have been used.

can you get a closeup of the slip rings?

it is very common to have one of the two showing more wear than the other, that is if it has a bunch of hours on it, if it shows equal and little to no wear, and the brushes are as veggie states about an inch long... it may well be that the unit as a whole was either never used or used very little, and just left in a wet/damp environment making it look worse than it really is.

you may have found a diamond in the rough?

have you looked down in the hopper to see the cylinder liner?  is there a bunch of flaky rust and lime buildup?  i would expect a nice coating of rust, so that would not indicate much but it it is free of flaky scale lime buildup that along with the oil looking so clean would lead one to believe that this thing may never have been put into service.

might be it sat around for a long time new, and someone pulled the box top off, didn't know how to connect a load to it and simply walked away leaving it in an unprotected area.

again, can you talk a picture of the slip rings?

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

dkmc

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #20 on: November 09, 2021, 12:08:45 AM »
Revolting developments and a sign from.......someplace?

Yesterday I ran the engine a bit as I said, and it started much easier. Run time maybe 10 minutes total.
I noticed a drip from under the oil pan the day before, and now again after just a bit of temp build up, it's dripping slowly again. Luckily, I'm able to pick it up high with the forklift and check the underside. I suspected the seal on the drain plug, so took it off. The rubber O ring (such as it is) was mashed flat and cracked. I installed a new one, and snugged the drain plug. Re-installed the oil.  More dripping.......!  So once again, I hoisted it up and got underneath for a really up close look. It was then I noticed the dent on the corner of the oil pan. And separately, nothing to do with the dent, I discovered a tiny crack in the pan under the drain plug. Crap!  But.....it gets better!

I drained the oil again last night. And I spent a lot of time thinking (when I should have been sleeping) about an approach to the problem. I did consider JB weld, but I wouldn't feel right about that. Today I picked it up from the handle above so no  forks interfering below. And I see the pan is not obstructed by the frame work. So I removed the pan bolts......

And here is where the horror show begins. But with a silver lining!
I half expected to see some.....SOME...... sludge in the pan, but nothing like this!  Not only was there about 1" of sludge, there was also a generous heaping helping of Foundry Sand. And the pick up screen was in-bedded in it and it seems about completely plugged. I have no idea how the oil pressure indicator was showing pressure.
It's hard for me to believe with this amount of sand, that this was anything other than deliberate. And this is a Changfa not a Listeroid.
As you can see from the pics, I was very relieved to see the important parts undamaged from sand and lack of oil. Somehow, it seems the tiny crack and annoying oil leak was a blatant cry (cry, dripping oil, crying tears, pun intended)  from the engine to implore me to remove the pan and rescue it from certain death.


« Last Edit: November 09, 2021, 12:31:22 AM by dkmc »

dkmc

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #21 on: November 09, 2021, 12:14:52 AM »

More horror........

The goo on the cookie sheet shows the amount of sand chunks on the right side.
Beefy chunks in gravy is what I actually said out loud when I scraped it out of the oil pan.
This explains the butter scotch oil that came out initially.





dkmc

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #23 on: November 09, 2021, 12:25:48 AM »
Now for the good news.  I don't think the slip rings will need to be investigated after you see these pics Bob.
Super lucky the sand apparently didn't make it into the oil passages and thru the bearings.....yet.
I am so glad I took the pan off! A bit of silver solder will repair the crack.

I don't know what the cam lobes and rod inserts might look like with 'hours' run time on them, but these don't seem to have much time at all.

Some rust in the cylinder below the ring travel........

« Last Edit: November 09, 2021, 12:36:44 AM by dkmc »

mobile_bob

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #24 on: November 09, 2021, 12:34:57 AM »
all i can say is wow!

that looks to me like sabotage by someone, maybe at the factory level, maybe someone after delivery?

maybe a previous neighbor that got tired of listening to the thing running outside his bedroom window?

this reminds me of a short story

i was 15yo, working pumping gas at a station on the edge of town,  i worked till closing at 10:30pm a few night a week.  in the winter months it got slow after about 8pm so i had time to do my homework while sitting at the counter.

just to my left side through an open doorway, was the aircompressor, and that damn thing was so noisey, not the common aircompressor noise but banging, squalling, raising hell sort of thing

every night in an effort to quiet the beast i would check the oil and find the dipstick covered in metal flakes and no oil at all.  so i would buy a can of "glitz" generic stp stuff that was about 200weight, thick stringy nasty, came in quarts, was cheap and the compressor would quiet down so i could live beside it.

this went on for months, then one day my boss having spotted the half quart of glitz sitting beside the beast asked me "bob, are you the one oiling my compressor?"

me:"of course, i am tired of listening to this thing pound"

boss: "how the hell do you think corporate will replace it if you keep oiling it?"

he was moderately serious!

so i quit oiling it, and it kept pounding for a few more months.

then one day they came in with a portable office, tore down the old station, took away the vending machines, and our beloved compressor.

they built a new station, and just about the time they were done the truck came back and unloaded a bunch of new looking vending machines, and...  wait for it,,,

the beast returned!  shit!

they hooked it up, i told them about our problem with it, me oiling it, and my boss having a fit,  and they told me "hey kid, its not my job"  basically get out of my way and let me get back to hooking this thing back up.

they got it installed, and fired it up... and what do you know, they overhauled the beast
and it ran quiet!  never heard it run that quiet ever...

your oil pan, and crap found within reminded me of what the mechanic must have thought when he tore into the beast and was faced with a ton of metal flake and sticky glitz oil treatment.

i am thinking he was having similar thoughts that you had when you dropped the pan on your engine.

like   "wtf" 

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

dkmc

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #25 on: November 09, 2021, 12:50:31 AM »
Great story Bob!  I do admit my heart sank when I saw the contents of the oil pan. Sorta looked like bad meatloaf night.
I could only imagine the rest of the engine was TOAST.  And I'm not in any way familiar with Changfa's so the nearly-metallic whack when it fires had me thinking it was perhaps an actual rod knock instead of typical fuel knock. By no means a 'silent' generator. More like crude, rude, and obnoxious. I kinda like it...

mobile_bob

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #26 on: November 09, 2021, 02:19:39 AM »
they make a sharp "bang", "bang", "bang" as they are spooling up and then once they settle down to a steady rpm they still have a sharp diesel knock.

its hard for me to imagine that crap being in their from the factory, they do a pretty good job of cleaning the interior castings, and they also paint pretty well too... a tiny bit of sand maybe, but what you have?

somebody either was having a bad day, or didn't like that engine, or its owner.... or maybe all three?

you may want to pull the oil pump and check it for scoring or damage?  iirc the pickup screen is pretty fine and should sort out the bigger stuff just fine, but the really fine stuff? 

i am thinking that you would have seen some crap in the rod brg if it got into the oil pump.

also look at the crankshaft, there is a plug(s) that allow you to clean out the rifling/drilled passages within the crank... you might want to pull them and run a wire up and see if anything got into there?  my manual refers to those passages as being part of the maintenance of the engine, so maybe the design traps grit in the crank rifling/drilling so it can't make it to the brgs?  there must be some reason that the manual refers to removing and cleaning out those passages in the crank... i never gave it a lot of thought until this came up.

it might be that the centrifugal force of the spinning crank might force the grit into the pocket behind the plug in the crank, and in doing so keep it from going directly to the rod brg.  i think it is possible?

look carefully around the cheeks of the crankshaft near the rod journal, i think you will find at least one such plug, maybe one on each side? i just don't remember.

fwiw

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

veggie

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #27 on: November 09, 2021, 09:18:40 PM »

WOW !!  :o

Lucky that you stripped it down.
After a good cleanup and re-assembly it should be a good runner.
As mobileBob noted, parts are available easily for these engines.
AliExpress has lots of parts at good prices.


- 6/1 GM90 Listeroid - Delco 33si Alternator
- Changfa R175 - Lease/Neville Alternator
- JiangDong R165 Air cooled - 2 kw

guest18

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #28 on: November 09, 2021, 11:23:06 PM »
Yes you were lucky.

dkmc

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Re: Chang-chai and ST head, deal? Or no deal?
« Reply #29 on: November 10, 2021, 02:03:45 AM »

Never ordered from Aliexpress, skeptical. I've seen some things on there of interest, (more of a wholesale industrial nature) but when I've sent an inquiry I've never heard anything back.



WOW !!  :o

Lucky that you stripped it down.
After a good cleanup and re-assembly it should be a good runner.
As mobileBob noted, parts are available easily for these engines.
AliExpress has lots of parts at good prices.