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Messages - mobile_bob

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Engines / Re: SL1 stalling warm
« on: October 06, 2020, 11:06:36 PM »
+1 for cobbadog

it seems to me that "if" one were wanting to tear down the engine for overhaul, you would be removing the generator head anyway
so what harm would be to eliminate the head as a possible cause of the problem?

been giving this thing more "thunking" and i recall over the years some really expensive problems relating to similar problems

1. back in the late 80's while working in seattle, we had a used IH 4070B cabover in the shop because of low power and excess smoke
the diagnostics lead the foreman to conclude that it needed a new turbo, so it got a new turbo
when that didn't work, they put in a set of injectors,
when that didn't work they did an inframe overhaul,
when that didn't work, the condemned the transmission, and exchanged it
when that didn't work they removed the front and rear differentials, and of course found nothing

i came to work for the company after all this had been done, and was tasked to find the problem

the first thing i did was ask to talk to the former owner, i asked him how it ran for him

"well, uh it ran fine up to 3 years ago when we parked it!" 

ok... hmmm i wonder

i took down the air cleaner stack and found a huge birds nest clogging the bonnet, and of course it clogged off a huge portion of the air needed to run properly, removed the nest and waalaaa... back to full power!

lesson learned

2. i got a call from one of my customers with a p30 stepvan, with a chevy 350 early throttle body
the truck started fine on a monday morning, ran 30 miles without issue, and up restarting after his first stop
it couldn't make 15 mph, and even at that it took about a 1/4 mile to get to 15mph

i removed the dog house engine cover and started the engine, and notice that when i pushed down on the gas pedal
the intake flex house seemed to move just a bit, i removed the hose from the aircleaner and started up again, this time pushing the pedal to the floor, and that is when i saw the top cover suck down so that the wing nut was about 1/4" loose..hmmm

took a look up into the snout,and saw what appeared to be an extension spring, maybe 3/8" diameter, thinking it was something to do with the thermo door, i grabbed ahold and gave it a yank.... "HoLy Crap!"

out came the biggest rat i ever saw! he apparently crawled up from the flex hose to the air cleaner snout and when the driver started the engine he got sucked up to the thermo door and then made a 30 mile trip which sucked all the juice out of him... but he effectively jambed the door and the intake so there was little air flow available for the engine.

lesson learned?  A. never ever overlook the simplest of possibilities, and B. bring a change of undershorts because you never know what you might have on the other end of whatever you pull on.

the point is this, over 40 plus years of twisting wrenches i have seen a lot of crazy stuff,  and i have seen mucho dollars spent trying to correct a 50 cent problem.


two other examples of what i am talking about

a kenworth boom truck with a 400 big cam cummins,  runs with good power, little to no smoke, not problems, until you come in off the road and shut it down and try to restart in 15 or 20 minutes, then if you do it will turn the whole world blue, smoke everywhere, massive engine knocking,  and oil coming out of the expansion joints of the exhaust manifold... and i mean running out and looking/feeling like engine oil.

cummins shops, they sent it in to two for two different opinions, both quoted near the same for a major overhaul

problem ended up being a 3 dollar fuel tank vent, which plugged and built up pressure, cummins injectors being cam actuated and pressure time type will continue to dribble or nearly spray fuel into the cylinders if there is pressure in the tank...  so fuel continued to be issued to the cylinders and when the engine started of course it is near hydro locked, and fuel that is chared looks just like engine oil.

3 dollar vent and the company was saved a $22k dollar overhaul bill

i found this problem twice in the 90's and cummins sold one engine overhaul and when that didn't fix it they would not stand behind the
problem and try to make it right with the customer.

another example

another boom/crane truck,
the crane when placing roof trusses on the plate line would swing slowly then without warning sweep at a vastly faster rate, knocking off framers, which if they are on a second story get really grouchy.

the company had it in to 3 hydraulic crane/boom shops in the seattle olympia area, spent $55k dollars and still no fix

turned  out to be a pressure gauge that measured lift and sweep pressures and had a double check valve in it do that it could read
for one function or the other, not both.

the gauge was broken, cost was about 200 bucks, so one of the shops at some point connected the two lines together and removed the gauge, "who needs a stinking gauge anyways?"

it took me about 2 weeks of spare time research to determine that "if" you connect both of those 1/4" lines together you connect two pilot valves, one for lift one for sweep together, the result is the pilot for sweep senses the higher pressure from the lift circuit and increases the pressure and flow to the sweep valve and away to the races you go

bottom line, before you tear things all apart, spend all the time needed to eliminate all the cheap and easy possibilities, unless you have a lot of spare time and money to expend.

bob g

Engines / Re: SL1 stalling warm
« on: October 05, 2020, 12:39:18 AM »
if the injector is atomizing properly, that is it is spraying a good pattern and not a squirt and dribble

if that is true and the engine is over fueling the rpm will rise in relation to the amount of fuel being injected

i am not familiar with your particular unit, so i ask the following

is the intake unobstructed?  all the way to the intake port?  no rubber parts/couplers collapsing in the intake air cleaner piping
(this might not apply to yours but i have seen rubber elbows collapse and stall an engine)

from what you post, the engine does not stall or exhibit this stalling problem when under a 1500 watt load?  but does with a higher load?

another thing to check would be the output voltage under load, does it stay stable and  even after the problem first starts to show its
ugly head? 

does it slowly taper downward just a bit, but stay relatively stable until the engine shows signs of having trouble running?

or does it run relatively stable, and then show a sharp or sudden reduction in voltage, (doesn't need to be much, but under a fixed load
i would expect perhaps a small and slow droop in voltage under load, but i would not expect a sudden drop of even 5 or 10volts.

without load, i am to understand that the thing will run and not show signs of stalling, run just fine, smoke consistent in quality/color?
and under 1500 watts or less 1.5kva it runs fine, smoke consistent in quality/color?

under a heavier load of say 1.75kva or 1750watts, the problem shows up?

how about this

check the voltage at 1.5kw load, let it run for 20 minutes or so and chart the output voltage

then raise the load and let it run for 20 minutes of so and chart the output voltage

what i am getting at is this, coppers coefficient of expansion is fairly high, and copper windings in the stator core are wound tightly
and packed closely together, it might be that under enough load the copper gets warm enough to expand enough to press against another winding and breakdown the insulation/varnish so that there is a short.

the reason i am on this track and wanting you to eliminate the possibility is based on the following

sometime back in '07 i having built a changfa s195 into what i referred to as a trigenerator, it drove a pair of prestolite/leece neville 110-555-jho alternators 12volt nominal, i was working with running one of the alternators in 24volt nominal operation (28.8vdc). under one of the tests the 195 exhibited very similar problems to what you are experiencing.

the problem was related to the alternator having been fitted with 30v avalanche diodes and when i ran the system up to 28.8 and as things warmed up the voltage at the alternator bumped 30volts... this in turn basically created a short and made the alternator into a really effective electric brake. 

the 195 would lose rpm, but not quite die, the reason was as the rpm dropped the alternator would drop below the 30volt avalanche threshold and allow the engine to speed up, and of course this cycle is very fast and in effect just dropped the rpm to reach equilibrium and not stall the engine.

so basically the stator was shorted by the avalanche function

now you don't have that problem, but the theory of operation is similar in that "if" you have windings in the stator that are old enough, and have broken down insulation, they might well start to short under load when things warm up, and because the short cannot go away like my alternators did (below 30vdc the avalanche shuts off and so does the short), then it continues the loading until the engine stalls.

i am not suggesting tearing down the genhead, what i am suggesting is removing it as a possible problem by running some voltage tests, and if you have one of those laser temp guns, check the stator core for hot spots, that is if you can get to it fairly easily.

if you don't have a laser temp gun, just feel around the outside of the generator housings to see if anywhere seems warmer to the touch than the rest of the housing, you might feel a hot spot that way?

it just seems really odd to me, that the engine is actually seizing up, i would expect other problems caused by that happening, and none of them are good.  and i don't think that 1.5kva of load would be enough to cause a problem, but if there is a short the actual load would be much higher then 1.5kva or even 1.75 for that matter.

most times it is the simple things that we overlook when it comes to diagnostics, so carefully make a list and check off everything, when it comes to hard to find problems, more info is always a good thing.

bob g

Engines / Re: SL1 stalling warm
« on: October 04, 2020, 07:16:14 PM »
i am suspicious of the generator head, possibly a short in the stator windings?
after reading the topic thread i didn't see anything about whether the head is connected to a load or not?

check the leads in the junction box, make sure nothing is has rubbed through or is rubbing on the case.

from what i gather, the engine stalls out after running until hot,
from the clips it appears that the engine begins to slow down, and there is a noticeable increase in exhaust smoke
the smoke looks dark, not white
the owner reports that the engine still turns over freely after it stalls, that tells me it isn't seizing up.
if a diesel seizes, it generally damages the piston/rings and/or the cylinder walls, losing compression, making it harder
to start if not impossible to start.

if the timing was the issue, i would not expect this problem
if the fuel was overheating, not sure that is even possible without serious engine damage happening first
if there was a pump problem, i would expect difficulty restarting after shutdown, loss of prime issues and,
if that were the case i would expect to see the exhaust smoke clear up as the engine starts to die out, same thing
if the fuel was vaporizing

also if the exhaust valve is too tight, not enough clearance, generally there is a huffing sound coming from the exhaust
and clearly audible when the engine stalls and coasts to a stop.

intake valve being too tight, that can be heard barking back up the air cleaner, easy to hear with the air cleaner removed

so in recap

don't believe it is seizing ,  easy to turn over after stall
don't believe it is a fuel issue, or you would have to reprime to start
if you can't hear the exh or intake valves barking or hissing probably not the problem either
(after the engine dies, immediately roll the engine over and see if you hear hissing back passed valves)
exhaust smoke seems to increase as the engine is stalling, indicating a load to me,

something about the generator head is suspicious to me
maybe run the thing to stall and take a temp gun and check for hot spots on the stator, junction box, etc

hard to tell from here, with short youtube clips, a poor audio from my laptop, and not much else to go on.

bob g

Things I want to Buy / Re: Petter-Type Diesels Anyone Have One ?
« on: October 03, 2020, 01:33:20 AM »
i have a 3.5 hp mini petter, indian manufacture
still in  partial crate, never been fired since it left india,
that is if it was even fired up then.

water cooled version.

not sure where you are located, this would probably have to be picked up
here in central kansas, my back is such that i can't do much to get it shipped

bob g

General Discussion / microcogen.info
« on: July 18, 2019, 08:33:01 PM »
has been offline for a few weeks now, i haven't had much time to get it sorted.
today i finally got enough information from simplemachines and hostmonster to get it sorted out again.

i realize the microcogen forums are all but nearly dead, however there is in my opinion information from years ago
that might be of interest to others, so i will keep it going.

we resolved the issue, so it can now be accessed as usual, however i will have to do some upgrades over the next couple
weeks to get it completely done and available for however long there is interest.

not trying to take anything away from this forum,  just wanted to let folks know what happened over there.

back to the political grind

bob g

General Discussion / Re: Microcogen - New Look
« on: September 24, 2017, 09:31:19 PM »
back up and working now, thanks for your patience

bob g

General Discussion / Re: Microcogen - New Look
« on: September 24, 2017, 09:26:09 PM »
just having a renewal issue with the domain... got it paid but they are having issues getting the darn thing unlocked... i am working with them now to resolve the issue(s).

i got distracted with other stuff, and apparently i thought i was paid up for another year, but that was for the forum and not the domain... that and having my oldest daughter coming to visit (haven't seen her in 6.5 years) so things slipped by me

sorry for the inconvenience
bob g

in mainland china and the orient in general i would not surprise me to find out there are over 100!

bob g

a day late and a dollar short is bad enough, but...

a day late and "nothing" short is just inexcusable!


bob g

General Discussion / Re: reply to the detroit question
« on: March 05, 2014, 01:05:30 AM »
back when they were used in trucks, pre '85 or so, detroit would not warranty for oil consumption until it exceeded 1 gallon per 800 miles

1 gallon in 4000 is very good in my opinion, most never came close to that good even when new.

as for how long will it live? no way to tell other than it should have another couple hundred thousand in it given the oil consumption criteria and if it is well maintained and not abused.

problem is there are any things that can take it out long before then, it could be 200k more miles or it could be 10k more miles... all it takes is a liner o-ring failure and antifreeze contaminating the oil, lack of attention and you loose bearing material pretty quickly... or  a bad water pump, blown coolant hose and a severe overheat and the engine is then due for an overhaul.

in my opinion, if you have no records of the last overhaul, or if the thing is 20-30 years old , or some combination, then you really can't say how long it might last.

bare minimum, if i knew nothing of the records of the engine, i would at the very least
drop the oil pan and have a look at the brgs, pressure test the coolant system and check for weeping around the bottom of the liners (*more on this below)  and if all looked good button it up... then replace the water pump even if it shows no signs of leaking, and replace all the upper end coolant hoses at the very least (they are the ones that run the hottest and under the most pressure and likely first to fail)

lastly (because i forgot to mention)  if the brgs look like they have a bit of wear, i would replace them while your in there... brgs, hoses and waterpump, along with new tstats are cheap insurance.  minimum oil pressure hot at idle is around 5psi, so don't freak out if it isn't much above that.

also... take a look at the air box drains!  the tubes below the air ports along the side of the engine right below the inspection covers... make sure these tubes are open to the ground and not connected back to the pan via some sort of check valve thing. there is a tube at the rear of the block on both sides and these must be open to drip on the ground...

reason being the 92 series has water above the ports on the liner, if the liner orings start to leak the tubes must allow this coolant to drip on the ground, else it will end up in the crankcase and brg failure is the end result. 

there were a few years of production where detroit used the check valves and ported the tubes into the crankcase!!  this proved to be a very costly mistake for detroit and they put out a service bulletin calling for the removal of the checkvalves and porting the tubes so that they could leak on the ground.

not all of those engines got the alteration/recall done on them, it might be this engine has them and that would be the first thing i would remove.... if the engine has them and you remove them, then yes you will get some oil on the ground where you park, that is just part of the fun of living with a detroit... far better to deal with some dribbling than to have crankcase contamination and bearing failure in my opinion (and also in the opinion of detroit)

*getting back to checking for seepage at the liner packing... the only way to really check this is to pressure test the cooling system, and leave it pressured up for a couple hours, both hot and cold test, and look for drops on the ground under those pee tubes (airbox drains)  if you have any signs of antifreeze on the ground, you must then remove the airbox covers from the side of the engine and check around the liners above the ports for seepage of coolant... this can be quite a challenge because access is tough in most cases, so maybe one of the new fangled video probs could be pressed into service to aid in checking thing over...

if you see no antifreeze seeping around a liner, but coming down under the ports along the bottom of the airbox, and if the engine is turbocharged it will have an intercooler, which might have an o-ring failing or a crack in the cooler core itself. 

in any case, there should be no signs of antifreeze coming out of those pee tubes.

having said all that, you might see some water droplets under some conditions, such as cold running and very humid days, the water in the air can condense (will condense) and show up with the oil droplets on the floor... don't worry about that source of water, it is normal
you do a taste test to determine if it is water or antifreeze (yes i know folks are gonna gag on this one)  just dip the end of a finger into the water and touch it to the end of your tounge, if it isn't sweet, but just tastes like oily water your ok!  if it tastes sweet it likely has antifreeze leaking somewhere.

in closing these engines are quite durable and can provide a long service life, given decent maintenance and driven properly.. don't overheat them, and don't allow them to run unloaded any longer than is absolutely necessary... use straight weight oil only, minimum 30weight, preferably 40weight series 3 diesel oil only... do not use multiweight oil unless you want to see the oil consumption to escalate.

and never ever ever let any mechanic do any sort of adjustments, valve/injector setting, rack setting or even lift a valve cover and definitely never the governor unless he is an experienced and certified detroit 2 stroke mechanic! 

water pumps, hoses, tstats and even bottom end brg replacement a qualified diesel mechanic should be ok there, but don't let anyone mess with the top end.

doing otherwise and 999 times out of 1000 the engine will not run right till you get it to the guy that should have been working on it in the first place.

good luck
bob g


General Discussion / Re: Membership to microgen forum?
« on: January 11, 2014, 12:19:58 AM »
seems like that is what takes so long to clear new members, i have to do a check on their email addy and their isp to see if they are linked to any spammer problems

if it weren't for the spammers it would be a simple matter to clicking approval and letting them right in.

too bad we live in such a world of morons

bob g

Everything else / Re: close quarters 90 degree drill head needed
« on: January 11, 2014, 12:17:43 AM »
i have seen these angle drills at many pawn shops, they generally always work and can be bought reasonably...  never pay the sticker price, dicker with them and you can usually get around 30-40% off the listed price.

failing that, harbor freight sells some smaller angle drills, however the are limited to 3/8 inch

they also sell a three piece step bit set, the smallest of which is 1/2inch on the largest step

these bits really work well, just keep them cool with a dribble of water and the drill right through.

great for enlarging holes

good luck
bob g

Everything else / Re: Gelled lube oil ???
« on: January 11, 2014, 12:13:36 AM »
i have seen this a couple of times over the years, both times we attributed it to
contamination of the lube oil with antifreeze.

now your engine being aircooled rules that out, so my best bet would be someone mixing oils
or simply adding makeup oil with whatever he had laying around...

one would think that if it were some other oil, it would dissolve with some sort of solvent/thinner/diesel or something like that, and one would also think that it would be flammable too.

the stuff doesn't want to burn leads me to think maybe there was some used oil dumped in the engine as makeup oil... that used oil likely was contaminated with antifreeze.

that is the only thing i can think of, i just cannot imagine what else it could be.

hmmm very interesting

how much would it cost to have an oil analysis done?

sure would be interesting to know what the reason behind this is.

bob g

General Discussion / Re: Membership to microgen forum?
« on: January 10, 2014, 01:34:32 AM »
sorry i got way behind with registrations over there, and it looks like they are piling up here too.

you have been cleared and should have an email to that effect, if not let me know.

looks like i am going to be busy this weekend, clearing the applications

bob g

Lister Market Place (things for Sale) / Re: A other Lister on E bay.
« on: December 31, 2013, 08:57:01 PM »
i remember a few years back we did a poll to see what the average cost of a members 6/1 was once all set up and generating... that means a frame, cooling system, and exhaust system at a minimum, and of course belted to an st5 genhead

at the time the average was 5 grand, so maybe even at 3 grand its not at all bad in my opinion
at least for someone that is set on a lister/oid.

everyone thinks he is going to save a pile of money doing all himself, but in the end it all works out about the same.

like the old "mr. goodwrench" commercial

"pay me know or pay me later"

where i might have issue is someone asking 3 grand for an off name listeroid in the crate. that is a bit rich in my opinion, by about twice what i probably ought to be worth.

but then again, what something is worth, comes down to what a seller and a buyer come to terms with,  and that in some cases might be 3 grand for a listeroid in the crate?

great gig if you can get it

bob g

bob g

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