Micro CoGen.

I am starting to turn my thoughts to a bigger alternator for my boat. I have a Kubota M35B engine in there and at my cruising speed of around 2300 engine RPM I get a measly 30 amps of charge into my batteries. I haven't yet figured out what the current alternator is but it could be as small as a 60 amp rated unit. At this point I am not sure why I see only 30 amps max charge even with the batteries down to 50% SOC but all will be revealed in time ... I hope.
Anyway, the marine alternators from Balmer as sold through Defender Marine are VERY dear and can be well over $1k once you approach 100A units. I imagine that this is because they are rated to be ignition proof? Since I run a diesel engine, do I need to be concerned with that or can I run something much cheaper? Casual browsing shows new alternators between $200 and $300 on ebay which seems much more reasonable.

Anyhow, I am wondering if there is any reason to spend a fortune on a marine rated unit or will an automotive unit give me similar reliability (key is reliability). Which alternators are considered the best as far as reliability is concerned ?

Thanks !

At the risk of being tarred, feathered and run out of town, I thought I would bring up the issue of boilers.
As some of you may know, I ran a Listeroid 20/2 for roughly two years for heat generation. Originally the plan was to generate electricity and feed it to the grid but the cost of the grid connect system as well as the permits etc made this a non-starter. This is when I ended up using the Listeroid to generate electricity to heat water and captured as much waste heat as I could in order to heat my house as well as pre-heat the domestic hot water.
The engine required a lot of attention and it occurred to me that since all I was using it for is to generate heat, why not stop fiddling with all that moving 'stuff' and just heat water directly with a waste oil heater.
My question is rather straight forward: Have any of you had experience with waste oil boilers? Specifically, the commercial kind that can be installed in a residence without the insurance company throwing a giant snit-fit. Something that can be inspected, certified, permitted, stamped, signed and whatever else the 'authorities' want to do with it. I am looking for something below 100k BTU with the idea being that I would heat a large amount of stored water and use that stored hot water to heat my house hydronically.
I am looking for reliability, very little maintenance and unattended operation.

My hydro rates are going to jump 25% next year and possibly another 25% in a couple of years after that so I am looking for alternatives.

As we rarely have a power outage, I would replace my Listeroid with a self contained diesel genset strictly for generating electricity just in case but would expect this set to only run 6 hrs per year for system testing. The boiler would run a couple thousand hours per year and might be augmented with solar heat collectors for summer operation when no space heating is needed but we still need domestic hot water.

Thoughts ?

I am having issues with posts not showing up - more so than usual.
I don't know if other people are experiencing this or not but in the last hour there were at least three posts that were apparently accepted by the board but never made it. I suppose this could be related to higher frequency of other people posting / possible simultaneous posting but whatever it is it is extremely annoying. I might spend 10 or 15 minutes putting my thoughts down on 'paper' only to find that the posting ended up in a bit bucket someplace without any comment to me that anything went wrong in the posting.
I will not repeat myself if a post is lost and I find myself thinking twice before bothering to post with a 50/50 chance that the post will actually show.

I have run across something rather unexpected and thought I would share it ...

My thermal storage system consists out of three 60 gallon hot water tanks. They are arranged as a sequence where hot water flows into the top of the first tank, out of the bottom of the first and into the top of the second, then out of the bottom of the second into the top of the third and from the bottom of the third back to the engine heat exchanger. The idea was to stratify the water temperature during a run and have the coldest water return to the engine. This works very well all around.
Tank #2 has two 3600 (?) watt dump loads in it to serve as a load to the engine.
Tank #3 has a 5 gallon external tank that serves as an expansion reservoir. There is one circulation pump that sucks water out of tank 3, sends it to the engine heat exchanger from and then it flows into the top of tank #1.
In theory, this is all nice and dandy. There should never be air in tanks one and two. Only tank 3 is vented to the atmosphere and will either be over-full when hot or slightly low when cold.

I have had issues with the expansion tank overflowing on occasion and I have finally tracked it down.

It turns out that the dump elements create air bubbles which get trapped in the top of tank #2 which is not vented. The air displaces water which then pushes out and overflows the expansion tank.

The reason this is so surprising is because I was always under the impression that any water gasified by a heating element would recombine to form water (condense) as it separates from the heating element and cools down in the surrounding water. This might happen to some degree but certainly not completely. BTW, this water has been essentially the same for over a year so any air should have separated out other than maybe air entrained due to water falling into tank #3 when it isn't quite full.

I will be venting the tank separately.

Anyhow, I hope this tidbit of info might be useful for someone.

Could someone explain t me the function of the valve stem cap ? Is it just there to prevent wear on the valve stem ?
In what must be one of my more brilliant moments, I somehow managed to assemble Thumper with one of the little buggers missing and this was a while ago and I have no way of retracing my steps. I even managed to adjust valve clearance without noticing It's been running fine without it but I am sure there most be a reason for it's existence. I could just turn a cap on the lathe but it wouldn't be hardened. Is there anything critical about it ?

It appears that I have had a head gasket failure on Thumper. In any case, she is in bits and pieces again. I have 3 options in regard to head gaskets that I would like to run by the group.

1) re-use existing gaskets after doing the floor wax thing with the in-between layer and copper coat on the outside

2) use new gaskets after doing the floor wax thing and copper coat thing

3) Order new gaskets from Gaskets-to-go (but this will probably mean a two week wait)

What would you do ?

A fellow I know has a setup for hydro that gives him 15 gpm and 41 psi static pressure. He is only using it for his domestic water needs. Can this kind of a flow generate worthwhile power ?
He seems to think it can't but even 100 watts over 24 hrs is an appreciable amount of power ....

A weird issue is cropping up with my 12V electric starter which I am running at 24V. I crank the engine over, the starter releases as I stop cranking but the motor doesn't stop right away. It spins way up in speed (sounds like a jet engine winding up) and then eventually, after maybe 10 to 20 seconds, it slows and stops. Sort of as if the internal contacts that engage when the solenoid brings the drive gear out toward the ring gear is getting stuck.
Anybody ever encounter that ? Is this a precursor of a starter failure ?

FWIW, the solenoid is operated by 12V but the starter motor itself runs on 24V even though it is only a 12V starter.

Thumper now has a proper over/under voltage sensor on the generator. If the belt should pop off it will shut down. I have also placed an order for some 110 degree C thermo snap switches. These will act as secondary heat shutdowns and will be located on the heads.
Has anybody looked at the best location for a switch of that nature on a listeroid head ?
I could just clamp them to the side of the head but am curious if there is an advantage to one location vs the next. I am thinking that the location should provide quick shutdown .... say that the coolant dumps for unknown reasons. This would disable the regular coolant based high temperature shutdown and the engine would be completely at the mercy of the snap switches. I would want a direct and short path for the heat to go from the combustion chamber to the sensor. Of course the head is riddled with passages so this mystery spot may not be that easy to find. Heck, maybe it really doesn't matter all that much since the head absorbs some of the heat. I don't know. I thought I would ask and see what the more knowledgeable people had to say.

This morning I started Thumper as usual. Everything was just fine until, about an hour later, I decided to go and fill up my diesel tank. As soon as I stepped out on the deck I could hear that something was terribly amiss as I could hear the slapping of a belt. Damn !!!!
I rush underneath the deck to check and sure enough, Thumper had wrapped her power transmission belt around her crankshaft and was beating everything silly. I shut her off and examined the situation .....

The belt was completely shredded (this is an 8 rib industrial belt, about $120 each, no longer available in town as the outfit closed down). The belt had jumped off (which it had done plenty times before) and somehow managed to wrap itself around the crankshaft (which it had never done before). Yesterday, I had switched my circulation pump from being powered by the generator to being powered by the house power to avoid the short term boiling of coolant that happens when the engine shuts down. This turned out to be a big mistake. In the past, when the generator stopped spinning, the cooling pump stopped which caused head temperature to rise which caused the over temperature sensor to trip which shut everything down. With the coolant powered by regular ac, nothing overheated and nothing shut down.
Chances are that the belt was just sitting there for a while as it always does and eventually, somehow, it caught and started whipping around. As it whipped, it caught my oil drain pipe (1/2" steel) and ripped that off and bent a couple of other bits of pipe. Luckily, I had a second shutoff that happened to be closed. Had it not been for that secondary shutoff (this was an afterthought, purely luck that it was there), all engine oil would have drained followed by lubrication failure and another engine rebuild !!!!
Had I installed an oil level sensor on my sight glass, it may or may not have caused an engine shutdown as it was also affected by the whipping belt.

The industrial belt being much heavier than a standard automotive belt was doing a fair bit of bouncing on the slack side which is why I think Thumper was prone to throwing her belt. I have a temporary automotive belt on Thumper now and there is absolutely zero slapping on the slack side. Unfortunately, with the pulley grooves not matching the belt ribs, starting Thumper is a bit of an issue as there is not enough friction on the generator pulley. Another odd side effect - zero chirping on the flywheel.

It looks like I will need to cut some new grooves on the pulley for the standard automotive belt profile.

A few interesting questions arise .....
My overheat sensor is the only temperature sensor on Thumper - what happens if it fails for whatever reason. I completely depend on it for shutdown each and every run. It might be a good idea to install a secondary temperature monitoring system of some kind.
The engine RPM is measured for overspeed ... but is measured at the generator and becomes inoperative when the generator doesn't spin. There is no sensor yet for underspeed.
Even if I had an oil level sensor, I can now see a scenario where failure can happen under the right circumstances.
There are entirely too many possibilities of failure to this setup ...... I thought I had things pretty well covered but this incident clearly shows that this is not the case.

A side question that is nagging in my mind ..... suppose you had a pressure lubrication system such as on a Changfa. Let's say you have a pressure sensor on it that shuts down the engine if you loose oil pressure. Will the shutdown procedure, with an estimated time to complete stop from between 30 seconds and 60 seconds, be fast enough so that no damage results? I have heard it said that in an automotive engine, by the time the oil light comes on you already have engine damage.

Last night I noticed a distinct lifting motion of one of my rockers during operation. After closer examination I also noticed lots of cast iron dust. I pulled the assembly today and there is about 80 thou wear on the pivot shaft and maybe 1/16" wear on the hole in the rocker itself. There is similar wear on the pivot shaft on the side that was still working ok.
Since water had made it up the head stud holes and was steaming off, I suspect that lubrication was lost and failure ensued.
I have not used grease for the rockers since day 1 and basically dribble oil all over (including the top hole) every time I lube the valve guides.

Questions:
Has anyone experienced failures of the rockers ?
What lubrication method did you use ?
How did you fix your issues ?

What I am thinking of doing is boring out the rockers themselves to get a true hole and inserting a bronze sintered bushing. I was also going to replace the pivot shaft with a solid shaft with springs on the end just like the original units.

Thoughts ?

I think I asked this question before but never did get a reply ....

How much oil do you put in your Listeroid ?  The one and only reference I found is one fellow suggesting to fill the crankcase just below the castle nuts on the big end. Basically as much as you can fit in while keeping the crank and big end out of the oil. This seems to correspond to the full mark on my dipstick.

I have also read that having too much oil in the crankcase can overwhelm the oil rings causing oil to get burned.

In the previous incarnation of Thumper, the engine burned a lot of oil with a full crankcase which is why I tended to run the oil level a bit lower and eventually what caused the failure. Well, here we are, Thumper V2.0 and we have the same oil burning issue. It seems I am burning about a quart per 5 hrs of run time (best guess).

With pretty much all the guts inside being new, I would like to understand what would cause one engine to burn oil and another not being affected (apparently burning oil is not common).

I assume some of the oil burning is caused by rings not fully seated (new) - how much of the oil burning is likely to be caused by this and how long can oil consumption be attributed to non-seated rings ?

I am about to start on reassembling the fuel system on Thumper. I will have a large number of joints AFTER the fuel filter. I have previously used teflon tape but there is always a risk of getting a chunk into the system and I would rather not take this risk in this particular installation due to the many joints involved. What is the normally suggested/approved method of sealing tapered pipe thread joints in these situations?

... and for those of you who want to know just exactly why I have so many joints, the filters will be by the fuel tanks, then there will be shutoffs', a T to join the veg oil and dino feed, a pump,another T at the engine, a shutoff for each cylinder, a whole slew of hose barbs, nipples and other hardware. There are just too many possibilities to take the risk even though I will run fuel through for washing the lines prior to startup.

http://www.xconomy.com/detroit/2010/11/01/khosla-gates-are-betting-on-ecomotors-engine-technology-to-transform-autos-into-cleaner-cheaper-and-more-powerful-machines/?single_page=true

Sorry about the huge URL ........

Here are a couple of articles (book reviews) of Chryslers attempts to put a turbine into a car. It seems like there were only up-sides to the turbine powered cars including considerably longer life to a turbine compared to a piston engine as well as being able to run on anything flammable.

There are a few small turbine engines around. I have no idea of costs or life expectancy as these engines are used to power airplane models. I have not dug any further on this but I think it is a very interesting subject and should merit some discussion.

A picture to ponder - an engine the size of 5 gallon bucket including a gear train to bring the speed down, directly coupled to a generator head, the exhaust running through a heat exchanger to recover the large amount of heat that comes out of the exhaust.
Running at 60000 rpm or more, there is no issue with flickering, engine speed would probably be rock steady, no vibration etc etc etc ....

http://online.wsj.com/article/SB10001424052748703369704575462133272933798.html

http://jalopnik.com/5662006/the-rise-and-fall-of-americas-jet+powered-car

Has anyone tried high friction paint on flywheels in order to increase the grip of a belt on the outside rim of a flywheel ? I had chirping issues in the past so I am thinking that maybe this might improve things.
I am not interested in the 'just mix in some grit' solution that is often used on stair treads or similar as I suspect it would be very hard on the belt.

I am slowly putting Thumper back together and I will be asking some questions while I am doing this. Here are the first two:

I slipped the crankshaft back in today and I will need to adjust the tapered roller bearing preload. I am wondering what the best procedure is for doing that. All I can think of is reducing the gasket stacks symmetrically until the crankshaft feels too tight to rotate and then remove one thin gasket to make it feel 'right' .... doesn't seem too scientific to me. Any better methods ?

Sooner or later I will need to install the cylinders. The gasket thickness at the base of the cylinder needs to be set for correct piston clearance. The way that looks to me is to pick a number of gaskets, install them, install the cylinders, install the pistons/connecting rods, install the big end caps, install the heads, insert a small piece of soldering lead as a gauge, torque everything down and pray. If not right, take the whole friggin' thing apart again and start over ..... I am fine with most of that except for the concept of taking half the engine apart to try a different thickness gasket if the clearances are slightly off. Is there any way of doing this in a smarter way ?

Wish me luck with the camshaft timing .... I am not looking forward to that!

I asked this before but did not receive an answer - anyone know the torque specs for a listeroid twin central bearing support carrier ( a large donut shaped kinda contraption with the bearing shell on the inside of the center hole)?
While I am at it, anybody happen to know the torque for the bolts that hold the counterweights to the crankshaft ? I have set them at 50 ft lb but this is just a guess ....

On my 20/2, the oil line going from the gallery to the crankshaft central bearing has cracked straight through. It appears to me that this was a metal fatigue failure. It happened at a bend in the line.
Has anyone run into this problem before with this particular section of steel line ? In other words, would it be likely to fail again if I replaced the line with a similar line .... or would I be better off installing some kind of flexible line ?
If you have replaced the line, did you purchase a replacement part or did you purchase stock steel line of some kind and make up your own? If you made up your own, how difficult was brazing the ends without blowing through the thin line ? Would standard steel brake line be suitable for this or is there a better alternative ?  Would brazing a sleeve over the break be sufficient of a fix ?

I just had a call from the machine shop here in Victoria that I used to rebuilt bits and pieces of Thumper. I can not believe what people will pull .....

I had initially brought down the crankshaft and then added the counterweights, the two old piston assemblies with connecting rods, two new piston wrist pins (as per their request), a new piston and two sets of rings. I asked them to regrind the crank (that was changed to regrinding one journal since I could only get one set of oversized shells), replace one piston with the new one I had supplied, install the two new wrist pins and, making an assumption, I figured since I supplied new bearing shells it would imply they would actually fit them to the crank.
I also asked for the assembly to be balanced.

When I picked up my pieces the other day I found out that they were unable to balance the assembly because of a lack of bob(sp??) weights heavy enough. Apparently the did set things up on their balancer and did phone some outfit in California for instructions on how to do the balance but they were unable to do the job. Nevertheless, they decided to charge me $80 for their attempt at doing the job. They also did not attempt to fit the bearing shells to the crank except for the one journal that was re-ground. They reground one journal, polished the center bearing, the second journal and the two crankshaft seal surfaces for the princely sum of $200 ....
Pulling the wrist pins in both pistons, removing one piston and replacing it with the new one supplied, removing one set of rings and installing two new sets of rings supplied also cost me $80.

When I got home with the finished parts I discovered what I thought was casting sand right next to the new wrist pin in the re-used piston. I was not thrilled. I took the piston back and also decided to talk to them about fitting the bearing shells onto the crank (they did say that they fitted the shells to the one journal that was ground). Turns out that apparently I never asked for the piston to be cleaned hence the grit that was left over and, as it turns out, the majority of the deposits on the underside of the piston crown. It seems that $80 does not get you a cleaning and that installing a new piston wrist pin does not imply to clean up the area behind (or beside) it.
After some discussion they foreman (he was the guy doing the job) said that he didn't want me to feel ripped off so he agreed to cleaning up the piston and to fit the bearing shells as well as reduce the charge for balancing by half.

Today's call was to tell me that the second piston shell needed a shim and could I please supply it.  Apparently these things are not a dime a dozend in an engine rebuild shop. I was surprised to hear that these things were somehow related to hens teeth and quite rare so I asked if they had a pair of scissors and some shim stock. Well as it turns out, they do have a shim stock assortment but don't you know that the thin stuff gets used up first ......
BTW, each of the two bills I paid included a shop supplies charge of around $9.50 and a similar environmental levy.
Anyway, it turns out they do not have any shims for me and can not make any up and not only that but they managed to strip the two studs holding together the center bearing support and it will take about an hour to fix that. Implied in this was that I was going to be charged for fixing this if I requested it. Apparently they torqued the bolts to about 35 ft lbs when they both stripped (and they never did figure out if shims were required in the center bearing support assembly which begs the question of why they torqued the thing down to begin with  ... but hey, what do I know)

I told the foreman that I will come and pick up my pieces tomorrow and will fix the pulled studs myself.

Maybe I am out of touch with reality - if so, somebody please set me straight. Loose grit right above where the oiling holes are for the big end bearings?  Can't make up an f'ing piece of one thou shim ? Charge me for balancing when the balancing wasn't done? Stripping studs and expecting me to pay to fix things ?

Bob, I realize you don't like it when people bash suppliers and I apologize in advance but I had to vent ! I tried to sort this out with them but all it got me is more grief !

For those of you located near Victoria, BC and contemplating any machine work, email me for the name of the place ....