Preparing for extended run times

[SCOTT]

I would like to detail my in-process Lister type installation with the purpose of exposing flaws and possible failure points.  I am preparing to run the system for extended periods.  This will also serve as a test for what is possible of an engine run straight from the factory.  Blast away, I have a thick skin.

I live in southern Connecticut and the reason I am involved with these engines is to net meter with the utility.  The utility is onboard and I am in the final approval process.  I did receive resistance when I went to my city for my electrical permit.  After a bit of educating they gave me the go ahead.  The primary concerns the city had were with noise and possible odors.  The regs state that the noise level can not exceed 55db measured one foot beyond my property line during daytime hours (8am-8pm) the allowable noise level is reduced to 45db at night.

I have a 12/1 and  6/1 power line brand.
The generator is installed in a free standing one car garage that is only about 30 feet from the property line.  The 12/1 at 1000rpm was just too loud to run for extended periods, it was so loud that I got a call from a neighbor complaining about the noise.

Issue # 1 noise levels:
I have a generic auto muffler and down stream the exhaust flows into a buried 30-35 gallon steel drum.  The noise level using this setup on the 6/1 @ 650rpm is about 60db when loaded to 3500 watts.  If I drop the rpm to about 525 the db with a 2100 watt load the level drops to 55db.  I think with some sound dampening in the garage I could drop the db level further.  I am considering Homosote, but at about $24 per sheet this is not a cheap option.  Based on the research I have done plain sheet rock, even in multiple layers, offers little sound reduction.  If anyone has other suggestions I am all ears.

Issue #2 Safety
Assuming I can reduce db to an acceptable level and I have enough free WVO, I could conceivably run the engine 24/7.  If I do run for long periods I would like to run the engine at a lower rpm, 450-500 is what I am targeting.  I have a pulley on the way for this speed.  I need to feel confident running the generator unattended, for that I need some safety controls built in.
I would like to have automatic shut downs that activate on:
Over temp
Over speed
Low oil
The sensors for these are available in one form or another.  What I have not been able to find is the mechanical actuator that would be used to shut off fuel and or air.  I envision each sensor with its own relay all connected to 2 common shut off devices.  One would be the fuel cut off and the other would be the air cut off, so any of the sensors could cause a shut down.  I would like the actuator to turn off when electricity is cut off, i.e. a spring would be countered with an electromagnet which allows the fuel or air to flow, and when the electromagnet is off the spring would shut off the fuel or air.  Perhaps there is a fuel solenoid available that has a normal position of off that when energized it will open?  All suggestions are welcome.



Issue #3 lube Oil

If I run this engine for long periods I need to make sure it has clean oil. A bypass filter will also allow fol extended oil changes and open up the possibility of using detergent oil.  I am thinking of adding a bypass filter to the system in addition to the standard full flow spin on filter.  I have a good idea of the filter I want to use, but I do not want to use the onboard pump, because I think the pressure is too low and I would rather not have to cut into the existing plumbing.  I envision adding a pipe to the oil drain hole which will lead to a small electric pump.  I would like suggestions on what pump to use and weather I should put the pump before (to push oil through the filter) or after the filter (to pull oil through)  I will have pressure gauges before and after to indicate when to change the filter media.  The filtered oil will be pumped into the hole next to the compression release valve, as others have done.  I may add a thermal sensor that would activate the oil pump when the oil temp is above 80-90f  if I find it can not handle cold oil.  Does anyone have suggestions on pumps that may work?

Hotater I believe you have the most experience with long run times, do have any advise on what to look out for, or any suggested  procedures or systems?

Best regards
Scott

[rmchambers]

Scott,
   I can't comment on the rest of your questions but on the question about sound reduction however I have some thoughts.

What component of noise is the loudest?  is it a low frequency noise or high frequency? 

I put some homasote under my floorboards of my first floor (hardwood floors) from the basement side and then put some fiberglass insulation and some 5/8" sheetrock over that which did deaden the sound quite a bit in the high frequency range but the low frequency sneaks in.

The homasote would definitely absorb some noise, but would it absorb the kind of noise you have an excess of?

5/8" sheetrock is $12.75/sheet at HD (yesterday when I bought some) so you can double up that for the same price as homasote and the nice thing about 5/8 is it's fireproof especially doubled up.  Something to think about anyway.

I worked in a couple of machine rooms where they had the anechoic foam stuck to the walls, that makes a lot of difference too, it actively absorbs sounds and does a good job in the high frequencies.  I'd think any decent foam would help, might not be optimal but wouldn't hurt.  It's flammable though so mount it on a double layer of 5/8" sheetrock.

Robert

[hotater]

Scott--

I still don't have any kind of emergency shutdown stuff, but I have a design running around in my head that will cut fuel, air and release compression at the same time...I just haven't done it yet.

I regularly  leave my 6-1/5kw running when I go to town or snowplowing and haven't had a problem at all.  Of course  'long run times' means different things to a home genset and a RR reefer or ocean-going ship's system.  I've run the new engine more than 30 hours twice, but usually I shut down once a day and check oil level and squirt some lube in the rocker shaft. I  have visual sight gages on coolant and fuel so there's really not a lot to do!!

I'm about finished with  a centrifugal oil cleaner that runs from the side of a flywheel.  Hopefully that'll extend oil change intervals as for CERTAIN will supply cleaner oil to the engine.  The selling point for me is that there's no cartridges to buy......(and I can invent something that most folks don't understand so it makes me 'smart'.)   

Originals sometimes had remote, added oil sumps for extended running.  This new engine has never used a DROP of oil....once I found out at what level it quit blowing it out at.   One gallon is perfect for this dropsump PS-Jkson kit.  I run between 250 and 300 ours with no additional oil needed, but it still loses some through the breather.  I wrap a paper towel around it to keep the goo from collecting on the engine.

[xyzer]

Scott,
Talk to BioBill about some noise ruduction tricks. He is running his in the house and has tracked down a few noise issues and reduced them to a livable tolerance.
Dave

[rcavictim]

Pressed panels of rockwool about 1 inch thick are available from your local building supply in 4x6 foot panels.  If you place these flush with the interior walls of yor genset room they will do a terrific job of absorbing and lowering the machine noise.  The needlelike particles that come off rockwool are more dangerous to get into the lungs than the same stuff from pink fiberglass so it is a good idea to put a aluminum window screen covering over the panel surface.  Rockwool does not support combustion, nor does aluminum screen.  If you were to put this on the inside of a double thickness of 5/8 inch drywall you would have a pretty quiet setup I think.

If you double thickness the rockwool you will increase it`s over all effectiveness and lower the frequency of it`s effective absorbtion.

[rcavictim]

I'm about finished with  a centrifugal oil cleaner that runs from the side of a flywheel.

That is a system I have high interest in building also.  Could you describe yours perhaps in a separate thread?  Thanx!

[cujet]

A shut down device needs only to cut air. A tennis ball or similar could drop on to the intake manifold spout. Also a piano hinge with a metal "D" flap and a bob weight would work. All that needs to happen is a momentary solenoid needs to actuate and release the (ball) or hinged flapper. Quite simple and sure to shut the engine off in a hurry.

I use a standard Motorguard air filter as a bypass. I use the original pump and it's whopping 5PSI to push the oil through. It works perfectly, and the oil is very clean indeed. I used a one way check valve to prevent back flow when shut down. It also acts as a restriction, as I put a 0.040 orifice in the check valve outlet. There truly is no need for an additional pump. The filter gets warm right away and the flow rate is sufficient for a Lister (slow, but not glacial).

Concrete block (maybe brick) is the answer for noise. I have found nothing else that works for a Listeroid.

The vibration issue is another thing. I think modern liquid filled motor mounts for a big engine would help. The Listeroid combustion event is the vibration source, the heavier the load, the more the ground shakes. I have some elastomeric dampers from helicopter blades. I will be trying them soon.

Chris

[biobill]

 Scott,
    This stuff here looks promising though a bit pricy.
http://www.quietsolution.com/html/quietrock.html
 
  With no claims of being an expert, in my experience, stuff that sounds like a drum when you tap on it will transmit sound the same way, sheet foam, dry wall,  included.. Irregular surfaces can help break up the sound waves so they aren't "drumming" so hard - so the wave doesn't hit a flat surface all at the same time. I've heard of egg cartons working well though not appropiate in an engine room. Studio sound suppression is usually shaped like a grid of  pyramids or wedges. You can also quiet things down quite a bit by tinkering with the engine. Getting the backlash right on the cam drive gears makes a big difference. (talk to xyzer)
  I'm not convinced that automotive mufflers are the way to go because of the frequency differences. With a stationary engine you don't have to design the muffler to fit under a car - seems to me that bigger is better. I built one out of a 100# propane bottle that sounds like heavy breathing at full load. Literally. You have to get real near the outlet to hear it at all. A large truck muffler might be good too. 

[hotater]

  A 20# propane bottle is my muffler and I can't hear it from where I sit now....perfect!!

To REALLY deaden sound takes something with a lot of mass.  Lead sheeting is the stuff they put in custom cars and yachets.  You can buy it on ebay but it's    pricey!!

Look at what the custom aircraft fitters use...don't touch, though. It's priced by the square inch!

Exhaust noise is the easiest to get rid of.  The thumping of the power stroke under  load is much harder to mask.  The frequency is near the 'felt but not heard' range.  With my new engine there is no ground movement except for an occasional transiet series of 'shivers' that can be barely be detected once or twice a night....or maybe it's a dog scratching downstairs....

[SCOTT]

Thanks for all the input.

For the noise I think most of it is higher frequency from the engine, so it will hopefully be relatively easy to deal with.  I will look for the rock wool to place between the studs and over that put standard 5/8 drywall.  If more is needed I will try the homosote over the drywall.  I plan on putting generous beads of silicone between the studs and the drywall in an attempt to provide a bit of vibration dampening.  If the homosote is needed the company advises not attaching it to the studs, but only to the drywall.  I may need to attach some plywood backers to the drywall so the screws have something to bite into.  The exhaust noise is under control, and is basically just the noise from the gas exiting the pipe, like Biobill said, like heavy breathing.  I added a 3’ stainless flex pipe that decouples the engine from the exhaust this made a big difference.  I plan on adding additional sound mitigation as needed.

For the oil filtering, I am unclear how I would tap into the existing pump and get enough oil to the TRBs and the oil slinger.  Cujet did you cut the line after the stock filter then feed the output from the filter to a “T” with a ball valve on each side?  This is how I would envision regulating which path gets what amount of oil. 

For the safety kill switch I am hesitant to cut off the air except if there is a runaway situation.  I am using WVO and I fear if the injector is still firing into a hot chamber as the engine spins down the oil may polymerize and foul the rings.  Just thinking out loud here, it may not be a justified fear.


Keep the good ideas coming.

Scott

[jtodd]

I can comment on what I'm doing for the shutoff:

I found a fuel rack shutoff solenoid from Trombetta, which is specifically designed for the task.  It is a big honkin' solenoid with a spring keeping it "extended" until power is applied. It has two electromagnets: one to draw the rod back into the solenoid, and then a smaller (less amperage) electromagnet at the base that holds the solenoid in place at it's fully "retracted" position.  There is a little solid-state widget that controls all that for you.  The downside is that it's not cheap - something like $150 all said and done with shipping.

Available (with switching modules) from http://www.murcal.com/
Trombetta Model P613-A1V12 21 pound pull, 1.5" stroke 40 pounds hold.  $94.00
S500-A60 controller price $53

Then, I just made a plate for it.   The pictures below aren't from the "final" result, but it's a pretty good idea of what I've got going (I cut a notch in the plate to allow use of the existing fuel shut-off lever without having to shorten it.)  The system is based on 12vdc, which is what I'm using for all control systems on the engine.  If there is a loss of power to the solenoid, it will push back out and extend the shaft, pushing against the fuel rack (via a little bumper I bought from McMaster/Carr) and shut down the system.  I've not yet tried it with the engine running (that'll be a month or two yet or more at the slow pace I'm building things now) but I think it should work.  The only thing I might need to do is get a stronger spring for the solenoid since it doesn't _quite_ seem to close the fuel rack when the engine is cold.  However, that remains to be seen if it's effective when the engine is operating.

http://www.loligo.com/lister/pictures/30.html
http://www.loligo.com/lister/pictures/31.html

JT

[dkwflight]

Hi Cujet
I understand the standard Motorgaurd air filter has plastic parts that will melt if they get hot enough,
I bough one of those and I will use it cold.
The motorgard filter I bought for hot oil has copper internal parts.
Good luck
Dennis

[cujet]

I have a twin, so the oil tap is at the top of the oil pump. It is a large cap, that I drilled and tapped. I then threadded in my check valve and aeroquip tubing.

The motorguard is available from Ralph Wood. He modifies them properly for hot oil duty. Do a google search for Ralph Wood motorguard.

I am currently using the plastic element, as I purchased the air version. However the Listeroid oil temp is very low, so the plastic is OK for a while.

No problems at all shutting off the engine with an intake manifold device. You will not likely use this method of shutdown very often. But there are other options, such as a spring loaded device on the main shutoff lever. Have a catch made like a trigger so when the lever is pulled into the run position it stays, regardless of spring pressure.

Your solenoid can release this trigger.

Chris

[rcavictim]

Thanks for all the input.

For the noise I think most of it is higher frequency from the engine, so it will hopefully be relatively easy to deal with.  I will look for the rock wool to place between the studs and over that put standard 5/8 drywall. 
Scott

Scott,

You may have misunderstood what I was explaining  to dio with the rockwool.  It needs to be put on the outside surface of the drywall.  It will be the first thing the sound waves hit and it will trap the sound, converting it to heat. It will do nothing to reduce in room machine noise levels if buried underneath the drywall.  It works like the pyramidical acoustical sculpted foam absorber panels found in recording studios at a small fraction of the cost.  I use sheets of rock wool in my hi-fi llistening rooms to great advantage. It works very well.

[SCOTT]

rcavictim

You are right I did misunderstand what you suggested but after finding it on the web I realized that this is the same material that audiophiles use to build sound traps.  In any event I tried 2 good lumber yards and home depot, none had the rockwoll.  I can order it on line later if it is needed. 

I ended up just buying 5/8” drywall, R11 insulation, and Homosote.  So far I added the insulation and the drywall to the back wall.  I will hopefully finish tomorrow and have some before and after db numbers.

Scott