I posted this in another thread but I guess no one saw it. This may have been covered already but I (being new to diesel gensets) have a few questions.

The genset I have is a Master 5000w with a Yanmar engine. My questions are:

1) What spare parts should I have on hand/order now?

2) I've been trying to find a 12-volt 45-amp-hour battery. What brand/model number should I be looking for?

3) How much motor oil should I keep on hand and is it OK to use a multigrade (which says it is rated for diesel) such as RotellaT?

4) Would standard 8" in-the-wall garage fans provide adequate ventalation if I have one blowing air in, and another blowing fumes out? This would be in a COMPLETELY enclosed 5x12 cinderblock room.

Thanks in advance!

-TECH32-

-- TECH32 (TECH32@NOMAIL.COM), June 11, 1999

Answers

1) What spare parts should I have on hand/order now?

Make friends with a diesel mechanic at the nearest truck stop. He can not only recommend spares, he can tell you where to get the best prices. :)

2) I've been trying to find a 12-volt 45-amp-hour battery. What brand/model number should I be looking for?

See above. (Boy, that's a dinky battery; my car battery has 10 times that capacity. A motorcycle shop should have one that size.)

3) How much motor oil should I keep on hand and is it OK to use a multigrade (which says it is rated for diesel) such as RotellaT?

I would say yes, but again, see the mechanic. If you're thinking long-term, I'd store for several oil changes. (Compared to the cost of the generator, the oil is cheap.)

4) Would standard 8" in-the-wall garage fans provide adequate ventalation if I have one blowing air in, and another blowing fumes out? This would be in a COMPLETELY enclosed 5x12 cinderblock room.

I would route the exhaust outside (some standard "flex" muffler pipe would work, and again, your mechanic friend could tell you where to get it). The pressure differential ("suction") from the diesel's intake should be enough to pull intake air in through a standard home heat/air filter, without the fan. (That's how we do it, anyway.)

If you let the diesel exhaust into the room, it's going to get sooty and nasty in short order, even with the fans.

-- Stephen M. Poole, CET (smpoole7@bellsouth.net), June 11, 1999.

1. I would ask the person at the parts desk of whoever imports Yanmar, which items they sell the most of for that model.

2. Brand/model don't mean anything. You want one big enough to do the good, and yes that is tiny. IF the genset charges the battery, consider putting in a large deep cycle as just one more back up source. The only disadvantage to a large battery on a small genset is that many small starter motors should only be cranked for X seconds and then allowed Y minutes of cool down. Proper engine maintaince avoids this problem, like keeping your filters clean, so stock up on air, oil and fuel filters.

3. Use whatever the manufacturer recommends for oil. Figure how many hours you think you will be running the unit, then calculate the number of oil changes/filters you need.

4. The Yanmar is air cooled I assume? This depends on whether your cinderblock is below grade, incoming air temp, level of gen load, heat from roof, etc. 2 8" pulling and pushing seems awfully small. Your generator's efficiency will go down the more it heats up. I'ld say 2 18" or 24" window fans on high speed would be more like it. Suction fan at the roof, feeder fan at the floor. Agree with Poole have the exhaust go into a larger exhaust pipe (to prevent back pressure problems), say 2", and vent that to the outside.

-- Ken Seger (kenseger@earthlink.net), June 11, 1999.

2) I've been trying to find a 12-volt 45-amp-hour battery. What brand/ model number should I be looking for?

See above. (Boy, that's a dinky battery; my car battery has 10 times that capacity. A motorcycle shop should have one that size.)

Stephen, Be carefull here, there is a big difference between the car battery ratings of "cold cranking amps" and amp/hour ratings. Marine batteries around here are rated in amp/hour while auto batteries have the max before melt-down number. (The difference is much like audio amplifier output ratings of RMS power verses peak power.)

Wall-Mart should have a 45 A/H marine battery that will work for the generator. You do not need an exact match here, close will work and IMHO bigger is better. If you would rather have the automotive style terminals then match the battery size of the rated marine battery and you should be in the ball park. I don't think a motorcycle battery will work, those tend to be between 8 and 12 A/H rated.

Jim

-- Jim (jimed@iglobal.net), June 11, 1999.

TECH 32:

Battery: Interstate Battery, group 24 or 24F, local auto parts store, should give you 60 amp hours. This is a common battery and inexpensive.

Exhaust: Route exhaust out the top of any side wall.

Intake: Pipe intake (combustion air) from bottom of any opposite wall if service includes hot weather (80 degree ambient) operation, above snow accumulation line if applicable. Minimum six feet away from exhaust. Connection to air intake on engine does not have to be air tight, and does not even have to be physically connected unless able to do so. Should be minimum 1 1/2 inch diameter, PVC pipe is OK. Should at least be close to air intake on motor, within six inches if unable to make hard connection.

Engine exhaust and intake connections cannot be rigid, must be flexible to allow for vibration otherwise will break manifolds. Cheap exhaust pipe can be made from 3" smoke pipe and ells as used on gas hot water heaters. Wrap joints with aluminum tape if you wish, but does not have to be absolutely air tight.

Ventilation / Cooling:

Warm ambient operation, 80 degrees or above.

Given room size of 5' X 12' X (?) 8' equals 480 cubic feet.

Use 20" X 20" intake louver (passive, no fan) and 1000 cfm exhaust fan with thermostat set at observed 80 degrees F on.

Exhaust fan on same wall as exhaust pipe, intake vent on opposite wall.

Low ambient operation, 30 degrees F or less, the intake and exhaust ventilation louvres should also be motorised and open at 75 degree observed room temperature.

Motor oil, choose according to manufacturer recomendation based on outdoor ambient.

These are guidlines, your milege may vary.

The outdoor combustion air and outdoor exhaust promotes cool operation environment for high ambient conditions and should not be passed on.

The ventilation set up is for the purpose of stable engine room temperature, whether water cooled or air cooled it still applies.

For low ambient operation, below 30 degrees F, the addition of a rheostat to cut exhaust fan speed (and cfm) is desirable. The goal is stability for engine room temperature.

-- Tom Beckner (tbeckner@erols.com), June 11, 1999.

As a diesel mech I can tell you that the only spares you will most likely need will be an upper and lower radiator hose, thermostat, fan/alternator belt or belts, starter, alternator, radiator cap and possibly a spare set of injectors. By all means your biggest concern will be fuel. Get plenty of fuel filters. I see this more than any thing else. the other posts have great advice, be sure the exhaust is vented outside and your unit stays cool. If your unit is new, you care for it properly, it will last a long time before major breakdown. good luck. PS, rotella is great oil, don't forget filters.

-- dozerdoc (dozerdoc@yahoo.com), June 11, 1999.

Thanks for the great advice folks. My garage is 3/4 underground as it's built into a hillside and has a small cinderblock room in the back. That's where I planned on running the generator but after reading these message I think I'll be building something enclosed outdoors so I don't have to worry about digging up the back of the garage to provide adequate ventalation.

Stephen: I understand the usefulness of having a friend who knows engines but I think it's kind of sleazy to 'buddy up' to someone just to get something from them. I don't know any mechanics now and I just can't bring myself to use someone like that.

Ken: Yes the Yanmar charges the battery and yes it is air-cooled.

Tom: I had planned on using 3" flexible aluminum conduit (like for a dryer) taped over the muffler to vent exhaust fumes, but as I stated above, I now think I'm just going to stick the whole thing outside. As far as intake goes, I have no idea where the air intake is on this thing so I wouldn't even know where to hook up an intake pipe. Also, I'm only planning on running this until things get back to normal so I figure by the time it's warm outside I won't need to be using it much (but hey, I could be wrong!!).

dozerdoc: Thanks for the parts list. That's what I needed so I know what to ask for when I call. I will order mucho filters and I will have mucho oil by the end of next week (the 500gal sled tank arrived this week, which will compliment the 500gal tank I already have in the ground).

So, any of you folks have ideas on how to build a generator shed that's QUIET?? Most of my neighbors know I'm prepping but I for sure don't want to advertise to anyone just walking by that I have juice.

What I'm thinking of is a 6x6x6 shed with a concrete floor surrounded by cement filled cinderblocks for walls, and a poured cement or concrete ceiling (a good friend of mine is a mason and is helping w/my Y2K preps as he will be staying here if things go bad). I was thinking of lining the walls with sound dampening foam.

Does this 'sound' like it might work?

-TECH32-

-- TECH32 (TECH32@NOMAIL.COM), June 12, 1999.

You can purchase sound absorbing foam that is specific for high temperature applications. High temp = above 80-120F.

If you go the cinderblock route, don't fill with concrete, take a page from the Wharfdale book and fill with sand instead. This would tend to absorb more sound, particularily lower frequencies. You can purchase concrete blocks that have slots in them that "help" with sound absorbtion, but they're not worth much. I would just cover the interior with accoustical material. If it is unidensity foam glueing with a tacky never harden glue would work fine. On some types of variable density foams you'ld want to put the low density side toward the genset and then either tacky glue it or let it hang 1-2" out from the wall. You can get great sound absorbtion by hanging sheets of the accoustic material from the ceiling seperating the sheets 6-12" apart. Please note that if you have a moderately dense foam allowing it to be non-flat helps. If you REALLY want to get exotic have the shack have no parallel walls (no standing waves), but that's a bit much. I would suggest having the ratios between wall-wall and floor-roof distances be 5:3:2 or distances that are not multiples of each other or multiples of their portions. Of course having a peaked or sloping roof would be better than a flat roof. That 6x6x6 would have a resonance at 94, 188, 282, 376 Hz that would loosen your fillings. A cube has the worst possible accoutics for resonance.

Puting a 90 degree angle or two in your hot air exhaust outlet would help, though that increases your wind resistance, also lining the exhaust "duct" if you go outwards, 90 degrees down and then have the outlet pointed at the earth. Another idea would be an oversized tunnel with sound absorbing 1/2 baffles. On the exhaust gases you might want to go to your friendly Caterpiller dealer and purchase some expensive airtight ribbed 2" exhaust pipe with threads at each end if you want to run the exhaust into a buried (loose back fill to absorb the vibration) 55 gallon drum as a resonator and then wahtever for the outlet of the barrel.

If you want to get radical and have access to a microphone, there exists software that will let you plug the mic into your computer and do a frequency analysis of the noise. If it is a low frequency (which carries farther than highs) and is centered around a specific frequency, you could make a 1/4 wave tuned dampener. Example, if you have a peak at 160 Hz, the speed of sound is 1130 feet per second, velocity/frequecy = wavelength so that is a 7' wave. A tube (say 4-6" diam.) 21" long is 1/4 wave, put a flat solid bottem on one end and stuff the tube with polyester pillow filling. Bingo, one 1/4 wave absorber.

I assume you know all about; keeping water out of the diesel fuel to prevent fungal growth, anti-fungal, anti-gel, and PRI fuel additives? Also that offroad dyed fuel avoids the road tax and is better for your engine since it has a higher sulpher count?

-- Ken Seger (kenseger@earthlink.net), June 12, 1999.

Ken,

Thanks for the great info. I'll pass it on to my mason friend.

>I assume you know all about; keeping water out of the diesel fuel to prevent fungal growth, anti-fungal, anti-gel, and PRI fuel additives?

Yes, I have 3 big bottles of PRI-G (doesn't it also take care of the fungus?)

>Also that offroad dyed fuel avoids the road tax and is better for your engine since it has a higher sulpher count?

Yes, that's why I'm using home heating oil.

-TECH32-

-- TECH32 (TECH32@NOMAIL.COM), June 13, 1999.

Yes, if memory serves me PRI is anti-fungal.

This is gilding the lily at bit, but when you purchase your concrete blocks, if they happen to have some overruns and are selling blocks that have those decorative wedges on one side, or scoops like the oldfashioned bush hammer blocks, that would tend to (a little bit) break up resonance and reflection. I say overruns because I would NOT bother to pay more, but if they are the same price or cheaper, why not.

On haydite(sp?) versus concrete accoustics, not significant enough to fiddle with. If the haydite is cheaper and your mason prefers it, fine, but I don't think they'll be much difference in that small a space.

-- Ken Seger (kenseger@earthlink.net), June 13, 1999.