Oil weight in the MEP 002a

[Heavyopp]

I'm trying to decide which weight oil to use for a Mep doing winter backup duty in NH. My problem is with the cutoff temps for 10 weight and 30 weight.

10 weight up to 30 degrees

30 weight over 30 degrees.

The problem is that what oil should you use when the temps fluctuate between 20 and 40 degrees? I know 40 is warm for a NH winter but those big ice storms come when it's too warm for snow.

So what worse for the engine --- Engine oil thats too light for warmer temps or oil thats too heavy for cold weather???

Anyone run multigrade oil in the winter? What weights?

I'm interested to hear what others are doing.

 

[jbk]

i found a 1977 lo that listed 15/40. that was superceded by a lo issued in 1990 dropping the 15/40 and listing the 30 weight for temps. above 30 degrees and 10 weight below 30 . why they dropped 15/40? i know the civy onan recomends it and alot of guys here use it. it could be somthing as simple as fluid commanality not wanting to stock it. i used 15/40 for a few years changing it for winter but stopped because i have two many gens. now to afford it so i stay with straight 30 and temps down here rarely get below 30 degrees.

 

[PeterD]

This will be an interesting thread... I was running 15W-40 (Rotella) in my MEP-004, and I think it may be too heavy at colder temperatures. I'm actually wondering if a synthetic might be better for those wild variations in temperature, as the OP noted in NH, we can see swings from -20 to +45 in a period of a week.

Oh, and to Heavyopp, where in NH are you going to be?

 

[Carl_in_NH]

Me, I use straight 30 weight in my MEP-003A - and then keep the generator in the garage. While the garage isn't heated, it is typically warmed by the Sun enough that the temperature rarely gets much below 30 degrees F at night - even in extended cold snaps.

It's a lot easier to start because it's been inside, too; these generators are typically hard to start when it's cold out. Make certain your GPs all work, and your batts are fully charged at all times; a couple cheap trickel chargers will handle the job. These need every advantage you can give them to fire off once the temperature drops down below freezing. That also points to using a lighter weight oil when cold - so the starter can crank it fast enough to light off.

How are you planning to store the generator while it is on stand-by?

 

[PeterD]

I think my setup is about the same as Carl's. In the shop during the winter, no heat unless I'm working (then I bring it up to about 60 degrees). Temps are rarely below freezing inside however (it is insulated, which helps).

I may rethink my use of 15W-40 and go with straight 30. Of course I'll now have to go buy some new oil since I've only got stocks of 15W-40 on hand for diesels!

My main worry is that should this set be needed for a multi-day outage, I have the problem that I won't be running it overnight (we have backup wood heat). That leaves me with either sitting it out to get much colder each night, or pulling it back into the shop each evening. But with a quick disconnect on the power end, that may be the best move for me.

 

[Isaac-1]

A couple of things to keep in mind, the MEP-002 and MEP-003 are air cooled diesels, therefore the oil temperature tends to get higher than water cooled diesels, this may be a reason to consider using a synthetic oil with a higher break down temperature. I don't live in the great frozen north, however one of the regular posters over on the Onan section of the smok stak board (BTPOST) lives in the wilds of Alaska and has used Onan Diesel J series units in that environment for prime power for over 20 years. It may be worth asking him his thoughts on oil for J series engines.

Ike

 

[jbk]

i use a mep-802a as my go to set and have in the past used rottella 15/40 synthetic and switched this year to amsoil 10w30/sae 30, thats right it confused me too, they told me this is to take the place of 10w30 and straight 30. i have it in this set now. guess ill see this winter how it acts. seemed ok over this summer the few times i ran it. i have straight 30 rottella in all of my 002s now but thats thick stuff at 35 and below. i was considering this amsoil in one of the 002s.

 

[rcflyer70]

I've been using Rotella 30 for years with no issues. Here in Kansas we see 0 to 100 degrees. I religously start my MEP-002 every month and it sets outside with only a cover.

 

[Heavyopp]

Ok Here's some more info...

The Mep will be used as backup power for my sisters home in NH. I'm in NJ.
I'm doing the best I can to idiot proof this thing for them. Her husband is all thumbs.

I am mounting the Gen on a trailer. I will be building an enclosure out of angle iron, sheet metal,
and most likely some rigid foam sheeting to dampen the noise. I will also be building and electrical panel with various
receptacles for ease of use. Machine will be hooked up to the existing transfer switch thru a 30 amp locking connector.
The house is already wired for a genny with the plug outside.

The machine will be enclosed but not heated. I guess I could very easily provide room for a Mr. heater to be used
to heat the enclosure if need be.

The generator will not be run constantly. They basically want it for the well - don't really care about anything else.
There will be other circuits active when the MEP is running. Wood for heat. Oil furnace is backup for most of the
winter anyway. Propane for cooking.

As I said before, I'm in NJ. I have 50+ acres of land in Warner NH. No house but plans to build sometime in my life. I don't get there nearly enough.
My sister lives in New Boston, NH.
For the past 2 years power has been wiped out by an Ice storm for about a week at a time.
The Generator will do winter duty in standby position in New Boston. Standby position will be fairly close to the house,
within reach of the Aux power cord. Plugged in and ready to go with the flip of a few breakers.

During the summer we will move the whole setup to a storage position on her property. I'll still be able to run it
but it won't be right next to the house. I'll always be able to take it to my place in Warner if I so choose.

So I'm still unsure what oil to use. I don't have any other air cooled diesel engines.
Plenty of water cooled which I use rotella 15/40 all year round. I do have quite a few gas air cooled engines.
Snow blowers are the only ones that call for a multi grade oil 5-30 I believe. Everything else I run 30 weight.
I'm not really sold on changing an older engine to synthetic oil. I've heard too many horror stories
of unexplained oil leaking from the old seals and always though of it as something that shouldn't be done.

Thanks again for your thoughts

 

[rosco]

It doesn't matter what weight/viscosity the oil is, if you put heat on it to start it. I run 15-40 Dello in everything. So I have only one flavor oil around. Heat should always be avaliable to start things. A weed burner, 20# propane bottle and a length of stove pipe w/elbow - works for anything, especially if you throw a tarp over it. If it is cold, the most important thing is not the weight of oil, but the "heat". I know you can start stuff colder, but its not good for it. Never start anything when its colder then Zero, with out heat, of some kind!

 

[Isaac-1]

OK, a couple of thoughts on idiot proofing, first issue is batteries. In my experience people can not be relied upon to maintain generators (that is start them regularly, let them run long enough to keep the battery charged, etc.) So if there is electricity at the storage site add a float charger to maintain the batteries (there was a guy on ebay selling new guest brand 24v chargers for a fraction of retail, I bought 2 a while back), if no electricity available at the storage site, then I would suggest a solar panel charger. Also these engines are notoriously hard to start in the cold, so I would strongly consider some type of block heater (I have been told the oil pans on the the military Onan engines are aluminum, so magnetic heaters will not work), and I would consider setting them up with a pair of external 12V batteries in series to get 24V that could be connected to the slave port for starting in case they run the internal batteries down trying to get get it to start since most people don't have a way to jump start anything with a 24V electrical system. I might even go as far as to double wire this external battery bank for 12V and an isolation switch so if could be recharged with jumper cables from a 12V vehicle (perhaps using an SB connector on one end). I assume you will be mounting some type of fuel tank on the trailer also, if you happen to go with one of the white aux bed tanks that Tractor Supply sells, I strongly suggest giving it an extra coat of paint. I bought one of their 100 gallon tanks last year and it is already getting some surface rust (mainly around the data plate welds).

Ike

 

[PeterD]

...


My sister lives in New Boston, NH.
For the past 2 years power has been wiped out by an Ice storm for about a week at a time.

OK, New Boston is not too bad, roughly the same weather that we get (without the effects of Monadnock!)

The Generator will do winter duty in standby position in New Boston. Standby position will be fairly close to the house,
within reach of the Aux power cord. Plugged in and ready to go with the flip of a few breakers.

We use wood when the power is out (could use it all the time, but my wife doesn't like it...) No well, but we do want lights.

During the summer we will move the whole setup to a storage position on her property. I'll still be able to run it
but it won't be right next to the house. I'll always be able to take it to my place in Warner if I so choose.

So I'm still unsure what oil to use. I don't have any other air cooled diesel engines.

Personally (and I don't have much air-cooled diesel experience) I'd say 30 weight may be best. But I think that synthetic may off some advantages in the cold.

Plenty of water cooled which I use rotella 15/40 all year round. I do have quite a few gas air cooled engines.

I do run Rotella 15W-40 in my diesels (all water cooled) and don't have serious problems except when the cold is extreme. But all are located in the shop where there are fewer extremes in temperature.

Snow blowers are the only ones that call for a multi grade oil 5-30 I believe. Everything else I run 30 weight.
I'm not really sold on changing an older engine to synthetic oil. I've heard too many horror stories
of unexplained oil leaking from the old seals and always though of it as something that shouldn't be done.

Thanks again for your thoughts

I've not experienced many problems with synthetic leaking around seals. I've experienced problems with 15W-40 leaking when cold because of higher oil pressure (stupid oil filter!)

 

[Heavyopp]

OK, a couple of thoughts on idiot proofing, first issue is batteries.

Yes there is electricity under normal conditions. A 24 volt float charger is a good idea.

Also these engines are notoriously hard to start in the cold, so I would strongly consider some type of block heater

Block heater would only work for the 1st start. They don't expect to run the machine constantly. At some point they will have a cold engine. Maybe some way to warm the enclosure with propane would be best.



I would consider setting them up with a pair of external 12V batteries in series to get 24V that could be connected to the slave port for starting in case they run the internal batteries down trying to get get it to start since most people don't have a way to jump start anything with a 24V electrical system.


This is a great idea. Easy enough when planned for ahead of time.




I assume you will be mounting some type of fuel tank on the trailer


I was actually planning on giving them a 55 gallon drum and having them get it filled with home heating oil. I just need to check if heating oil will gell in the cold. Might have to treat it or go a different route.

 

[skidunits4you]

Heating oil will gel and will need to be treated. Should be treated with a good additive as it doesn't have any of the additives that Diesel has( I treat all my diesel with power service). I run 15/ 40 in all my Diesels air and water cooled (heat if extremely cold). My MEPS 004,005,006 and 275kw unit. All have added block heaters (tank style )with thermistatic controls. run 5/30 in the 3 Kolher Propane units (30 kw, 12.5 kw) All units have battery conditioners and are started once a week.