36 HP Generator oil?

[callbay]

I am planning on buying a 20 KW, 36 HP Guardian generator. It is supposed to have a Guardian air cooled engine that holds 1.9 quarts of oil. I keep hearing about the oil shearing on big air cooled engines like this.

What oil would you recomend for the mid south.

 

[tig1]

A good friend of mine is a Guardian repair man, and when he does an annual inspection he replaces the oil with Mobil 1 10w30. Also the local install shop for these generators also use the same oil.

 

[Pete591]

ZDDP:
These days with lower levels in automotive oils in order to get 1200 ppm levels you need to "shop around"

Amsoil ASE SAE 30-wt/10w-30 does not have Viscosity Improvers that can and will shear down with heat and frictional forces.

Unique product and the one I use and would use if I have your piece of equiptment.

 

[JTK]

Is this a natural gas or propane powered standby unit? A once per year oil change type thing?

Joel

 

[callbay]

It's going to be run on propane and it will be a yearly oil and filter change, unless I had to use it a ton I would change it more often.

 

[Bror Jace]

callbay, a lot of us here are HDEO fans (Heavy Duty Engine Oil - approved for gas as well as diesel service) for outdoor power equipment.

1) They have a robust anti-wear package.

2) They have a robust package to deal with fuel dilution ... especially good for preventing corrosion in machines that sit and sit.

3) They are more resistant to shear than PCMOs ... passenger car motor oils.

For a new machine run down south, I would use either 10w30 or straight 30 ... then maybe switch Watch the oil consumption with the 10w30, especially during break-in. Check the oil every 2-3 hours initially until you see a pattern.

Once the machine has 30-50+ hours on it, I might switch to the heavier 15w40 ... especially if you get consumption with 10w30 and starting on cold issues is an issue with the straight 30.

I also like to use MMO or Lucas UCL at about 1/2 the recommended treat rate in the fuel to ensure the rings break-in gradually. This will also reduce oil consumption. Not sure this is possible with a LPG-powered engine.

 

[tig1]

I would check the manuel before using a 15-40 oil.

 

[JTK]

+1 to Bror's recommendations. From a quick glance online, the Guardian/Generac sets have a 3yr warranty, but it doesn't state what oil/filter must be used from the literature I saw. I'm not quite sure who makes the "Generac" brand engines, but they do look similar to the Briggs Vanguard series. Very nice engines. I too would go with a HDEO if it were mine. If you are not comfortable with a 40wt variant, HDEOs can be had in 30wt ranges. I'm partial to Shell Rotella, but they're all good.

Joel

 

[tig1]

Generac makes there smaller engines. On some of their larger generators they use the Ford 5.4 truck V8. 100 KW, etc. Stick with the 10-30.

 

[JTK]

Originally Posted By: tig1
Generac makes there smaller engines.
.

Interesting. Strong looking engines for sure: http://www.brandnewengines.com/generacengines.aspx

Joel

 

[Bror Jace]

"I would check the manual before using a 15w40 oil."

Understandable ... but notice Callbay is from the "south." Assuming that's a fair peace further south than Illinois, I would think a 15w40 would be better in the heat than an XW-30 ... which would likely shear under extended use in hot weather. The 15w40 should be fine in moderate temps and if it thins and shears a full grade ... it'll still be in the recommended weight range.

If you are using an XW-30 and it thins/shears, protection could be compromised ... and the oil consumption could increase without warning.

I used 15w40 in OPE for years in upstate NY with no issues ... oil was without shavings when drained and I even did a used oil analysis on our Honda Tractor which looked excellent.

If this engine has a spin-on filter, I would consider using a shear-resistant synthetic or synthetic blend (Amsoil, Schaeffer, etc ...). Normally, I don't bother with synthetics in engines without a filter because the oil becomes contaminated with metal shavings.

Still, it was a veteran of this site that lived in Florida and had gone through a number of gensets with Honda engines using some sort of 30 weight oil ... and now only uses Mobil 1 15W-50.

 

[callbay]

I finally found on the Generac site their oil recomndations at least for the 36 HP. It is a little crazy to me. They recomend straight 30 weight from 32 degrees F to above 100. 10-30 from -10 to +40 degrees and Synthetic 5-30 from below -20 to +10 degrees. That would mean that one should change the oil after the summer each year to one of their winter recomendations.

Also, I had always thought straight 30 weight was to be used only down to 50 degrees F. These engines go to from cold to full speed in 10 seconds. Wow, at 32 degrees to full power with 30 weight in 10 seconds. They also say now a 2 year or 200 hour OCI recomended. How does that work with changing the oil twice a year because of the viscosity? Have they really thought this through?

 

[tig1]

You are making this difficult for yourself. If you would notice my earlier post on you thread that my friend is a service tech on these generators. The only oil he uses for his customers is Mobil 1 10w30, year round.
Also my daughter has a Generac 15KW unit and her tech also uses Mobil 1 10w30 for his PM work.
Change it once a year, unless you had a very long use time.

 

[Best F100]

Originally Posted By: tig1
You are making this difficult for yourself. If you would notice my earlier post on you thread that my friend is a service tech on these generators. The only oil he uses for his customers is Mobil 1 10w30, year round.
Also my daughter has a Generac 15KW unit and her tech also uses Mobil 1 10w30 for his PM work.
Change it once a year, unless you had a very long use time.



I figured I would add my "two cents" since I own a Generac 15KW and have used it during extended power outages. Mobil 1 10W30 is just "OK" in this application. Everyone uses it because it is commonly available for both Generator techs and homeowers. The problem I found is, that in 90F temperatures, it "burned off", the oil level dropped to below 1 qt (my oil capacity is only 1.7qt to begin with), and the generator shuts itself off in the middle of a power outage(after 48 continous hours). You then must refill the unit to get it started again (Your wife may not want to do this if she is home alone). To avoid this hassle you can do two things:

1) Use an extended capacity oil filter to increase the oil capacity. Generac makes one. I am using a Purolator. My oil capacity went from 1.7 qt to 2 qt.

2) Use a better oil for this hot application. My opinions in good, better, best categories if you want to use a 30wt oil, like the manual says:

Good - Mobil 1 10W30

Better - Mobil 1 Extended Performance 10W30, maybe Pennzoil Platinum 10W30 (I have't tried this one).

Best- German Castrol 0W30, Red Line 10W30, Mobil 1 High Mileage 10W30 (I haven't tried this one, but it has better HT/HS and flash point specs than the first two Mobil 1's mentioned). Minimal Oil Consumption issues for me with the GC and Red Line. I would throw in Mobil 1Racing 0W30 if you have deep pockets to buy it.

Hope this helps. Don't flame me too badly guys.