Oil recommendations for HD portable generator

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3
Location
WA
Thread starter
Hi all, new to the forum as a registered user, but I have been driving down the oil nerd rabbit hole of valuable information on here for at least a year, and I'm hooked! Thanks to all the contributors here for their great advice and frankly civilized behavior compared to many forums out there. I recently lucked out purchasing an 8kw (running) portable generator from 1991 with a US assembled Vanguard 16hp V twin with force feed lubrication and an external oil filter. Some farmer ran it for 45 minutes when he bought it, changed the oil, and stashed it in his basement for 18 years under a tarp! I have taken this generator to it's knees over the course of a 4 day on and off power outage a couple weeks ago running water pumps, heat pumps, and even the dryer. Started out with synthetic 5w30, but I want something that will stand up to the high oil temps I will see as this thing will sometimes run for a couple days straight. It is set up to run on propane as well, and I am having a 120 gallon tank brought in just for the generator, so fuel dillution shouldn't be an issue (I don't think). The generator is in a kind of lean-to shanty against the side of the house, it has lots of airflow, and the exhaust is ducted outside of it, but it still gets to be 70 plus degrees in there when the generator is running even when it is below freezing outside. My issue is I may need to start this thing and run in super cold temps, I live in NW Washington, but I could see temps approaching 0°F, but then once it's up and running, it will be toasty warm, and powering the whole house, potentially for a couple days at a time. Not quite sure where to go. My thought is to run a decent 5w40 synthetic like T6, or Valvoline PBE, which I could probably have on hand for my truck (6.7 Cummins). I currently run Valvoline PB 15w40 conventional in my truck as I only do 5k OCI about annually, but I may start blending in one jug out of three of PBE 5w40 synthetic to get a better winter rating, so I could have both on hand. I can't justify running different oil in the cold months (in the truck or the generator really) as I will only be doing annual oil changes unless I rack up a ton of hours during an exceedingly long power outage. I'd love to hear some opinions of 5w40 synthetic vs 15w40 conventional (or something else that might work better) in this application considering how hot the oil will get, and how many hours I can stretch out the OCI on this thing since it has a nice spin on oil filter. I probably ran for a total of 50 hours in 4 days this last go, but ya never know, it would not be impossible to wind up needing to run for over 100 hours straight. Thanks! I have attached the Vanguard oil recommendations as well.

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Messages
35,852
Location
ME
Electric start or pull cord? The first five seconds of running are where you'll get most of your wear, as this thing flies up to 3600 RPM. Your 5w40 synthetic sounds great. Not sure why you're blending it in your truck, I'd run the 5w40 year round in it also.
 
Messages
6,639
Location
South Florida
10W30 Delo or Rotella Mobil high mileage synthetic 10W30 Is what I would use for your location and engine, assuming its a full pressure lube engine. And you'll most likely use it in the winter.
 

CT8

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15,408
Location
Idaho
Use a HDEO 5W-40. I use the 5w-40 in every ope and diesel engine I own because of freezing weather starts. Otherwise i would run 15W-40
 
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3,194
Location
Ca.
I run most of my gensets on M1 0W-40 and in the case of my diesel 8000 had no problem up to 300 hours on a tiny sump. The UOAs looked like it had never even been run, they are posted here. UD
 
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3,507
Location
Slovenia EU
Originally Posted by CT8
Use a HDEO 5W-40. I use the 5w-40 in every ope and diesel engine I own because of freezing weather starts. Otherwise i would run 15W-40
This! Use sae40......HDEO....or EU PCMO....stay away from your ILSAC (fuel conserving) oils... You are chasing/want oil with a higher HTHS
 
Messages
3
Location
WA
Thread starter
It is electric start. I was thinking of blending in one jug 5w40 synthetic PBE to get some of the cold start benefits while still using two parts (jugs) of the 15w40 PB that I stocked up on during a deal for $8 a gallon ...
 
Messages
3
Location
WA
Thread starter
It uses the Briggs & Stratton 491056 oil filter currently. Same filter as my lawnmower with a 20hp Briggs and Stratton. Cross reference chart shows Wix 51348 or 51348xp would work, which is the same oil filter I was using on my Tacoma when I had it, funny coincidence...„.
 
Messages
912
Location
Pennsylvania
I am currently running Rotella T6 5w-40 in both of my generators because they could theoretically be called into service anywhere from 0 - 100 degrees F. 10W-30 Mobil1 High Mileage with its 3.5 HTHS is a good alternative. A Fram 3614 filter should work for you also. I use the TG3614 on my Briggs V-Twin.
 
Messages
15,226
Location
N.H, U.S.A.
The suggestion of "run any 5w30 synthetic" is a "Fool's Choice" I've had top synthetics shear to water in an hour. SO I went on a quest. Why #1 they are not synthetic - regardless of what the bottles says ( see: NAD - BBB ruling) #2 They are not developed for air cooled ODPE - but for fuel economy and converter life on pressure lubed engines Seeing I may have to Start the thing in 10 deg F weather, I ended up with Valvoline Racing 10W30 Synthetic with a TBSP of LUBRIMOLY. That one quart - Its still in there 12 year later. Looks good runs great. NO warm Knocking like PCMO synthetics I do have to change that (!)
 
Messages
641
Location
Chicago Suburbs
I have been running 5w30 full synthetic quaker state QSUD in my gen sets with Briggs motors for years biggest run was a full week in 80-85 degrees F only stopping to refuel My small one is 10 years old and still starts on the second pull m once a month I do run them once a month for 15 to 20 minutes
 
Messages
15,226
Location
N.H, U.S.A.
Originally Posted by Nitronoise
I have been running 5w30 full synthetic quaker state QSUD in my gen sets with Briggs motors for years biggest run was a full week in 80-85 degrees F only stopping to refuel My small one is 10 years old and still starts on the second pull m once a month I do run them once a month for 15 to 20 minutes
What engine? My generac 5500 (?) has some "chinese honda copy" 390cc OHV and that would start knocking with a PCMO oil when hot. Are you sensitive to engine racket and performance devolving when overstressed?
 
Messages
1,262
Location
Indiana
In my experience none of this OPE stuff is developed with synthetic oils and any of the syns you put in are a bonus. The stuff I've had fail is mechanical like broken exhaust valves, con rods, et unrelated to lube.
 
Messages
3,507
Location
Slovenia EU
Originally Posted by ARCOgraphite
Originally Posted by Nitronoise
My small one is 10 years old and still starts on the second pull m once a month
What engine? My generac 5500 (?) has some "chinese honda copy" 390cc OHV and that would start knocking with a PCMO oil when hot.
You both need to adjust valves on your generator(s)....
 
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