Was going to say something similar. Engine oil temperature, once up to operating conditions, aren't affected by ambient temperatures outside as much as people seem to think. Even Kohler says a 30 or 50 weight oil is fine (and obviously a 40 weight is too) for 0 - 100º F operating temperatures.
Super Tech 20W50 VS Diesel rated 15W40
- Thread starter z71bill
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FWIW, pop a dipstick on a running engine some time on a slash lube engine. You are going to have a heck of a mess! IMO it doesn't make a difference.
Just my $0.02
I turn the hose on full blast - open the washer wand with the tennis ball and let it run - it always sputters for a while until all the air is out of the line -
When I put it away last time I took a 4 foot piece of hose I had and connected it to the inlet - removed the outlet hose - took a funnel and filed the hose with Preston radiator treatment - anti rust protection for your radiator!
Then with no fuel in the tank I cracked the starter rope maybe 10 times until a little foam came out of the outlet.
IDN - it seemed like a good idea at the time - aluminum radiator treatment - aluminum pump - I was going to start it up yesterday but just getting it out of storage and set up wore me out - its too hot!
Far as the oil temp - it is hard to believe that the temp would be about the same on a 50 degree day as a 100 degree day on an air cooled engine - but I will not disagree because I have never measured the oil temp and I believe what you all are saying.
Thinking about it -
Lighter oil may dissipate heat faster so it could be cooler!
The more important question may be at XX degrees does 5W20 provide an adequate oil film to protect moving parts and prevent them from going metal to metal.
If you had a choice a little too thick or a little too thin which would you pick?
Not even a serious question is it?
Anyone say I want my oil a little too thin?
Thinking about it -
Lighter oil may dissipate heat faster so it could be cooler!
The more important question may be at XX degrees does 5W20 provide an adequate oil film to protect moving parts and prevent them from going metal to metal.
If you had a choice a little too thick or a little too thin which would you pick?
Not even a serious question is it?
Anyone say I want my oil a little too thin?
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I run a 0W-12 in a 30 year race engine so I'm not the one to answer that question.
I will say though, in some stock and built kart classes with ~200 cc 1 cylinder 4 stroke engines, some built rather radical and turning high rpm, guys will run 0W-20 and 0W-16 oil for both power and cooling. They run an entire season on an engine with minimal bearing and cylinder wear so the MOFT is certainly there. These are 200-224 cc engines making 20+ HP at 7000+ rpm.
One team saw 20°F hotter oil temp with Rotella T6 5W-40 than with Driven KRT 0W-20, a combination of higher hydrodynamic friction and higher specific heat capacity from the higher viscosity contributing to the higher temperature. Similar ambient conditions and head temp.
I will say though, in some stock and built kart classes with ~200 cc 1 cylinder 4 stroke engines, some built rather radical and turning high rpm, guys will run 0W-20 and 0W-16 oil for both power and cooling. They run an entire season on an engine with minimal bearing and cylinder wear so the MOFT is certainly there. These are 200-224 cc engines making 20+ HP at 7000+ rpm.
One team saw 20°F hotter oil temp with Rotella T6 5W-40 than with Driven KRT 0W-20, a combination of higher hydrodynamic friction and higher specific heat capacity from the higher viscosity contributing to the higher temperature. Similar ambient conditions and head temp.
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You worried about losing oil pressure at redline or something?
Ball bearings and rings aren't going to give a rats. More splash more better.
Actually… oil temp on air cooled equipment is absolutely tied to outside ambient temperature.
For example, on a 100 degree F day, you might expect perhaps 250 degree oil. If you ran the same engine on a 100 degree cooler day at 0 degrees F, you can reasonably expect the oil to be “about” 100 degrees cooler, running 150 degrees or so.
As we all understand viscosity and temp, it’s pretty easy to understand that a 20W50 at 250 degrees is thinner than a 5W20 at 150 degrees. This is why 20 weights are more than appropriate for arctic conditions. You don’t really want to run a 5W20 at a 250 degree oil temp in air cooled equipment, but at 150 degree oil temp , 5W20 is a good choice.
How often do you change the oil?
After every race or everyday?
I also think with a go kart the engine moving / air flow would help with cooling- my pressure washer will be sitting still in the sun and even when not running would probably get up to 120 degrees.
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I've done exactly that test, multiple times, and the operating oil temp changes less than 10°F. The only difference is it took longer for the oil to get there in the colder ambient temp. The oil simply doesn't care much when it's passing through a 300°F bearing and splashing on a 450°F cylinder.
The rest I can agree with in theory, but not in practice. The little fart machine isn't making enough load on the oil film for it to matter. We also have to consider the splash lubrication situation where you don't have a positive displacement pump constantly feeding the bearing. You're relying on what that splash arm can scoop up. If the oil is too viscous to effectively flow into the bearing, more so an issue during warmup than at full temperature, then you're going to get premature bearing wear.
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Usually every 3 races on race gas, every 1-2 races on alcohol. Head temps range between 350-400°F depending on ambient temp and load. On a bigger track where the driver can flat foot it all the way around, upwards of 425°F head temps aren't unheard of.
Far as start up goes - forecast is for 99 degrees today - it doesn't seem like start up would be much of a concern at these outside temps.
What is the difference between SAE 30 and a 20W50 during a start up at 90+ degrees?
I wish these small air cooled engines had higher oil capacity - the Kohler manual says it holds almost 20 ounces but put more than 16 and it over flows. Hard to believe there is 4 ounces of oil stuck up inside.
Why not just make them a quart?
I know nothing about go kart racing - I googled it and it said average time is 8-10 minutes per race
So is one race - including getting up to the starting line and back to the "pit" under 15 minutes? Three races would not even be an hour of engine run time on the oil.
If my time guess is correct (let me know if it isn't) that doesn't seem relevant to me running a pressure washer for many hours straight between changes.
Is your 0W12 oil already starting to degrade after less than an hour run time - or do you change it because a couple $ worth of oil is no big deal compared to the cost of a new engine?
(1) An SAE 30 at 100°F is typically ~75 cSt. A 20W-50 at 100°F is typically ~180 cSt.
(2) I completely agree. A 1 quart sump capacity would be great.
Popping the dipstick on any single cylinder engine (and many twins) regardless of splash or pressure lubricated will make a mess because of the piston movement down pressurizing the crankcase and spew out oil under considerable pressure (like hits the ceiling )in the garage. 3 cy or more are usually pressure balanced so pulling the dipstick is a non event. 2 or less will make a mess.
Rod
My point exactly so I don’t think 40 or 50 weight oil in OPE is detrimental. As I type this my Wen is running with 5w40 in it at the WoO at Beaver Dam.
Just my $0.02
I got the back of the house done - 4 hours yesterday and two today.
Started with the 10W30 (that was new / changed after last year's job was done) then changed it out to the 20W50.
Amazing the 10W30 oil looked pretty dark after only a few hours - but IIRC the oil looked a little on the dark side when new.
Washer engine started on the first pull - not bad for being stored for about a year.
I had way more problems with my scrubber - worked fine at first then stopped spinning -
Take apart - full of crud - clean and re-lube - still will not spin. Well who would have thought installing the thing backwards would matter.
Messed around with it and finally figured out the problem it work for a while then stopped a few more times.
I think the little nylon washer / bushing is wearing out - wish I could find one to try but I may just buy a back up scrubber.
Front of the house is a much bigger job - and I hate it when my tools don't work it just makes things x times harder.
Started with the 10W30 (that was new / changed after last year's job was done) then changed it out to the 20W50.
Amazing the 10W30 oil looked pretty dark after only a few hours - but IIRC the oil looked a little on the dark side when new.
Washer engine started on the first pull - not bad for being stored for about a year.
I had way more problems with my scrubber - worked fine at first then stopped spinning -
Take apart - full of crud - clean and re-lube - still will not spin. Well who would have thought installing the thing backwards would matter.
Messed around with it and finally figured out the problem it work for a while then stopped a few more times.
I think the little nylon washer / bushing is wearing out - wish I could find one to try but I may just buy a back up scrubber.
Front of the house is a much bigger job - and I hate it when my tools don't work it just makes things x times harder.
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Any current VOA of ST 20w50? I would just RETURN IT.
I'd take a spec'd diesel oil over any unknown entity.
I'd take a blend over a conventional, and a synthetic over a blend. So, that would be two votes for the blended 15w40 over the 20w50 conventional.
Since Kohler recommend 10w50 and a synthetic at that, and you're in a warm climate, Walmart has 5 quart jugs of M1 15w50. That would be my 1st discounted choice. My 2nd choice would be any 50 grade full synthetic V-twin motorcycle oil that still cheaper than Kohler 10w50.
If the sump is too big, the engine might last too long. How will I make money if I don't sell enough of them often enough? So... no 1 quart sump for YOU ever with your small engine.
Just look at lawnmowersgeneratorsPSIwashers... and other small engines with their 8, 12, 14, 16, 18, 20, 24 28... ounce make believe sump capacities when a quart would've been just too easy.
I wonder if those race engines would even survive a typical soccer moms year round hyper commuting in the minivan or SUV? with start/stop enabled? So, I don't ever compare my vehicles, or my small engines, with super duper race engine running whatever or however. Yes, its a pressure washer. Nobody cares how it relates to my Toyota, VW, or a race engine, their visc, oil temps/psi, or engine misengineerings.
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Or M1 10w40
Simple but brilliant!!!
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