mower oil question

[black-xj]

Waste oil is for lighting the fire...

And Anthony, i have a couple of secondhand 3.75 horsepower Briggs motors
if you are interested...

[anthonygubbin]

Thanks for the offer. Don't know if a Briggs would fit though a mine has a different 4 stroke engine, Techashuma, something like that. ATM I am happy to put in the oil. I ended up with the SAE 30 but might just go 20W 50 when the litre I bought runs out. I don't need to go to the point of using sump oil. I mean 300ml every 2 weeks is ok by me. If the engine completely cacks it I will get another mower from Cashies, they have them for about $60-$70. I may even have my 6hp Briggs/Rover over here from the mainland before too long and the current mower might last until then with a bit of luck. . One thing I will get done though Ed is when I get my Super 600 Victa here is get you to replace the crank bearing/seal. I will slip off the engine to save time. But I failed doing a crank seal once before so will leave it to someone who knows what they are doing this time.

Regards A

[black-xj]

Tecumseh is what it is i reckon, and a briggs should fit in its place...
I won't want much for either of them, but they are there if you need...

I sold my super 600 Victa when i had no more use for it, and ran
out of room for storing it undercover...was a good jigger though !

[roscoea26]

I have a John Deere ride-on with a B&S air cooled engine the manual stipulates to only use SAE30 specified for air cooled engines only. There is a warning not to use normal engine oil. My understanding is the normal engine oil is not suitable for air cooled engines as this type of oil is not specified to handle the heat generated by an air cooled engine.

[layback40]

Originally Posted by roscoea26

I have a John Deere ride-on with a B&S air cooled engine the manual stipulates to only use SAE30 specified for air cooled engines only. There is a warning not to use normal engine oil. My understanding is the normal engine oil is not suitable for air cooled engines as this type of oil is not specified to handle the heat generated by an air cooled engine.

This is not the case. Modern multi grade oils are far more heat stable than the old mono grades. I suspect B&S just havent upgraded their instructions in the last 30 years. Air cooled motorcycle engines & racing engines run far hotter than an old B&S side valve. Mono grade oil used to be much cheaper than multi grade & I suspect this is why it was specified for such applications where there was not much load on the engine.

[black-xj]

As mentioned in a previous post, Briggs recommend SAE 30 because it lasts the longest
in the engine over an oil change period....the old side valve engines don't have valve stem
seals and will burn a small amount of oil compared to a car engine...

For example; Honda 4 stroke brushcutter engines when first introduced into the market,
were listed with a consumption rate of 2 mls per hour of use, they only hold 100 mls of oil in the first place...

2 stroke oil on the other hand, i will strongly recommend not to use water cooled oil in an air cooled engine,
as the thermal qualities are not as good...
Water cooled engine oil is highly likely to break down and not lubricate an air cooled engine sufficiently
in the midst of summer temperatures, potentially leading to seizures or other failures...

[layback40]

Originally Posted by black-xj

As mentioned in a previous post, Briggs recommend SAE 30 because it lasts the longest
in the engine over an oil change period....the old side valve engines don't have valve stem
seals and will burn a small amount of oil compared to a car engine...

For example; Honda 4 stroke brushcutter engines when first introduced into the market,
were listed with a consumption rate of 2 mls per hour of use, they only hold 100 mls of oil in the first place...

2 stroke oil on the other hand, i will strongly recommend not to use water cooled oil in an air cooled engine,
as the thermal qualities are not as good...
Water cooled engine oil is highly likely to break down and not lubricate an air cooled engine sufficiently
in the midst of summer temperatures, potentially leading to seizures or other failures...

Can you please provide some technical data to justify these claims.
When I have looked at oil properties I find that the mono grade oils are no more heat stable than many of the better multi grade oils. I have large diesels (& petrol ones to) that the manufactures recommended mono grade oil for, that the recommendation has been surpassed by the oil companies & the engine manufacturers agree with the change.
I am aware that some of the early multi grade oils were a problem eg BP super viscostatic.