Need Weight of oil for OLD engine

[FarmboyBill]

What wgt oil should go in a late 50s B&S engine of around 7 or 8 hp??

[Harry Chickpea]

Standard weight has always been 30, but people will sometimes go thicker or use an additive if the rings are worn.

[arabian knight]

Ya 30 to 40 same as many use in things today. I use 40 in my lawnmower. As it is 20 years old. The only difference I sure would go for Straight Weight like 30 or 40 not multi-viscosity 10w30.

[coolrunnin]

Originally Posted by arabian knight

Ya 30 to 40 same as many use in things today. I use 40 in my lawnmower. As it is 20 years old. The only difference I sure would go for Straight Weight like 30 or 40 not multi-viscosity 10w30.

Why not multi-viscosity? Makes it easier to start, makes absolutely no difference in lubricity.

Oils have come a really long ways in the last 20 years, not even remotely the same.

Age of motor really makes no difference, but wear does if it uses oil then rebuild it because these bogus additives can be harmful and make a rebuild nearly impossible.

[arabian knight]

This is basically why and in a older engine one that might be used most of the time wide open throttle, etc. Like my lawnmower I set the speed on high and there it stays.

Drawbacks of Viscosity Improving additives
Multi-grade motor oils perform a great service not being too thick at cold startup to prevent engine wear by providing more instantaneous oil flow to critical engine parts. However, there is a draw back. These additives shear back in high heat or during high shear force operation and break down causing some sludging. What's worse is once the additive begins to be depleted the motor oil no long resists thinning so now you have a thinner motor oil at 210 degrees. Your 10W-30 motor oil can easily become a 10W-20 or even a SAE 10 (10W-10) motor oil. I don't have to tell you why that is bad. The more VI additives the worse the problem which is why auto manufacturers decided to steer car owners away from motor oils loaded with VI additives like the 10W-40 and 20W-50 viscosities.

Either you change it quite often so the Additives Stay put or that is what will happen.
And like a lawnmower operating at a high speed for a long person of tie it gets HOT remember these motors like this are air cooled.
I want that higher protection for a longer period of time.
Even in a old truck working Hard in the Heat of the Summer a good 40 weight is good to use. Pulling trailers in hot temps etc.
Now I do use a heavier multi-viscocity when I hauled horses around the state in my old Dodge PU. I used 20 W 50 Racing Oil~!


http://www.upmpg.com/tech_articles/motoroil_viscosity/

[FarmboyBill]

Ive got both. Ill use the 10W 40

[coolrunnin]

Originally Posted by arabian knight

This is basically why and in a older engine one that might be used most of the time wide open throttle, etc. Like my lawnmower I set the speed on high and there it stays.


Either you change it quite often so the Additives Stay put or that is what will happen.
And like a lawnmower operating at a high speed for a long person of tie it gets HOT remember these motors like this are air cooled.
I want that higher protection for a longer period of time.
Even in a old truck working Hard in the Heat of the Summer a good 40 weight is good to use. Pulling trailers in hot temps etc.
Now I do use a heavier multi-viscocity when I hauled horses around the state in my old Dodge PU. I used 20 W 50 Racing Oil~!


http://www.upmpg.com/tech_articles/motoroil_viscosity/

AMSoil really???? One of the worst out there psuedoscience at its finest

[ct01r]

Farmboy, I don't know what the weather is in your neck of the woods, but I'd go with the 10W 40 if it's cold, so the oil cirulates. I've used both multi-weights and straight
30W, and my engines typically outlast their housings. I get 20 to 30 years out of the engine, but the mower deck, wheels, etc. will have to be replaced a couple of times. Curt

[logbuilder]

I use 30W non-detergent in my old machines. I've gotten it at my NAPA store. I suspect it will be harder and harder to get so I stocked up last time I saw it on sale.

[rambler]

EPA took the lead out of gas.

They also not so long ago took the zinc out of oil. The zinc made some fumes through the cat converters, so had to go.

That's fine for the new engines which have roller tappers. Bit our older engines depended on the zinc as one of the additives to lube that friction rub on the tappets.

Now I think most fuel and oil additives are snake oil; but this is a real issue, and you might want to look for an oil or additive that deals with this if you have an older engine.

Paul

[FarmboyBill]

I see where gas has gone up 13@

[coolrunnin]

I looked this up and it appears the lower zinc and phosphorous levels only affect the break in of older engines. but I can't really find anything deffinitive.

http://blog.hemmings.com/index.php/2...omment-page-2/

[FarmboyBill]

Id think that all OLD engines would have already been broken in, other than with a overhaul.

[Sawmill Jim]

Originally Posted by rambler

EPA took the lead out of gas.

They also not so long ago took the zinc out of oil. The zinc made some fumes through the cat converters, so had to go.

That's fine for the new engines which have roller tappers. Bit our older engines depended on the zinc as one of the additives to lube that friction rub on the tappets.

Now I think most fuel and oil additives are snake oil; but this is a real issue, and you might want to look for an oil or additive that deals with this if you have an older engine.

Paul

They didn't take the lead out of the gas They just quit putting it in the gas