What oil is best? and what ratio?

[mdavlee]

Not questioning this, just want to know the reasoning behind it.

What is the difference between benol in a motorbike or chainsaw 2 stroke?

Load and BMEP. 80cc chainsaw ported is 8 hp. Bike is 25-30.

 

[bwalker]

Not questioning this, just want to know the reasoning behind it.

What is the difference between benol in a motorbike or chainsaw 2 stroke?

Its not even a good choice under most circumstances for a bike.

 

[bwalker]

Not questioning this, just want to know the reasoning behind it.

What is the difference between benol in a motorbike or chainsaw 2 stroke?

As far as why it's not good for use in a saw. It attracts moisture leading to corossion of internal parts, it burns very dirty, it's in general harder to turn, it seperate in temps below 40 degrees.
Note that Benol is 100% castor and oils like 927 and ST are castor blends with maybe 20% castor in the blend. Even the blends have many of the same down points. Further a saw is such a low output, low stress application your double shooting yourself in the foot using it.
As I have mentioned earlier I will use a blend when doing certain things with a bike, but the load and BMEP are much, much higher for what I'm doing.

 

[bwalker]

This isn't my pic, but is one of a piston run on castor. When guys like Bell and Jennings talk about de-carboning when using castor this is what they are referring to.

 

[bwalker]

I had a friend running Blendzall in his CR-500. His expansion chamber gained 20+ lbs in carbon gunk in a season of riding.

 

[junkman]

I had a friend running Blendzall in his CR-500. His expansion chamber gained 20+ lbs in carbon gunk in a season of riding.

927 would line the inside of my 250r pipe with that black junk also ,would have to scrape it out and burn it with a torch to clean it .

 

[stihl saws]

This isn't my pic, but is one of a piston run on castor. When guys like Bell and Jennings talk about de-carboning when using castor this is what they are referring to.View attachment 22599

That is a total mess.

 

[junkman]

Hey were are on Bubba Stewart's page 259

 

[bwalker]

927 would line the inside of my 250r pipe with that black junk also ,would have to scrape it out and burn it with a torch to clean it .

Some of that can be prevented by jetting properly, but alot of it is just a characteristic of castor. The stuff doesn't burn like a mineral or synthetic oil. Instead it polymerizes and forms the gums and varnished associated with it.
Really, the only time it should be used is if you have an application that's torn down regularly and is high strung from a BMEP and heat stand point that the motor has seizure issues under load. If you squeek a motor on castor you have serious issues with your motor. I have detonated pistons to death while running a castor/blend yet never seized the motor. A straight castor provides for an even higher level of seizure prevention.

 

[Brewz]

Now this is the info I am after

So perhaps benol would be good as a 20% blend for applications like milling where I may open the saw up more often to check it due to the added load and heat.

Perhaps first tank run in of a fresh rebuild?

 

[stihl saws]

I will agree that any of the castor containing oils burn dirtier. After many years of running 927 for many hours in different bikes and tearing them down, I've not seen anything that would make me switch based on cleanliness. It's not going to be great for your kids bike, putting around though.

 

[mdavlee]

Some of that can be prevented by jetting properly, but alot of it is just a characteristic of castor. The stuff doesn't burn like a mineral or synthetic oil. Instead it polymerizes and forms the gums and varnished associated with it.
Really, the only time it should be used is if you have an application that's torn down regularly and is high strung from a BMEP and heat stand point that the motor has seizure issues under load. If you squeek a motor on castor you have serious issues with your motor. I have detonated pistons to death while running a castor/blend yet never seized the motor. A straight castor provides for an even higher level of seizure prevention.

Super and benol work good for mixing with methanol and nitro. Some nitro fuels smell like they have Super in them. 18%oil in those mixes as well

 

[porsche965]

I had a friend running Blendzall in his CR-500. His expansion chamber gained 20+ lbs in carbon gunk in a season of riding.

Did he actually weigh it? Any pictures? 20#s of gunk in an expansion chamber? Really?

 

[bwalker]

Now this is the info I am after

So perhaps benol would be good as a 20% blend for applications like milling where I may open the saw up more often to check it due to the added load and heat.

Perhaps first tank run in of a fresh rebuild?

There is no application where I would use even a blend in a saw.

 

[bwalker]

Did he actually weigh it? Any pictures? 20#s of gunk in an expansion chamber? Really?

Yes, and It was actually 25 lbs.
The guy is over on Bannedcr500.com. I didn't see pics, just repeating what he stated. I am not terribly supprised, especially with the rich jetting most guys run.

 

[bwalker]

I am not saying 927, benol, or ST are bad oils. What I am saying is they have their place and chainsaws are not it.

 

[Brewz]

I just picked up and mixed some of the valvoline racing oil I put a picture up of.

Its thinner than benol, mixes easy, has a fairly unofensive oil smell at 40:1 in BP 91 RON.

I will run it for a while and see how it goes.
It doesn't burn my eyes in the garage like the penrite MC2ST.

That stuff is nasty

 

[jake wells]

guess i will start buying the cheapest i can get my hands on.

 

[porsche965]

guess i will start buying the cheapest i can get my hands on.

Lol. Why not?

 

[jmssaws]

I'm still running valvoline and royal purple. Burn a gallon of one then a gallon of the other. Tune easy and run great