Octane question

[056kid]

Octane boosters do every little. I wouldn’t run 87 in a saw e free or not.

I have been running 87 in ported saws for like 2 decades.

 

[pistolpeta]

I know this thread has grown to be quite the topic (had to bust out some popcorn and read through the comments), but I thought I'd let you guys know I took the CS-620P out on its maiden voyage today.
Pulled 3 times with choke until start, decompress, turned the choke off and let her rip!
Let it slow idle for the 100 yard walk back to the tree (30-40 seconds), ran at half mast for about 15 seconds, didnt see that much oil coming off so I backed out the oil adjustment all the way, got some oil but still seemed light (using Echo's bar oil, will watch it tomorrow when I head back out again and see if it'll send more once I start opening her up after her second tank has been consumed).
Limbed and bucked about half an oak today (I've yet to be able to distinguish oak varieties, larger leaf variety haha) and dropped the remaining 25'-30' that was left standing after the storm. The oak took down a beech tree with it that I'll be cutting up as well (dont know much about burning beech wood but i suspect it'll burn well).
Tree was pretty large, probably 28" diameter or more (where I was cutting the hinge).

Definitely have got alot to learn, you can see how un-level my cuts were after I fell the remaining stump haha, will spend more time ensuring that is set right before I continue next time.
Had a pretty decent lean to it so I gave it a shot , that plus no risk of damaging anything (other than myself) if it went somewhere other than planned.

Anyways, thanks again fellas for pointing me in the right direction.
I'm definitely at the base of the learning curve and will always take whatever words of wisdom you all provide.

I posted a video of todays shenanigans to get anyones weigh in/pro tips:

 

[bwalker]

Perhaps I wasn't clear...

The Klotz Octane Booster ("KOB") is not an oil. KOB will increase the octane rating of gasoline. One (1) ounce of KOB per gallon of gasoline raises the octane rating by two (2) numbers. This is a mix ratio of 128:1. If the pump gas starts with an octane rating is 87, then one (1) ounce of KOB per gallon would raise the gasoline octane rating to 89. In my area, I can readily find ethanol-free gasoline with an octane rating of 88. I like to run 90+ octane in my 2-stroke engines, so I use the KOB to reach the 90 octane rating. I then add the appropriate amount of 2-stroke oil (Klotz R-50). My preference is to run a mix somewhere between 40:1 and 50:1...usually a bit closer to the 40:1 level.

JQ

That's 2/10 of 1 pump number.
Think of what KOB octane would have to be to raise 128oz by 2 pump numbers...

 

[Jonny Quest]

That's 2/10 of 1 pump number.
Think of what KOB octane would have to be to raise 128oz by 2 pump numbers...

You may be referring to "points" rather than numbers. Raising 2 "points" would be going from 87 to 87.2 octane. Raising 2 numbers would be going from 87 to 89 octane. The following quote is from the Klotz website:

Octane Booster: 1 oz. of Octane Booster per gallon of gasoline will raise octane by 2 1/2 numbers.

I might be all fouled up, but I've run Klotz for years now in high-performance engines to increase octane in pump-gas where detonation may be a problem. In my experience, the stuff works as advertised.

JQ

 

[scut207]

I know this thread has grown to be quite the topic (had to bust out some popcorn and read through the comments), but I thought I'd let you guys know I took the CS-620P out on its maiden voyage today.
Pulled 3 times with choke until start, decompress, turned the choke off and let her rip!
Let it slow idle for the 100 yard walk back to the tree (30-40 seconds), ran at half mast for about 15 seconds, didnt see that much oil coming off so I backed out the oil adjustment all the way, got some oil but still seemed light (using Echo's bar oil, will watch it tomorrow when I head back out again and see if it'll send more once I start opening her up after her second tank has been consumed).
Limbed and bucked about half an oak today (I've yet to be able to distinguish oak varieties, larger leaf variety haha) and dropped the remaining 25'-30' that was left standing after the storm. The oak took down a beech tree with it that I'll be cutting up as well (dont know much about burning beech wood but i suspect it'll burn well).
Tree was pretty large, probably 28" diameter or more (where I was cutting the hinge).

Definitely have got alot to learn, you can see how un-level my cuts were after I fell the remaining stump haha, will spend more time ensuring that is set right before I continue next time.
Had a pretty decent lean to it so I gave it a shot , that plus no risk of damaging anything (other than myself) if it went somewhere other than planned.

Anyways, thanks again fellas for pointing me in the right direction.
I'm definitely at the base of the learning curve and will always take whatever words of wisdom you all provide.

I posted a video of todays shenanigans to get anyones weigh in/pro tips:

Breaking forum rules trying to bring thread back to original topic...

 

[michael j]

If that's where the carbon deposits are located.. then absolutely.. Decades ago, when I was a much younger man, getting an engine " de-coked" ( de carbonized) was a regular maintenance thing. Literally, putting a hose down the intake of a running engine was a method of removing carbon deposits from an engine. The detonation of the steam i the combustion chamber shook the carbon loose.
Now, we use Seafoam .. It doesn't detonate the carbon off from the combustion chamber, it dissolves it.
Even with today's gas formulas .. we're still burning a carbon based fuel.

We used to take 'em out for a 110 mph tune up!

 

[benelli7d]

Well... ummmm NO! Dieseling is caused by carbon deposits in the combustion chamber that are hot enough to ignite fuel. Dieseling, as you noted, can be solved with a "turn of the screwdriver".. That's true, if you look at it that you've made the idle mixture too lean to run without a proper spark from a plug.
70s' cars used what was called an "anti diesel solenoid" which basically was a base against which the idle screw rested. It was electrically operated. When the ignition was turned off, the anti diesel solenoid made the throttle plate completely close. Hence the engine couldn't diesel, as there wasn't any fuel to do so with.
Leaning out any fuel source may well stop dieseling, but the root cause of dieseling in a carbureted engine is carbon deposits that are hot enough to ignite incoming fuel mixtures, and a throttle plate and mixture setting that continues to supply a combustible mixture to the combustion chamber.. Compression has nothing to do with it.

Well....ummmm NO! While this is one of the triggers for dieseling, it's not the main cause. Case in point. When I was a mechanic at a Pontiac, GMC and Cadilac dealership, back in the day, I had a guy bring in his new '68 GTO, bought two weeks before, and he was complaining about his car dieseling. I took it to my stall and leaned out the idle mixture screw and didn't hear from him again. Now, I'm relatively sure there was no carbon build up in a two week old engine so again, it's purely a rich condition which causes dieseling. No matter what the heat source may be, a rich mixture is the cause and adjustment is the cure. All cars leave the factory tuned to run at sea level, the worst case scenario, and we were at 4200 feet of elevation so, naturally the car was running rich.

 

[benelli7d]

It means about the same thing to you as you being a race engine builder means to me.

Well excuse me for giving a little context to my comment. It sure would be nice to be all knowing and condescending to all about you. It's good to know that while we have you around we can address all of our questions to just a single source and be enlightened! Thanks for being here for us!

 

[bwalker]

You may be referring to "points" rather than numbers. Raising 2 "points" would be going from 87 to 87.2 octane. Raising 2 numbers would be going from 87 to 89 octane. The following quote is from the Klotz website:

Octane Booster: 1 oz. of Octane Booster per gallon of gasoline will raise octane by 2 1/2 numbers.

I might be all fouled up, but I've run Klotz for years now in high-performance engines to increase octane in pump-gas where detonation may be a problem. In my experience, the stuff works as advertised.

JQ

2/10th of one pump number. Do the math I suggested.

 

[HarleyT]

Anyways, thanks again fellas for pointing me in the right direction.

Which direction is that?

 

[rogue60]

I posted pictures on here of detonation in a STOCK ms660 years ago.
Fuel was stale what made me think something isn't right was the saw was running very hot so shut it down after few hrs running it like that lol.
On pulling the cylinder the piston had bubbles melted into it and worse out towards the squish band. The combustion chamber had bubbles melted into it also.
Anyways cleaned it all put it back together and learned it's best to stick with fresh fuel seeing how rubbish pump fuel is now day's, the saw run for years more after that.
I still have the saw might pull it down again and get more pictures of the detonation that apparently never happens in stock saws lol

High octane or low octane I can't tell the difference running either in a saw but one thing I do know if fuel has ethanol in it it's about useless running it in saws in summer boils and vapor locks in minutes total rubbish. I have to buy 98 octane pump fuel in summer as it doesn't have ethanol in it down here. And yes our octane ratings are different to the USA.

 

[ZeroJunk]

Typical response from a guy that doesn't understand the basics of engine theory...

Yeah, I'm sure being a laborer at some oil place gives you a key understanding.

GM dropped the compression ratio on their flagship engines from 10 to 1 or thereabouts to 8.5 to 1 in 1971.

Obviously no point in doing that if they could have just talked to Walker or Benelli .

 

[bwalker]

Yeah, I'm sure being a laborer at some oil place gives you a key understanding.

GM dropped the compression ratio on their flagship engines from 10 to 1 or thereabouts to 8.5 to 1 in 1971.

Obviously no point in doing that if they could have just talked to Walker or Benelli .

In the first place I am not a laborer. In the second a laborer in the oil industry makes three times the money a guy that fixes power equipment makes and it takes more education and knowledge to boot. So who is the dumbell?
It's pretty apparent you don't have a clue what the hell your talking about most of the time.
Its.well known that all the auto mfgs dropped compression in and around 1971 along with many other changes. What's your point?

 

[benelli7d]

Typical response from a guy that doesn't understand the basics of engine theory...

I think you're 100% correct here Ben. I think this guy is just one of those who likes to hang around and cause hate and discontent whenever possible without actually contributing any measurable beneficial knowledge to a discussion. And, there's probably a reason for that!

 

[bwalker]

I think you're 100% correct here Ben. I think this guy is just one of those who likes to hang around and cause hate and discontent whenever possible without actually contributing any measurable beneficial knowledge to a discussion. And, there's probably a reason for that!

Thats exactly it.

 

[ZeroJunk]

In the first place I am not a laborer. In the second a laborer in the oil industry makes three times the money a guy that fixes power equipment makes and it takes more education and knowledge to boot.
It's pretty apparent you don't have a clue what the hell your talking about most of the time.

Actually, I retired when I was 50 years old, 19 years ago. Cause I never made any money I suppose.

I do work on Stihl OPE on Tuesdays and Thursdays from 7 AM till whenever.

You handily ignored why the dropped the compression ratio.

Just hadn't met you and Benelli .

 

[ZeroJunk]

That's funny, wonder if the will delete outdooor power equipment.

 

[bwalker]

Actually, I retired when I was 50 years old, 19 years ago. Cause I never made any money I suppose.

I do work on Stihl *** on Tuesdays and Thursdays from 7 AM till whenever.

You handily ignored why the dropped the compression ratio.

Just hadn't met you and Benelli .

I didn't ignore that at all. I am just waiting on your take as to why.. this should be good.

 

[scut207]

why ya'll need to get in tallywacker measuring contests is beyond me.

The simplest way to avoid this is to provide citations. If youre going to get in a heated discussion. provide a scientific source to back your opinion.

I'm an electrical engineer, the field is so vast that I hate telling people what my degree is in during normal conversation. They'll ask me some relatively easy circuit question that I could have probably answered off the top of my head 20yrs ago, but I have CRS, the thimble is full. I get imposter syndrome all the time, I'm only comfortable being an expert in such a very small niche corner of it. Given time I can usually figure the stuff out, but on the spot, no.

All truly intelligent & wise people are completely open to the suggestion that their opinion can be incorrect, and are open to modifying it when presented real quantifiable data that is counter to that opinion.

 

[ZeroJunk]

why ya'll need to get in tallywacker measuring contests is beyond me.

The simplest way to avoid this is to provide citations. If youre going to get in a heated discussion. provide a scientific source to back your opinion.

I'm an electrical engineer, the field is so vast that I hate telling people what my degree is in during normal conversation. They'll ask me some relatively easy circuit question that I could have probably answered off the top of my head 20yrs ago, but I have CRS, the thimble is full. I get imposter syndrome all the time, I'm only comfortable being an expert in such a very small niche corner of it. Given time I can usually figure the stuff out, but on the spot, no.

All truly intelligent & wise people are completely open to the suggestion that their opinion can be incorrect, and are open to modifying it when presented real quantifiable data that is counter to that opinion.

If I said the Earth is round bwalker would say it's flat. About that simple.