661 Oil Test 32:1 vs 40:1 vs 50:1 ?

[Marshy]

She was nice and normal during most of the cuts and got wet at the end. (Longer idling and much less load).
She runs Marshy, don't know why you would think otherwise

Im sure it runs, just joshin ya. Lets see a cut with that beast.

 

[Marshy]

been talking to homelite about the Iowa GTG. Sounds like there will be some good wood there.

Also looks like I might be able to do some tests after maulhead's ported 661 kicks my muff modded 661's azz!


Test I was thinking of that might be fun:

661 - 18" wood. 20" 24" 28" 30" and 36" bar - do some cuts see how the times differ and if temp of saw differs with different length bars.

The above would be with 3/8ths tsumura bars. I could also do .404 bars as well.

Im sure theres a little extra resistance from having to turn more chain but you'll have the same number of teeth in the cut so I wouldnt expect a significant difference between cuts.

 

[Moparmyway]

Lets see a cut with that beast.

I gave up on videoing my stuff ...............
When mdavlee ran it after he ported it, he said that he was impressed.
So am I !!
He might have posted a video of it somewhere

****
Just an aside, she was wearing a 25" RS square filed with deep rakers.
Unless the tip was buried, she would 4 stroke in the cut.
I didn't want to lean her out anymore, WOT was already above 14,000
She was built for the bigger stuff, not general bucking, more for stumping.

 

[bikemike]

Looks like unburnt fuel is coming out your exhaust. Can you post a video of this saw cutting if it runs?

Put a torch to the exhaust gasses as its running maybe it will burn the saw dust up too

 

[Marshy]

Sounds like your leaving a lot of performance on the table with your tune then. Unloaded RPM just gets you in the ball park for tuning. Its not something I would use to set my final tune on a saw. I just go by ear and feel in the cut. Ideally, it should cleanup right after it enters the cut and not need moderate to heavy pressure to get it to clean up in the cut... jut my $0.02...

 

[Moparmyway]

Sounds like your leaving a lot of performance on the table with your tune then. Unloaded RPM just gets you in the ball park for tuning. Its not something I would use to set my final tune on a saw. I just go by ear and feel in the cut. Ideally, it should cleanup right after it enters the cut and not need moderate to heavy pressure to get it to clean up in the cut... jut my $0.02...

I only used WOT as a reference, if you read into what I wrote in those posts, it might weigh heavier on you.

 

[Marshy]

I only used WOT as a reference, if you read into what I wrote in those posts, it might weigh heavier on you.

Just sayin, having to bury a 25" bar to get it to clean up is FAT. Probably why the top of your piston is shiny.

I said fat, I hope 08f150 doesnt post a pic now.

 

[bikemike]

One of my saws runs 25:1 mix who has a problem with that? Thats what is recommended for this 15cc pig

 

[Marshy]

One of my saws runs 25:1 mix who has a problem with that? Thats what is recommended for this 15cc pig View attachment 420599View attachment 420600

Is it ported?

 

[bikemike]

Is it ported?

No to port it it would need a dental grinder. Im going ro leave it stock. I paid 40 for it and the cheepest one on ebay and craigslist is 400 to 600

 

[Trx250r180]

Looks like unburnt fuel is coming out your exhaust. Can you post a video of this saw cutting if it runs?

I bet it runs like this

 

[Marshy]

It almost sounds like its ported.

 

[Moparmyway]

I bet it runs like this

It sure dang does !!!!

 

[Moparmyway]

Just sayin, having to bury a 25" bar to get it to clean up is FAT. Probably why the top of your piston is shiny.

I agree. However, if I did tune the saw to that little bar, the WOT would have been above 15,000.
She was built to run a 36" .404 stumping, not flex its muscles cutting 22" cookies.
Excess RPM's on something known to spin main races is just asking for Mr. Murphy to join in.

 

[blsnelling]

It almost sounds like its ported.

I bet that thing is leaking bar oil into the crankcase.

 

[bikemike]

I bet that thing is leaking bar oil into the crankcase.

Or it needs high tack low sling oil for all the power it makes

 

[bwalker]

Thanks Capt Obvious


She was nice and normal during most of the cuts and got wet at the end. (Longer idling and much less load).
She runs Marshy, don't know why you would think otherwise

You must be happy with your equipment running like ****.. the H1R ran saw.looks hardly ran, but it's building up unburnt oil in the muffler too.

 

[bwalker]

I went through the entire thread again. Kind of a summary of key points:


- A chainsaw was a low stress application relative to motorcycles and other small engines with the same displacement but far more hp being squeezed out of it.

- All ester oils burn clean - obviously not true as Stihl ultra is pretty dirty. So it depends.

- Some agreed that the amount of oil was more critical then the quality. Figuring oils we are looking at, were designed for more stressful applications. 32:1 stihl ultra included in list. We know ultra burns really dirty specially at 40 and 32:1, so I'd have to disagree with them on the quality.

- Carbon Build up - Seems the over all consensus is that we want thinks as clean as they can be.

- Solvents - bwalker - noted that solvents typically don't work to remove carbon. And that solvents break down oil. So it would seem some are ok. But a lot would be less than ideal.

- Some say the high flash point oils (r2, k2, 710, lucus) don't combust very well or at all and leach heat and horse power out of the combustion chamber. They believe you do not see the benefits of these heavy viscosity oils in a low stress application like a chainsaw. They support the lower flash point oils that they view as offering more complete combustion and offer more horse power. They view the film strength loss with said lower flash point oils as a problem of the past.

- While others support the higher flash point heavier viscosity oils. (r50 800 h1r) especially in the ported saws or saws used for milling. Protection seems to be the primary reasoning. Citing bearings last longer with more oil, ring seal is better, more compression, hp is higher.

- either of these sides seem to favor a 32:1 ratio. adding my 2 cents...I am of the opinion that the higher viscosity oils should be used, but tested/tried at lower ratios than the accepted norm. Such as 36:1 40:1 42:1 45:1. Especially in stock saws.

- synthetic vs conventional - It was noted that you need less synthetic because it burns slower.

- PIB is noted as doing a great job of preventing scuffing. Also noted is that Scuff resistance is largely a component of the viscosity. And that the viscosity of PIB is much higher than the viscosity listed. Viscosity listed is the over all. my two cents...after looking into PIB further it has been stated it is the component of some synthetic oils which causes "glazing".

- Strato - it is noted that they like to be run more lean. Also noted that the mtronics tend to run rich. adding my 2 cents... maybe this is why the 361 and 661 seemed to like 45:1 while the 660 liked 40:1 in my tests.

- certified oil JASO ISO - this seems like it would make things easier. But I would note Stihl Ultra is Jaso- and it burns dirty.

- dyno - one person cited that the increases in hp with increased oil - could likely be a direct results of the saw being leaned out.

I could correct all that's wrong with this post, but it would take all day.

 

[Moparmyway]

I could correct all that's wrong with this post, but it would take all day.

...hell a fair amount of it, is stuff you said!

Priceless

 

[blsnelling]

- All ester oils burn clean - obviously not true as Stihl ultra is pretty dirty. So it depends.

I spoke with a customer of mine that runs Stihl Ultra @ 40:1 and the crown of his pistons are completely clean. The difference? He runs 100LL fuel. This would suggest that the fuel has as much to do with it as the oil. Food for thought