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

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Which makes testing very hard..unless your someone like Cahoon or the like

luckily I pre-tested this problem and found a solution..

email to another member here that I bounce stuff off of.

Played with 28 cannon 3/8ths wide tip vs 28 tsumura 3/8ths and also the 36 cannon wide 3/8ths tip vs 36” tsumura 3/8ths.

Spent a lot of time fcking around with these bars today. I spent some the other day fcking with them as well. Here are my observations…


First I started by doing single cuts in ash. The degree in which I applied pressure and how warm the saw varied. But here are the times.


7pin 28 can = 19.7 sec saw warm natural pressure.

7pin 28 tsu = 20.8 sec saw not warm natural pressure.

7pin 28 tsu = 21.6 sec saw warm but light pressure

7pin 28 can = 24.3 sec saw not warm but light pressure


Basically I was just hoping I could get a clear sense of the differences with out much work. The last cut threw me off. I knew they were close the other day.


Ok so going more scientific now. So thinking light pressure = slow times on the cannon let’s try all max pressure and see what we think. Max pressure = just below what would really bog down the saw.

7pin can – saw warm/ready, MAX pressure. 22.4 22.1



7pin tsu – didn’t do my normal burn cut to get saw warm/ready, max pressure. 21.6 19.1 so first cut slow.



So at this point there is some confusion …but let’s try 8pin.


Tsumura first this time.

8pin tsu – saw warm/ready, MAX Pressure – 19.0, 19.4 so these were back to back from the 7pin max pressure cut. Ok consistency. GOOD. But confusion…I’ve got MAX Pressure on 7pin and 8pin and I’m coming up with same times 19s. Lol moving on



8 pin can – saw warm/ready , MAX Pressure – 19.7 19.1 ok WTF I had max pressure on 7pin and was doing 22 sec cuts. Now I have max pressure with an 8pin and I have 19 sec cuts? You would think the wood was bigger before. But my very very first cut of the day…in this email was a 19.7. 8pin can – continued…I did a 3rd cut with just medium heavy pressure. Basically a little more than natural - 18.3 sec. LOL

 
Moving on to 36” (different logs) these are 7pin based on my 7 vs 8 pin test with 36” bar.

36 can warm up cut 24.3



36 can warm and ready – 23.6 21.1 I know the first cut was heavy pressure and I think the 2nd one I was getting tired of doing max pressure so I don’t think I was putting as much force on it. Saw was warm and ready as I did a warm up cut.



36 tsum warm up 23.3 so about 1 sec faster than 36 can



36 tsu 19.4 19.4 19.4 1st and 2nd cut natural pressure 3rd cut max pressure.



Ok taking all this data into consideration. Including the data from the other day.


Tsumura - Seems the tsumura doesn’t care much if it’s 7 or 8 pin on the 28 and doesn’t seem to care much if it’s natural pressure up to max pressure. The warm cuts with natural and max pressure were all 19s. This seems to hold true with the 36” bar on a different log. Granted I only did 7pin stuff.


Cannon – This bar is picky..


- You have to tension it just right. I think it’s VERY easy it get it too tight. The tsumura is far more forgiving. Obviously it has to do with the wide nose on the cannon.

- It doesn’t care for light pressure and it doesn’t care for max pressure.

- The bar seems to thrive on chain speed. Given how the times vary with different pressure, seems pretty fcking indicative that the wide nose has some sort of effect on torque.


So I think I’ll test my theory and try for natural pressure on the cannon with 7 and 8pin vs 8pin tsumura natural on 28”. Also do the 36” again natural on both. Also I think when I test 404 on the 28’s that stuff is pretty much self feeding so it would be highly interesting if natural pressure holds true or the extra torque the 404 requires shows the cannon for what it’s for….increases chain speed and depends on that and reduces torque. Anyway at this point I’m just curious if I can make it faster than the tsumura. I wouldn’t use it for the oil test. It’s too sensitive to pressure…thus inconsistent. Furthermore it’s easy to screw up the tension. But it is interesting to me as it seems to have the capability to be a racing bar. Maybe I”ll try 36” RSLF as well …with an 8pin.


OIL TEST –


So at this point it’s 28 tsumura with RD3 carbide chain 8pin figure the carbide will be easy to sell, won’t dull, and will provide a little more resistance vs RS. Ie. Take longer…which is fine. I ordered some and will get it on Thursday I hope and evaluate it.

Or

28 tsumura with 404 RS. Saw still has the power to pull this stuff…30 is pushing it. Your talking 83dl vs 91dl. Anyway 404 7 sprocket is right in the middle IIRC of the 7 3/8 and 8 3/8. Provides enough resistance that you get a nice self feed from natural pressure. It should be some what easy to sell, but I’ll have to remake it into custom lengths.

OR

28 total super bar with 28” RS chains. Just don’t know if this chain provides enough resistance. The .050 would be nice for resell. Total is a solid bar and runs same speed as tsumura well just a touch slower. Probably due to the heat dissipation of the cut outs on the light bar.


few days later ...


i did the 36" cuts with natural pressure.

36 tsumura = 19s nat pressure
36 can = 22.5 then 25.1 lol nat pressure cut1 22.5, then I must of lightened up or something...I honestly don't know! cuz i got 25.1 lol

36 tsumura again just to test it ...19.7

ok trying 3/8 full skip

36 tsumura with full skip 3/8 7pin - 28s nat pressure
36 tsumura with full skip 3/8 8 pin - 26s nat pressure
36 cannon with full skip 3/8 8 pin 25s finally bar won. 8pin with wide nose and a full skip chain = a lot of chain speed.


so what does all this sh*t mean? best I can figure...

the wide tip, Basically creates some sort of different gearing. Which..

1. makes the bar depend on chain speed more or the new gearing creates more chain speed.

2. must reduce torque or something cuz it's very inconsistent if your pressure is mildly inconsistent. Just don't know how else to describe it. The Tsumura doesn't seem to give a fck. Just pumps out the same times no matter what. Cannon is all over the place. AND I know this wasn't true of the narrow tip!!! So it's just that fcking wide tip.

All that said about the wide tip - I still like it a ton. I just love how it cuts....i dunno just something about it. BUT it's just not consistent for this test.
 
Later on I tested carbide with 7 and 8 pin and it just wasn't going to maintain the same speed for as many cuts as I need it to. It's great stuff but I'm asking it to be the same speed after about 100 cuts. It's close but it's just not going to happen.

Today I was figuring out what ratios to do. 32 40 and 50 are the obvious ones. So I made this up to see the percentages differences that are in play...

32:1 has 12.4% more oil in the mix than 36:1
32:1 has 25.0% more oil in the mix than 40:1
32:1 has 40.8% more oil in the mix than 45:1
32:1 has 56.3% more oil in the mix than 50:1


36:1 has -11.0% less oil in the mix than 32:1
36:1 has 11.2% more oil in the mix than 40:1
36:1 has 25.2% more oil in the mix than 45:1
36:1 has 39.0% more oil in the mix than 50:1


40:1 has -20.0% less oil in the mix than 32:1
40:1 has -10.1% less oil in the mix than 36:1
40:1 has 12.6% more oil in the mix than 45:1
40:1 has 25.0% more oil in the mix than 50:1


45:1 has -29.0% less oil in the mix than 32:1
45:1 has -20.1% less oil in the mix than 36:1
45:1 has -11.2% less oil in the mix than 40:1
45:1 has 11.0% more oil in the mix than 50:1


50:1 has -36.0% less oil in the mix than 32:1
50:1 has -28.1% less oil in the mix than 36:1
50:1 has -20.0% less oil in the mix than 40:1
50:1 has -9.9% less oil in the mix than 45:1



beyond that the most interesting tid bit of the last few days, is the testis I have done in pre-testing between different oils. It seems that viscosity may just end up playing the largest role here.

basically...

the lowest visc's have been doing best even at 32:1

I talked to andrew about it.

summary -

- higher visc oil...much stronger film strength but is causing a film strength that is slowing the piston down. IN a chainsaw! Cuz we are talking much higher horse power with bikes etc vs chainsaws.

- and you can't really reduce the film strength of a high visc oil with out reducing ratio well past 50:1 or a point/ratio, that is probably unsafe.

- visc is obviously not the only factor in play. Lubricity - is also at play. So while you may have a oil with a low visc is still may end up being slower than a high visc number due to it's lesser lubricity/quality.

Point - most likely the lower visc oils are going to prevail. And it would seem to make sense to take the fastest performer (indicator of high lubricity) with the highest viscosity (film strength) at a ratio which ya'll can live with. I think Temps will play a key role in determining if a ratio is too high.

All that said - checking some of the dedicated chainsaw oils out there - from what i can tell they all have viscs in the 7s and 8s.

there really aren't any metrics on "lubricity". it's not exactly easy to get a number to compare. So you have to test the oils.
 
the lowest visc's have been doing best even at 32:1

I talked to andrew about it.

summary -

- higher visc oil...much stronger film strength but is causing a film strength that is slowing the piston down. IN a chainsaw! Cuz we are talking much higher horse power with bikes etc vs chainsaws.

- and you can't really reduce the film strength of a high visc oil with out reducing ratio well past 50:1 or a point/ratio, that is probably unsafe.

- visc is obviously not the only factor in play. Lubricity - is also at play. So while you may have a oil with a low visc is still may end up being slower than a high visc number due to it's lesser lubricity/quality.

Point - most likely the lower visc oils are going to prevail. And it would seem to make sense to take the fastest performer (indicator of high lubricity) with the highest viscosity (film strength) at a ratio which ya'll can live with. I think Temps will play a key role in determining if a ratio is too high.

All that said - checking some of the dedicated chainsaw oils out there - from what i can tell they all have viscs in the 7s and 8s.

there really aren't any metrics on "lubricity". it's not exactly easy to get a number to compare. So you have to test the oils.
What are you referring to when you say lubricity?
I would also not discount how an oil influences combustion. Some oils inhibit combustion while others dont.
 
Wide nose can't change "gearing". It's an idler wheel.
What does widenose do better or not? Should bore and cut better with the nose buried as the radius isnt as small and the back edge of the tooth isnt hitting the wood at such an extreme angle with more resistance?
 

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