.404 vs 3/8 chain test - Stihl 661 w/ 28" tsumura

[redbull660]

test saw - 661R
test bars - tsumura 28" 3/8 .063 & 28" tsumura .404 .063

7 pin rim sprocket for both 3/8 & 404

Test chains -

new Stihl Rapid super 3/8 .063 91DL
vs
new Stihl Rapid Super .404 .063 83DL
vs
new Custom made Rapid Super Half Skip 3/8 .063 91DL
vs
new custom made rapid super half skip .404 .063 83DL
vs
new custom made rapid super "double skip" Ground down every 3rd cutter 3/8 .063 91dl
vs
new custom made rapid super "double skip .404 .063 83DL

RS .404 full comp - awesome in the softer wood including the oak. little rough in the rock elm or whatever it is...hard as a rock is what it is! ...so the rock elm was rough with all the chains.
RS 3/8 full comp - very smooth. 661 pulls this at 36" with no problem.
RS .404 half skip - really smooth and stays sharp forever. Wish they made it!
RS 3/8 half skip - really smooth...maybe too smooth.
double skips - really really really smooth but SLOW! oh well it was interesting to do it.

- surprised .404 full comp was fastest
- pleasantly surprised .404 ran cooler

 

[CR888]

l run 404 on many saws that would come off the shelf with 3/8. My ported 660 has a 20" 404 setup and loves it. The cutters hold up better in hardwood and take far more of a beating in between sharpening. lt is also better value than 3/8, you get a lot more cutter which equates to more filings. l run it on my 6400 Dolmar too, no problems. At the end of the day l think it cuts as fast if not faster than 3/8 but even if it did'nt, l'd still run it for its durability qualities and longer chain life. .404 is not the flavour of the month around AS but in Aussie hardwood that will sink straight to the bottom when put in water, it rocks! l find it also increases production with greater cutting time between sharpenings.

 

[Moparmyway]

I love .404 !
I converted over to it on my 90cc saws and never looked back.
I just might get .404 bars for the 70cc saws the next time I find myself needing a new bar ................

Redbull,
What pin count did you run ?
I am assuming 7 pin on the .404, but what about the .375 ?

 

[CR888]

l have an eight pin .404 which is larger in diameter than a nine pin .325 sprocket! So a seven probably works best under most conditions but even a seven is larger than an eight pin 3/8. Nice noodling chain, l use canola bar oil and use the noodles to smoke pig necks. Very tasty.

 

[Moparmyway]

l have an eight pin .404 which is larger in diameter than a nine pin .325 sprocket! So a seven probably works best under most conditions but even a seven is larger than an eight pin 3/8. Nice noodling chain, l use canola bar oil and use the noodles to smoke pig necks. Very tasty.

Yeah, I have mine running a 7 pin .404 and noticed that its larger than the .375 8 pin
That's why I was wondering what pin rim he used on both ............... better to be sure than to ASS u ME ........

I cant imagine an 8 pin .404 ........... what size bar do you run that with, and how hot does the bar get ?
The chainspeed has to be ridiculous and the torque loss has to match, no ?

 

[Moparmyway]

test saw - 661R
test bars - tsumura 28" 3/8 .063 & 28" tsumura .404 .063

Test chains -

new Stihl Rapid super 3/8 .063 91DL
vs
new Stihl Rapid Super .404 .063 83DL

RS .404 full comp - awesome in the softer wood including the oak. little rough in the rock elm or whatever it is...hard as a rock is what it is! ...so the rock elm was rough with all the chains.
RS 3/8 full comp - very smooth. 661 pulls this at 36" with no problem.

- surprised .404 full comp was fastest
- pleasantly surprised .404 ran cooler

RB,
I just watched the full comp video ............. did you notice anything particular (between the .404 and the .375) when making the cuts ?
Particularly the time section of 3:35 - 3:45 ?

 

[buzz sawyer]

Yes, sounded like it was 4 cycling more - either running richer or less load, but the rpms didn't seem to increase much?

 

[blsnelling]

You would have to run a 8-pin 3/8 sprocket for this to be a test of the chain. You're making quite a bit more chain speed with the larger diameter .404 7-pin sprocket.

 

[HuskStihl]

Super surprised. Given equal sharpness and chain speed, the narrower 3/8 should be doing a whole lot less work than the .404

 

[blsnelling]

He ran a much larger diameter sprocket with the .404, which equals significantly higher chain speed. Obviously, the saw had the power to pull it.

 

[redbull660]

7 pin on both.

3:35 - 3:45 - that piece of oak was moving on me, so I probably didn't have as much pressure on it as I normally would. I doubt it made more than a 1 sec difference.

Still amazed that they are as close in times as they are.

On the 7 pin vs 8 pin issue - I did a test a while back with my 660 + 20" bar with 7pin vs 8pin. 8pin just lost so much torque....even at 20". Found the thread - http://www.arboristsite.com/community/threads/7-vs-8-pin-on-660-461-20-bar.267224/

 

[blsnelling]

7 pin vs 8 pin - I did a test a while back with my 660 + 20" bar with 7pin vs 8pin. 8pin just lost so much torque....even at 20". Found the thread - http://www.arboristsite.com/community/threads/7-vs-8-pin-on-660-461-20-bar.267224/

The number of pins is not what matters. It's the diameter. This is gearing. Look at the two sprockets you used. The 7-pin .404 is much larger than the 7-pin 3/8. You would have to use a 8-pin 3/8 to equal that out.

 

[blsnelling]

As i recall there isn't THAT much difference in diameter between the 7pin 3/8 and the 7pin 404. But i'll have a look see.

There is a lot of difference.

 

[big t double]

3/8 8t measures 1-5/8" diameter for what its worth. im staring at one now....

 

[blsnelling]

I'll be so bold as to say that if it was faster with 7-pin .404, it'll be faster yet with 8-pin 3/8. If I were home I'd measure one for you. The 8-pin 3/8 is by far the closest in size.

 

[blsnelling]

Would you guys be able to measure the circumference for us? Either that, or diameters measured with a caliper.

 

[redbull660]

well according to big t double in post #17 8 pin 3/8 measures 1.625".

So
7pin 3/8 is 1/8" smaller than 7pin 404
and
8pin 3/8 is a 1/8" larger than 7pin 404

all theory & speculation til it's tested.

just send me one.

 

[Outlaw5.0]

I do R&D type work so this stuff really interests me, keep up the good work.

 

[Trx250r180]

I see the .404 has a lot less drivers ,do you have a scale to weigh the 2 chains ? I have always been told .404 will weigh down my bar ,I have a feeling it can not be a whole lot of difference ,In the semi dirty wood i was cutting yesterday ,I think the .404 would have lasted longer before went dull . I want to try some out cutters per foot may be a factor in power and cut speeds also ,i bet you lose at least one per foot maybe 2 if measure them .

 

[blsnelling]

As measured with a caliper. Thanks Randy.

Rim - Diameter - Circumference - Difference
3/8 7-pin = 1.389" = 4.36"
.404 7-pin = 1.521" = 4.78" = + 8.8%
3/8 8-pin = 1.605" = 5.04" = + 5.4%

The 3/8 8-pin is larger than I thought, but still closer. My apologies. I still think you would find it faster than the .404, but maybe not.

To be honest with you, I was thinking 3/8 7-pin vs .325 8-pin. Those are very close, only 2.8% difference.