Welp, here's my vid dismantling the Brad Snelling saw!
Husqvarna 350 comparison video with cut times!
- Thread starter Mattyo
- Start date
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Mike Gott
ArboristSite Guru
Why are you dismantling his saw?
Because Brad told me to... otherwise I wouldn't have done it. This is an independent investigation into what's inside a Brad saw. 
when I work on saws, they are mostly completely trashed saws.... I try to go in, do what I need to do, and get out. I don't do nearly as much tinkering with port timings and numbers and this and that as most of the porters. I just want to have saws that run well, and call it a day
when I work on saws, they are mostly completely trashed saws.... I try to go in, do what I need to do, and get out. I don't do nearly as much tinkering with port timings and numbers and this and that as most of the porters. I just want to have saws that run well, and call it a day
Yeah, why are you tearing my saw apart? And then he just threw it all in a box and sent it back to me!
Paragon Builder
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Damn. Hopefully you know someone that knows where all the pieces go...Yeah, why are you tearing my saw apart? And then he just threw it all in a box and sent it back to me!
hopefully I put all the right pieces in the box 
Paragon Builder
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Brad, thanks for making the effort to be a part of this. It was cool to have so many saw builders be part of this gtg! Btw, I was showing some pics and video to my local stihlership and turns out he is friends with you on Facebook and knew about it but didn't know where. Jason from beaver brook saw shop.
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
I'll clarify a few things I noticed in the video.
Squish on this saw was only .014". I machined the topend for my 346 where it was more like .018". On A small saw like this I wasn't too concerned about it being .014". I don't consider .018" tight at all on a small saw like this.
The reason you got .018" is two fold. First, you must check two sides at the some time in order to prevent piston rock. Second, you must use a dial caliper to measure it. The squishband is tapered and you need to measure the tightest spot, right up against the cylinder wall. It's much narrower than what can be measured with a micrometer.
The oval exhaust port... It's all about ring wear. Square is better for performance, but I don't want to catch a ring, especially when it's 70% of the bore wide. I match the factory curve and widen it. No rings cross the intake so it can be as square as you want.
Opened up transfer ducts... This was an experiment. I normal case match and then quickly taper it into the duct, not enlarging the duct at all. However, I modded this cylinder like I did on the Dolmar 7910, which worked very well. I widened the main transfer port towards the exhaust, rather than widening the secondaries towards the intake. That matches up well with the case matching on the base. So, I took the widened transfer intake all the way on up into the duct to match up with the widened transfer port. I guess it worked I will be testing this further when I get it back.
Did I miss anything? Oh. Transfer port timing was 120 on the mains and 122 on the secondaries, staggered. I recommend either a tiny flex light that fits siren into the cylinder or a small pen light that only shines into the cylinder. That will make it much easier for you.
Hope this helps.
Squish on this saw was only .014". I machined the topend for my 346 where it was more like .018". On A small saw like this I wasn't too concerned about it being .014". I don't consider .018" tight at all on a small saw like this.
The reason you got .018" is two fold. First, you must check two sides at the some time in order to prevent piston rock. Second, you must use a dial caliper to measure it. The squishband is tapered and you need to measure the tightest spot, right up against the cylinder wall. It's much narrower than what can be measured with a micrometer.
The oval exhaust port... It's all about ring wear. Square is better for performance, but I don't want to catch a ring, especially when it's 70% of the bore wide. I match the factory curve and widen it. No rings cross the intake so it can be as square as you want.
Opened up transfer ducts... This was an experiment. I normal case match and then quickly taper it into the duct, not enlarging the duct at all. However, I modded this cylinder like I did on the Dolmar 7910, which worked very well. I widened the main transfer port towards the exhaust, rather than widening the secondaries towards the intake. That matches up well with the case matching on the base. So, I took the widened transfer intake all the way on up into the duct to match up with the widened transfer port. I guess it worked
I will be testing this further when I get it back.Did I miss anything? Oh. Transfer port timing was 120 on the mains and 122 on the secondaries, staggered. I recommend either a tiny flex light that fits siren into the cylinder or a small pen light that only shines into the cylinder. That will make it much easier for you.
Hope this helps.
Great work Ol Buddy.
sounds good Brad... thanks again
cedarshark
Addicted to ArboristSite
Thanks to Mattyo for compiling the video and Brad for a peek at some very nice work. That saw pumping out 5.3 h/p just blows me away. The power of a 372 in a compact/lightweight package is just too nice !
lets wait for the polynomial graphs to come out before we figure out what peak hp is likely to be... the peak hp ratings on the graphs may not be entirely accurate due to the fact that if the operator wasn't super smooth with the brake the hp numbers go way up. that said, no matter how you slice it, I think Brads motor was fairly consistently above 5hp over a good rpm range.
That's why I didn't post the graph showing over 6HP. That was an anomaly. The other two were within .1 HP with a similar curve.
ok, I can do a 2nd order polynomial graph in excel, but I can't export it.... ie, its not repeatable...and I can't overlay it w/ anything else for some reason
cedarshark
Addicted to ArboristSite
Matt, did you get to run your 350's on the dyno ?
yup, and I have the graphs, just trying to figure out how to make them readable....
Are yours different than mine? Two of the three of mine were nearly identical. The other was an obvious anomaly so I threw it out.
what I may do is manually manipulate the data... the graphs can be very different between runs because the amount of data collected is a result of TIME ...not RPM..... plus the more Bill ran the dyno, he got better at using the brake/dyno and was able to get smoother data....
what I'm going to have to do is merge all the data for the 350 runs somehow, and plot all those different lines color coded in a graph form.... gonna take time, and I have very little ambition right now ....
what I'm going to have to do is merge all the data for the 350 runs somehow, and plot all those different lines color coded in a graph form.... gonna take time, and I have very little ambition right now ....
Were there not at least two of the three graphs similar in curve and max HP for each saw?
One of mine showed well over 6 HP but the other two were nearly identical in curve and within .1 HP at 5.2-5.3 HP. It was obvious the one was off so I threw it out completely.
One of mine showed well over 6 HP but the other two were nearly identical in curve and within .1 HP at 5.2-5.3 HP. It was obvious the one was off so I threw it out completely.
