First Chainsaw Build, Ratty Husky 351 to Ported 346xp

[Rickick91]

Hello Everyone,

Long Time Lurker here soaking up all the wonderful knowledge and experience on this forum. I had dabbled with muffler mods on my new 562xp and MS241CM when I got them over the last few years but didn't want to screw them up as they were good and shiny. Lots of reading and the cult-esk following of the 346xp caused me to gravitate to it for a good 50cc class saw. I kinda jumped to the less plentiful sizes first with 60cc and 40cc, but its just the way it went. Now I'm back tracking to the 50cc to fill out my lineup and found a decent 351 on fleabay that surprise to me ran when received after replacing the pull starter. I am building it into a 346xp with an OEM piston and cylinder, and some mild port work and thinner gasket to get about .020 squish. From what I gather from those who have done this hundreds of times that is a safe number. Here are some pics so far. I know the 346 is a bit played out, but hadn't seen one ported exactly the way I did this one and wanted to get feedback on my choices for the transfer shape. I tried to flare them and case match without increasing CC volume to much. I flared the Intake side transfers both toward the intake and into the center divider to give it the maximum flow, and the exhaust sides which had more case space to work with I only flared to the exhaust side. I tried to remove any imperfections but only flared the first third of the ports to keep low volume and didn't really touch the outlets. I figured this layout would give all 4 ports the most equal cross section of the charge to give even flow. I also widened the exhaust by 2mm to 27 mm width at the port, and squared it slightly. I was going to go to 29mm to be around 65% of the diameter, but chikened out as the port walls were getting below .120" in places. I matched the outlet to the gasket and polished with cratex on the dremel and the buffer wheel. The intake was trued to the boot, and a bit of the bulge on the one side filed out a long with the casting flaws. sorry for the long post. I' ve done a lot on it the last few weeks.

 

[rupedoggy]

Just me but I don't like the look of the finish on the cylinder walls

 

[Rickick91]

A question I have for the knowledgeable is that the piston and cylinder on the 351 as I recieved it look like a closed port 350 jug, but are 44mm and I confirmed that by the fact that the 44.3 mm 346 piston will not fit. I thought all the 351s were 44mm open port and could not find any info to the contrary. The jug seems to be OEM (Husky symbol on transfer covers) am I missing something or is this an odd cylinder?

 

[Rickick91]

Just me but I don't like the look of the finish on the cylinder walls

It wasn't perfect from the factory and had 1 tiny spot in the nikasil that i could catch with my nail. I bought second hand so it couldn't be returned to the dealer and wasnt anything i thought would cause issues. The pictures make the honing look bad, but it is very smooth aside from a few tiny wups marks from me. I'm not happy about them, but couldn't help the tool jumping or the jug jumping out the vise. I just lightly hit those spots with the scotch bright. I don't think any of it will have a measurable affect on the performance, but even if it does I cant afford to buy another cylinder right now so it will have to do.

 

[Huskitoter]

A question I have for the knowledgeable is that the piston and cylinder on the 351 as I recieved it look like a closed port 350 jug, but are 44mm and I confirmed that by the fact that the 44.3 mm 346 piston will not fit...

Sure looks like a 45mm 350/353 cyl.

Good looking saw. GL with the build.

 

[champion221elite]

I have no input on the build, but wanted to comment on your photography skills. Very nice pics. Well lit, clear and nicely composed. Well done!

 

[pennsylvaniaboy]

isnt the 351 a bigger saw than a 346??

 

[buttercup]

Just me but I don't like the look of the finish on the cylinder walls

I would question that dude, I see mostly honing traces and just one trace of the piston going up and down at 10k rev, you want to point out what should not be there?

Ah... you're makin a joke - sorry I'm not gifted with the sense of humor

 

[rupedoggy]

isnt the 351 a bigger saw than a 346??

You have never had a 346 have you?

 

[Deleted member 117362]

You have never had a 346 have you?

I have owned several and sold several. What is so special?

 

[pennsylvaniaboy]

You have never had a 346 have you?

nope, hence my question....pleace enlighten me. My saw knowledge is 365 special, 028av, ms290, and 039.....so not well versed.

 

[rupedoggy]

A good massaged 346 will keep up with your 365 in small wood and be lighter. Those other three aren't even in the running.

 

[buttercup]

A good massaged 346 will keep up with your 365 in small wood and be lighter. Those other three aren't even in the running.

Yeah, but that cylinder is not even run in, looks like brand new to me

 

[pennsylvaniaboy]

A good massaged 346 will keep up with your 365 in small wood and be lighter. Those other three aren't even in the running.

no, not saying they were, just that i know of nothing related to the saws in the thread. just curious why the "downsize" according to internet specs

 

[Yotaismygame]

Playing with transfers can net some good gains, specifically when the rest of the ports have been altered. But be careful, too much taken out of the transfers can make a lazy saw. Case compression is goooood.

 

[Huskitoter]

no, not saying they were, just that i know of nothing related to the saws in the thread. just curious why the "downsize" according to internet specs

I made the same incorrect assumption. The 346 cyl is an xp (extra performance) design which produces more power/cc than their "regular" models like the 351. Double check the specs - it makes more hp at a higher rpm.

 

[Rickick91]

I have no input on the build, but wanted to comment on your photography skills. Very nice pics. Well lit, clear and nicely composed. Well done!

Thank you champion221elite!

belive it or not they are all from my samsung s6 edge plus cell phone which is 3 years old. I always thought it took great pics for a cel phone cammera. I wanted the details to show through so the real porting gurus out there could see well enough to give feedback.

 

[Rickick91]

nope, hence my question....pleace enlighten me. My saw knowledge is 365 special, 028av, ms290, and 039.....so not well versed.

the 346xp NE (44.3 mm) while smaller than the 350 and 353 (45mm) is actually bigger than 351 (44mm). This 351 apears to have a 44 mm closed port top end similar to a 45mm 350 353 top end with the removable caps, and i cant figure out what its off of. I boughr a better micrometer this past week and will be measuring everything to see if i either have an odball 44mm closed port oem cylinder, a 45 mm cylinder, or some knock off stuff. As far as i can tell both my cylinders are oem and the 346xp NE is truly 44.3 mm

 

[Rickick91]

I set the cylinder today. Had to make a .004 gasket to get the squish over.017. Minimum squish was .0175 on the intake side. I cou;ldnt wait to test the compression and proceeded to knock all the carb. parts into the sawdust on the floor. Luckily I found them all whithout stepping on them. Compression was just under 175 psi. very hard to crank her over without handles. Please ignore the flip flops. Lazy Sunday was in progress. also got new covers to dress er up. The originals are in tact yet they are brown.
Next job will be getting a new muffler as The aftermarket one I tried to mod didn't go the way I wanted. I try to preserve the factory spark arrestor screens and mucked this one up trying to make a new deflector.

 

[cuinrearview]

Upon proper measurement you'll see that the original is a 45mm 350/353 cylinder.

Do you have plans for the salmon colored covers? If not I could use them.