357xp mods
- Thread starter Tothemax
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sunfish
Fish Head
Check squish & delete base gasket, then do a muffler mod. Good gains here. Next step is porting.
357 is an impressive saw!
357 is an impressive saw!
sunfish
Fish Head
Easier if you search squish & base gasket delete. But squish is the clearance between the piston and top of cylinder. You want that the be around .020" and that is usually what you get when the gasket is removed. There are a number of sealants to use at the base of the cylinder.
Tothemax
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Ok I Googled and read up on the squish. Easy enough to do.
I feel comfortable porting and if I read right, removing a 1/8" around the exhaust is the way to go. Do you keep the same outward bevel or is it 1/8" from exhaust to the piston?
What about intake side? Just polish?
Thanks for all the help
I feel comfortable porting and if I read right, removing a 1/8" around the exhaust is the way to go. Do you keep the same outward bevel or is it 1/8" from exhaust to the piston?
What about intake side? Just polish?
Thanks for all the help
sunfish
Fish Head
Don't mess with the bottom or top of the ports, this changes timing. Just widen them about 1/8". The outlet of the exhaust port can be opened up a fair bit. No need to polish the intake. Do a lot more reading before ya do any grinding, that's a very good saw.
Tothemax
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OK. So I did a little more reading.
If I understand right just bore out the exhaust 1/8" on the left and right side of the port. Dont touch Upper and lower parts. Polish and Nothing else is needed.
Also, the muffler should be opened up by drilling out the middle baffle as much as possible. Along with that, a 1" hole along with a pipe should be welded into the upper corner of the muffler.
Does that sound right? Any other things I should do? I know I am asking lots of questions but I want to get this right before I start cutting.
If I understand right just bore out the exhaust 1/8" on the left and right side of the port. Dont touch Upper and lower parts. Polish and Nothing else is needed.
Also, the muffler should be opened up by drilling out the middle baffle as much as possible. Along with that, a 1" hole along with a pipe should be welded into the upper corner of the muffler.
Does that sound right? Any other things I should do? I know I am asking lots of questions but I want to get this right before I start cutting.
jr27236
Addicted to ArboristSite
1"! Really? Where did you read that info from? That's the huge whole in addition to the stock port on the muffler. At that point why put a muffler lol
Chainsaw Jim
CJ Saws, LLC
You need better tools for muffler modding than you do grinding on a cylinder. A good rule of thumb for muffler outlet is 3/4 the size of the cylinder exhaust port opening. Plus the additional enlarging to compensate for what the screen restricts. Usually anything in the muffler that prevents the volume of flow is removed with cutting burrs and other tedious methods.
Matching the cylinder transfers where they meet the case will give it very good gains along with the muffler mod.
Matching the cylinder transfers where they meet the case will give it very good gains along with the muffler mod.
sunfish
Fish Head
$50 isn't a bad price for a modded muffler and it's an easy bolt on.
Port matching the lower transfers, just match the lowers in the cylinder to case. Use the base gasket to compare.
sunfish
Fish Head
No problem, questions are good. Look up 346xp & 372xp build threads, with pictures. Basically same saws as the 357 just different size.
Tothemax
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Here is the muffler: http://www.ebay.com/itm/Muffler-fit...293407?hash=item2815320c9f:g:GJMAAOSwo0JWHWn3
That's not really a modded muffler, it's the way they come stock on the saws in Europe and other parts of the world. Probably a little more open than a USA model but still could use to be opened up some more.
Assuming yours isn't a cat muffler you can just open it up as much as you can under the stock deflector, then add an additional port if you decide you want more. A simple vertical slit on one side that's pryed open like a louver vent works fine...
Assuming yours isn't a cat muffler you can just open it up as much as you can under the stock deflector, then add an additional port if you decide you want more. A simple vertical slit on one side that's pryed open like a louver vent works fine...
sunfish
Fish Head
That muffler is easier to mod because it has no baffle inside.
