346xp race build.

[Dfurka50]

Hi everyone just want see your 346xp race builds. Thinking about doing race build to my 346xp

 

[Thesandman]

Must be everyone switched to 4910,s

 

[farminkarman]

Must be everyone switched to 4910,s

4910's are appealing because they are pretty inexpensive and have decent power potential, but they are not a 346xp replacement in my opinion. I have a ported 4910 and I would definitely not trade it for a Stihl ms241 or a 543xp. The 4910 is only a 1/2 lb heavier than the 241, but has way more grunt...iirc mine (ported by @Red97 ) dynoed 5.2hp and has a pretty broad torque curve. Anyway, back to the OP's question, what do you consider to be a "race" 346? I have a work 346 with a pretty low exhaust that will happily kick a stock 572xp's rear in any wood up to 18-20" diameter. I just don't have a use for a 346 that can only cut fast in an 8"x8" cant.

 

[Thesandman]

I'm working on a 350 so I was wanting some responses to op. Farminkarman, what do you consider a low exhaust? I'm new to this also.

 

[farminkarman]

I'm working on a 350 so I was wanting some responses to op. Farminkarman, what do you consider a low exhaust? I'm new to this also.

108-109

 

[Dfurka50]

100

 

[farminkarman]

100

Are you suggesting 100 is a low exhaust or that is what you would be looking for in a race 346?

 

[srcarr52]

Are you suggesting 100 is a low exhaust or that is what you would be looking for in a race 346?

I've build race 346's as low as 104 on the exhaust.

 

[Dfurka50]

Are you suggesting 100 is a low exhaust or that is what you would be looking for in a race 346?

I was talking about 100 is low. 108 109 isnt

 

[farminkarman]

I was talking about 100 is low. 108 109 isnt

100 degrees ATDC is a pretty high exhaust for a 50cc saw and will rob them of the torque they need for normal use. 105 is probably considered a normal exhaust roof height for a 50cc work saw, but the 346 can get away with an even lower roof because you can make the exhaust port pretty wide.

 

[cus_deluxe]

thats the difficulty of this kind of stuff, does low mean physically low? or lower duration? i try to reference things in terms of duration so theres less chance of confusion.

 

[drf256]

Part of why Stihl 1121 series need so much machine work to be good worksaws. They come from the factory with an exhaust roof in the 96* range. Getting them to 105 is quite a challenge.

 

[Ketchup]

346 tends to have lower exhaust timing than other 50cc. Seems like most woods ported 346 sit around 108 or 106 (ATDC). If it’s a non-piped racer you could get away with higher but I doubt it will have enough gut above 100. With a pipe 96 sounds like the ballpark, but I don’t know much about pipes.

 

[82f100swb]

Part of why Stihl 1121 series need so much machine work to be good worksaws. They come from the factory with an exhaust roof in the 96* range. Getting them to 105 is quite a challenge.

I have one that I built under the influence of a bottle of half a bottle of whiskey that I didn't put a timing wheel on for a year after I built it. I always run 3/8 on it, and it will drag along a 25 without being too cranky, but it hates any sort of muffler mod at all. Turns out the exh. is at 92....

 

[BarkersSaws]

346 tends to have lower exhaust timing than other 50cc. Seems like most woods ported 346 sit around 108 or 106 (ATDC). If it’s a non-piped racer you could get away with higher but I doubt it will have enough gut above 100. With a pipe 96 sounds like the ballpark, but I don’t know much about pipes.

My 2150 build with 346 topend with exhaust close to your pipe number in it.

 

[Dfurka50]

My 2150 build with 346 topend with exhaust close to your pipe number in it.

Your 2150 runs really well!