Saw Pipes

[Stihl Racer]

I was just curious if any one knew how to calculate the size, length etc for expansion chambers and pipes for a saw.....mine being a 046.

 

[saws43]

No soliciting without being a sponsor.

I was just curious if any one knew how to calculate the size, length etc for expansion chambers and pipes for a saw.....mine being a 046.

 

[timberwolf]

it aint easy. lots of calculations to do it manually, lot of places to make an error in the calculations.

You can find some free software on the net but from personal experience it won't in general work. Not without at least reading the tuners handbook a couple times and doing some cross checking and tweaking the numbers the software spits out.

Even at that I have found it necessary to fine tune the length of the dwell (belly) length of the pipe buy testing cut times.

 

[Chopwood]

Contact a quality builder. EHP, KD, FMC and big Dave come off the top of my head. This is a science to say the least. It all depends what you want the pipe to do for you. Are you racing, or do you just want to make noise?

 

[GOBRDGO]

I've played with pipes on two strokes and have found gains, though never built one for a saw. If you are on a budget, find a welder buddy, hit ebay for a tuned pipe for a scooter, ( Gopeds have pipes and range from 23 - 60 cc's, those pipes WORK!), and or a dirtbike pipe. Dirtbike tuned pipes start at 50 cc's and up. Heck, lots of old hotsaw pipes are nothing but modded go kart tuned pipes from the 100cc class. You can straighten out a pipe and or bend it to work for your saw( try to preserve the basic diameter contours the best you can). Suck up to a local saw tuner to bum his portable tachometer to gauge your results. Close your wallet and do some R and D of your own, and I'm sure you will be surprised with the results.

 

[saws43]

pipes

my friend you are wrong

 

[GOBRDGO]

OK Nevermind my rants, Go pay a sawbuilder to make you one.

 

[Crofter]

Making a good performing pipe really involves much more than first meets the eye. The first thing you need to know is the rpm range closest to your particular saws best performance. It should be tuned to enhance both crankcase negative pressure clear back to the carb as well as boosting the cylinder filling pressure. The margin for error is very small. If it aint right it could very well give less rather than more orses. Making it fit the jug and clear chain brake handles etc., as well as give firm support so it doesn't crack off takes a bit of doing. I made two pipes with EHP's coaching and calculations. The 026 is bang on and gives excellent gains; the one for the 372 I am still playing with. Unless you are going to go for nitro and all the whole racing scene, the novelety of having a pipe hanging 3 feet off your saw will get old quick. But if that is where you want to go, it is the only way to get there. To get a good pipe tailor made for your saw will likely cost at least $250. Doing it yourself without exact dimensions would be like winning the lottery

Frank

 

[ehp]

Glad to see you posting Frank, I should be going up by your place next week on a parts run Stilh Racer, like I said before just tell Ned you need a 088 to whip those gas 3120 pipe saws up there at the fair race

 

[timberwolf]

Even 250$ is cheep.

It's a good days work to do a pipe up with a mig welder, plus gas wire and sheet metal. Not counting anything for design and shop cost.

And if it is tig welded or done with a torch there is more time yet.

Stihl Racer whats your set up for welding?
Are you making the pipe for the stock 046 or the modded?

 

[rahtreelimbs]

Can a MIG welder be used for pipe building? Or is TIG the best option?

 

[timberwolf]

I have put 4-5 pipes together with a mig. I have used 24 gauge rather than 26 gauge. The 24 gauge is much easier to weld. Using 80% argon 20%co2 and .23 wire.

The inside of the pipe seams are smooth, but the outside finished weld is not a pretty as a tig welded pipe. Good chance my welding is partly to blame though.

 

[rahtreelimbs]

I have put 4-5 pipes together with a mig. I have used 24 gauge rather than 26 gauge. The 24 gauge is much easier to weld. Using 80% argon 20%co2 and .23 wire.

The inside of the pipe seams are smooth, but the outside finished weld is not a pretty as a tig welded pipe. Good chance my welding is partly to blame though.

Did you have to stitch or pulse weld???

I have a Lincoln SP-100 with the same gas mix/wire setup as you.

Twenty four gauge isn't the easiest metal to weld!!!

 

[timberwolf]

I can run a bead for 1/2 an inch or so at a time and then need to let it cool. Found runing the wire into the weld at an angle (20-30 degrees from horizantal) helped control the heat and penetration.

Using a lincoln mig 15

On the 26 gauge I needed to run spot welds basicaly.

 

[timberwolf]

Mig welded pipe on 260

http://www.arboristsite.com/attachment_19600.php

Inside example

http://www.arboristsite.com/attachment_19708.php

outside example

http://www.arboristsite.com/attachment_19709.php

 

[GOBRDGO]

Check out my mac 10 10 thread guys.

 

[HELSEL]

my friend you are wrong

This man here called saws43 is the best pipe builder we know of.He makes all of our pipes and they really work..So thanks John for the great work.



Rick