Canadian farm boy
Stihl learning
- Joined
- Sep 8, 2014
- Messages
- 181
- Reaction score
- 255
Let me first start by saying that I'm new to the forum. I have read almost every thread I could find that deals with the stihl 038 saws.
I work as a professional heavy truck mechanic and have done a lot of different work on a lot of different types of engines. I've done some port and polish work before on car engines. I've never really done much work on small 2 stroke engines.
Now to my build plans.
I recently acquired a stihl 038 avs. electronic. The saw was built in Brasil and originally purchase in 1993. The saw didn't run when I got it. I found that the piston and cylinder was shot. I've done my research and decided to install a mag p&c. I'm aware of the necessary modifications that need to be done to the cylinder mounting holes.
The muffler that came with the saw is a dual port and is in excellent shape. I plan to do a muffler mod as soon as I get my new p&c. I plan to measure the exhaust port on the cylinder and mod the muffler outlets to total 70-80% of the port outlet area. Gasket match muffler to the cylinder.
I've read that a lot of guys will leave the cylinder base gasket out as a means of increasing the squish. I too was planning to not use the base gasket as long as I have enough clearance between the piston and the top of the cylinder(0.020" minimum I believe)
I want to clean up the casting flaws in the intake port and the transfer tubes, leaving the surfaces slightly rough to assist with fuel and air flow into the crank case and into the cylinder. I may try and open up the intake runner but haven't decided for sure yet.
I plan to open the exhaust runner between the muffler and the cylinder port opening as much as I can and polish it being careful not to change the opening height. I was planning to widen the exhaust port opening as much as the piston will allow for. Leaving 0.100" of piston skirt width on either side of the port for a good seal.
I plan to run a 7 tooth sprocket and a 28" bar with 3/8 chain. Would an 8 tooth sprocket be better?
I know this saw is known for its torque and is one of the best saws stihl ever built (IMO). My 038 will be a working saw that I plan to keep for along time. Ultimately I want this saw to preform as well or better then a stock 044 or 046.
Please let me know your thoughts. I want to learn from the best so please be honest and don't hold back, if I'm out to lunch on my build plans please tell me.
I work as a professional heavy truck mechanic and have done a lot of different work on a lot of different types of engines. I've done some port and polish work before on car engines. I've never really done much work on small 2 stroke engines.
Now to my build plans.
I recently acquired a stihl 038 avs. electronic. The saw was built in Brasil and originally purchase in 1993. The saw didn't run when I got it. I found that the piston and cylinder was shot. I've done my research and decided to install a mag p&c. I'm aware of the necessary modifications that need to be done to the cylinder mounting holes.
The muffler that came with the saw is a dual port and is in excellent shape. I plan to do a muffler mod as soon as I get my new p&c. I plan to measure the exhaust port on the cylinder and mod the muffler outlets to total 70-80% of the port outlet area. Gasket match muffler to the cylinder.
I've read that a lot of guys will leave the cylinder base gasket out as a means of increasing the squish. I too was planning to not use the base gasket as long as I have enough clearance between the piston and the top of the cylinder(0.020" minimum I believe)
I want to clean up the casting flaws in the intake port and the transfer tubes, leaving the surfaces slightly rough to assist with fuel and air flow into the crank case and into the cylinder. I may try and open up the intake runner but haven't decided for sure yet.
I plan to open the exhaust runner between the muffler and the cylinder port opening as much as I can and polish it being careful not to change the opening height. I was planning to widen the exhaust port opening as much as the piston will allow for. Leaving 0.100" of piston skirt width on either side of the port for a good seal.
I plan to run a 7 tooth sprocket and a 28" bar with 3/8 chain. Would an 8 tooth sprocket be better?
I know this saw is known for its torque and is one of the best saws stihl ever built (IMO). My 038 will be a working saw that I plan to keep for along time. Ultimately I want this saw to preform as well or better then a stock 044 or 046.
Please let me know your thoughts. I want to learn from the best so please be honest and don't hold back, if I'm out to lunch on my build plans please tell me.