Degree wheel recommendations
- Thread starter DieselTech
- Start date
DieselTech
Well-Known Member
- Local time
- 9:51 PM
- Joined
- Sep 18, 2021
- Messages
- 7,078
Can someone help me how to compute/figure out port timing using a degree wheel? I under stand the degree wheel, but how do you measure the timing? Do you check when port opens,then measure when it closes & subtract the 2 figures. Also trying to tune for happy medium between torque & speed. What kind of port timing would be reguired for that? Any help greatly appreciated!
Karl Snarl
Well-Known Member
Look up the tuners handbook. Or drop a pretty penny on it. You'll love the read and it will teach you a poop ton.
DieselTech
Well-Known Member
- Local time
- 9:51 PM
- Joined
- Sep 18, 2021
- Messages
- 7,078
Ok thanks I'll try & look it up, it wont go to link for me.
DieselTech
Well-Known Member
- Local time
- 9:51 PM
- Joined
- Sep 18, 2021
- Messages
- 7,078
Ok I believe I have found right manual, Gordon Jennings handbook to 2 stroke tuning.
Karl Snarl
Well-Known Member
Its a great read, you'll be coming back to it over and over again.
Street Ryderz
Well-Known Member
First there are different types/styles of degree wheel, some have full 360 degree markings (my preference) and some are 180 or 90 degree segments. Use of it for the 2 stroke is not really covered in the tuners handbook so many just go to you tube to get the gist of it. The degree wheel is mainly used for finding the port durations by starting at tdc with an indicator/pointer rigged to be at 0 or tdc on the wheel, then you rotate until the piston top just uncovers the port being measured and take note of the degrees, continue rotating through bdc until just closed and take note of the degrees, this is the duration of that port or called it's timing with the higher the number the more duration it has. There are online calculators that allow you to use linear depth measurements to get the same results such as Labretta's port timing calc's that make this task much easier for most folks, you just input the measurements you take into the appropriate fields and it does all the math/work for you and they are very accurate.
For a good happy medium between torque and higher rpm tbh the stock port timing is not that bad the ports just need to be clean flowing and mostly need to be widened to improve flow rather than altering timing, this along with a good pipe makes a huge difference but if you want a bit more it's best to get a better understanding of blow down and it's effect along with what the pipe your going to use is meant to do so as not to be short circuiting the cylinder fill at some point of the rpm range.
I can give you some good timing points to go on but I'd try matching everything first, getting the flow right again makes a huge difference, I've given out port timing numbers here that perform really well but they are more to the performance side of things and require the use of a good pipe and bigger carb so that the volumes match each other so let me know if you want some help!
DieselTech
Well-Known Member
- Local time
- 9:51 PM
- Joined
- Sep 18, 2021
- Messages
- 7,078
Yes I would love the help, I'm going to read over Gordon Jennings handbook to 2 stroke tuning to get a better understanding of everything. Then we can see where I want to go. I've been doing a lot of reading here & learning from the pro's like you. Thanks for the help. Much appreciated!!!
