anybody wanna talk about port timing?

[brandoz28]

has anyone actually mapped a cylinder, and are any of the builders willing to discuss a few things about what they do for a real aggressive trail/mx port? are most of your changes in the intake? exhaust? or is it spent in the transfers? is one more important than the others? i know there is no be-all end-all for 2 stroke porting and everyone has a slightly different method, but i'm looking to give this a shot, and want to go a little farther than Ken showed in his DIY.


Also when correcting the timing for the stroker, do you just try to get the timing back around stock?


some tougher technical questions than what is usually asked around here, but i'm wanting to be able to get a handle on this so i can hopefully do my own porting this winter and possibly go to a +3 stroker.


just general/rough answers are ok, i understand that R&D is expensive and time consuming, but someone has to carry the torch when the current builders aren't doing it anymore!

 

[OConnor Racing]

This is the best answer I can give you. I've tested Johns product and it works. He also sends a booklet and advises other changes you can make.




Race Logic: What is the SportPort Porting Template System?

 

[brandoz28]

thanks for the link Ken. I'm probably going to try out some software too to aid in this little project...ii really liked your DIY vids but that i'm hoping to take that to the next level.

 

[OConnor Racing]

Here you go. It's less than $30 for both programs and it works pretty good. I used it to work up figures on a 8,000 RPM Blaster and then compared the results to the Sport Port template. Almost exactly the same. It's not TSR but it costs a lot less. TSR does tons more than this program but @ $500, you better be doing more than one cylinder. Let me know how you make out.

porting-programs.com

 

[brandoz28]

thanks again, i'm going to do my cylinder to start, its only got 1 or 2 useable bores left, so i'm not out much if i really mess her up

 

[hudack]

i knew ken was gana be the only one to answer this. have some green ken.

 

[2_Smoked]

What kind of port design do you plan on doing? Mild trail, aggressive dune ect?

 

[brandoz28]

from the first post, agressive trail/motocross, probably going to be a race gas motor, or at least a 50/50 mix

 

[xJust_Causex]

Rep sent, btw just if you knew they people making and supporting tsr retired and won't be selling it anymore?

 

[brandoz28]

so.....would anyone be interested in a detailed "this is what i did and why i did it" if i do this project this winter?

 

[OConnor Racing]

I'm very interested in your project. I didn't know the TSR people retired. Glad I got mine while I still could.

 

[Flyin5]

Blaster transfer ports are the bottleneck. Most of your power will be gained from opening the transfers.

Rule of thumb. Wider is going to give you more bottom end, taller is going to give you more top.

Honestly a base spacer setup and widening your ports and spending time cleaning casting flaws does a world of difference.

 

[FLOTEK]

being that people make their living off their proven designs there is only so much info that a builder is going to freely give not to mention liability concerns if jethro hacks his jug apart becuase he doesnt have the right tools ,skill ,or ability ..know this :*most all the potential power is in the transfers and exhaust port ..matching the ports to the casting and cleaning out flaws and such helps some but for wide high reving power that isnt going to be good enough,knowing what to raise it to isnt good enough either .. angles shapes widths and contours can alter the power just as much as the rasing or lowering of the port durations.most guys think if they copy a builders intake picture and maybe clean some stuff up and polish their exhuast they will have a certified screamer.that is like putting whip cream on a dog turd and calling it desert

 

[brandoz28]

being that people make their living off their proven designs there is only so much info that a builder is going to freely give not to mention liability concerns if jethro hacks his jug apart becuase he doesnt have the right tools ,skill ,or ability ..know this :*most all the potential power is in the transfers and exhaust port ..matching the ports to the casting and cleaning out flaws and such helps some but for wide high reving power that isnt going to be good enough,knowing what to raise it to isnt good enough either .. angles shapes widths and contours can alter the power just as much as the rasing or lowering of the port durations.most guys think if they copy a builders intake picture and maybe clean some stuff up and polish their exhuast they will have a certified screamer.that is like putting whip cream on a dog turd and calling it desert

I'm really not asking for anyone's big deep, dark secrets, R&D is long and expensive. however someone has to carry the 2 stroke torch when you, and the other builders are no longer doing engine building.