tnGRbanshee Posted March 19, 2008 Report Share Posted March 19, 2008 got a set of used jugs from a guy locally they are ported ,but they have been polished smooth inside is that good or bad i would think a little texture would be better for atomization im really not sure any advice greatly appreciated. sorry i have no pics. ,camera f'd right know Quote Link to comment Share on other sites More sharing options...
Fireroad Express Posted March 20, 2008 Report Share Posted March 20, 2008 i have heard of people polishing the exhaust port to a shiny finish , but not the intake or transfers. Quote Link to comment Share on other sites More sharing options...
FasterThanU90 Posted March 20, 2008 Report Share Posted March 20, 2008 good on exhuast, you want the atomized fuel to tumble through the intake and transfers Quote Link to comment Share on other sites More sharing options...
blowit Posted March 20, 2008 Report Share Posted March 20, 2008 We have never found that rough intake ports increase atomization, only increase the boundary layer and increase fuel pooling. Ultimately, air flow depends largely on port shape and surface finish. The rougher it is, the less it flows. Our testing included many tool and sanded finishes. We noted specific changes in velocity patterns and negative pressure levels within the port as well. We are convinced the best place to induce maximum atomization it at the point of combustion through the Xfer tunnels and head design. It would be a given that smooth finishes that extends well into the micro finishes is desired in the exhaust to maintain maximum velocity and negative wave activity in the exhaust tract. Brandon Quote Link to comment Share on other sites More sharing options...
tnGRbanshee Posted March 20, 2008 Author Report Share Posted March 20, 2008 thanks alot for the info still debating on giving it a try, hmm Quote Link to comment Share on other sites More sharing options...
trex banshee Posted March 20, 2008 Report Share Posted March 20, 2008 (edited) I polish the crap out of exhaust ports and i was told to go no finer than 180 on the intakes. intake exhaust Edited March 20, 2008 by trex banshee Quote Link to comment Share on other sites More sharing options...
tnGRbanshee Posted March 21, 2008 Author Report Share Posted March 21, 2008 i am gonna rough the intakes up a bit. also gonna polish some more on the exhaust i can get it alot smoother than already is. thanks alot for the info, wasnt really sure how rough on the intakes Quote Link to comment Share on other sites More sharing options...
blowit Posted March 21, 2008 Report Share Posted March 21, 2008 i am gonna rough the intakes up a bit. also gonna polish some more on the exhaust i can get it alot smoother than already is. thanks alot for the info, wasnt really sure how rough on the intakes Not sure why you want to make it slower but it is your baby. Roughing your ports will NOT make your bike faster. If you want prrof of that, next time you are at a pro MX race, ask one of the OEM teams to show you a cylinder. "If" you get that accomplished, you will learn a lot. Those are the guys that truely understand porting. When I attended Kawasaki school of performance, this was all on the table. Also, polishing the exhaust without the addition of porting it, will yield very little gain. I would not recommend you take your engine apart for this. If is already apart, I guess, why not. Brandon Quote Link to comment Share on other sites More sharing options...
FasterThanU90 Posted March 22, 2008 Report Share Posted March 22, 2008 do you kno why polishing the exhaust port works blowit?? Quote Link to comment Share on other sites More sharing options...
blowit Posted March 22, 2008 Report Share Posted March 22, 2008 do you kno why polishing the exhaust port works blowit?? Not real sure but I heard it was the "in" thing to do. :biggrin: B Quote Link to comment Share on other sites More sharing options...
flotek Posted March 22, 2008 Report Share Posted March 22, 2008 polishing the exhaust port is really only done to prevent carbon buildup ,i nactuality theres a slight gain by having it rough though(boundry layer) ,the best builders porting i nthe country is often hacky looking as far as texture goes ,the fact is for banshee owners texture does very little performance wise it is far more important to get your sizes shapes and durations correct ,its better to focus your efforts on things that make real world practical power iMHO .but i like to apply some practical everyday things into my cylinders that i like to use for the porting process ,like observing airplane wing shapes are designed and why a dimpled golf ball goes further than a smooth round one ,velocity over volume is the key Quote Link to comment Share on other sites More sharing options...
blowit Posted March 22, 2008 Report Share Posted March 22, 2008 polishing the exhaust port is really only done to prevent carbon buildup ,i nactuality theres a slight gain by having it rough though(boundry layer) ,the best builders porting i nthe country is often hacky looking as far as texture goes ,the fact is for banshee owners texture does very little performance wise it is far more important to get your sizes shapes and durations correct ,its better to focus your efforts on things that make real world practical power iMHO .but i like to apply some practical everyday things into my cylinders that i like to use for the porting process ,like observing airplane wing shapes are designed and why a dimpled golf ball goes further than a smooth round one ,velocity over volume is the key We were hoping for staggering flow data with ID dimpling in R&D but it simply induced too much turbulence in an ID environments. One of the things we were able to establish was the rapid changes in velocity and the pressurized air, does not seem to work with dimples. Now, my aerospace Eng may not agree with me but I feel that the irregular surfaces and inconsistent methods for dimpling cause the most problem. All in all, an increase in eddy currents or boundary layer and decrease in flow. If we had better ways to test the surfaces, we might be able to make it work but too many months in R&D for us. As far as airplane wings, you are spot on. I love seeing knife edge this and that. Makes no sense either. Sub-sonic air - super sonic fixins. Coming from aerospace, I learned airflow before porting. One thing that is kind of neat is to look at the nose of "most" aircraft. pointy means super sonic, bullnose means sub sonic. Of course there are other reasons for sharp, irregular edges too.. B Quote Link to comment Share on other sites More sharing options...
tnGRbanshee Posted March 23, 2008 Author Report Share Posted March 23, 2008 Not sure why you want to make it slower but it is your baby. Roughing your ports will NOT make your bike faster. If you want prrof of that, next time you are at a pro MX race, ask one of the OEM teams to show you a cylinder. "If" you get that accomplished, you will learn a lot. Those are the guys that truely understand porting. When I attended Kawasaki school of performance, this was all on the table. Also, polishing the exhaust without the addition of porting it, will yield very little gain. I would not recommend you take your engine apart for this. If is already apart, I guess, why not. Brandon im guessing you didnt read the first post on this topic "i bought a set of ported jugs that the intakes were also polished" and yes i it is apart i wouldnt take the top end off to polish my exhaust ports i dont think anyone would Quote Link to comment Share on other sites More sharing options...
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