2003LimitedBanshee Posted March 30, 2009 Report Share Posted March 30, 2009 Alright, so I've recently gotten inspired to start my porting project. Not sure what kicked it in, but after two evenings that turned into early mornings, I've got one jug almost entirely done. I need a couple longer burrs to reach into the intermediate portion of the transfers and some sanding drums and flaps to finish off and polish up the exhaust. The specs are as follows: 188* Exhaust duration 127* Transfer duration 129* boost port duration Main transfers have been widened 2mm towards the exhaust Now, I don't at all claim to have turned out a jug that is near perfect or quite as smooth as the pro's do it. But, I do really think they should make good power and I think they are shaping up pretty alright. Let me know any thoughts or "enjoy" (?) the pics??? Intakes Side by Side Ported Intake Exhaust Side by Side Another exhaust One transfer after changing the port timing, one prior Notice it has been widened towards the exhaust also Exhaust has not been worked yet. Transfer and part of exhaust Can sort of see the difference between stock transfers and modified Anyway, sorry if I'll bore anyone with these... - Brian Transfers from base Quote Link to comment Share on other sites More sharing options...
tidos76 Posted March 30, 2009 Report Share Posted March 30, 2009 looks good. here are mine that i did about 3 years ago. Quote Link to comment Share on other sites More sharing options...
2003LimitedBanshee Posted March 30, 2009 Author Report Share Posted March 30, 2009 I'm not planning to enlarge my intakes any as far as the opening into the cylinder. But, I knew that I needed to work the roof of the intake a little more. I smoothed it out quite a bit, but it is not a constant slope from the roof down into the port... yet. Quote Link to comment Share on other sites More sharing options...
J.J. Posted March 30, 2009 Report Share Posted March 30, 2009 looks good from where I'm sitting, hat off to you. Gotta get those edge radii spot on if you want your rings to last. Quote Link to comment Share on other sites More sharing options...
tidos76 Posted March 30, 2009 Report Share Posted March 30, 2009 yep gotta do that. i got luck and had my builders specs and took them to him for inspecion and tips when i was done. they turned out really good and pulled great. i think next winter i;m goin to tear it back down and try to do a more aggressive drag port Quote Link to comment Share on other sites More sharing options...
Facetious Posted March 30, 2009 Report Share Posted March 30, 2009 I don't really know what you are talking about or what I am looking at, but it looks good....lol. I'd like to learn about this kind of stuff though. What exactly do those values mean? Is there a resource online that gives detailed explanations? Someone is sellin CD's on ebay that supposedly teach you porting. Anyone ever check them out? Quote Link to comment Share on other sites More sharing options...
sheerider1026 Posted March 30, 2009 Report Share Posted March 30, 2009 looks good man, how did she run?? the next set that i port will get 188 on the exhaust, and 128 on the tranfers, should be a good running bike all-around.. Quote Link to comment Share on other sites More sharing options...
2003LimitedBanshee Posted March 30, 2009 Author Report Share Posted March 30, 2009 I don't really know what you are talking about or what I am looking at, but it looks good....lol. I'd like to learn about this kind of stuff though. What exactly do those values mean? Is there a resource online that gives detailed explanations? Someone is sellin CD's on ebay that supposedly teach you porting. Anyone ever check them out? The numbers I mentioned up above are the degrees of crankshaft rotation that each of the ports mentioned are open. All of those durations are greater than the stock port durations, which translates into longer intake period, i.e. more fuel/air, somewhat shorter power stroke before the exhaust begins to open. I read up quite a bit from the two stroke tuner's handbook by gordon jennings. It has quite a bit of information on the theory behind how a two stroke engine works. It doesn't really explain that much "how to" port, but it explains the concept that basically tells you "why" to port. Now, I had a set of port durations recommended to me, I didn't arrive at these numbers through calculation. With the information you can learn from Jennings though, it would be possible and it made sense as I was putting the number together with what I was reading. Just google the title and author above and you should be able to find a downloadable PDF out there. I downloaded it for free about two years ago, but not sure if it is available free still? looks good man, how did she run?? the next set that i port will get 188 on the exhaust, and 128 on the tranfers, should be a good running bike all-around.. Only have the first cylinder done so far. Hopefully I will finish the exhaust on the first and finish the second cylinder this week, that way I can potentially fire it up next week. I still need to mic the cylinder though to see if I can get away with a touch up hone at my house or if I am going to need to have it bored just slightly. The cylinders are in very good condition, so I believe I will get away with just a simple three stone honing. I need to figure out a way to mount the cylinder though so I can jig it for the hone on my drill press. The stones on my drill powered hone are floating and in theory can be run by a hand drill, but I usually prefer the press. What kind of durations did you do on your first port job? I'm running the mods in my sig and only ride the sand out here in Oregon, so the slightly higher exhaust numbers are to hint towards the top end. I can already tell that this is going to make the addiction worse though. I already forsee starting on my current cylinders once I pull them to throw these on. Then I'm going to want CPI's and higher exhaust figures. Geez!!!! :biggrin: Quote Link to comment Share on other sites More sharing options...
Duneman101 Posted March 30, 2009 Report Share Posted March 30, 2009 Someone is sellin CD's on ebay that supposedly teach you porting. Anyone ever check them out? Don't get that CD from Ebay, My bro bought it, it didn't have any useful information at all, no numbers, no real advice just showed some pics of some ported cylinders, and showed a picture of the tools that work best, but didn't explain or show anything of any use. Quote Link to comment Share on other sites More sharing options...
2003LimitedBanshee Posted March 30, 2009 Author Report Share Posted March 30, 2009 looks good. here are mine that i did about 3 years ago. Do you have any pictures of the transfers, exhaust etc.? Did you change the port timing or just smooth out the intake? I will definitely say that doing this right is not the economical way to do it. Quite some time ago I purchased the 90* tool from CC Specialty, which alone ran me about the same as what a good port job from any builder on the HQ would cost, excluding a drag port most likely. But, even if I only turn out 65-70HP instead of maybe mid 70's, I have the satisfaction of saying I did them entirely myself. God, I can't wait to get this thing on the dyno and see what it pulls now, then swap cylinders and see what I was able to do with it! Quote Link to comment Share on other sites More sharing options...
Facetious Posted March 30, 2009 Report Share Posted March 30, 2009 This kind of stuff is very interesting to me. I was doing some net searching and reading different topics on two-strokes and porting and came across this site, http://macdizzy.com/2stroke.htm It is a great read for anyone interested in delving deeper into how's and why's of two-strokes and porting. It is very detailed. The author of that site actually mentions the book by Jennings in his posts too. Quote Link to comment Share on other sites More sharing options...
deckheight Posted March 30, 2009 Report Share Posted March 30, 2009 Looks real good, little cleanup here and there, polish the exhaust and looking sweet! Good durations for an "all around power band" IMHO :cool: . Blow down timing should help compensate on the bottom hit from raising the exhaust. Sounds like your getting real good advise and how about that 90 deg. handpeice from C.C. :biggrin: Just curious though, how come you are opening the Bust before the main and 5th transfers? Not that it will matter much from a couple deg. in crank rotation, just don't normally see that. What are your plans for head dome volume and fuel? Good work... Quote Link to comment Share on other sites More sharing options...
Snopczynski Posted March 30, 2009 Report Share Posted March 30, 2009 Flatten down the step into a ramp in the roof of the intake. Quote Link to comment Share on other sites More sharing options...
2003LimitedBanshee Posted March 30, 2009 Author Report Share Posted March 30, 2009 Looks real good, little cleanup here and there, polish the exhaust and looking sweet! Good durations for an "all around power band" IMHO :cool: . Blow down timing should help compensate on the bottom hit from raising the exhaust. Sounds like your getting real good advise and how about that 90 deg. handpeice from C.C. :biggrin: Just curious though, how come you are opening the Bust before the main and 5th transfers? Not that it will matter much from a couple deg. in crank rotation, just don't normally see that. What are your plans for head dome volume and fuel? Good work... The 90 degree tool from CC is awesome; it's a spendy bugger, but I'll tell you, I worked the transfers over as far as timing, as fast as any other part of the porting. I got the specs recommended from my by Dan Wade (Patriot) back in the day a few years ago. As I recall he said he felt it helped with top end scavenging; As you said, you can't even "see" a difference, but it is there, even if a couple degrees of crank rotation. I know Snop knows Dan, I wonder if this sounds like familiar recommendations? Yes Snop, need to work the intake roof lip more for sure. As far as domes are concerned I'm actually not sure, I wanted to ask around. I'm running 20cc currently and I kick 175psi at 1900' elevation, which I know is way higher than most feel it should be. I would actually like to maintain close to that, probably around 185 at sea level, currently right over 190, but I'm not sure what size to run. I have some 19's but guessing those probably won't be small enough to maintain that PSI. Okay running a healthy mix of Trick 116 at that PSI... Quote Link to comment Share on other sites More sharing options...
2003LimitedBanshee Posted March 30, 2009 Author Report Share Posted March 30, 2009 Deckheight, what do you recommend for polishing off the exhaust? That finish was just my rough in with the burrs; no sanding, polishing yet... Quote Link to comment Share on other sites More sharing options...
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