broke Posted July 22, 2004 Report Share Posted July 22, 2004 (edited) I have been reading alot of full drag, dune, MX, woods, trail/play porting and was just wondering if anyone knows their port specs. This has just come up recently in my head because I am looking to build a stroker. I wanted to compare the specs of my porting to others. Not for bragging rights, but just to see what makes different types of porting run the way they do. This may be a question for the builders, but "how do you calculate the durations of a stock port when turning into a stroker." I have been told that my current porting isn't going to work with a +4 because of my transfer duration. I guess I am just looking for a little bit of knowledge as to why it won't work rather than "it just won't." broke Edited July 25, 2004 by broke Quote Link to comment Share on other sites More sharing options...
roosthrower Posted July 22, 2004 Report Share Posted July 22, 2004 I'll post my exhaust and transfer durations when I get my cylinders back. They will be ready by sometime next week. I told the guy that I pretty much wanted an agressive play port. He said that he would get me in the 60hp ballpark range. I got a degree wheel sitting in the garage somewhere. Quote Link to comment Share on other sites More sharing options...
roosthrower Posted July 22, 2004 Report Share Posted July 22, 2004 Does no one know the port timing on their ported motor? I am kinda interested in this topic as well. Quote Link to comment Share on other sites More sharing options...
broke Posted July 25, 2004 Author Report Share Posted July 25, 2004 I guess there is almost no interest in this topic. Does anyone know where the extra ports come into play in something along the lines of the 12 ports that have become popular recently. I know that a Banshee is only an 8 port design to start with and there are to intake port added in this type of porting. But where do the other 2 come from, Exhaust maybe? I guess I will hope for something out of this bump. Quote Link to comment Share on other sites More sharing options...
bkabina Posted July 26, 2004 Report Share Posted July 26, 2004 Talk to Jim (passionre) He'll tell you anything you need to know. Quote Link to comment Share on other sites More sharing options...
broke Posted July 26, 2004 Author Report Share Posted July 26, 2004 Talk to Jim (passionre) He'll tell you anything you need to know. I'm sure Jim would tell me all that I need to know, but I thought this thread could have the potential to contain information that others might be interested in. I have discussed my future motor build with Jim over many PM's, he has been nothing but helpful. I was just trying to strike up what I hoped was going to be a thread that I could compare port work with the way the motor actually runs. I know quite a few run large carbs with strokers, I hoped someone would chime that was running small carbs. Hopefully it will, but if not, oh well. broke Quote Link to comment Share on other sites More sharing options...
tats4life Posted July 26, 2004 Report Share Posted July 26, 2004 my specs............it just flat out hauls ass for a mx motor................i didn't ask and Dan didn't tell........ Quote Link to comment Share on other sites More sharing options...
glock221 Posted July 26, 2004 Report Share Posted July 26, 2004 go over to PS and ask that question all the fast guys in cally and arizona hang out there. Quote Link to comment Share on other sites More sharing options...
broke Posted July 29, 2004 Author Report Share Posted July 29, 2004 go over to PS and ask that question all the fast guys in cally and arizona hang out there. I was going to, but I figured I would end up with a bunch of drag porting specs. Which I wouldn't mind, but I kind of wanted to see what people here ran. Oh well, I'll give PS a try. Quote Link to comment Share on other sites More sharing options...
roosthrower Posted July 29, 2004 Report Share Posted July 29, 2004 I got my cylinders today. I am going to figure out the port timing right now. I'll probably start a new thread and I'll have some pics. Give me an hour or so. Quote Link to comment Share on other sites More sharing options...
nater006 Posted July 30, 2004 Report Share Posted July 30, 2004 Dan's building me a 4mm stroker right now. He recommended 28mm carbs to me, also. Have heard nothing but good stuff about his work so, like tats said... not gonna question it Quote Link to comment Share on other sites More sharing options...
banshee370 Posted July 30, 2004 Report Share Posted July 30, 2004 One reason why this post hasnt gained any momentun is the fact that port timing is only part of the big picture. First off MOST engine builders dont want their "port specs" broadcasted across the net. Any builder that knows better will tell their customers, but most people wont understand what they are talking about anyways. The shops with something to hide are just affraid that someone will try to copy their work. Something that most people dont know or realize, is that the transfers, roof angles and sometimes even the liner cut away will make the most gains (along with porting of the intake/exhaust) Cant forget domes (head) either. Compression is everything Quote Link to comment Share on other sites More sharing options...
broke Posted July 30, 2004 Author Report Share Posted July 30, 2004 Yeah, I figured the reason that this hasn't received much response is that most don't know and for that matter don't care what theirs are and those that do know may not want to share. I was just seeing "if" there might be some response to it anyway. I know that alot more goes into porting than just the port timing, but it's the easiest part to compare. I figured most shops wouldn't want to share, but Dan had no problem sending mine to me, and I would expect that from a service that I paid for. I would have a problem with a builder that would not tell me "whatever" I wanted to know about my own motor. I guess I was just looking for generic answers to my questions. I can't even figure out how to convert duration into port heights. I'm basically an idiot when it comes to this and was just looking for a porting 088 class. I don't really want to know how to port and I'm not looking to copy anyones work, I was hoping to find out why different things lead to different results. I guess most either already have this knowledge or really just don't care as long as it runs right. Thanks for all the responses anyway. broke Quote Link to comment Share on other sites More sharing options...
banshee370 Posted July 31, 2004 Report Share Posted July 31, 2004 As much as I hate to give this jackass any credit.... it is due. http://macdizzy.com/2stroke.htm Rick Kirmil has a great amount of info found on his site. Take your time and read as much as you can. Dan is awesome when it comes to explanations and support. None of this is rocket science and there are no real "secrets" Good luck and enjoy the reading.... Quote Link to comment Share on other sites More sharing options...
broke Posted July 31, 2004 Author Report Share Posted July 31, 2004 Thanks Walt, I spent many hours on MacDizzy's site when I was first building the RZ motor. There is a lot to be learned from the site, even if some of the physics of the work is way over my head. Why do so many seem to not like Macdizzy too much? We can let this one die now. broke Quote Link to comment Share on other sites More sharing options...
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