donkeypuncher Posted October 24, 2009 Report Posted October 24, 2009 Thank you very much for the input. The animation was good to see! I really don't want to port the cylinders so I'll probably go with the short rod crank. I'm thinking that a long rod with porting may be a little much for the riding I do. I mostly ride trails in the upper peninsula of MI. No dunes here. I'm curious what might be the best set up with the short rod would be. The cylinders I have will have to be rebored, they are currently at 20 over. why would you stroke it without porting it? that just doesnt make sense. i agree with alf, seems like your doing things backwards. if you dont plan on porting your cylinders to go with the stroker crank then dont buy the crank. i think you would be a lot happier with trail ported cylinders and a stock stroke crank. Quote
RILS Posted October 25, 2009 Report Posted October 25, 2009 I agree a good port job will bring you alot more then a 4mil crank and if you run stk cylinders with a stroker crank at a minimum you will need to drop the floors to the new bdc. A stk crank with a good port job will run real hard, much harder then a stk port 4mil. Quote
mercury65 Posted October 25, 2009 Report Posted October 25, 2009 4mill suck with out proting a well ported stock stroke is faster then a unported 4 mill, in fact i just did a port job on a 4 mill because he put in a 4 mill and the powerband was so short, i might even say the quad was slower then b 4 the 4 mill, did the port job and wow what a diff. like night and day. Quote
yooperbanshee Posted October 25, 2009 Author Report Posted October 25, 2009 I was under the impression the porting will take away some of the reliability of the machine? Quote
RagunCajun Posted October 25, 2009 Report Posted October 25, 2009 Long Rod/Short Rod comparison Wow is that drawing to scale? If so i didnt think it was that dramatic of a difference. Makes me glad i went with a longrod. But hell, if both work fine, it dont matter to me. Quote
RILS Posted October 25, 2009 Report Posted October 25, 2009 I was under the impression the porting will take away some of the reliability of the machine? Get somebody that knows what they are doing and it will be fine. For what you will have in a stroker crank setup you cold get a badass port job that will make you forget about that crank unless your like me just cant get enough but I really like a hard running 350. Quote
alf44 Posted October 25, 2009 Report Posted October 25, 2009 TRUST US DUDE. You will be completely satisfied spending $350-$450 for a good woods/trail type port. Best bang for your buck and no it does not make you machine any less reliable. A port job, a coolhead, or milled stock head, some k&n pods, and +4 timing you will be 100% happy and satisfied. Once you get used too that new power then look into doing a 4mill. Ive rode my dune ported true 350cc banshee for 2 years. Right now I have no desire too do a 4mill. I love the bottom end power and they way it pulls all the way throught the band. Its perfect for all types of riding. Hit up Kevin at herr juggs. He is also a site sponsor and will take care of ya. just click one of his banners on this site. Quote
No Limit Powersports Posted October 25, 2009 Report Posted October 25, 2009 When I built my 4mill cub I had this conversation with Dan Hull at a&s. I allready had the shortrod crank and didnt want to buy new domes to run 68mm unless there was enough difference to justify it. I was told by him the long rod was making a little better torque curve but the short rod would rev faster and make a little more hp on the dyno. I ended up with a 65mm cub and the short rod crank and dont have any complaints. If you plan on going to a bigbore in the future the bb pistons are easier to come by for the longrod crank, last time I looked you had to go with vitos or wsm for a bb and shortrod. I had a 68mm cub at one time but sold it in favor of the 65mm mainly because of piston availbilty with the shortrod crank I couldnt tell any difference in the power. Big bore pistons in the shortrod are not scarce wiesco 9768mo6800 for a 68 bore short rod readily availble i always stock them for this is one of my more popular motors. That animation was great! sometimes a picture IS worth a thousand words.. lol VERY good info! Sometimes you just have to see it. For some people its just that omg moment that they just dont understand. Esp when you apply the principles to a 2 stroke the correct rod ratio can make a considerable difference. Wow is that drawing to scale? If so i didnt think it was that dramatic of a difference. Makes me glad i went with a longrod. But hell, if both work fine, it dont matter to me. There are advantages to both. Shorter rods open the ports longer, longer rods are easier on the rotating assembly, cylinder walls, and dwell where the power is made tdc. Quote
RILS Posted October 26, 2009 Report Posted October 26, 2009 Big bore pistons in the shortrod are not scarce wiesco 9768mo6800 for a 68 bore short rod readily availble i always stock them for this is one of my more popular motors. Thanks for the info. How long has that piston been availible last time I looked for a set was around 06 and nobody mentioned this series. Nice info all the same. 1 Quote
yooperbanshee Posted October 27, 2009 Author Report Posted October 27, 2009 Guys, I really appreciate the help. Obviously, I'm new to this so I need all the help I can get. After reading these posts I'm convinced I should just rebuild from top to bottom with a 4mm, ported heads, cool head, etc... I have all winter to rebuild right. Like all of you, got the need for a badass ride! Any advice on exact setups would be great and thanks again. Quote
RILS Posted October 27, 2009 Report Posted October 27, 2009 Guys, I really appreciate the help. Obviously, I'm new to this so I need all the help I can get. After reading these posts I'm convinced I should just rebuild from top to bottom with a 4mm, ported heads, cool head, etc... I have all winter to rebuild right. Like all of you, got the need for a badass ride! Any advice on exact setups would be great and thanks again. All depends on wht u want to do with the bike and how much money u have. Quote
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