bigredburb Posted January 3, 2009 Report Posted January 3, 2009 Been lurking around here for awhile (Great site bye the way) and had a Question about some parts i just picked up. The deal is I got these cylinders that are set up for a 4mill crank was told they make good power but im kinda suspect of the porting on them. Was told they made 80 wheel hp with fmf fattys, 35pwks, +4degree timing, at 145 psi. So im just wondering if this looks like a 80hp port job on a 4mill with those mods? Quote
locogato11283 Posted January 3, 2009 Report Posted January 3, 2009 ill tell you right now they werent making anywhere near 80 hp with that setup. im guessing maybe 60. Quote
bigredburb Posted January 3, 2009 Author Report Posted January 3, 2009 Thanks for the help that was kinda what I figured, Least it was all fairly cheap. So I guess I will send it off to my porter and see what I can get done to it. Quote
spurdy Posted January 3, 2009 Report Posted January 3, 2009 Thanks for the help that was kinda what I figured, Least it was all fairly cheap. So I guess I will send it off to my porter and see what I can get done to it. Hard to tell from the pics because its all in measurements on the ports. But that intake looks pretty damn rough. Your prot guy should be able to tell you if he can get good numbers out of whats left. Depending on who he is. Lots of good port guys on here, just do some checking. SP Quote
bansheefreak Posted January 3, 2009 Report Posted January 3, 2009 the intakes just looks like they took the paint off... the transfers look pretty decent.. but the power is in the exhaust port.. hard to tell by the pics but they look pretty wide... id say 50hp to 60hp at the most Quote
Snopczynski Posted January 3, 2009 Report Posted January 3, 2009 Your gonna have to measure the port heights and widths. The bottom of the tranfers look fairly ground out though. You can get some good numbers from moving the exhaust, but the banshees bigest downfall is the restrictive transfer ports. You open those up and you start seeing some great numbers as long as you can keep good port velocity. This is the 250r cylinder. 75cc bigger and the transfers are f%$#ing huge. Thats why those motors make great power with a port job. Quote
BigRed350x Posted January 3, 2009 Report Posted January 3, 2009 Your gonna have to measure the port heights and widths. The bottom of the tranfers look fairly ground out though. You can get some good numbers from moving the exhaust, but the banshees bigest downfall is the restrictive transfer ports. You open those up and you start seeing some great numbers as long as you can keep good port velocity. This is the 250r cylinder. 75cc bigger and the transfers are f%$#ing huge. Thats why those motors make great power with a port job. those motors make great power?? lol Quote
wesw Posted January 3, 2009 Report Posted January 3, 2009 you will need some inframe drag pipes: cpi/shearers to get that kind of power. fmf wont allow it to breath as well. also besides having your porting looked over, you will need shit load more compression than 145. it will be a dog off the bottom end and better look into some race gas or 100LL with your compression. shoot for 170+ psi. Quote
bigredburb Posted January 3, 2009 Author Report Posted January 3, 2009 Like I said got this stuff cheap, I got the cylinders with 65.0 795 wisecos a new in box hot rods 4mill long rod crank thats trued and welded, and a noss head without dones for 600. Figured it was a good deal since I planned on building a 4mill anyway. If the cylinders are to far gone I have a set of standard bores that came from my banshee that will get sent off for porting and fresh bore. This whole deal started when my nephews both got new Suzuki 450s and they wanna go to the dunes and all I have to ride anymore is a 600 grizzly. So I started looking for a banshee to build just to show them what an old 2 stroke can do but after I been on here reading I started to figure out its gonna take more than just a piped, headed, timed banshee to run with them. In my search for a builder banshee I found a 01 local that ran but had no power and backfired badly. Overall its in good shape and I liked the fact that the only mods to it was fatty head pipes so it was just what I was looking for at a price of 1k. After getting it home figured out the broblem to be a tore intake boot but I tore it down anyway in my quest for more power. So the plan is. 4mill stock cyl that runs on 50/50, 33mm-35mm carbs, cpi or shearer inframes, and a override trans ith lockup. I figure that with some good paddles and swinger should be able to do the trick. Quote
bansheefreak Posted January 3, 2009 Report Posted January 3, 2009 should work just find ya a biulder to look them over.. Quote
bigredburb Posted January 9, 2009 Author Report Posted January 9, 2009 Well got the cylinders in my hands now and took some pics. Was going to send them off but they have had alot of work done on them so I think its going to be a waste of time. So I think im just going to try em out and see what they do, then if they bring the suck send off my stockers to get worked over. Anyway here are the pics. Quote
yamaha11 Posted January 9, 2009 Report Posted January 9, 2009 Well got the cylinders in my hands now and took some pics. Was going to send them off but they have had alot of work done on them so I think its going to be a waste of time. So I think im just going to try em out and see what they do, then if they bring the suck send off my stockers to get worked over. Anyway here are the pics. why not just have a builder look at them and see it cant cost much to have them looked at and maybe they can help you with them Quote
RIPPEN Posted January 9, 2009 Report Posted January 9, 2009 why not just have a builder look at them and see it cant cost much to have them looked at and maybe they can help you with them I agree.. The little bit of time and money it would take to send them off to be checked out may prove to be handy and well worth it... Most everything a banshee engine is about hinges on porting.. Id send them.. Otherwise at a glance they look pretty clean.. RIPPEN Quote
uwenr Posted January 10, 2009 Report Posted January 10, 2009 (edited) IMO the exhaust port is too wide, thats prob why you got new pistons with it. With it that wide the piston will rock and crack. If you look they go past the transfers. Again just my opinion Edited January 10, 2009 by uwenr Quote
Snopczynski Posted January 10, 2009 Report Posted January 10, 2009 IMO the exhaust port is too wide, thats prob why you got new pistons with it. With it that wide the piston will rock and crack. If you look they go past the transfers. Again just my opinion The exhaust width can be 70% of the bore size in mm. You can stretch it up to 75%, but thats pushing it. Quote
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