WynoT Posted April 4, 2011 Report Share Posted April 4, 2011 Hi, I read somewhere in this forum than If I buy a 4mill crank and put it on my engine I will not be able to use a set of jug that has been ported for a non-4mill engine. And not even been able to adjust the porting to the 4mill (lower the exhaust to BDC etc.) Is it true ? The problem is that I have a set of jug ported that I was hoping to modify a bit to fit to a 4mill and put all that together instead of paying an expensive 4mill porting for a set of stock jug. I also really want to do the job myself, I know many guy out there will tell me to give the job to a pro builder but it's not what I want. I prefer do all the job myself quite of loosing a bit of power. Quote Link to comment Share on other sites More sharing options...
mopar1rules Posted April 4, 2011 Report Share Posted April 4, 2011 wether or not you can use your ported stock stroke jugs w/your 4mill depends on how aggressively timed the ports are. what pipes do you have? what are your current stock stroke durations? Quote Link to comment Share on other sites More sharing options...
Tf705 Posted April 4, 2011 Report Share Posted April 4, 2011 im wondering the same thing. i have a set of drag ported cylinders done by hjr. my stock stroke crank is going and i would like to go to a 4 mill but dont want to buy new cylinders. cant i just get cut domes for the stroker or will the port timeing be way off. Quote Link to comment Share on other sites More sharing options...
mopar1rules Posted April 4, 2011 Report Share Posted April 4, 2011 im wondering the same thing. i have a set of drag ported cylinders done by hjr. my stock stroke crank is going and i would like to go to a 4 mill but dont want to buy new cylinders. cant i just get cut domes for the stroker or will the port timeing be way off. your port timing will probably way too aggressive. to help get the port timing back in the neighborhood that works good for a 4mill stroker, when going from a stock stroke ported jug, you will need to have the bases of the cylinder machined to help lower the ports. only problem is the domes will need to be custom now, to have a deeper step cut in them for the additional clearance, but you gotta watch how close the top ring is getting to the top of the cylinder. i would just buy a good used set of stock cylinders and have them ported for a 4mill stroker. sell you stock stroke ported cylinders, to help offset the cost of 4mill ported cylinders. Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted April 4, 2011 Report Share Posted April 4, 2011 have a builder check your cylinders and see if they will work with the 4mil setup. Kevin Herr can measure your setup and let you know if it will work with a 4mil or not. - Jared Quote Link to comment Share on other sites More sharing options...
WynoT Posted April 5, 2011 Author Report Share Posted April 5, 2011 Ok thanks, so my best way to go should be to sell my ported jug as is and take the other stock port one that I have and port them... And what kind of porting a 4mill need ? I know I have to lower the exhaust port to BDC but for the transfert and intake what should I do ? I want a trail bike setup with load of midrange not a high-rev drag setup... For the pipe, for now I have a set of T5 and T6, I didn't think the T6 will handle the 4mill so it will be T5 for now... But I'm looking for a set of Pro Circuit. What do you think of that pipe on 4mill ? Do you have better idea on trail pipe for this setup ? Thanks ! Quote Link to comment Share on other sites More sharing options...
gotta_goatsfast Posted April 5, 2011 Report Share Posted April 5, 2011 Sounds like you're on the right track. If you need to purchase the jugs and then have them ported, you should really consider a Serval cylinder. The torque below the powerband is quite impressive for a Banshee. Quote Link to comment Share on other sites More sharing options...
WynoT Posted April 5, 2011 Author Report Share Posted April 5, 2011 Ok thanks, but I have a set of stock port jugs on my garage so I'll take them. I was wondering of taking my ported jugg to save time on grinding the port but I think it will be easier to start from 0 One day I'll buy Serval cylinder for sure. They look very interesting for trail riding but it's too expensive for now. Quote Link to comment Share on other sites More sharing options...
gotta_goatsfast Posted April 5, 2011 Report Share Posted April 5, 2011 That was my first thought, too. You can pick up a serval top end for under $1200. Sell both sets of cylinders and recoup say $300-$350, and its costing you $850-$900 for a new cylinder, pistons, and domes with gaskets, stud extenders, and a few misc goodies. Price up having the stockers ported and you end up with $300ish for a port, $85 for domes, $250ish for bore/hone and piston kit. Suddenly the serval isn't much more than worked over stock cylinders... but the gain is MUCH more. This was just my thought and deciding factor when I built my 421 serval. Quote Link to comment Share on other sites More sharing options...
WynoT Posted April 6, 2011 Author Report Share Posted April 6, 2011 Thanks Man ! Yeah it's not as expensive as I tough but I'm planning on doing my own porting so I'll save 300 buck And I really want to begin with my own porting to learn something new. But I will certainly switch to Serval when more HP will be needed. Do anyone could tell me number ? Transfert time, blow down, exhaust etc. As I said I want a load of mid-range power. Quote Link to comment Share on other sites More sharing options...
mopar1rules Posted April 6, 2011 Report Share Posted April 6, 2011 This is where you really need to know your shit. You don't have your timings right on your ports and it can run like a turd. You can ruin a good set of cylinders quite quickly and then be out a good $300. Not to mention you need the 90-deg handpiece from cc specialties to do the proper work to the transfers. Your $30 dremel won't work here, or even any good elsewhere for that matter. Quote Link to comment Share on other sites More sharing options...
Tf705 Posted April 7, 2011 Report Share Posted April 7, 2011 please dont try porting them yourself. 2 stroke porting is not simple. Quote Link to comment Share on other sites More sharing options...
WynoT Posted April 7, 2011 Author Report Share Posted April 7, 2011 I already have a Long neck 5'' grinder, 90 angled air grinder, a micro pencil air grinder and a standard grinder. I swear it's more than enough to do the job, all I need to know for now is a bit of theorie and some # cause I never port a banshee. I can do the calc, I found some good topic here on this forum about how to use the degree wheel and mesurement, Yeah i'm a novice and I yes it's a bit risky too but I think it worth the cost and if I don't try I'll never know But, I don't know much about which work on the port will do what and I don't want to end up with a Drag oriented banshee or a messed up duration so i'm sure someone here can help me out. Quote Link to comment Share on other sites More sharing options...
gotta_goatsfast Posted April 7, 2011 Report Share Posted April 7, 2011 This is an area that a lot of guys post up saying they want to try and learn. Well, I suggest that if you just ask for numbers, you won't know what they really mean. Its more than numbers. How you shape the transfers to blow into the cylinder, for instance is not measured in degrees. My point is, if you are truely in it to learn then pick up a copy of Gordon Jenning's two stroke theory and any other in depth reading material. Then you can determine what you need to do to produce a satisfactory port job. It is a lot more involved than you might think. Take off 1mm more than you intended in the wrong area and you have a peaky short rpm motor or worse, a motor that runs like shit. Quote Link to comment Share on other sites More sharing options...
armyvet Posted April 7, 2011 Report Share Posted April 7, 2011 While i agree porting is something that does require a bit of knowledge its not exactly a "black art" as soome will lead one to believe.Everybody had to start somewhere,not like theres a banshee tuning school.Half of these so called banshee "experts" where nowhere around in the early 90s.I say start small with lil'bit of touch ups before trying to get carried away.Hogging out ports wont necessarily give you the most power>Its all about velocity and volumetric efficiency,its bacically a air pump.Been doing my own cylinders since 89'.a wise man once told me"people that have never f@#ked anything up have never did anything".Only 1 way to learn,you mess up banshee cylinders are easy to come by.just my .02 Quote Link to comment Share on other sites More sharing options...
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