4 mill stroker

[serius4play]

So im thinkin i wont to put a 4 mill crank in my banshee, Its already ported and polished, v forse 3 reeds Lightened flywheel +2 degrees timing .20 over Pro circit pipes (i dont wont to change these eather so dont try to convince me that i need to) 34mm keihn carbs K&N Filters, 43 tooth rear sproket, 14 front, 6in extended swing arm, 18 paddle paddle brats on 8in ITP sport rims,

 

So im wondering if there is anything im going to have to change or just take it apart after i get the kit and put the crank in and put it back together? I have a stock head and im thinking im going to put a cool head on it with 20 or 19cc domes. will all this still work without any other mods?

[kodie]

You will need 795 series pistons and if you are going with a cool head you will need custom cut domes or if stock head a spacer plate. Cut domes are more reliable.

[JasonsBanshee]

I believe you may need new cylinders if they are already ported for a stock stroke crank because they port specifically for a 4 mil. Someone correct me if I'm wrong, but that is what I've been told.

[01banch]

Depending on the agressiveness of the port jo they can sometimes scavenge a set of stock ported cylinders to work with a 4 mil but it is rare.

[serius4play]

ooo hmmm so sounds like it would be cheaper to boer it a bit and just get a cool head. keep stock stroke and or maby some NOS!!!!!!!!

[sled]

you'll need a spacer plate if you wanna keep the porting you have. If you decide to do that you don't need the domes to be cut. I would take you cylinders off and have a porter look at them and see if you can have them set up for the 4 mill. If they can be your not gonna need the spacer plate but your gonna need the head cut or with a cool head cut domes. You'll need the 795 series pistons if you go with a long rod set up, which is a good idea as it makes the cranks bearings last longer. if you don't you can just buy normal pistons.

[serius4play]

ok so check and have someone look at my port job. where would i get a spacer plate? iv decided to keep my stock head for now.

[Wildcardracing]

you'll need a spacer plate if you wanna keep the porting you have. If you decide to do that you don't need the domes to be cut. I would take you cylinders off and have a porter look at them and see if you can have them set up for the 4 mill. If they can be your not gonna need the spacer plate but your gonna need the head cut or with a cool head cut domes. You'll need the 795 series pistons if you go with a long rod set up, which is a good idea as it makes the cranks bearings last longer. if you don't you can just buy normal pistons.

Acctually, cylinders ported for a stock stroke crank may end up having too much transfer port duration if used with a 4mil....a spacer plate would only amplify this problem. It will all depend on how aggressively the transfer work was done. If they have too much transfer duration the bike will probably run decent in the low to mid but will fall on it's face in the upper rpms and not rev out to it's potential. As for the longrod, it's not easier on the crank bearings, it places less of a side-load on the piston skirts resulting in longer piston/bore life. Best to have your builder measure the transfer ports to see if a stroker will work with your current porting.

[studroes]

definately start out by taking your cylinders to a builder and seeing if they can be ported for a 4mil. if they can then i would say go with that and run stroker domes. if not then you can use a spacer plate($20 on ebay) it wont let the 4mil reach its full potential as domes but its a start until you can get cylinders to be ported for a 4mil.

[serius4play]

SCREW IT!!! GETIN SOME NOS!!!!!!!!!