some questions about stroker cranks

[catch me if u can]

i have a esr 310 top end and i was thinking about putting a 4mm stroker crank in the bottom end will i be able to run the pistons that i get from esr or will i need a different kind of piston ? also i was wondering if i would have to get my bottom end trenched to accept the stroker crank and if i do have to get it trenched where is a good place that can do it for me and about how much does it cost?the last question is with a 310 head and a 4mm stroker crank what would the motor be a (310,320,330) just wondering what size the motor would be and how much performance does it add to the motor (sorry about all the questions i just dont know much about stroker cranks)

[atcsteve]

ESR pistons are fine to run.No need to trench out either,its a longer rod kit.The cyl starts at a 295 and bores up to a 310!It will be night and day from the stock cyl.!!!!!!The stroke adds to the cc's too!

[Mert]

pie x r(squared) x height, or pie x half your bore(squared) x stroke, thats how you get your displacement

[catch me if u can]

does anyone know about how much it would cost(the amount a good shop would charge) to put a stroker crank in my 250r and what do they mean when they say you have to change port timming

[bushwesl]

If your cylinder is already ported for a stock stroke crank, the likelihood that you can re-port it for a stroker crank is unlikely. If you already have the ESR TRX9 porting than I'm confident that you will not be able to re-port that cylinder for a stroker crank. When porting for a stroker crank you have to adjust the port timing to accommodate the increased stroke. If the cylinder has already been ported, like yours, the proper port timing adjustments can not be made. Sorry, but you're stuck with your stock stroke 310.

[catch me if u can]

that is what i thought

[fulltiltrider]

Originally Posted by atcsteve

ESR pistons are fine to run.No need to trench out either,its a longer rod kit. You say Im dumber than you thought. The cyl starts at a 295 and bores up to a 310!It will be night and day from the stock cyl.!!!!!!The stroke adds to the cc's too!

Longer rod kit ???? Stroking a crank has nothing to do with making the rod longer. Putting a longer rod and a spacer plate on a stroked crank, only aids in reliveing the rod angle. Stroking a crank is placing the crank pin farther from the center of the crank...... So yes, if you go farther than 4mm on a 250r you will need to trench the cases.

Originally Posted by bushwesl

If your cylinder is already ported for a stock stroke crank, the likelihood that you can re-port it for a stroker crank is unlikely. If you already have the ESR TRX9 porting than I'm confident that you will not be able to re-port that cylinder for a stroker crank. When porting for a stroker crank you have to adjust the port timing to accommodate the increased stroke. If the cylinder has already been ported, like yours, the proper port timing adjustments can not be made. Sorry, but you're stuck with your stock stroke 310.

Exactly correct. Unless you have a cylinder that just has the clean up port, it probably wont work. You can do some adjusting with spacer plates and head cutting but once it was ported for good power its probably too far

[Bad Ass Honda 250r]

Originally Posted by catch me if u can

does anyone know about how much it would cost(the amount a good shop would charge) to put a stroker crank in my 250r and what do they mean when they say you have to change port timming

send all the parts and the motor to me and i will do it for 100 bucks...