crankshafts

[Dan Thompson]

whats the difference between a stock crankshaft and a 3+ crankshaft

 

[stabor1122]

+3 is 3mm longer stroke. It throws the piston 3mm further each cycle.

 

[brandoz28]

the stroke is 3mm longer, so instead of being 57mm, its 60mm. this will enhance low end torque.


the 3mm stroker also has stuffer blocks molded onto it

 

[Dan Thompson]

ok thanks what are stuffer blocks? and wont that hit the head? so im guesing it needs machining

 

[brandoz28]

it comes with a spacer plate, but the better way to do it is have the head cut and have the ports adjusted to the stroker.


stuffer blocks go in the "voids" in the crank that would be open to decrease crankcase volume and help with throttle response

 

[Dan Thompson]

oh right cool, are they worth buying?

 

[scotj77]

yes it is a definate power upgrade and the porting work will cost you about the same as getting a stocker ported and head redesigned. only downfall is once you start going this far you need to upgrade to atleast a 30mm carb and prob an exhaust upgrade along with it. so as you see doing one mod leads to many others to actually get the performance you will want out of it.

 

[brandoz28]

if you can afford the supporting mods, yes they are.



don't forget with all this new found power, your clutch is probably going to be on its way out, but you already started a thread that has info on what to do about that

 

[Dan Thompson]

so should i get a crank and then get the porting to suit and shizzle and ive already got an exhasut and will be getting a carb

 

[brandoz28]

you're going to want to upgrade that exhaust if you get the stroker and the porting.

 

[Dan Thompson]

so what exhasut should i get?

 

[brandoz28]

if you're mainly trail riding, a toomey would be a decent choice, but the f7/trinity/ct/powerpros is what most will recommend, and i love mine as well

 

[Dan Thompson]

so whats wrong with mine like

 

[Drifz1]

you can get cheap toomey packages in ireland

 

[Dan Thompson]

so basically i need £500 ish

 

[lasxgames]

fyi all new cranks you should make sure they are balanced (True). Even new out of box!!

If you don't you may have problems

Crankshaft True and Tig

 

[brandoz28]

especially vito's!

 

[Dan Thompson]

what so should i wait a bit till i get enough money get a new crank then get it ported to suit and get a 30mm carb and a new exhasut even tho i dont see anythin wrong with mine.. oh and a new clutch

 

[brandoz28]

that's how i would do it, you can reuse your exhaust for now, but it won't be optimal. you could reuse the stock carb too for a little bit, but the big thing is that the porting and the crank need to happen at the same time, the clutch really should so you aren't breaking it open all the time. it just makes more sense, and will be cheaper in the long run if you do it all at once

 

[Dan Thompson]

ok why does the crank and porting need to happen together? and would i have the send the whole engine to get ported?