CRF 510 stroker
Posted 15 December 2011 - 02:49 PM
Posted 15 December 2011 - 03:31 PM
Posted 15 December 2011 - 06:42 PM
Posted 15 December 2011 - 11:58 PM
The piston and rod in a CRF450 already experiences G-forces similar (or even exceeding) those of an F-1 Racing engine. A stroker crank increases average piston speed, increasing those G forces. A big-bore forged piston hanging on the end of a stroker crank will just multiply the forces trying to tear the rod and piston in half even more.
Either do a stroker, or do a big bore. Don't do both if you value reliability, and without a cam and portwork, a big bore will not actually get you any more power.
Posted 16 December 2011 - 11:47 AM
You'd need a longer cam chain too, along with a spacer under the cylinder. If you were +5 on the con rod, with the +3 crank and the big bore, it may run ok if you had the head done big. Like a flat track head.
This can be done. How much money you got?
Posted 16 December 2011 - 04:44 PM
Posted 16 December 2011 - 11:55 PM
i beleive the rod length frees up some friction reduction
Ya, and it will reduce the piston speed too so the thing can rev again. And that reduction in piston speed will calm the intake pulse at the opening event too.
Long rods are good. At least that's what she told me LOL...
Posted 17 December 2011 - 04:04 PM
I have had a big bore motor that felt like it signed off early on a suzuki I had. I really want to avoid that. I hated the way it felt. I had a stroker yamaha YZ426 that ran liked a raped ape.
I was planning on spending around 1500 or so on the motor (not including little stuff such as new bearings and gaskets) to push out the most power as possible. Thank you for all of the advice and i apoligize if there are many threads like this one.