I'm brand new to this forum and have been riding for two years. I currently own a 05 cbr600f4i and it's a great bike. I'm considering finding a 954rr or a good 929rr. I was wondering how you actually build an engine for more power without forces induction or nos. I understand the intake and exhaust but I was mainly wondering about more aggressive cranks, how to tune, and how to increase a redline. Thanks for the help

 

That depends on what your purpose is on building an engine. Increasing redline doesn't depend on crank. The crank would be good to get balanced for desired redline( rpm) and lightened to get some moving mass out of the engine internals.
But a balanced oem crank should allso be fine. And there is no benefit increasing redline if the bikes power is allready dropping before redline. You will have to get peak hp:s rpm up which is normally done by better flowing exhaust, intake, better flowing head( ported head), agressive cams and higher compression.

 

better internals make the bottom end able to do what you want it to (whether thats raised rpms or a stroker motor that can still make the stock rpms). you want the pistons to have a better compression ratio than stock

and from there, it's all about volumetric efficiency and head flow. more flow into and out of head makes more power, and the best volumetric efficiency lets you make the most power. cams that open the valves for a longer duration help your extremely top end power


like mika said, it depends on what you need/want the motor to do. him and i are both building 954 motors at the moment. and while our motors will share a few characteristics with the bottom end, we're trying to do different things. his motor is being built for much higher rpms. so his cams should have more duration than mine, and he'll need heavier valve springs, better retainers, and much more efficient head flow to see the benefit at the top end, all of which he's getting.

im trying to keep my top end not quite as crazy because i'm planning on stroking it. with that in mind, because of the extra stroke, i won't be able to make the rpms as high as he will be able to - but i'll have the leverage on the crank from the increased stroke to get my power. i still need to get all of the flow and efficiency out of the head - however i won't need quite the duration in the cams or the heavier springs (heavier springs close the valve quicker - the more rpms, the faster the valve needs to close), retainers, guides, etc. that he needs.


he'll make more top end power than mine will, but mine should make better mid range than his. its two ways of going about it. he's keeping his as a true superbike, mine is going to be a streetfighter. we'll want different things, except we both want to go faster

 

I feel like increasing redline is a lot of work for a little gain. These bikes are already very highly strung.

 

Both of our motors developed a quite bad piston slap so if it has to be torn apart you can build the motor for allmost same trouble. Nobody nows about gains before dyno but i've seen relatively good gains in Gixers, Busas etc. One magazine here in skandinivia got allmost 160 rwhp from old zxr1100 which made 100 rwhp before building the motor and thats about what it makes stock.

HP = Torque x RPM ÷ 5252
http://www.epi-eng.com/piston_engine...and_torque.htm

If the power doesn't move up there isn't any reason to increase redline. You can
increase redline by buying pc3usb and ignition module. That doesn't cost that much.

For Conrice:
Actually everything in my head is stock except valve springs, ports and valve seats( machined from stock). Ti-retainers didn't fit in my budget.

 

If you want to reliably increase it don't you need to upgrade connecting rods pistons and crank? Also the ignition like you said

 

I use oem crank which is balanced for higher revs and crank journals are polished, forged h-beam rods and Wiseco pistons. I would say the rods are only thing you really need to upgrade but if you wan't move the hp up adding little compression will help. And the bearing clearences are good to be at the loose side of the specs for higher revs. There is no need to upgrade the ignition. The power commander ignition module just gives you change to adjust the ignition and increase the redline so that i don't have to use aftermarket ecu.

 

Would you be able to increase the redline on the cbr600f4i to make it similar to the 600rr? Meaning 14 to 16

 

It won't make any more power by increasing the redline. The F4i:s hp will start to drop after 12.5k rpm so there is no more power after the redline. You would probably have to add compression whit pistons or decking the head, get the head ported for more flow and get aftermarket cams to even get the need to increase redline. Probably the 600RR has allso bigger throttle bodies, valves and better airbox and exhaust. And the older 600RR should make peak hp near 13k rpm. The never makes it petty much at 14k rpm.