I am building a 500 cc engine with bigger piston and cilinderkit.
well cost is one, but if done properly it will last just as long....and im curious what compression you are running TNT?? most of my builds are close to 15:1...just didnt know whos done that yet and if it liked it or not, have you played with different deck heights on the can ams? seems to be .030" total squish is a good "safe" number on most other quads...not sure what the ds is from the factory as i havnt cracked one open yet but my list of goodies keeps getting bigger sitting here!!!why run a sleeve and not a cast cylinder that has nickasil lining?
I think I will try the epoxy work in the intake.We run a 495, JSR out of wichita, ks has them. We never epoxied down the port are you going to? In theory it should gain more Tq if thats what you want. We have a very torqued quad tunned for mx, around 50 hp 36 tq lots of throttle response and light weight it will tire you down if not in good shape. We held up fairly good to HON's, Suks, KTM's @ 60+ hp/38+ in Open A nats. I really think a stroker would have woke the bb up and made us more competitive but afraid of the reliability. Then again seen lots others blow bb motors too. We had a steel sleeve made, best way to go imo. CP piston.
The head has big long ports, with their angle, not sure much you can improve by just opening them up epoxy can help the velocity but also the flow by raising the floor an redirecting the port to flow through the intake valves better. So a head with better flow will be good for the 450 or 500. with fuel injection you don't have to worry about fuel atomization like on a carburetor setup, but velocity still fills the cylinder better an the right port design help prevent backflow.
I think the race teams have already proven that epoxying down the intake port gains torque on 450's, noone has on bb's I know of but in theory it should make better torque if properly done. They tried bb's back in 08 with little succees, but maybe they have evolved w/more experimenting. We did it since back in the beginning of 09, the 450 power was unknown and just as unreliable as bb. Today I think it is a known fact proven by Warnert, Motoworks, BCS, Rossier, that just as much relable power can be gained by 450 vs 500, one reason along with others being as I said the epoxy may be more effective. A stroker/bb kit is ideal opposed to just bb. Stroker is good but you have to consider reliabilitty the xtra piston ring/wear from longer storkes and additional loads on bearing's, etc. Sounds like MR Hp has tested this but more testing may be needed to say it's proven reliable.Does it bring more bottomend response or is it just to make more rpm?
I do not run with the mapsensor only on the trothle sensor to make it more responsive on the trothle.
Setting the injection is no problem for us because we are running a very good adjustable Cdi with Lambdacontrol.
Lets try it out in a few weeks.
Atomization is the combining of fuel-air molecules for effective power strokes. The faster this chemical reation occurs the faster the power is delivered w/ more torque at any rpm, but mainly when the piston is moving fast(high rev's) depending on tranny and drive train gear ratio's. Yes it's good to divert fast air directly to the intake valves at the same time produce port angles that create a low pressure area is the trick. Problem with flow benches is they don't show the delta P between the port and combustion can in a vaccum, so one has to guess at a combination of port conic shapes which in the bigger picture the interface cone between the air filter and exhaust.
So the lower the pressure at the port combined with higher velocity allows vaccum air to be pulled to the intake and combustion yes preventing backflow. With that the need for faster atomization grows, some roughen the EFI port to promote this. In a carb this all happens in a the carb body, not the fuel rail-manifold/head, so the need for a rough port and atomization post injector is reduced.
Adding a 02 sensor loop or load timmer makes the throttle more responsive, in this case as load is applied to the engine the 02 sensor senses the oxy level in the exhaust and trims the fuel map. PC 5 autotune does this, it's like getting a dyno tune while riding.
stroking it shouldnt add ring/piston wear. most spec out the rod so its at the same or better angle than the stock configuration...
The stroker goes up and down farther....well actually it only goes down farther...but anyway. Lets say the stroker motor can get the bike around the track with a quicker et while only having to turn 8000rpm. Meanwhile the stock stroke motor has to turn 9500rpm??? Just a passing thought.stroking it shouldnt add ring/piston wear. most spec out the rod so its at the same or better angle than the stock configuration...
im going to agree with TNT, anytime you make the piston go up/down farther you will have that much more wear.
also the more stroke you give it the more side load you will have on the piston...meaning more wear....yes you can make it to a long rod stroker for less side loads but in the end you will still have more wear than stock