Dyno Results

[slickta]

We dynoed the 520 yesterday. It made 55 rear wheel horsepower and 35 lb/ft of torque. We made 5 pulls with it and every pull the horsepower increased. What I am trying to figure out is the graph. The bike made max power at 8500 rpm and went into a sharp decline after that all the way to the 10500 rev limiter. The A/F ratio stayed good across at wide open. What could be causing this drop and low rpm power max? I am wondering if the carb is not big enough or if the port job is not enough? This was done on an air brake dyno. What would you recommend to remedy this problem? I am very unhappy with it at this point and know there is much more potential.

Falicon billet stroker crank
athena big bore cylinder
JE 12.5:1 piston
cylinder is zero decked
ported head
+1 intake and exhaust valves
Web Mysto cam
Kibblewhite springs guides and valves
LRD Pro 4 exhaust
Magnum cdi
Edelbrock 40mm carb
custom air intake (no air box)
K&N filter

[2004exrider]

im pretty sure that every engine starts to loose power after a certain rpm.

Jimmy

[slickta]

The cam is good to 13,000. The rev box goes to 10,500. That is below the stock rev limit on a 450R.

[2004exrider]

i just no that when they dyno cars the power will go up to a certain rpm then start dropping. Not sure though since your cam and rev box can hanlde more, hopefully someone else will chime in that knows. I guarentee that if you pm cals400 he could answer that for you!:)

[slickta]

I put it in the DASA forum, but Dan did not reply. I am just looking for other opinions. We talked to Mark Baldwin at the races and he said we definitely needed the fcr carb and crf ignition, but did not get time to ask him about the porting and valves. Tim was getting ready to race. I saw two of Dan Lamey's engines run and the one was a bad machine. It looked to be the fastest Honda. I would really value his opinion.

[GOTFEAR]

Big motor two mutch timing. try retarding the timing and if that dont work you might have two mutch advance in the cam.

[cals400ex]

maybe you need a larger diameter pipe? the stroker will definatly make more power at low rpms too.

[keihin fcr]

An engine is only capable of so much 8500 and then nothing is normal. AS long as it doesnt fall off and then come back up thats a timing or jetting problem. Think about it 8500 rpm out of a single cylinder thats spinning fast.those are good dyno results. My 426ex stops making power at about 8000 in 5th gear on a road i have mini tach on it.