rasputin;28503 said:
that's what the update is about... low end power and quality.
r
The bore shape/size of the PV's in the cylinder is what it is and can't be changed (well it can but not without re-working the cylinder part) What I mean, the new PV
HAS to fit into that space. The cut of the angle and or how close it extends into the cylinder while still not grazing a 12,000 RPM piston is the factors that are probably changed. And since this is a drop in replacement, I would not think that Husky would try for a 0.001" clearance so as to avoid liability and ots of roasted top ends.
Simply the PV's alter the exhaust timing and change the characteristics and increase the torque of a two cycle at low to mid engine ranges. This is up to a point as after a while the exhaust gasses cannot effectiveley exit and there is no form of creating a "supercharging effect" to forcing exhaust out and with that being said the volume,angle,length of the design of the expansion chambers which sucks the exhaust gas out plays a big part especially at high engine revs and this also effects the vacuum effect back to the gas charge coming through the engine.
The concept of port altering is not new. The PV on most bikes has the movement of the valve at about 8000-9000 rpm and the movement of the valve is generally either 'on' or 'off'. Little "progression" and variance is what I mean. Watch one woking with the cover off to see what I mean......kinda "lightswitchy".
By altering the timing of any of the many variables in a 2 smoker such as charge induction start,charge duration,charge induction close, transfer ports and openings and closings and duration,piston port timing and durations and piston port opennings and closings and duration, exhaust ports openning,durations and closings,the list is very big at what you can change on a two cycle engine and it is all timing relative to the degree of crankcase revolution.They changes will change the aspects of torque,power,boost,reliability,fuel consumption, starting, engine temperature etc. See what they did to the 07 CR and the 08 WR with the ports.
What is my rambling on my passion for 2 strokes meaning?????
All these parts are linked in relation to timing. (no jokes on "they should have had the factory timed so these parts came on the bike from the get go"......at least they are "Husky-ing up if your know what I mean)
It will probably aim at having an effect of increasing engine vacuum and flow and the effect of advancing the timing (not actually physically advancing it) relative to the degree of crankcase revolution which would give more response, low end, and overalll "enduro ridability.
There......I am done.
Joe
