porting???????

[racerMX]

what is porting?

what is realy done to the cylinder?

Is a port job worth $300.00

And how much different is a ported cylinder
than a none ported cylinder?(riding wise)

$300 race Porting is only a good thing if you have a larger carb on your bike,,,that is if your running a 400ex..

[Lasher]

On a 2 stroke engine, porting is where you get real power. But as Rico said, just port work with everything else stock, will not gain (if not hurt) you power. But once you put together the entire package, you will see a huge power gain.

[400exJOE]

i might get a 38mm lectron w/ my 440. I am only recreational. SHould I bother w/ porting and/or polishing?

[racerMX]

i have a 88 MX 250r............the motor runs an 86 pistion with a
spacer plate between the cylinder and the crank case.
I also just bought a keihin 38m air striker carb.Some time this
next year i am going to buy a Duncan PC 2000 power valve cylinder.So i am thinking about doing the port work untill then.
My race season starts in Feb.

[trx400ex]

next year (march) im sending half of my engine to LRD for 3 weeks,,, one of the things there gonna do is port it, he said it will be 400$ for full race port and polish, i told hiim what i was goin to run on the engine (pipe 416 etc., stock carb) and he said the diffrence would be night and day, he also said adding a 39mm FCR would work well with it too.. but im still deciding if the oversize valves are worth another 300$:confused:

[Lasher]

To others with a 4 stroke, I am not sure how much porting will affect your power.

To racerMX – Yes, porting can be worth $300 and even more than that if , IF, done correctly and set up for your application. There will be many hackers out there that say they can port and in reality they cannot. Either go with a big name place that is reliable or find a local person that does quality work.

Shortly after getting my R I went to a local place that came recommended. I had him port the motor and it is fast. Difference of night and day. One of the benefits of going local, is if any problems come up I can drive up to the guys shop to have it fixed or the jetting checked.

I have the same carb as you and I really like it. Do you have an aftermarket exhaust? If so is the exhaust set up for low end, mid range, or top end? Depending on your application (ex MX you need low/mid range where drag racing you need top end) match your porting work to the pipe.

I too would love (and still think about) to get the DR Powervalve motor. But from what I have heard, the cost of the cylinder to the benefits are not that worth it yet. All the powervavles run basically the same principle, at least for quads. It is exhaust pressure that moves the diaphragm. I would like to see the electric powervalve taken from the 2002 CR 250 and put into the quad.

If I was you, I would get a good port work, matched pipe before going for the powervalve. You may be surprised at how much power you will actually gain from those.

This winter I am looking into a new top end, fully ported. I am leaning towards ESR since I have heard many good things about them.