powroll 352cc stroker for 250x

[wanta250r]

has anyone tried this kit. will it out run a 400 ex

[rooster300ex]

i'm pretty sure a 352cc that is ported,polished and all the works will out run a 400ex.

[wanta250r]

so its probably worth the 1200 then if it has all this
BORE KIT

STROKER

CAMSHAFT

VALVE SPRINGS

CARB KIT

AIRBOX LID

[bradley300]

thats not a bad price for all the work, does that include labor?

[bwamos]

It either doesn't include headwork, or doesn't include labor for splitting the cases.

If it does.. you found yourself one hell of a bargain!

[bradley300]

thats kind of what i was thinking

[wanta250r]

Im not sure if that includes labor
mickey dunlap makes a 390 that is probably the biggest
that would be around 1500 with cam and valve springs

[wilkin250r]

I don't think Powroll DOES any labor. I think they only sell kits, they don't offer shop services except for stroking the crank (and most likely, they send that out to a crank shop).

Without headwork, I don't think you'll outrun a 400EX. The ports on the 250X are kinda small, and a 352cc is a HUGE jump in displacement. Those small ports are going to choke the top end off that poor motor.

You want real power, throw another $250 at your engine and get some headwork done. Open the ports, maybe oversized valves. Whoever does your headwork, be sure to tell them what engine kit you're getting. The breathing requirements for a 352cc monster are going to be different than a high-performance 250cc, you don't want just a standard "cookie-cutter" port job.

[bwamos]

Could do the 350 kit.. and then toss the head to Sparks to port for a 350. ;)

Might see what he can do for ya too. I kinda like the pros to match the whole motor up rather than be adding together a bunch of bolt on parts, and hoping it works together.. lol.

It's kinda like putting Axis valving in a Works body with Elka springs, and an Ohlins Res. Odds are it won't meet its potential.. lol.

[2muchquad]

Without headwork, I don't think you'll outrun a 400EX. The ports on the 250X are kinda small, and a 352cc is a HUGE jump in displacement. Those small ports are going to choke the top end off that poor motor.

you would be surprised at how well it will run EVEN with "the small ports".i wonder where this falacy ever came from.i think too many people believe what they "heard" instead of what they see.remember,velocity velocity velocity.thats gonna be high,thats where you make your money,regardless of what you heard.very few motors pick up HUGE gains from ported heads,sad but true.people that dont understand the internal combustion engine will digress,but its true.:rolleyes:

[bwamos]

Yea, but the proper shape and angle of the air coming into the cylinder makes a huge difference. The 300ex/250x has a horrible horrible (did I say horrible?) intake angle. This is the thing that makes the bigest difference on the 250x/300ex.

Bigger isn't always better, I agree. Look at a Harley, lol. But, there is also a point when it's just too small. A 250x stock head intake ports are going to seriously limit you on a motor over 330cc's at higher RPM's. Especially without a custom cam. It will be a torque monster at low rpm's though.

[2muchquad]

250x stock head intake ports are going to seriously limit you on a motor over 330cc's at higher RPM's. Especially without a custom cam.
this is true BUT at the same time,the 250/300ex use a older heavier rocker arm design which isnt exactly ideal.its also air cooled so i wouldnt want to get to carried away.leave to high rpms to the new 4 fiddys and 250fs:D