County Park Racing 440EX

[countypark]

Here is my new quad:)

440 Stroker
Ported and Polished
GT Thunder Suspension

37 HP with Airbox lid on and HMF Quiet Core In

[Dobber]

looks pretty nice..i think you should get some graphics to make the plastics flow together better thought..but thats just my opinion

[countypark]

The dyno run showed 36.5 HP with the main jet running rich. After I dyno'd it I leaned out the main so I'm guessing 37+ HP now with an HMF Slip-on with quiet core and the airbox lid on.

With the core out and lid off it runs 40+ HP.

Below is the chart showing mine and an HRC 450R.

[Wheelie]

Nice score. It's good to see another 440 stroker on the board.:macho

[killer400ex]

why would you run a slip on with a port and polish, and a 440 stroker? ans why the hell do you still have the lid on the airbox? you are starving your engine for air and power, and i would also consider new cams with the port and polish, a 450r carb and a full exhaust, you would be holding on to your ex for dear life

[countypark]

Without the quiet core and lid the torque gains are pretty good.

Ignore the titles these curves are only from my quad.

[countypark]

Originally posted by killer400ex
why would you run a slip on with a port and polish, and a 440 stroker? ans why the hell do you still have the lid on the airbox? you are starving your engine for air and power, and i would also consider new cams with the port and polish, a 450r carb and a full exhaust, you would be holding on to your ex for dear life

I'm pretty happy with a 400EX that puts out better numbers than an HRC 450R.

GNCC Rules for sound are 99dbs and the HMF pipe is way above that without the core. Many a riding areas have been closed down due to obnoxiously loud pipes. The stock head pipe is stainless and didn't cost anything.

And every cross country race I've ever been in has a considerable amount of mud and water so the air box lid comes in pretty handy.

I'm pretty sure that my GT Thunder Suspension will make up for the 5 HP I'm losing with the lid and core.

The 400EX has one cam and mine is a Stage 1 Hot Cam. Very smooth power. This engine will be very reliable and it has more than enough power.

A 450 Carb might add a HP but big deal. If they are so good why do the 450 builders change them to CRF 450 Carbs?

[countypark]

Originally posted by Dobber
looks pretty nice..i think you should get some graphics to make the plastics flow together better thought..but thats just my opinion

Thanks for the compliment.

I just got done putting this together from a bunch of ebay parts and a basket case quad. Graphics will be coming soon.

Along with nerfs, hand guards and a stablizer.

[countypark]

Custom 400EX Chassis
- sub frame mod'd
- battery box relocated
- gusseted
- metallic silver coating
Hot Rod +4 Stroker Crank and bearings
Stage 1 Hot Cam
CRF 450 timing chain
CP 11:1 Stroker Piston
GT Thunder Heavy Duty Head Studs
Hinson Clutch Basket
Port and Polish by Matzack Porting
+2 +1 a-arms
GT Thunder front shocks (450 conversions)
Flexx Bars
GT Thunder Rear shock(400ex conversion) and XC Link
Durablue axle and Lonestar carrier
Clarke 5.5 gallon tank
PRM Full chassis skid
Custom brake stay skid and sprocket guard

[Dobber]

Originally posted by countypark
Thanks for the compliment.

I just got done putting this together from a bunch of ebay parts and a basket case quad. Graphics will be coming soon.

Along with nerfs, hand guards and a stablizer.

post some pics when you get everything done..i cant wait to see it

[stringbean]

countrypark, your mailbox is full. 107.50 tyd for the parts you asked for.