Where to mill head and port cylinder?

[kdx310]

I have a 2004 KDX220 with Boyesen reeds, FMF Desert Pipe and airbox lid removed.

I am considering buying a Billetron Pro and getting the head milled and cylinder ported as part of this upgrade process. RB no longer offers this service. Jeff Fredette said he can't get around to it until quite a bit later, and Eric Gorr appears to be retired.

Are there any other options for getting this work done?

And is it worth the time and cost to do this considering that I'm upgrading to a Billetron Pro?

Thanks!

[SS109]

Yes, it's worth getting the head squish done regardless of what carb you're running. There is more to it than just easier jetting with the head mod. It would run better even if it was running fuel injection. It helps combustion efficiency throughout the entire rpm range which equates to lower fuel consumption and more power.

Getting the cylinder ported is something different. It is normally only a power related mod. It can shift the power in the rpm range depending on how it's ported but the idea is to increase overall power.

Millennium can do both for you on the KDX.

[Kawibunga]

Did not know that Eric Gorr was packing it in! Immediately went to the website to check it out........

If you're really creative and with the know how, Chuck78 posted some really good info in a thread om the milling of heads, and links to a spread sheet that you can us to play with the numbers and profile. Long tern goal of mine is to run the numbers and give it a go with an ebay head........

[Chuck78]

The 220 definitely benefits significantly from machining the head. If you simply just mill it, you're going to be stuck running 93 octane or higher (US octane scale, highest pump gas available or race gas). Ron Black completely rechambered the heads when he does them. Milled significantly, then slightly altered squish band width with a more sharp transition from squish band to dome/chamber, and then completely rechambered in order to bring the compression back to near stock levels. Is where not at all a high compression head so to speak, but rather ahead with a completely adjusted squish clearance height, which makes the squish band portion of the cylinder head actually a highly effective tool and mixing the air fuel and properly with the port timing and ignition timing. With the lazy clearance the stock 220 had, it was not nearly as effective as it could have been, as you need no more than 1.4 mm clearance to really utilize the squish band design. Anything over 1.6 mm piston to head including compressed head gasket thickness doesn't have much of a significant effect.

[Chuck78]

Millennium Technologies definitely as we know how in capabilities to do a KDX head like this for you.

Tom Morgan Racing as well. Now that Jeff Fredette is perhaps nearing retirement, Eric Gorr advertising semi-retired and only doing select work and smaller jobs, and Ron Black almost entirely retired and not likely to respond to emails, Tom Morgan Racing and Millenium seem to be the top two choices for cylinder porting and head work for us. Ken O'Connor Racing perhaps as well, know as much about Ken's shop and work.

Due to all this and me owning an old antique South Bend Heavy 10 L metal lathe, I have been interested in making a fixture to hold the KDX head in a 4- jaw chuck and learning myself how to do calculations and work that Ron Black had done. This will probably end up being a winter project for next winter though, now that we are into the riding season.


EDIT - I also HIGHLY RECOMMEND the Lectron Billetron Pro Series + optional Xcelerator metering rod + Lectron long body adapter + custom order Barnett cable part # "TODD MILLER" (search my Billetron thread here for engineering drawing), + Boyesen RAD Valve....
Even better than a well jetted PWK35 Air Striker with #5.5 or #6 slide & CCN needle...