Hi All,

Can anyone comment on the average quality of XT 660 cylinder heads with regards to casting imperfections? Do these heads generally benefit from a porting job? I'm talking about optimizing flow not adjusting valves or increasing port sizes.

I understand it will vary from head to head just wondering what the general consensus is.

Cheers!

use to be called blueprinting....
those casting dags etc weren't on the blueprints
"CAD files these days" but happen in the casting process
so removing them is bringing the motor closer to what the
blueprints "Cad files say it should be...

So remove them.. theres nothing to lose....
I polished my TTR250 head to near mirror finish...
took 3 days with a mico die grinder...


..

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I Have not had a reason yet to actually get the head off nor do I expect to have one soon. I'm looking into additional performance gains that's why I was asking whether these head generally benefit from porting / blueprinting Not sure if it will be worth the effort is the head isn't off yet.

Perhaps I'll have a look into the manifold's sides to see what I'm working with.

Found this in the raptor conversion topic in case anyone is interested:

http://www.xt660.com/showpost.php?p=97770&postcount=123

All the gains in these motors are from the inlet side, adding +2mm inlet valves + 1mm exhaust + a Raptor 5050 cam will get the most flow rate through the head, you will need to add displacement + compression to get this combo to work correctly.

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Mods that I have done to my XTX's

My 04 XTX
Stage 1 & 2 DNA filters / Kev fuel mod / snorkel mod / Drilled air box mod / Engine breather mod / Fork Spacer mod / 15w fork oil /
[
My 07 XTX
Raptor 700 cylinder 102mm / Modified Crank Case to take a 105mm Raptor Cylinder / 11:1 102mm JE Raptor piston / Stage 1 Raptor Hot Cam / Ported head / Colder Spark Plug / +2mm Throttle body / DNA stage 1 & 2 filters / Modified Air Box / Snorkel removed / Worry Brothers stage 2 filter cover / 6mm & 8mm Bolts Replaced with Titanium Bolts / Recovered seat in Black / O2 Eliminator /

My 09 XTX
59HP at the rear wheel / Stage 2 Raptor Hot Cam / DNA stage 3 Air Box / Carbon Can Exhausts / Modified Exhaust Link Pipes / PCIII With Custom Fuel Map / Wideband Commander O2 Data logger / LCD100 Dyno Jet display & fuel adjuster / 2500 OHM HT lead instead of a 10K OHM XT lead / Extra Coolant Cooler / Protaper Fat Bars / Tail Tidy With LED Tail Light / OKE Protection Knobs / LED indicators / AIS blocked / Modified rear sprocket rubbers / Rear Foot Pegs removed / 09 ECU With 02 Sensor Changed To A 06 ECU / Complete wiring harnes Changed from 09 to 04 / Home made LED resistor flasher / Hole drilled in the fuel tank filler neck to allow quicker filling / Modified Bar End Weights / Progressive front fork springs, 15W fork oil, forks lowered 25mm, used XTR rear links lowering the rear 20mm, rear spring one click stiffer / Changed front & rear guards from blue to black / 47T rear sprocket / Speedo Healer V4.0 / Kev throttle cam mod / Throttle grip mod / The new 2010 O2 sensor mod is out, works a treat, The new 2012 O2 Controller is out, PM me for details

Now ride a 2018 MT09SP ABS + TCS

My KTM 990 SMR Mod book. http://www.ktmsmt.com/viewtopic.php?f=13&t=4946