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need advice for engine build

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im in the process of ordering up parts for my ‘09 dualsport 450X which so far include KW SS valves for the intakes (should i buy new kw seals as well or use the stock ones??)  

im also going to put an R cam in it but not sure exactly which one would suit my needs best...ive read a LOT of info here and crfsonly so i have a basic understanding of the characteriistics of each one. i want a cam that rolls of idle smoothly (less flameout maybe??) and has a meaty grunty low to mid range and decent top. basically i want tractability but still want it to rip. im running 14/50 gearing but swap a 13 when hitting trails. i see the ‘08 R cam is readily available, how how bout the earlier ones?

also, what do you think of getting porting done in conjuction w the cam swap? is a higher compression wiseco or je piston worthwhile (maybe the trx piston) or keep the stocker. i have a fmf muffler w powerbomb header coming soon

please keep in mind my bike is a dual sport so i need it to run on pump gas and stay somewhat civil

if anybody could give me some solid advice it is greatly appreciated

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okay after a bit more searching around, im thinking a great way to go would be an ‘08 r cam with ported/polished head..im gonna keep my stock piston until it needs replaced, then consider going up to a 12.5:1. question, along w the above mods will a higher compression piston be detrimental compared to stock??

maybe a stupid question but would adding a flywheel weight kinda negate the above performance mods? i still want to have a fun bike to rip around on the streets but still be able to single track without issue

 

Edited by Sumoman

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The 08 R Cam will serve you well.
A good port and polish from a shop that knows X's will benefit the build greatly.
No need for a flywheel weight, the X engine already has a great deal of reciprocating mass, heavier flywheel, heavier crank, starter clutch assy.
Go with a 12.5:1 JE...
Use the KW stem seals, better than OEM.

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thanks Doc! i appreciate the time to post. as you can see im still learning a lot on a building an engine, esp to work as a package. im going to go w exactly w what you posted. i have a local shop w a great reputation, just hoping they know how to massage the 450X head?? i was already kinda thinking to send my head to ASR if thats still an option

 

 

Edited by Sumoman
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have a question for Doc or whoever...ive read everything i could find on the R cams regarding their engine characteristics from ‘02-‘07, but havent come across any seat of the pants impressions or reviews of the ‘08 cam. i know the ‘08 was the only year of its grind and the last of the R cams to drop into the X’s. i just ordered an ‘08 R for my ‘09 X plus kibblewhite intake kit and 12.5:1 JE..plus gonna send my head off for a P+P

cant wait..just stoked to see how she’s gonna run after she’s all tuned up

 

 

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just an update on the build...im gonna be dropping off the bike this week for a suspension revalve/respring...its sad it took a year to get around to getting that addressed...ive been back riding for over a year now (15yrs riding street) and been pretty disappointed with my ‘skills’ lol...im sure my skills are still lacking but i need to set up my suspension- bout 80lbs over the factory spec 

 

 

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On 11/10/2017 at 3:20 PM, Sumoman said:

have a question for Doc or whoever...ive read everything i could find on the R cams regarding their engine characteristics from ‘02-‘07, but havent come across any seat of the pants impressions or reviews of the ‘08 cam. i know the ‘08 was the only year of its grind and the last of the R cams to drop into the X’s. i just ordered an ‘08 R for my ‘09 X plus kibblewhite intake kit and 12.5:1 JE..plus gonna send my head off for a P+P

cant wait..just stoked to see how she’s gonna run after she’s all tuned up

 

 

The 08 R cam is a hair detuned from the 2002 but similar characteristics...adds power everywhere and is very linear. It will respond very well to a bump in compression and a Stage 3 Port and Polish.

 

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On 11/15/2017 at 2:06 PM, CRF DOC said:

The 08 R cam is a hair detuned from the 2002 but similar characteristics...adds power everywhere and is very linear. It will respond very well to a bump in compression and a Stage 3 Port and Polish.

 

sounds good to me, thanks again Dr 👍

as we speak my bike is getting a suspension spring/revalve as well as a revalve on the damper.. will get the fmf powerbomb put on and the engine piston/cam done after the holidays... sweet 😁

next up could be a nuetech tubliss system

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