need advice for engine build

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

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

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.

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

That is always an option Sumo!! Getting things to work together is always better than just throwing high dollar parts at it.

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

 

 

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 

 

 

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.

 

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

Im using the 08 R cam in one of my bikes and thus far have been pretty happy with it --- riding it back to back with the stocker shows a big difference

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