Best valve/head Job?

My 06 CRF450R in getting some motor work done soon. I thinkin of going with HotRod crank (stock stroke), OEM piston, new valves/head work. Im considering the BigBoreThumpers bolt on head for $550. Then maybe sell my stock one for $100-200. Looking to build a bike that will be very strong, reliable, and last a long time. Whats everyone doing with your heads and valves? Mail it out to a shop? Do you use local shop? Whos a good shop to mail to?

I had mxtime do my head, havnt had any problems yet, going on three years, I did alot of research on here before sending it to them, do some research and see what you come up with, do a search on mxtime on here, I read alot of good stuff about them.

Doug

How reliable are the Big Bore Thumper heads?? Ive been thinking about that setup also.

Who is running a BBT head?? How is it holding up??

Who is running a BBT head?? How is it holding up??

me!!

it was 550$ + 50$ shipping, so 600$ CAD for a brand new 2008 crf450r head with SS intake valves and appropriate springs for my 2005 crf450r.

2 weeks later I bolted it on and have ran it hard for 60 engine hours now. not one single problem starting it, havnt even checked the intake valves yet, I imagine theyre dead on still or within 90%. I couldnt be happier.

last summer I build my old head locally, and with OEM parts bought individually. it cost over 1000$ took 6 weeks and in the end didnt last 50 engine hours because had the seats cut wrong because I brought it to a normal vehicle engine shop, it has to be a guy who specializes in CRF heads!!!!! they wanted to lap my TI valves and everything, it was a disaster. TT saved my ass, but I still brought it to the wrong place/wrong guys.

I did lose a little bit of top RPM and top speed because of the heavier SS intake valves... but who needs to go 140 km/h anyways...120 is still plenty fast!!

next time I need a new head.. if ever! I will definitely be buying another BBT head, their prices cant be beat and quality is pretty damn good too!

ps: I also thought I would be able to sell my old, dead, stock one for a few hundred... not gonna happen. its pretty much a fancy boat anchor now as far as im concerned. barely worth rebuilding so its only worth its weight in aluminum... unless someone wants to fix the seats and then use shorter valves, but its not worth it when you can get a whole brand new head for 550$...

also, one more thing I should throw out there. I built a yz 125 (144) and I put a hotrod crank in it. after buying the hotrod crank and then looking them up I found quite a few people on TT had problems with hotrod cranks... more than you normally find when looking up a product. personally, I would stay away from a hotrod crank after reading so many negative posts. a falicon crank would be nice if you got the $$$. but im sure hundreds of people have used hotrods with no problems. I got a friend who has had one for a while now with no problems, and that yz144 is still running strong with the hotrod crank so who knows!!

Thanks for the good words. We take pride in offering the best deal going on 250 and 450 heads, and having them on the shelf ready to ship in most cases.

Wow...Over $1000 to rebuild your old heqd... We can supply a brand new fully race ported head for less than that.

http://www.bigborethumpers.com/heads.html

Jay

Thanks for the input cdf and jay! An '08 head is on my short list.

Thanks for the good words. We take pride in offering the best deal going on 250 and 450 heads, and having them on the shelf ready to ship in most cases.

Wow...Over $1000 to rebuild your old heqd... We can supply a brand new fully race ported head for less than that.

http://www.bigborethumpers.com/heads.html

Jay

What is the differance between the stock and race ported heads? Would the race port head work with OEM bore, stroke, piston, crank, ect.? What exactly is ported on the head?

What is the differance between the stock and race ported heads? Would the race port head work with OEM bore, stroke, piston, crank, ect.? What exactly is ported on the head?

It'll bolt right on.

They improve the flow characteristics of the intake and exhaust ports.

You're a two stroke guy, huh? :smirk:

You could also have your stock crank rebuilt for a fraction of the the price of a new one.

You could also have your stock crank rebuilt for a fraction of the the price of a new one.

Where and what fraction of $250

just getting back cut valves and race cut seats will enhance the low to mid lift flow numbers.... even without porting.... +2~3% power

porting can add fully +10% across the entire powerband if done well....

What is the differance between the stock and race ported heads? Would the race port head work with OEM bore, stroke, piston, crank, ect.? What exactly is ported on the head?

:smirk::thumbsup:

port3.jpg

http://www.bigborethumpers.com/porting.html

whats the prices if we sent in our own heads to get worked on?

whats the prices if we sent in our own heads to get worked on?

See the link in the post above yours.

hmm.. i have an extra head laying around.. i might have use for you guys one day.

How reliable are the Big Bore Thumper heads?? Ive been thinking about that setup also.

Who is running a BBT head?? How is it holding up??

I got one off there race ported heads for my 05 crf450, there work is amazing well worth the dollars.Also makes insane power havent had on dyno yet hopeing for 60hp.My bike eats aprilia 550's down the straghts,road racing.

i had new valves (i bought somewhere else online) put in a new cam chain and new piston put in...with parts and labor is was around $600. it was a local shop in columbia missouri. they do great work and really know what they are doing. its called Revlimit powersports

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