RE: 146cc takegawa dohc build

Shop deals on ebay
Find deals on amazon
Advertise with us
Mini Dirt Bikes & Pit Bikes Forum

Help Support Mini Dirt Bikes & Pit Bikes Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
S

storminnorman07

Well-Known Member
Joined
Jan 10, 2007
Messages
159
Reaction score
5
i'm new to this forum figured i'd add my 2 cents and see what everyone thinks of the build i have going on now. it started out with a crf70 bottom end and put the 2 bros stage 3 124cc dohc kit to it. i put a tokyo mods ignition lightly ported it put a bbr custom dohc pipe on it and different intake valves at first. http://i50.photobucket.com/albums/f349/storminnorman07/Image1.jpg here is the last dyno it pulled at rear wheel.

As everyone knows rkfinch has some bad ass motors with high hp and torque. after talking to him and fatcat got the wheels spinning to up the displacement and see what it will pull. ok now to what i'm doing. i sourced a place threw fatcat for a 57mm bore cylinder which i now have the cases bored and thats ready. http://i50.photobucket.com/albums/f349/storminnorman07/146 dohc build pics/case-2.jpg http://i50.photobucket.com/albums/f...6 dohc build pics/sideviewofnewcylinder-1.jpg i am also going to take my takegawa crank and stroke it to 57mm which should put me in the neighborhod of about 145 146cc. my goal is to put bigger valves in it which already taken care of. it started off with two 21mm intake valves and two 18mm exhaust. it now has 21.8-21.9 intakes and 19mm exhaust. i am also throwing the idea of getting a custom set of cams done for it also. here are some pics of what i have going on so far

pic of new intake valves sorry haven't gotten around to take pics of the new exhaust valves http://i50.photobucket.com/albums/f349/storminnorman07/146 dohc build pics/newvalvesinhead.jpg
stock piston from the top http://i50.photobucket.com/albums/f349/storminnorman07/pistontopview.jpg
stock piston from the side http://i50.photobucket.com/albums/f349/storminnorman07/pistonsideview.jpg
couple pics of new valves vs stock vales http://i50.photobucket.com/albums/f349/storminnorman07/sidebyeside2.jpg
http://i50.photobucket.com/albums/f349/storminnorman07/sidebyside1.jpg
http://i50.photobucket.com/albums/f349/storminnorman07/bottoms.jpg

thats all i have for now. my only 2 hold ups are crank and piston. i might have my piston problem figured out. my 2 options where have a custom piston made which rould run me around 700 usd or custom make one which i opted for the later than the 700. so i have a piston on the way and i should get it next week. as far as cranks goes thats not going out as planed. the stroker pin i had picked out for it they no longer make it. so i'm throwing some ideas around with that if nothing else i know where i can find a 56mm crank for it just really wanted to go with the 57mm stroke. when i get something else done i'll post it up and when its all back together i plan on getting it dynoed again and seeing what it has.
 
mate you must of spent a fortune on this crazy machine hope you been training otherwise its gonna rip you arms off on the slightest amount of stick.
 
yeah i have a pile invested but not as much as you might think. i got a deal on the kit at dealer cost because i use to race for them a long time ago so i spent like 3200 or 3300 on the kit, 600 for the pipe, 800 for the ignition, 260 on valves, 50 on the piston coming on the way crank not sure what i'm going to have invested in the crank still trying to work things out with that to get at 57 with the takegawa crank. all the labor i've done myself so roughly about 4900 or 5000 g's into the motor as when i'm done with this 146 build without the price of the crank. not a great price but i know alot of other guys that spent over that on a 2 valve set up. and as far as power i think i should be alright i was twisting its neck before i did this looking for more power but then again never know til i get it together for all i know might be slow and get out of its own way.
 
well starting to finally progress on this build has some new pics. i have a 56mm crank just case the 57mm blows it apart. right now as i stand i have the 57mm crank together and mocked it up once i had a little clearance issues but i should be able to get clearance cause were it is hitting the oil pump the takegawa rod wasn't flattened its still slightly round and there enough meat there i should be able to take a lil more out for extra clearance.

56mm on the left half of the 57mm on right- http://i50.photobucket.com/albums/f349/storminnorman07/crankpics005.jpg

close up of 57mm half- http://i50.photobucket.com/albums/f349/storminnorman07/crankpics006.jpg

close up on 56mm- http://i50.photobucket.com/albums/f349/storminnorman07/crankpics007.jpg

intake port- http://i50.photobucket.com/albums/f349/storminnorman07/intake001.jpg

intake valve openings- http://i50.photobucket.com/albums/f349/storminnorman07/intake003.jpg

exhaust ports not finished yet- http://i50.photobucket.com/albums/f349/storminnorman07/newexhaustport003.jpg
 
 
All that i can say is wow. That thing will destroy everything in it's path. wow
 
Wholly shit that has got to be the closest sounding too a 250f I have heard to date. Good luck holding on! hehe
 
get a vid of her in action, i think thats what everyone wants to see. well down with the build you should be very happy, want to swap.:D
 
lol i would love to get a action vid but i destroyed my wrist at work and i can't twist the throttle wtfo let alone try to hold on to it. i'm working on tryin to get it to a dyno. only reason why it has went yet is cause right now the only dyno around where i am at that will let me dyno a 50 is not a dyno jet and last graph i posted i got alot of static how it was a fact cause it wasn't a dyno jet so i have been hounding a guy to let me do one on his dyno jet i think i just about got him to let me do it. if no unfornatly everyone with this have to seatle for the other dyno place i'll just try to have him show all the different things on the graph when he prints it out as you can tell i don't know a god damn thing about dynos. and the only reason i know dyno jets are good cause like i said i got all kinda of static how my last dyno was a fake.
 
That thing sounds just like a real mx 4 stroke. Revvs so fast and smooth for a minibike it sounds like it will rip your arms from its socket.
 
Only 1 word need be said

"DUDE"!!!!!!!!!

That thing is crazy. I can't believe you've gone to such trouble and expense, but top marks man, thats excellent.

Just shows what can be done if you think crazy enough!! hahahhah.
 
Nice motor

Ripping motor mate, my lifan 134cc sounds just like it and cost under a $1000. China is taking over. Interested to know how much extra power twin cams produce though if any. Good luck.
Ride on.
 
thats engine is sick i like the bbr exhausts but alot off $$$
 
how can a $5000+ crf50 compare to a 1000 changa bike , i dont get it.Twin cams are much more powerfull and atleast twice the price of single cam kit ,i dont now the ful 411 on them but its obvious that they would pump out more ponies.Mybe sixeven can explian it for ya.China is not going anywere with some of the cheap shit that there producing looking at foxico
 
China's can go fast.

Why doe's every die hard recon china engines are dodgy just cause they are cheap.
Lifan's can be built into rockets. And they are reliable. My 134 oil cooled, Lifan screams. Only mods to stock engine high 6.9mm lift cam, high comp piston from akuna, china inner rotor kit, and revised gearing. Anybody want to bring your bike to jindabyne I'll prove how fast it is.
Peace, ride on.
 
You must log in or register to reply here.

Latest posts

Back
Top