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146cc dohc build

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19K views 224 replies 32 participants last post by  storminnorman07  
#1 ·
been curious to see how the 4 valve motors would run with a little more cc. so i have started a 145 or 146cc build with my take dohc. i will have a 57mm stroke by either a 57.5 or 58mm bore. just got the cylinder today here are some pics.



http://i50.photobucket.com/albums/f349/storminnorman07/P1010385.jpg pic of the 54mm piston in the new cylinder



http://i50.photobucket.com/albums/f349/storminnorman07/P1010392.jpg this is a pic of the stock takegawa cylinder on the head



http://i50.photobucket.com/albums/f349/storminnorman07/P1010389.jpg this is with new cylinder on the head
 
#132 ·
lastest update missed my dyno appointment today due to retarded a$$ doctors. i have been from doctor to doctor today since 9 and my appointment was at 3 so unfornatly i missed it and he said the quickest he can get me in is possible monday or tuesday next week but he said even that looks grim cause he plans on putting a bike on the dyno next week and once its on it isn't coming off til hes done he said he will give me a call if he can get me in sat maybe but if not he is really going to try and get me in monday or tues so hopefully everything will work out.
 
G
#135 ·
Don't forget to ask the details on the dyno (dyno type number... 150, 200, 250... and drum weight) and have them show all the run info on the chart... ie: correction factor, air temp, atm pressure, smoothing. Have them chart the horsepower and torque on the same scale and compare it to rpm instead of mph. If they have air-fuel meter have them include that as well. Make sure they don't have the rpm meter reading wrong either or your rpm's will be in half and your torque numbers will be double reality. Those are just the suggestions I'd give you to limit the grief people toss at you when you post big numbers.
 
#136 ·
thanks jordan greatly appreciate cause if does pull big numbers and i hear another person say its a fake i think i'm going to insane after all the work i have done trying to find a dynojet. lol oh yeah i know all about the rpm meter. the first time i dynoed my bike its max rpm was 7 grand i think and the torque number was like 17 ft/lbs and the guy was like pretty impressive i never thought a lil motor would pull something like that. i was like thats cause your dyno's fu-cked up. so we got into it and he asked why. so i told him one i know the motor revs higher than 7 grand and on top of that, that motor should never see that kind of torque it should be about the 8 range 9 if i'm lucky. well thats when he asked what is should rev i told him and he said that was way why he had the meter set wrong cause this 4 vavle wants to be idled at like 2500 if not 3 grand any thing lower it will stall out so he thought he had it wrong at first. but any way i will make sure to write all that down and show it to the guy. also i remember you saying a certain number the correction factor or maybe the smoothing should be set on. what was it?
 
G
#137 ·
SAE correction factor is what I like to use but lately I've been using STD cause that's what everyone else seems to be using (it shows slightly higher numbers. It depends on your run conditions and engines numbers. Around .3hp difference on these so nothing to huge but still a difference. You might see if he'll print on off with both correction factors). Your correction number should be anywhere from .95 to 1.08 depending on the run conditions. The number is calculated in the electronics to correct the dyno numbers to the standard run conditions (temp, pressure, etc). Any lower or higher number and people will get suspecious about the graph. Ex: I've seen a chart of an engine but the correction factor was 1.5. That means it takes the numbers the dyno reads and multiplies them times 1.5 (meaning 15hp peak would turn into 22.5hp).
 
#138 ·
ok got to the dyno very depressing in a way but in another great. hp wise kinda depressed i didn't gain more. far as torque loving it. its as flat as can be. as far as all the stuff that was asked to give i was able to get all over it except drum weight. so i got the number that was stamped on it maybe that will help its 13.742. its a dynojet 150i and all the rest is on the dyno sheets. i had him print it in sae and std. i wasn't going to post the number cause i know i am going to get a bashing i was going to wait til after i tuned it and redynoed it but hey it is what it is. if i get bashed for this oh well cause i know i can pull a higher number i should of listened to the "ACA" lmfao for anyone that hasn't followed this post it stands for against cylceriders advice. cause he told me i should tune my intake and after playing with it a little today i realize that it diffently needs tuned and i think it possible needs a bigger header and i personally think a good 28 would benefit especially looking back on cycles dyno post fron 26 to 28 carb. oh which reminds me cycle i lied its not 8 inchs i only have 6 inches from vavle face to end of manifold so i am way off to be tuned. but enough yapping already thanks to lukes racing here are the dynos and a vid








http://i50.photobucket.com/albums/f349/storminnorman07/dynosae.jpg



http://i50.photobucket.com/albums/f349/storminnorman07/dynostd.jpg
 
G
#143 ·
Before you get disappointed go back to the dyno you originally ran it on for a comparison between before and after. The dyno jet will read less than some of the other brands. Yea it isn't 20... yet. But people can't dispute the numbers. You jumped through every hoop anyone else has ever been asked too.
 
#144 ·
all the air temp and stuff should be on the graph. unfornatly the guy that dynoed it hasn't purchased the air fuel thing so i couldn't get a reading to see how close or how far i was off. thanks for the compliment. it diffently runs great i love how it runs now but i'm a perfectionist and i think i can get a lil better numbers with some tuning cause that has absolulty no tuning on it. its was bolted together and put the same carb same jetting as it had before i tore it done to make it a 146
 
#145 ·
yeah cycle i am going to try and get out to that other dyno this week but he said he doesn't know if he can do it this week or not i'm going to call tomorrow. cause i'm thinking that dyno read prolly 2 or 3 ponies more than a dynojet. but even at that yeah it would be a graph over 20hp but no one will believe it. i'm going to do the lil tweaks you told me to do i think i just might get the 1 and some odd change to hit 20 hp. just got to find somewhere to get about a 4 inch chunk of alum to make that spacer and find someone with a decent 28mm carb for a reasonable price cause i'll go to he-ll if i pay 269 or whatever 2 bros wants for a carb.
 
G
#147 ·
I don't know if it will be that big of a jump between them but it will be interesting to see.



Yea, all the run info is at the bottom of the charts like it should be. Good air temp, pressure, and correction number.



Don't worry Chad, 20 isn't that far off.
 
#148 ·
yeah i know thats whats driving me nuts its just right there and my little knowledge of motors i'm running out of options to try and get that extra horse or so. yeah i could pop the top and get retarded with compression or i could degree my cams for all revs and hit that number which i think that would of been no problem just crank those bad boys all they way out and i think i prolly would of hit but i wanted to get that 20hp and be a honest 20hp not 20hp umm i'm not sure how to say what i'm thinking but i'm sure you guys get my point you can get motors to make real pretty numbers on a dyno but run like **** in the dirt. the way my motors sits now its runs great everyone that has ridden it has loved it all have said way to much power for a 50 chassis but very nice power so thats what i would like to keep but hit the 20 hp mark that was set by god knows who. since i signed up on here that is all i heard 20 horse this 20 horse that and i have not seen a god damn one of them well take that back that one by tjr i think thats the company but its not a honda 50 motor its a nice motor. i guess its just a ego trip for myself to be able to say i have a true to life crf50 motor that pulls 20hp on a dyno and isn't a dyno queen 20.
 
#150 ·
For reference, the 20.5hp dyno TJR shows is actually a Honda 50 based mill, punched to 141ccs if I recall correctly. To say they reworked a head to get there though is a massive understatement. I don't think there is a single bit of the head's casting left untouched on that motor.



Go run that motor for a bit, get it to loosen up. You'll find some HP just by running it in some more. 20hp is sitting there, you've just got to tweak the tuning package to find it. Nice job on a KILLER motor, you've got something most of us will never see in a mini.
 
#151 ·
no i didn't play with maps i forgot in the mist of trying to get everything setup right with the dyno. next time i go out i plan on trying different maps. do you think a 30 will work cause i was looking at a 30mm carb on ebay and my dad thought i was a flipping retard.





kurlon you wouldn't happen to have that dyno and pics of that head and motor.
 
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