Porting!

[bigd]

i also noticed my intake measured 22mm and my carby is 25mm,
should i get a noticable gain by matching them ?

[tubes380]

is your carby really 25mm??? most china carbys are smaller than advertised

[bigd]

yep sure is, 25mm

[C50DRAG]

hi guys!my name is Gregory and i am from Greece.this is my first post.
i have an engine from a honda bike that is called honda supra.
is like your mini's motor.i have tune it many times with different set ups.from a 72cc and even 150+cc with 60mm piston and 54mm crank.all of these 2 years ago.
now i have a street set up at 128 with 55mm piston and 54mm crank that is very good[for me].i use a hand[machine]made camshaft with 318 durationin/out and 7.2 liftin a lifan head.
and now my question-how can i prevent the jb weld from fall in the compastion champer?i know that i most make some grooves in the port to catch from there but..i most do something else?

[Mack]

hey there greg, if the port is clean and you make good size grooves in two directions you will not have a problem with the weld moving. If you are still nervous then drill shallow holes in two directions as well. Make sure to do this only where you have available material.

[C50DRAG]

Originally Posted by Mack

hey there greg, if the port is clean and you make good size grooves in two directions you will not have a problem with the weld moving. If you are still nervous then drill shallow holes in two directions as well. Make sure to do this only where you have available material.

thank you Mark!i will do that!i will keep you informed for the progress!

[sean01]

ok, i just read all this post from start to finish just now(last couple hours)
i must say there is an awesome amount of info here and its good to see that ppl are starting to share there hp secretes.
1 question tho, since a couple of you have benchflowed your heads what are the standard flow figures?
and have you flowed them with the larger valves, cut at different heights in the camber. i would imagine this would have some sort of impact.
as in the past i have built different breeds of heads and have had to cut them differently to achive better flow. ie.. some heads require sinking the valves alot and some require them raised.
also have you tried 2 angle valve facing as i know this helps alot?
and also i have found flowtesting heads as the same as dyno's are only usefull if you are using the same flowbench/dyno all the time as all benchs and dynos are calibrated differently as well as the software gives different results but if using the same equipment it will show you improvements and losses.
and this is coming from experience from sending heads to different guys for flowing.
hey has any1 just tried using an oversized exhaust valve opposed to oversized inlet and exhaust as i would image the exhaust would be most of the restriction ,the 27mm inlet should be plenty for promoting good low end torque altho these engines dont mind to rev its just not good.

anyways guys iv said enough. and if my thought are true or false well i guess you's will let me know..

cheers ppl..

[C50DRAG]

Originally Posted by sean01

ok, i just read all this post from start to finish just now(last couple hours)
i must say there is an awesome amount of info here and its good to see that ppl are starting to share there hp secretes.
1 question tho, since a couple of you have benchflowed your heads what are the standard flow figures?
and have you flowed them with the larger valves, cut at different heights in the camber. i would imagine this would have some sort of impact.
as in the past i have built different breeds of heads and have had to cut them differently to achive better flow. ie.. some heads require sinking the valves alot and some require them raised.
also have you tried 2 angle valve facing as i know this helps alot?
and also i have found flowtesting heads as the same as dyno's are only usefull if you are using the same flowbench/dyno all the time as all benchs and dynos are calibrated differently as well as the software gives different results but if using the same equipment it will show you improvements and losses.
and this is coming from experience from sending heads to different guys for flowing.
hey has any1 just tried using an oversized exhaust valve opposed to oversized inlet and exhaust as i would image the exhaust would be most of the restriction ,the 27mm inlet should be plenty for promoting good low end torque altho these engines dont mind to rev its just not good.

anyways guys iv said enough. and if my thought are true or false well i guess you's will let me know..

cheers ppl..

i would like to know too!
can someone tell us if all this porting can make a different flowtesting results?and something else,can a chines head lifan or jialing make the same or better flow with the take plus r head in the same lifts?
[someone here is saying that use the rollers and the s35 cam from takegawa in a lifan head.with modifications of course1]if a take fhotos i will post them!]

[CYCO-VS]

hay guys yesterday i cleaned up the intake on my 140 looks alright also did a little bit on the head then i put it all back together started up re tuned the carbie and i noticed its a lot more responsive when you crack open the throttle haven't ridden it yet so don't know what its like to ride

[kesman20]

hello i am matias from argentina photo how porting head cylinder dedidas?