Porting!

[tubes380]

what do you guys do with the guides, grind em flush or leave them? i have read somewhere to keep the exhaust guide intact to keep heat away from the valve stem and grind the intake guide flush as there is no heat and really no need for it???? or can you grind both down flush?
whats everybodies experiences and thoughts on the subject?

 

[Custom]

IMO dont grind your guides, for the extra fraction of a H/P you are losing alot of reliability and life of the head

 

[Dirtrider]

I ground them both down, got a small hole to fill on the in take port i will just use that JB weld to patch it up. See how they go on the weekend. Opened up alot more room in the ports.

 

[Wogboy]

hello,

I wont to give this a try where abouts do i buy the porting kit and tools from and how much is it around??

Thank you

 

[ducar.r.spec]

u have to buy things like dremels/die grinders,dremel extensions,jb weld,tungsten carbide cutter bits,sand paper,stone grinding bits

 

[no_crf50_here]

I completed my frist p&p job with a cordless drill, stone grinding bits & sandpaper - took ages but got the job done for the right price. Wouldn't say it was the most attractive job in the world but made the world of difference.

 

[ducar.r.spec]

yuh i done p&p on my int manifold iwth a power dril and a carbide cutting bit

 

[tubes380]

no crf50 here, did you build the port floor up, and also did you take the valves out to do that job, i will post up some pics of my port and polish soon.

 

[myinnerrotorkits]

useful and maybe i can port on and test then make a module to sell like rocket

 

[no_crf50_here]

yes to sell them like a rocket... i three times two minus 6 in the sun.

 

[corey58]

it is funny to see how many people just go and take all the meat out of there head and that is far then wat u do when it come to porting the head.

mates and i had access to an flow bench with 2 difference heads to use (lifan/jaling)
we flowed both first and jaling kick it ass buy far.
and in the process we tryed all difference combos of port jobs and the one that work the best was the easyest in an way to do.all u really need to do is to take an tiny amout of meat out of the short side, clean around the glide and the reast of the port and for the exhaust clean the glide and tiddey the casting marks

over all the jaling and lifan intake ports could flow close to the same amout of air to suit our carby an manifold. but the jaling was an 1hour job at max where the lifan head took an lot longer

hope that helps someone

 

[ducar.r.spec]

it most probably would but
i can understand the chinese guy easier then i can understand you

 

[no_crf50_here]

it most probably would but
i can understand the chinese guy easier then i can understand you

hahahaha...

 

[corey58]

damn will i jst got toldd
i jst fix it up then for u

 

[ducar.r.spec]

hey corey btw what did u do with ur stock brake calipers??
i like the vert 1s as they have piston each side of caliper
lol ive been sussing the 07 expert out at work

 

[corey58]

hmm i wouldnt have an clue i might have it or i do remember give one to my mate but not sure srry

 

[Mack]

it is funny to see how many people just go and take all the meat out of there head and that is far then wat u do when it come to porting the head.

mates and i had access to an flow bench with 2 difference heads to use (lifan/jaling)
we flowed both first and jaling kick it ass buy far.
and in the process we tryed all difference combos of port jobs and the one that work the best was the easyest in an way to do.all u really need to do is to take an tiny amout of meat out of the short side, clean around the glide and the reast of the port and for the exhaust clean the glide and tiddey the casting marks

over all the jaling and lifan intake ports could flow close to the same amout of air to suit our carby an manifold. but the jaling was an 1hour job at max where the lifan head took an lot longer

hope that helps someone

So this is why the Jailing head is ditched by engine builders across the world in favour of the Lifan BVH?

 

[Dirtrider]

Corey58 have you got any photo's of the 2 heads you worked on?

 

[ducar.r.spec]

just finished porting intake
didnt seem to brake through anywhere
came up really nice
i will have to buy some jb weld and some stone bits a a new carbide bit tomoro
got halfway through exhaust and shattered my last stone bit
pics will come when its done
lol im porting this head not sure what it is but keeping my fingers crossed it fits the 138
i have 3 other spare heads so if this 1 doesnt fit 1 of those should
the reason i used this 1 though is because it already has 28/24 valves

 

[corey58]

So this is why the Jailing head is ditched by engine builders across the world in favour of the Lifan BVH?

not if u are using an 125cc motor. lifan BVH are only good in big bores no good in the 125cc motor