Porting!

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no_crf50_here

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last weeks effort :p It's going onto Michael's motard

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300+ laps of the motard track on full noise and head is still going strong :p Pulled it off and took out the exhaust valve and no excessive wear on valve stem (yet). I'm sure when it fails it'll be something instant not something that slowly happens.
 

pbk

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now one question and i wanted responses from people who have truly tested this as i see a some of you have and that is grinding away the whole valve guide???

isint it meant to be there for a reson ?

so if i wanted to do some porting should i just grind it all out or just make it very minimal?
 

no_crf50_here

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now one question and i wanted responses from people who have truly tested this as i see a some of you have and that is grinding away the whole valve guide???

isint it meant to be there for a reson ?

so if i wanted to do some porting should i just grind it all out or just make it very minimal?

Taking the valve gudie out is bad for those with low/no budget. It will cost you in the long run. Taking valve guides out will wear out the valve stems and could result in breaking/bending the valve. HOW ever if done well you will get more power, be it for a shorter period of time.

In short if you have spare top end around and your interested in playing go for it, if not do what Catus says and just do a series of small port jobs, and test inbetween.

Again i hacked at it because i could, not because i should!
 

HACKMUNCH

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no way bro, like i said before when it comes to porting, cheaper is not better. mike castro charges $300 and i think thats cheap. it takes a good 3-4 hours to port a head properly, at $100 an hour, well you know the math. porting and cleaning up a head is 2 different things.
 

mboyg1

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ahhh, had a good look through the thread and did a bit of research and tough i would give it a go on this only head i had... ill put pic's up once im done
 

HACKMUNCH

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dremmel is your friend, heads are cheap these days. concentrate on the valve guide area.
 

mboyg1

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woops I meant to say this OLD head I have, haha my bad, yerr i got a cordless dremel
 

linkenator

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hey guys,
i was looking at some of the latest photos and was wondering wat grit paper u r using to get such a smooth finish and does any one have any tips for removing carbon from the exhaust port
cheers
Davo
 

The_GDFP

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Zonger 125 head with 28/23 stainless valves, a little port work. Going on a 57x63 street CT70 engine. Screw-in valve caps, for stealth;)

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The_GDFP

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Noob question: What is the point of the screw in valve caps?

LOL. Stealth. Most of the big-valve Lifan-type heads have the 2-bolt caps, bragging up their large ports. Less an issue now than 5-6 years ago, when we wanted to disguise a 146 with big valves as a stock-headed 131;)
 

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