Author Topic: Where to learn how to do some head work  (Read 979 times)

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Offline MILO

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Where to learn how to do some head work
« on: March 04, 2011, 12:42:04 AM »
I'm wanting to learn how to do some head work on engines, just in general. I like tinkering and messing around with engines and I don't know where to even begin. So i thought I'd chuck it out there and see if anyone could direct me on where to begin!


Offline dave500

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Re: Where to learn how to do some head work
« Reply #1 on: March 04, 2011, 01:51:54 AM »
google what you can,bigger isnt always better,shiny intakes arent all their cracked up to be,learn about camshafts aswell.just removing factory casting flaws and matching intake manifolds to head inlets (blue printing)can release a performance increase,going too far will result in unsatisfactory drivability,you might approach a head reworking place and ask to have a look,although with health and safety laws the way they are these days?
« Last Edit: March 04, 2011, 01:59:26 AM by dave500 »

Offline MILO

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Re: Where to learn how to do some head work
« Reply #2 on: March 04, 2011, 02:19:12 AM »
Theres a head works place just down the road from me....called head works haha, and I drop in every couple of weeks to talk motorbikes with the guy there. He's doing my 550 head at the moment.

performance modifications just generally is what im interested in, not to make a business out of it, or money for that matter, just out of interest. so I can make my lawn mower and whipper snipper better lol.


Offline dave500

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Re: Where to learn how to do some head work
« Reply #3 on: March 04, 2011, 02:34:29 AM »
basic two stroke whipper snipper or chainsaw tuning(porting)is easy,no head work involved,get an old running whipper snipper,remove the piston and where the intake part of the skirt opens and closes the port,take an arc shaped cut about half a mill of the skirt,itll lose bottom end torque but itll rev higher and might start spitting fuel back out the carb at low revs,this is where reed valves come into play on dirt bikes,if you want to go further, on the barrels exhaust port,take about half a mill of the top edge of it,and remove any spark arrestors in the muffler,you might have to bend it open and closed to do this,make sure the rings wont go into the final hole before you do it,it might not idle well after but this is where head porting can take you,basic rough two stroke tuning,your results may vary,transfer ports and scavenging are a different matter.

Offline faux fiddy

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Re: Where to learn how to do some head work
« Reply #4 on: March 04, 2011, 02:56:26 AM »
basic two stroke whipper snipper or chainsaw tuning(porting)is easy,no head work involved,get an old running whipper snipper,remove the piston and where the intake part of the skirt opens and closes the port,take an arc shaped cut about half a mill of the skirt,itll lose bottom end torque but itll rev higher and might start spitting fuel back out the carb at low revs,this is where reed valves come into play on dirt bikes,if you want to go further, on the barrels exhaust port,take about half a mill of the top edge of it,and remove any spark arrestors in the muffler,you might have to bend it open and closed to do this,make sure the rings wont go into the final hole before you do it,it might not idle well after but this is where head porting can take you,basic rough two stroke tuning,your results may vary,transfer ports and scavenging are a different matter.

Two stroke porting is best done in stages.  My friend has two dt-50's one of which he is ready to begin with stage one. On the dt 50 it is clear where the restrictions are from the factory- a small notch where there should be a wideer port.

I should post pics of what he has going on with it. Two of the same bike. Nice to be able to have a test bike when modification minded..
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Offline dave500

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Re: Where to learn how to do some head work
« Reply #5 on: March 04, 2011, 03:36:45 AM »
port two strokes in stages on unfamiliar engines,most bikes have a proven set up that you get done,totally transforms the engine characteristics,expect to lose bottom end and some mid range torque,for experienced two stroke riders only,plenty of thumper guys cant ride two strokes,two stroke guys can ride both and still be happy on either!

Offline fmctm1sw

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Re: Where to learn how to do some head work
« Reply #6 on: March 04, 2011, 04:41:21 AM »
Head work?  Med school...   :D  I used a lot of trial and error.  Find an old engine to practice on..
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