porting
- Thread starter mini drag bike
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Porting and polishing can be done by any one its more about doing your homework than removing material a
here are two heads ported 14cc on the left and a stock 22cc on the right as for the polish I would only polish the exhaust port and not the intake due to air turbulence there are great books by a author named David vizard although they can some times be steep in price any question you have feel free to post or pm me I will do my best to point you in the right direction
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Vwfan79 is on the right track if you don't have air you can get a dremel does not have to be fancy your not going into production and a good selection of burs you don't want to use stones with aluminum also sand paper tapers and drums work great for a cheap start go to HF. But I can't stress reading the author I stated is fore front and backs his methods with flow bench numbers but most important power at the wheels
Sent from my iPhone using Morris code
Sent from my iPhone using Morris code
Carbide burrs are the way to go with a lower-speed grinder. I use a regular old die grinder with an assortment of 1/8" and 1/4" shank carbides and finish up with cartridge rolls. IMO, Dremels spin too fast. A few hundred RPM with lots of torque behind it works well.
I have an air deburr grinder that goes up to 100,000rpm. Not very suitable for porting. :blink:
I have an air deburr grinder that goes up to 100,000rpm. Not very suitable for porting. :blink:
From what we found the exhaust needs very little work.
The intake doing a little work on the short side radius, and bowl.
Shaping/trimming the valve guide helps quite a bit also.
Little at a time is a good place to start.
We did not enlarge the port at all, took of sharp edges, rounded them.
Also depends on your build... Bigger bore, bigger valves, bigger carb...etc.
This will effect on how you want to P&P your head.
On a stock bore and stroke engine, with stock carb...
We made the intake flow great, enlarged it but on the stock set up it lost too much velocity and lost performance.
Same head on a modified engine with bigger carb, bore and stroke, it gained performance.
The intake doing a little work on the short side radius, and bowl.
Shaping/trimming the valve guide helps quite a bit also.
Little at a time is a good place to start.
We did not enlarge the port at all, took of sharp edges, rounded them.
Also depends on your build... Bigger bore, bigger valves, bigger carb...etc.
This will effect on how you want to P&P your head.
On a stock bore and stroke engine, with stock carb...
We made the intake flow great, enlarged it but on the stock set up it lost too much velocity and lost performance.
Same head on a modified engine with bigger carb, bore and stroke, it gained performance.