Planet Minis

klxrider245

Wat you using a dremel

LongMooie

its a Dewalt tool and i used carbide burrs and then a sanding tool to smooth out the exhaust port, its not the best tool for doing head work as its quite big

cyclerider57

In very general terms focusing on the two major aspects, porting a head is 65% shape of the port and 35% size of the port... Until you get too big... Then there is little you can do to save it short of just making it smaller. Without spending a lot of time studying porting and airflow the best advice is merely looking at pictures of high performance heads and studying the shapes of the ports. Car guys are picture happy and doing online searching you can find a lot of pictures. Think Oval rather than round. Think flat short side radius. Keep in mind, the most critical area of a port is within 1 inch of the valve head.

__________________
The wise understand by themselves; fools follow the reports of others. Goodness speaks in a whisper, evil shouts. -Tibetan Proverb

LongMooie

Im having trouble finding photos of the ports, most of the photos just show the valves
can anyone post a race head port or ported head

thanks guys i just wanna see how far off i am with my attempt!

arlindsay1992

Here is my TB head ported by Mark at AHP. Not the best pictures, but it's all I have.

chasetheface123

Heres a head i had ported by "Dood"

LongMooie

Hmm well i dont think i did a too bad of a job seeing as its my first attempt, the valves are tiny on the 50 head so the porting looks small compared to the other shown there

one other thing is how do you remove the valves, im guessing you need a tool to do this?
i was wanting to clean up any carbon build up

arlindsay1992

Whoa, wait. You ported the head with the valves in? Most of the work needs to be done through the hole where the valve is to flatten out the short side radius. Not to mention that you would need to be VERY careful to not mess up the valve stem. And it's going to be damn near impossible to clean it all out if the valve is still in there.

LongMooie

yeah i done the porting you can see with the valves still in place, to be honest taking the valves out never came up when reading about porting as i thought it was just to make the inlet and outlet holes, like i said ive never done this type of work before!
if the valves have to come out then should i larger valves in while im at it?
what valves fit? xr70 maybe? i would not do this ill leave that to the pros

arlindsay1992

You can't simply put in larger valves, you need to cut the valve seats to match, and the valve seats can only go so far before there isn't enough material left and you will need to put in new valve seats. Porting should be done over the entire port. It is done to increase flow. You need to work over the whole port to make it all work together. Simply enlarging one end won't do very much. Here's a little 2 minute drawing to show that you need to work over the entire port.

LongMooie

ok cool i get the idea, i did know about the bigger valve needing the seating area to be machined or ground, ill leave that to the pros
this is just something fun to pass the time while im off work i intend to have a xr70 head ported/decked big valves along with a piston to match and a crank lightend n balenced by a shop

LongMooie

ok valves are out (thanks pax) and i just got a small dremel tool as the die gringer from work would be hard to use in the valve areas, now looking from the valve side of the port i can see the restriction as arlindsays diagram shows so om off to the garage for part two

arlindsay1992

The main thing to do is flatten out the short side radius. In stock form, it is sort of pinched in that area and gasses have to make a sharp tun whether going in or out. It would be ideal for the gasses to travel in a straighter line.

LongMooie

OK how do i install the valve springs???
im having trouble getting the clips to sit in the slot on the valve

arlindsay1992

Do you have a valve spring compressor?

LongMooie

nope! i guess ill have to get one unless theres another way to do it

arlindsay1992

A few people have made their own.

Big Daddy P

what about matching air intake manifold to the intake port? Does it matter if the manifold side is smaller?

Paxracing

call me you can do it by hand,

arlindsay1992

To gain full benefits, port match from the air filter to exhaust tip.