a note to be careful in porting

[crassius]

2nd customer this month bought new cylinder due to fouled up porting job - if you do it, do it carefully

 

[Musico336]

As in ????

 

[Frankenstein]

As in ????

Practice on some scrap aluminum, those carbide bits like to hop around sometimes, and they cut really well, so before you know it you can cut too much and ruin the cylinder. A friend of mine got a little excessive in clearing down the transfer ports, the wall was too thin and failed, of course the rings went with it and the rest of the motor with that situation.

As in that.

 

[Gasbikejerry1967]

Practice on some scrap aluminum, those carbide bits like to hop around sometimes, and they cut really well, so before you know it you can cut too much and ruin the cylinder. A friend of mine got a little excessive in clearing down the transfer ports, the wall was too thin and failed, of course the rings went with it and the rest of the motor with that situation.

As in that.

Sometimes hand tools give you time to think about what ur doing whereas power tools just grind away (something 30 years of carpentry learned me) measure twice think 5 times cut 1 time

 

[JerboaJohn]

show some boffed porting examples

 

[butre]

show some boffed porting examples

bad porting isn't necessarily ugly, sometimes it's just that some bonehead didn't do any math. you go too far in one direction, not far enough in another, mess up an angle somewhere else, and end up making less power than stock.

 

[JerboaJohn]

ohh so you might not know you messed up until it's all together and test it out.

question tho where should I attach a degree wheel so I know what the port timing is before changing anything? I think I can find a printout-able wheel and make a pointer. i can sacrifice the stock jug if I bungle it, I have a new one for backup

 

[crassius]

show some boffed porting examples

sorry, for some reason didn't see your post - bad ones got recycled, but usual problems are big gouge in cylinder when dremel slips or crack where they over tightened while holding it in vise