The best bit for porting

[Justin Taylor]

I need to find some bits that will hold up for a decent amount of time to port some cylinders any recommendations??

 

[Huskybill]

I been using these from amazon.

Good for roughing and even cuts out.

https://www.amazon.com/eBoTrade-Pieces-Tungsten-Carbide-tungsten/dp/B00JL4F1SM

Polishing if you want the ports smooth.


https://www.amazon.com/AUSTOR-Including-Sanding-Sleeves-Mandrels/dp/B07CYQXZSY

 

[Huskybill]

These carbine cutters don’t seem to cake up with material. If they did a tad of kerosene or light oil will keep them clean. I ported three cylinders and there still sharp.

 

[Justin Taylor]

Good to know thanks man

 

[Yotaismygame]

Get a split mandrel and use whatever sand paper you can get your hands on. Those barrel type aren’t what you want.

Cut strips of paper and you’re good to go. Start with 80 and work your way up to 500 or so. Intake only needs 80 grit. Doesn’t take long at all.

 

[Huskybill]

I do most of the porting with the 1/8” shank carbide cutters. Then I smooth it all out with the drum sanding barrels. Then I go with the simi chrome polish on the buffing wheels.

 

[trappermike]

I prefer to use 1/4" carbide cutters of various shapes,then finish off with sandpaper rolls of various grit. Be careful sanding,you can quickly move a port another 1mm or more before you realise it. I always grind my ports less than to specs,then smooth the ports to specs.

 

[trappermike]

Lotsa oil on the carbide bit when cutting,stop frequently and wirebrush any aluminum stuck in,you may have to do it a lot. If you don't keep the bit unclogged it will quickly plug up with aluminum,which will "chew up" and not cut the port cleanly.

 

[spladle160]

https://www.ccspecialtytoolstore.com/Aggressive-Carbide-burr-p/alumnihogset.htm

 

[Justin Taylor]

Lotsa oil on the carbide bit when cutting,stop frequently and wirebrush any aluminum stuck in,you may have to do it a lot. If you don't keep the bit unclogged it will quickly plug up with aluminum,which will "chew up" and not cut the port cleanly.

Thanks for more good tips

 

[Justin Taylor]

https://www.ccspecialtytoolstore.com/Aggressive-Carbide-burr-p/alumnihogset.htm

Too bad there not cheaper

 

[trappermike]

I dunno,with E-Bay and cheap stuff today can't you buy those bits cheap,I sometimes paid $25 to $30 for a bit in the old days,I paid $200 for a set of 8 (Which are still sharp)
When cutting aluminum which is soft,if the bit is any kind of good steel it should cut and last.
The oil you spray while cutting really matters,use whatever "Witches Brew" you believe in.

 

[Yotaismygame]

Too bad there not cheaper

I’ve used various amazon bits and they work just fine. Wouldn’t say they last a life time but for a handful of saws you’ll be good

I always say .5-1 degree less than what you want because polishing will take you there