Port and polish

[Cordogs]

Craig I don't doubt your abilities mate but your pic and the pic above are quiet different, I know your mechanical abilities far our way mine but I know a polish finish when I see it. I'll bet you that with the amount of money old mate spent on this engine he didn't leave it up to some bloke with a die grinder and a carbide tip in it.

 

[my67xr]

here is a professionals work, a hand ported head (not cnc)

 

[my67xr]

that's ok Corey,
think we'll will have to agree to disagree.

 

[Cordogs]

new you would understand! Haha

That linish job of yours looks top notch btw mate, I'm impressed!

Tell tale signs for me is slightly rounded edges on hard cut edges, if one was to polish by hand a cnc finish (with patients) it would look like my pic or Gero's whole bike!

With a flap wheel n die grinder there's always tell tale signs of linishing. Not saying its less of a finish just not as precise to the trained eye.

 

[my67xr]

my head was just a quicky job, i was trying to show a polished v's linished finish.
i wasn't trying to compare it to a CNC finish, it's far from it!
to me, polished means a mirror finish.
so the head in your pic is polished in the combustion chamber, and the ports have been finished with a sanding roll, or flapper wheel.
you can see variations in the finish if you look inside the ports.
CNC would be more exact.

this is a CNC ported Holley 4500 Dominator, straight off the Mill.



i have seen plenty of CNC'd items, i had a $300,000 CNC Mill in my old workshop for 4 months

 

[Cordogs]

also worked in one metal factory for 4 years with 3 Haas cnc's, 2 mill's n 1 lathe. Was also Qc of all stainless finished parts on Calgym manufacturing machines.

 

[my67xr]

lol, you win Corey !!!!

 

[Cordogs]

Any bloke that builds his own dyno has my respect pal! plus you do real nice work!
No argument here!!

 

[lil_fmx_kid]

Now that's nice

 

[GooseMan]

you two are too nice to each other lol.
Anyway those flappy discs are what I used on my head after die grinding. Took me about four hours total to finish all four valves.

P.s. I think craig is right about that first pic. notice around where the valve stems go it hasn't been polished yet.....

 

[Blender]

A bit of a bromance is nothing to be ashamed of

 

[Cordogs]

the combustion chamber area is all polished, but not down and inside the runners of the ports.
by the looks of it, they are just finished off with a flapper wheel maybe ?

Sorry Mate I misread your first post, I thought we were only talking about the combustion chamber!

Still my bestie? Xoxo

 

[Cordogs]

A bit of a bromance is nothing to be ashamed of

 

[lil_fmx_kid]

So it's totally worth while the effort?

 

[Cordogs]

Mate beats beats the hell outa me? I've always known with cars a port n polish is a good thing. And all these pictures above seem to be at least sanded smooth so to remove all of the cast finish!

 

[zwebx]

The easier it is to suck in the fuel and blow it out just means more power out of the same cc's
there is much flow to be gained in most air cooled or really meaty castings.. just dont mess up the sealing edge on the valve seat

 

[gottagetacheaperhobby]

do the tb head kits need porting and polishing as well?

 

[zwebx]

do the tb head kits need porting and polishing as well?

[video=youtube;PAdTzJ7hPgo]http://www.youtube.com/watch?v=PAdTzJ7hPgo[/video]
you can see the quality of the ports on here.. any racer would touch them up but there already much larger than the stock i would like to polish up my exhaust port when i get the time

 

[gottagetacheaperhobby]

so more a polish than port lol

 

[zwebx]

Yeah pretty much but i belive i will open the exhaust up a bit more (there's only really so far you can go) but comparing to my other engine the lifan 150 (could not even get a finger past the valve stems) the ports are pretty massive
aslong as they flow the same as your valves and lift allow theres no need to port.. the reason i would clean up and port the exhaust is to reduce carbon build up and keep the flow what i would like it and not choked in any way

on the intake i would be a little carefull if on smaller bores and cc's i belive they need the airspeed to make the carburettors tuneable and not splutter