D series Cyl Head port and polish results?
 

What kind of extra BHP can be expected from boring out a D series honda Cyl head, anyone know? I have heard around the 15BHP mark but spose this depends how well its done and what engine etc.

Re:D series Cyl Head port and polish results?
 

boring out?


depends whats done and to what spec...

bit more info, and not just a "stage XX"

Re:D series Cyl Head port and polish results?
 

yer sorry question was a bit bleak.... basically I shall be widening the ports prob 3mm extra all round not bothering too much with polishing. Has anyone got any Dyno figures from their mods and did they get it done professionally or homemade stylee?

Re:D series Cyl Head port and polish results?
 

3mm extra.. lol, say hello to the water jacket for me..

that will KILL your power if you manage to pull it off without breaking through the water jacket

leave it to someone who knows what they are doing please

Re:D series Cyl Head port and polish results?
 

lol ive left it with my bro who is sorting it out he is a CNC bod at aston martin so i hope he knows what hes doing. Mind you he's into doing up Fiats!! :o

Re:D series Cyl Head port and polish results?
 

ok, tell him just to take a few thou out.. 10 thou at the most..

if your going turbo tell him to take some material out of the combustion chambers too, it'll lower your compression