OST-013: Massaging a virgin ;)
09-13-2011, 06:10 PM
Post: #41
OST-013: Massaging a virgin ;)
Project D Wrote:
Quote:Does anyone have an idea why I don't mean that?

What does a 200+hp head have that none of my heads has?

Why is the above taper not as effective in one of my heads??

(one answer covers all questions)
Basically not the same goal (?)
if it's not the right answer I hope you will enlighten us with the right one (cause I want to know Thumbs up! )

I have another question for you (or loynings)
Why many tuner do this on guide bosses?
[Image: AEU86 AE86 - OST-013: Massaging a virgin ;)]
(This one is made by Toda)

PS: If this is to much off topic tell me :wink:

...... and the answer is (drum roll)........... Oversize valves Thumbs up! I've not as of yet had a head built for O/S valves. Because the valve is oversize, the port MUST be shaped to accommodate the O/S valve. If the port were that large for a standard valve, the velocity of the intake charge will suffer, and so will the torque.

I can't speak for anyone else's work........ I try NOT to do that*. What I've found is the tools designed to get that finish, require more room, so the guide bosses are shaped to accommodate the tool.


* - I try to minimize the guide boss, but I do try to keep it in its original shape, albeit a bit more narrow, and often not as tall. If you look at my intake port compared to the untouched port, I DO change the angle that the guide boss is directed towards. OEM is just there, where as mine the base is more into the center of the air stream.

Dan -

You can |Sad .... OR you can ask for help!!!

OST Porting service - http://hachiroku.net/forums/showthread.php?t=19991
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