SuzukiHayabusa.org

TECHNICAL => ALL MOTOR TALK => Topic started by: MJ Williams on April 28, 2016, 05:42:56 PM

Title: Valve guides protruding into port
Post by: MJ Williams on April 28, 2016, 05:42:56 PM
I've just had the valve guides in a Gen II cylinder head replaced.
The old guides in the head had been pressed down then ground to match the contours of the ports.
This time the machinist left the guides protruding in to the ports.
He says that it really doesn't make much difference in air flow to not contour them to the port but makes for better accuracy when cutting the seats on the next valve job. The second part makes sense.
Frank has been doing heads for 25+ years but isn't a Hayabusa guy. He has a flow bench and builds lots of R6 heads for roadrace guys and has built some bad-ass CR450F engines where he does all the porting etc.
He does gorgeous work and I'm really happy with his workmanship. Just wondering for myself if there is a worthwhile difference in contouring the guides to the port in a Hayabusa.
Thank you, Mike
Title: Re: Valve guides protruding into port
Post by: Jay on May 05, 2016, 02:23:19 PM
You got answered on psychobike
Title: Re: Valve guides protruding into port
Post by: MJ Williams on May 06, 2016, 11:39:55 AM
Thanks Jay, I had posted it in both sites on the same day. :tu:
Was down just a touch on hp after the rebuild and was looking at a couple things to cause it.
Did find out what it was.

Title: Re: Valve guides protruding into port
Post by: speedduck on May 06, 2016, 01:37:18 PM
So, was it the guides ?
Title: Re: Valve guides protruding into port
Post by: MJ Williams on May 06, 2016, 03:27:11 PM
No, issues with my STPs.
Title: Re: Valve guides protruding into port
Post by: speedduck on May 07, 2016, 07:04:34 AM
Ok, thanks. I been thinking about the same thing, if it was better to leave the guides unmodified.