« previous next »
Pages: [1]   Go Down

Author Topic: nice two valve heads  (Read 1889 times)

0 Members and 1 Guest are viewing this topic.

Offline turboguzzi

  • Old Timer
  • ******
  • Posts: 4,084
nice two valve heads
« on: February 19, 2012, 09:18:48 AM »
not for honda, its stuff for italian battle of the twins ducs, but just interesting what people are doing to good old two valve heads.

very flat CC, plenty of squish area but most interesting is the port divider

www.gg2.it
Logged

Offline Bill/BentON Racing

  • Really Old Timer ...
  • *******
  • Posts: 6,725
  • Ex Honda Service Manager, Cert. Honda Tech - Racer
    • BentON Racing
Re: nice two valve heads
« Reply #1 on: February 19, 2012, 12:07:03 PM »
TG,only on intake,must weld,machine for guide and valve? What are their claims? Haven't seen this before.Bill
Logged
BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
______________________________________
See our latest build 'Captain Marvel' CLICK HERE

Offline trueblue

  • A person who has had many interesting experiences, some of which are true, is known as an
  • Old Timer
  • ******
  • Posts: 3,124
Re: nice two valve heads
« Reply #2 on: February 20, 2012, 02:03:28 AM »
You may notice that head is for a twin spark engine, that fin in the port would be there to direct the air flow towards the spark plugs, thats my best guess anyways.
Logged
1979 CB650Z
Nothing can be idiot proofed, the world keeps producing better idiots.
Electronic Guages for your SOHC 4

Offline turboguzzi

  • Old Timer
  • ******
  • Posts: 4,084
Re: nice two valve heads
« Reply #3 on: February 20, 2012, 02:28:49 AM »
spoke with the guy at the stand they had in this weekend's major swapmeet in milan

he claimed that the fin reduces flow losses around the valve guide/ valve stem.

makes sense to me...

Logged

Offline trueblue

  • A person who has had many interesting experiences, some of which are true, is known as an
  • Old Timer
  • ******
  • Posts: 3,124
Re: nice two valve heads
« Reply #4 on: February 20, 2012, 02:35:06 AM »
Quote from: turboguzzi on February 20, 2012, 02:28:49 AM
spoke with the guy at the stand they had in this weekend's major swapmeet in milan

he claimed that the fin reduces flow losses around the valve guide/ valve stem.

makes sense to me...


I would believe that too, I would like to see some flow bench results to see how much difference it actually makes. 
Logged
1979 CB650Z
Nothing can be idiot proofed, the world keeps producing better idiots.
Electronic Guages for your SOHC 4

Offline mec

  • Hot Shot
  • ***
  • Posts: 503
Re: nice two valve heads
« Reply #5 on: February 20, 2012, 03:21:45 AM »
nice feature,

two thoughts:
would like to see it in the ex-port too
is it worth all the effort??

mec
« Last Edit: February 20, 2012, 04:24:18 AM by mec »
Logged
Honda Monkey
Takeuchi TB 070
Massey Ferguson

Offline turboguzzi

  • Old Timer
  • ******
  • Posts: 4,084
Re: nice two valve heads
« Reply #6 on: February 20, 2012, 03:52:45 AM »
well, 105hp from a two valve air-cooled 900 twin sounds pretty nice to me :)

they got dyno graphs in the site



Logged

Offline trueblue

  • A person who has had many interesting experiences, some of which are true, is known as an
  • Old Timer
  • ******
  • Posts: 3,124
Re: nice two valve heads
« Reply #7 on: February 21, 2012, 02:09:50 AM »
In the exhaust port there would be the possibility of the little fin collecting carbon, also the exhaust port isn't as critical as the intake as far a flow goes. 
Logged
1979 CB650Z
Nothing can be idiot proofed, the world keeps producing better idiots.
Electronic Guages for your SOHC 4

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,561
  • Big ideas....
Re: nice two valve heads
« Reply #8 on: February 21, 2012, 08:17:10 AM »
I have seen that before on car stuff and Harleys. I have seen a fin on the intake port floor at the entrance of the port on Harleys as well. I think it is more effective on large ports, large seat ID's with large valves.
Logged
Owner of the "Million Dollar CB"
Pages: [1]   Go Up
« previous next »