Twin cam Valve Guides.
Johns cams springs and valves are a good way to go for his head. The challenge is keeping the full lift load down to an acceptable level. His springs are stiff and can produce a very high full lift load if you don't set them up carefully and keep the seat load as low as possible. Install height needs to be around 35mm for the spring itself to keep seat load around 60 lb and full lift load for a 0.5 inch lift cam to around 210 lbs. 35 mm can be a challenge to get in a lot of heads without deepening the pockets which you don't want to do with Johns ported heads as there is not much metal between the top of the inlet port and the bottom of the standard spring pocket.
For your push rod you may want to talk to Larner as locally they have built more racing pushrods than anyone.
cheers
Rohan
For your push rod you may want to talk to Larner as locally they have built more racing pushrods than anyone.
cheers
Rohan
-
rgh0 - Coveted Fifth Gear
- Posts: 8425
- Joined: 22 Sep 2003
Despite the Holden markings these blanks ought to do the job for the new push rod head!!
They're 214N on 9/32" stems.
They're 214N on 9/32" stems.
Last edited by SJ Lambert on Tue May 27, 2014 9:49 pm, edited 1 time in total.
Ford Escort Mk1 Lotus Twin Cam
Elfin Monocoque (Twin Cam)
Elfin Type 300 (Holbay S65 - 120E) mechanic
[email protected]
Elfin Monocoque (Twin Cam)
Elfin Type 300 (Holbay S65 - 120E) mechanic
[email protected]
-
SJ Lambert - Fourth Gear
- Posts: 681
- Joined: 19 Nov 2010
Whilst chasing some Colsibro Guides to Cosworth MAE spec I discovered TROJAN as an even higher spec material!!!! - I'll be sticking with the Colsibro if I can get it!!
Colsibro
Is a copper-nickel-silicon alloy ideally suited for valve guides for internal combustion engines requiring high thermal conductivity, wear resistance and strength at varying engine temperatures.
Trojan
Is a copper-nickel-silicon alloy ideally suited for high performance valve guides for internal combustion engines requiring high thermal conductivity, wear resistance and improved mechanical properties over Colsibro.
Colsibro
Is a copper-nickel-silicon alloy ideally suited for valve guides for internal combustion engines requiring high thermal conductivity, wear resistance and strength at varying engine temperatures.
Trojan
Is a copper-nickel-silicon alloy ideally suited for high performance valve guides for internal combustion engines requiring high thermal conductivity, wear resistance and improved mechanical properties over Colsibro.
Ford Escort Mk1 Lotus Twin Cam
Elfin Monocoque (Twin Cam)
Elfin Type 300 (Holbay S65 - 120E) mechanic
[email protected]
Elfin Monocoque (Twin Cam)
Elfin Type 300 (Holbay S65 - 120E) mechanic
[email protected]
-
SJ Lambert - Fourth Gear
- Posts: 681
- Joined: 19 Nov 2010
Got some colsibro ones to suit 9/32" stems headed my way!
Ford Escort Mk1 Lotus Twin Cam
Elfin Monocoque (Twin Cam)
Elfin Type 300 (Holbay S65 - 120E) mechanic
[email protected]
Elfin Monocoque (Twin Cam)
Elfin Type 300 (Holbay S65 - 120E) mechanic
[email protected]
-
SJ Lambert - Fourth Gear
- Posts: 681
- Joined: 19 Nov 2010
Total Online:
Users browsing this forum: rgh0 and 27 guests