Effects of valve lift - worth it going higher?

[Bean]

Where was peak torque with the ...138s? Wondering because I still fancy to switch to their ...148s or even 149s if peak isn't too high.

[oldeskewltoy]

totta Crolla Wrote:Catcams say the same thing for their 9.5mm lift cams.
I guess you need to relieve some of the head casting for 10mm lift ?

Interesting question to ask....

@ 10mm of cam lift the cams DID just clear the castings.....



but not by enough... Ted's said .015" I couldn't get a feeler gauge in there... but that looked to be closer than .015" to me, so I just made sure all the lobes would not have any issues




Teds also has valve springs (additional option for valve springs) theirs have seat pressures of 62#s. For comparison stock is 35#s, HKS is 32#s, Toda and TRD are 52#s




**IF** you go with high lift, "short duration" cams, and you use high seat pressure valve springs.... I STRONGLY recommend a kevlar toothed timing belt.... Rotating those cams ,pressing down those springs adds CONSIDERABLE forces upon the timing belt....

[totta Crolla]

Well I never, HKS springs are lb rated lower than stock springs then.
I have not suffered valve float up to 8300rpm with HKS's and they allow at least 9.5mm lift so they are probably a good bet for sub 8500rpm and high lift cams. without putting undue stress on other components or robbing too much power.

[totta Crolla]

Bean Bandit Wrote:Where was peak torque with the ...138s? Wondering because I still fancy to switch to their ...148s or even 149s if peak isn't too high.

I will try to find the printout for you Bean.

[oldeskewltoy]

Totta... not sure WHICH (if there are different ones) HKS springs you have... but the ones we tested are only good to low/mid 8mm of lift....

[harkes]

@oldskewltoy
Good point with the timing belt. Can you recommend one in particular?

This one sound serious:

http://www.rhdjapan.com/power-enterprise...a-4ag.html

[Bean]

harkes Wrote:@oldskewltoy
Good point with the timing belt. Can you recommend one in particular?

This one sound serious:

http://www.rhdjapan.com/power-enterprise...a-4ag.html

I got a TODA one but honestly either one of these will be fine...
http://perfectrun.jp/quick/qui_home.php?...&submit=GO
better prices than RHD

[oldeskewltoy]

I'm pretty sure I used a Power Enterprises timing belt, likely purchased through horsepower freaks ($160 today)